Cardiology () is a branch of
medicine
Medicine is the science and practice of caring for a patient, managing the diagnosis, prognosis, prevention, treatment, palliation of their injury or disease, and promoting their health. Medicine encompasses a variety of health care pr ...
that deals with disorders of the
heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
and the
cardiovascular system. The field includes
medical diagnosis
Medical diagnosis (abbreviated Dx, Dx, or Ds) is the process of determining which disease or condition explains a person's symptoms and signs. It is most often referred to as diagnosis with the medical context being implicit. The information r ...
and treatment of
congenital heart defect
A congenital heart defect (CHD), also known as a congenital heart anomaly and congenital heart disease, is a defect in the structure of the heart or great vessels that is present at birth. A congenital heart defect is classed as a cardiovascul ...
s,
coronary artery disease,
heart failure,
valvular heart disease
Valvular heart disease is any cardiovascular disease process involving one or more of the four valves of the heart (the aortic and mitral valves on the left side of heart and the pulmonic and tricuspid valves on the right side of heart). These ...
and
.
Physician
A physician (American English), medical practitioner (Commonwealth English), medical doctor, or simply doctor, is a health professional who practices medicine, which is concerned with promoting, maintaining or restoring health through th ...
s who specialize in this field of medicine are called cardiologists, a specialty of
internal medicine. Pediatric cardiologists are
pediatricians who specialize in cardiology. Physicians who specialize in cardiac surgery are called
cardiothoracic surgeons or cardiac surgeons, a specialty of
general surgery.
Specializations
All cardiologists study the disorders of the heart, but the study of adult and child heart disorders each require different training pathways. Therefore, an adult cardiologist (often simply called "cardiologist") is inadequately trained to take care of children, and pediatric cardiologists are not trained to treat adult heart disease. Surgical aspects are not included in cardiology and are in the domain of
cardiothoracic surgery
Cardiothoracic surgery is the field of medicine involved in surgical treatment of organs inside the thoracic cavity — generally treatment of conditions of the heart (heart disease), lungs ( lung disease), and other pleural or mediastinal str ...
. For example,
coronary artery bypass surgery (CABG),
cardiopulmonary bypass and
valve replacement are surgical procedures performed by surgeons, not cardiologists. However, some minimally invasive procedures such as
cardiac catheterization and
pacemaker implantation are performed by cardiologists who have additional training in non-surgical interventions (interventional cardiology and
respectively).
Adult cardiology
Cardiology is a specialty of
internal medicine. To be a cardiologist in the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, a three-year residency in internal medicine is followed by a three-year fellowship in cardiology. It is possible to specialize further in a sub-specialty. Recognized sub-specialties in the U.S. by the
Accreditation Council for Graduate Medical Education are
cardiac electrophysiology
Cardiac electrophysiology is a branch of cardiology and basic science focusing on the electrical activities of the heart. The term is usually used in clinical context, to describe studies of such phenomena by invasive (intracardiac) catheter recor ...
,
echocardiography,
interventional cardiology
Interventional cardiology is a branch of cardiology that deals specifically with the catheter based treatment of structural heart diseases. Andreas Gruentzig is considered the father of interventional cardiology after the development of angioplast ...
, and
nuclear cardiology. Recognized subspecialties in the U.S. by the
include
clinical cardiac electrophysiology and
interventional cardiology
Interventional cardiology is a branch of cardiology that deals specifically with the catheter based treatment of structural heart diseases. Andreas Gruentzig is considered the father of interventional cardiology after the development of angioplast ...
. In India, a three-year residency in General Medicine or Pediatrics after
M.B.B.S and then three years of residency in cardiology are needed to be a D.M/
Diplomate of National Board (DNB) in Cardiology.
Per
Doximity, adult cardiologists earn an average of $436,849 per year in the U.S.
[Hamblin, James (January 27, 2015]
What Doctors Make
theatlantic.com
Cardiac electrophysiology
Cardiac electrophysiology is the science of elucidating, diagnosing, and treating the electrical activities of the heart. The term is usually used to describe studies of such phenomena by invasive (intracardiac) catheter recording of spontaneous activity as well as of cardiac responses to
programmed electrical stimulation (PES). These studies are performed to assess complex
arrhythmias, elucidate symptoms, evaluate abnormal
electrocardiograms
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the hear ...
, assess risk of developing arrhythmias in the future, and design treatment. These procedures increasingly include therapeutic methods (typically
radiofrequency ablation
Radiofrequency ablation (RFA), also called fulguration, is a medical procedure in which part of the electrical conduction system of the heart, tumor or other dysfunctional tissue is ablated using the heat generated from medium frequency alternati ...
, or
cryoablation) in addition to diagnostic and prognostic procedures. Other therapeutic modalities employed in this field include
antiarrhythmic drug therapy and implantation of
pacemakers
An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a medical device that generates electrical impulses delivered by electrodes to the chambers of the heart eit ...
and automatic
implantable cardioverter-defibrillators (AICD).
[Fauci, Anthony, et al. ''Harrison's Textbook of Medicine''. New York: McGraw Hill, 2009.]
The cardiac
electrophysiology study typically measures the response of the injured or cardiomyopathic myocardium to PES on specific pharmacological regimens in order to assess the likelihood that the regimen will successfully prevent potentially fatal sustained
ventricular tachycardia
Ventricular tachycardia (V-tach or VT) is a fast heart rate arising from the lower chambers of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple episodes over a short perio ...
(VT) or
ventricular fibrillation
Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and n ...
(VF) in the future. Sometimes a ''series'' of electrophysiology-study drug trials must be conducted to enable the cardiologist to select the one regimen for long-term treatment that best prevents or slows the development of VT or VF following PES. Such studies may also be conducted in the presence of a newly implanted or newly replaced cardiac pacemaker or AICD.
Clinical cardiac electrophysiology
Clinical cardiac electrophysiology is a branch of the medical specialty of cardiology and is concerned with the study and treatment of rhythm disorders of the heart. Cardiologists with expertise in this area are usually referred to as electrophysiologists. Electrophysiologists are trained in the mechanism, function, and performance of the electrical activities of the heart. Electrophysiologists work closely with other cardiologists and cardiac surgeons to assist or guide therapy for heart rhythm disturbances (arrhythmias). They are trained to perform interventional and surgical procedures to treat cardiac arrhythmia.
The training required to become an electrophysiologist is long and requires 8 years after medical school (within the U.S.). Three years of internal medicine residency, three years of cardiology fellowship, and two years of clinical cardiac electrophysiology.
Cardiogeriatrics
Cardiogeriatrics, or geriatric cardiology, is the branch of cardiology and geriatric medicine that deals with the cardiovascular disorders in elderly people.
Cardiac disorders such as
coronary heart disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pl ...
, including
myocardial infarction
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may ...
,
heart failure,
cardiomyopathy, and arrhythmias such as
atrial fibrillation, are common and are a major cause of mortality in elderly people. Vascular disorders such as
atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no s ...
and
peripheral arterial disease cause significant morbidity and mortality in aged people.
Imaging
Cardiac imaging includes echocardiography (echo), cardiac magnetic resonance imaging (CMR), and computed tomography of the heart.
Those who specialize in cardiac imaging may undergo more training in all imaging modes or focus on a single imaging modality.
Echocardiography (or "echo") uses standard two-dimensional, three-dimensional, and
Doppler ultrasound
Doppler ultrasonography is medical ultrasonography that employs the Doppler effect to perform imaging of the movement of tissues and body fluids (usually blood), and their relative velocity to the probe. By calculating the frequency shift of a ...
to create images of the heart.
Those who specialize in echo may spend a significant amount of their clinical time reading echos and performing transesophageal echo, in particular using the latter during procedures such as insertion of a left atrial appendage occlusion device.
Cardiac MRI utilizes special protocols to image heart structure and function with specific sequences for certain diseases such as
hemochromatosis and
amyloidosis.
Cardiac CT utilizes special protocols to image heart structure and function with particular emphasis on coronary arteries.
Interventional cardiology
Interventional cardiology is a branch of cardiology that deals specifically with the
catheter
In medicine, a catheter (/ˈkæθətər/) is a thin tubing (material), tube made from medical grade materials serving a broad range of functions. Catheters are medical devices that can be inserted in the body to treat diseases or perform a surgi ...
based treatment of structural heart diseases. A large number of procedures can be performed on the heart by catheterization, including angiogram, angioplasty, atherectomy, and stent implantation. These procedures all involve insertion of a sheath into the
femoral artery
The femoral artery is a large artery in the thigh and the main arterial supply to the thigh and leg. The femoral artery gives off the deep femoral artery or profunda femoris artery and descends along the anteromedial part of the thigh in the f ...
or radial artery (but, in practice, any large peripheral artery or vein) and
cannula
A cannula (; Latin meaning 'little reed'; plural or ) is a tube that can be inserted into the body, often for the delivery or removal of fluid or for the gathering of samples. In simple terms, a cannula can surround the inner or outer surfaces ...
ting the heart under visualization (most commonly
fluoroscopy
Fluoroscopy () is an imaging technique that uses X-rays to obtain real-time moving images of the interior of an object. In its primary application of medical imaging, a fluoroscope () allows a physician to see the internal structure and function ...
). This cannulation allows indirect access to the heart, bypassing the trauma caused by surgical opening of the chest.
The main advantages of using the interventional cardiology or radiology approach are the avoidance of the scars and pain, and long post-operative recovery. Additionally, interventional cardiology procedure of primary
angioplasty
Angioplasty, is also known as balloon angioplasty and percutaneous transluminal angioplasty (PTA), is a minimally invasive endovascular procedure used to widen narrowed or obstructed arteries or veins, typically to treat arterial atheroscle ...
is now the gold standard of care for an acute myocardial infarction. This procedure can also be done proactively, when areas of the vascular system become occluded from
atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no s ...
. The Cardiologist will thread this sheath through the vascular system to access the heart. This sheath has a balloon and a tiny wire mesh tube wrapped around it, and if the cardiologist finds a blockage or
stenosis, they can inflate the balloon at the occlusion site in the vascular system to flatten or compress the plaque against the vascular wall. Once that is complete a
stent
In medicine, a stent is a metal or plastic tube inserted into the lumen of an anatomic vessel or duct to keep the passageway open, and stenting is the placement of a stent. A wide variety of stents are used for different purposes, from expandab ...
is placed as a type of scaffold to hold the vasculature open permanently.
Cardiomyopathy/heart failure
Specialization of general cardiology to just that of the
cardiomyopathies
Cardiomyopathy is a group of diseases that affect the heart muscle. Early on there may be few or no symptoms. As the disease worsens, shortness of breath, feeling tired, and swelling of the legs may occur, due to the onset of heart failure. A ...
leads to also specializing in
heart transplant and
pulmonary hypertension.
Cardiooncology
A recent specialization of cardiology is that of cardiooncology.
This area specializes in the cardiac management in those with cancer and, in particular, those with plans for
chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs ( chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemothe ...
or whom have experienced cardiac complications of chemotherapy.
Preventive cardiology and cardiac rehabilitation
In recent times, the focus is gradually shifting to preventive cardiology due to increased
cardiovascular disease burden at an early age. According to the WHO, 37% of all premature deaths are due to cardiovascular diseases and out of this, 82% are in low and middle income countries. Clinical cardiology is the sub specialty of cardiology which looks after preventive cardiology and cardiac rehabilitation. Preventive cardiology also deals with routine preventive checkup though noninvasive tests, specifically electrocardiography,
fasegraphy, stress tests,
lipid profile
A lipid profile or lipid panel is a panel of blood tests used to find abnormalities in lipids, such as cholesterol and triglycerides. The results of this test can identify certain genetic diseases and can determine approximate risks for cardiovas ...
and general physical examination to detect any cardiovascular diseases at an early age, while cardiac rehabilitation is the upcoming branch of cardiology which helps a person regain their overall strength and live a normal life after a cardiovascular event. A subspecialty of preventive cardiology is
sports cardiology.
Pediatric cardiology
Helen B. Taussig is known as the founder of pediatric cardiology. She became famous through her work with
Tetralogy of Fallot
Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are:
*pulmonary stenosis, which is narrowing of the exit from the r ...
, a congenital heart defect in which
oxygenated and deoxygenated blood enters the circulatory system resulting from a
ventricular septal defect
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one ...
(VSD) right beneath the aorta. This condition causes newborns to have a bluish-tint,
cyanosis, and have a deficiency of oxygen to their tissues,
hypoxemia
Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia has many causes, and often causes hypoxia as the blood is not supplying enough oxygen to the tissues of the bod ...
. She worked with
Alfred Blalock
Alfred Blalock (April 5, 1899 – September 15, 1964) was an American surgeon most noted for his work on the medical condition of shock as well as Tetralogy of Fallot— commonly known as Blue baby syndrome. He created, with assistance from h ...
and
Vivien Thomas
Vivien Theodore Thomas (August 29, 1910 – November 26, 1985) was an American laboratory supervisor who developed a procedure used to treat blue baby syndrome (now known as cyanotic heart disease) in the 1940s. He was the assistant to surgeon ...
at the
Johns Hopkins Hospital where they experimented with dogs to look at how they would attempt to surgically cure these "blue babies." They eventually figured out how to do just that by the
anastomosis of the systemic artery to the pulmonary artery and called this the
Blalock-Taussig Shunt.
Tetralogy of Fallot
Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are:
*pulmonary stenosis, which is narrowing of the exit from the r ...
,
pulmonary atresia,
double outlet right ventricle
Double outlet right ventricle (DORV) is a form of congenital heart disease where both of the great arteries connect (in whole or in part) to the right ventricle (RV). In some cases it is found that this occurs on the left side of the heart rather ...
,
transposition of the great arteries
Transposition of the great vessels (TGV) is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels: superior and/or inferior venae cavae, pulmonary artery, pulmonary veins, and aorta. Congenital ...
,
persistent truncus arteriosus, and
Ebstein's anomaly
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart. It is classified as a critical congenital heart defect accounting ...
are various congenital cyanotic heart diseases, in which the
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...
of the newborn is not oxygenated efficiently, due to the heart defect.
Adult congenital heart disease
As more children with congenital heart disease are surviving into adulthood, a hybrid of adult & pediatric cardiology has emerged called adult congenital heart disease (ACHD).
This field can be entered as either adult or pediatric cardiology.
ACHD specializes in congenital diseases in the setting of adult diseases (e.g., coronary artery disease, COPD, diabetes) that is, otherwise, atypical for adult or pediatric cardiology.
The heart
As the center focus of cardiology, the heart has numerous anatomical features (e.g.,
atria,
ventricles,
heart valve
A heart valve is a one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart ...
s) and numerous physiological features (e.g.,
systole,
heart sounds,
afterload) that have been encyclopedically documented for many centuries.
Disorders of the heart lead to
heart disease and cardiovascular disease and can lead to a significant number of deaths: cardiovascular disease is the leading
cause of death
In law, medicine, and statistics, cause of death is an official determination of conditions resulting in a human's death, which may be recorded on a death certificate. A cause of death is determined by a medical examiner. The cause of death is ...
in the U.S. and caused 24.95% of total deaths in 2008.
The primary responsibility of the heart is to pump blood throughout the body.
It pumps blood from the body — called the
systemic circulation — through the
lungs — called the
pulmonary circulation
The pulmonary circulation is a division of the circulatory system in all vertebrates. The circuit begins with deoxygenated blood returned from the body to the right atrium of the heart where it is pumped out from the right ventricle to the lungs ...
— and then back out to the body.
This means that the heart is connected to and affects the entirety of the body. Simplified, the heart is a circuit of the
circulation.
While plenty is known about the healthy heart, the bulk of study in cardiology is in disorders of the heart and restoration, and where possible, of function.
The heart is a muscle that squeezes blood and functions like a pump. The heart's systems can be classified as either electrical or mechanical, and both of these systems are susceptible to failure or dysfunction.
The electrical system of the heart is centered on the periodic contraction (squeezing) of the
muscle cells
A muscle cell is also known as a myocyte when referring to either a cardiac muscle cell (cardiomyocyte), or a smooth muscle cell as these are both small cells. A skeletal muscle cell is long and threadlike with many nuclei and is called a mus ...
that is caused by the
cardiac pacemaker
350px, Image showing the cardiac pacemaker or SA node, the primary pacemaker within the electrical_conduction_system_of_the_heart">SA_node,_the_primary_pacemaker_within_the_electrical_conduction_system_of_the_heart.
The_muscle_contraction.htm ...
located in the
sinoatrial node
The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approxima ...
.
The study of the electrical aspects is a sub-field of
called
cardiac electrophysiology
Cardiac electrophysiology is a branch of cardiology and basic science focusing on the electrical activities of the heart. The term is usually used in clinical context, to describe studies of such phenomena by invasive (intracardiac) catheter recor ...
and is epitomized with the electrocardiogram (ECG/EKG).
The
action potential
An action potential occurs when the membrane potential of a specific cell location rapidly rises and falls. This depolarization then causes adjacent locations to similarly depolarize. Action potentials occur in several types of animal cells, ...
s generated in the pacemaker propagate throughout the heart in a specific pattern. The system that carries this potential is called the
electrical conduction system.
Dysfunction of the electrical system manifests in many ways and may include
Wolff–Parkinson–White syndrome
Wolff–Parkinson–White syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, ...
,
ventricular fibrillation
Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and n ...
, and
heart block
Heart block (HB) is a disorder in the heart's rhythm due to a fault in the natural pacemaker. This is caused by an obstruction – a block – in the electrical conduction system of the heart. Sometimes a disorder can be inherited. Despite the se ...
.
The mechanical system of the heart is centered on the
fluidic movement of blood and the functionality of the heart as a
pump.
The mechanical part is ultimately the purpose of the heart and many of the disorders of the heart disrupt the ability to move blood.
Heart failure is one condition in which the mechanical properties of the heart have failed or are failing, which means insufficient blood is being circulated. Failure to move a sufficient amount of blood through the body can cause damage or failure of other organs and may result in death if severe.
Coronary circulation
Coronary circulation is the circulation of blood in the
blood vessel
The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away ...
s of the
heart muscle
Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that ...
(the myocardium). The vessels that deliver oxygen-rich blood to the myocardium are known as coronary arteries. The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. These include the
great cardiac vein
The great cardiac vein (left coronary vein) begins at the apex of the heart and ascends along the anterior longitudinal sulcus to the base of the ventricles.
It then curves around the left margin of the heart to reach the posterior surface. It m ...
, the
middle cardiac vein
The middle cardiac vein commences at the apex of the heart; ascends in the posterior longitudinal sulcus, and ends in the coronary sinus
In anatomy, the coronary sinus () is a collection of veins joined together to form a large vessel that c ...
, the
small cardiac vein The small cardiac vein, also known as the right coronary vein, is a coronary vein that drains the right atrium and right ventricle of the heart. Despite its size, it is one of the major drainage vessels for the heart.
Location
The small cardiac ...
and the
anterior cardiac veins
The anterior cardiac veins (or anterior veins of right ventricle) comprise a variable number of small vessels, usually between two and five, which collect blood from the front of the right ventricle and open into the right atrium; the right margin ...
.
As the left and right coronary arteries run on the surface of the heart, they can be called epicardial coronary arteries. These arteries, when healthy, are capable of autoregulation to maintain coronary blood flow at levels appropriate to the needs of the heart muscle. These relatively narrow vessels are commonly affected by
atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no s ...
and can become blocked, causing
angina or myocardial infarction (a.k.a a heart attack). The coronary arteries that run deep within the myocardium are referred to as subendocardial.
The coronary arteries are classified as "end circulation", since they represent the only source of blood supply to the myocardium; there is very little redundant blood supply, which is why blockage of these vessels can be so critical.
Cardiac examination
The cardiac examination (also called the "precordial exam"), is performed as part of a
physical examination
In a physical examination, medical examination, or clinical examination, a medical practitioner examines a patient for any possible medical signs or symptoms of a medical condition. It generally consists of a series of questions about the pati ...
, or when a patient presents with
chest pain suggestive of a cardiovascular
pathology
Pathology is the study of the causes and effects of disease or injury. The word ''pathology'' also refers to the study of disease in general, incorporating a wide range of biology research fields and medical practices. However, when used in ...
. It would typically be modified depending on the
indication and integrated with other examinations especially the
respiratory examination.
Like all medical examinations, the cardiac examination follows the standard structure of inspection, palpation and auscultation.
Heart disorders
Cardiology is concerned with the normal functionality of the heart and the deviation from a healthy heart.
Many disorders involve the heart itself but some are outside of the heart and in the vascular system.
Collectively, the two together are termed the cardiovascular system and diseases of one part tend to affect the other.
Coronary artery disease
Coronary artery disease, also known as "ischemic heart disease", is a group of diseases that includes:
stable angina,
unstable angina
Unstable angina (UA), also called crescendo angina, is a type of angina pectoris that is irregular. It is also classified as a type of acute coronary syndrome (ACS).
It can be difficult to distinguish unstable angina from non-ST elevation (non-Q ...
, myocardial infarction, and is one of the causes of
sudden cardiac death
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
.
It is within the group of cardiovascular diseases of which it is the most common type.
[ A common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw.][ Occasionally it may feel like heartburn. Usually symptoms occur with exercise or emotional ]stress
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
, last less than a few minutes, and get better with rest.[ ]Shortness of breath
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...
may also occur and sometimes no symptoms are present. The first sign is occasionally a heart attack.[ Other complications include heart failure or an irregular heartbeat.]
Risk factors include: high blood pressure, smoking, diabetes
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...
, lack of exercise, obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's ...
, high blood cholesterol, poor diet, and excessive alcohol, among others. Other risks include depression. The underlying mechanism involves atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no s ...
of the arteries of the heart. A number of tests may help with diagnoses including: electrocardiogram, cardiac stress testing, coronary computed tomographic angiography Coronary () may, as shorthand in English, be used to mean:
* Coronary circulation, the system of arteries and veins in mammals
** Coronary artery disease
**Coronary occlusion
** A myocardial infarction, a heart attack
As adjective
* Referring to t ...
, and coronary angiogram, among others.
Prevention is by eating a healthy diet, regular exercise, maintaining a healthy weight and not smoking.[ Sometimes medication for diabetes, high cholesterol, or high blood pressure are also used.] There is limited evidence for screening people who are at low risk and do not have symptoms. Treatment involves the same measures as prevention.[ Additional medications such as ]antiplatelets
An antiplatelet drug (antiaggregant), also known as a platelet agglutination inhibitor or platelet aggregation inhibitor, is a member of a class of pharmaceuticals that decrease platelet aggregation and inhibit thrombus formation. They are effecti ...
including aspirin
Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...
, beta blocker
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack ( secondary prevention). They are ...
s, or nitroglycerin may be recommended.[ Procedures such as percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) may be used in severe disease.] In those with stable CAD it is unclear if PCI or CABG in addition to the other treatments improve life expectancy
Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...
or decreases heart attack risk.
In 2013 CAD was the most common cause of death globally, resulting in 8.14 million deaths (16.8%) up from 5.74 million deaths (12%) in 1990. The risk of death from CAD for a given age has decreased between 1980 and 2010 especially in developed countries. The number of cases of CAD for a given age has also decreased between 1990 and 2010. In the U.S. in 2010 about 20% of those over 65 had CAD, while it was present in 7% of those 45 to 64, and 1.3% of those 18 to 45.[ Rates are higher among men than women of a given age.]
Cardiomyopathy
Heart failure or formally cardiomyopathy, is the impaired function of the heart and there are numerous causes and forms of heart failure.
Cardiac arrhythmia
Cardiac arrhythmia, also known as "cardiac dysrhythmia" or "irregular heartbeat", is a group of conditions in which the heartbeat is too fast, too slow, or irregular in its rhythm. A heart rate
Heart rate (or pulse rate) is the frequency of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm). The heart rate can vary according to the body's physical needs, including the need to absorb oxygen and excr ...
that is too fast – above 100 beats per minute in adults – is called tachycardia
Tachycardia, also called tachyarrhythmia, is a heart rate that exceeds the normal resting rate. In general, a resting heart rate over 100 beats per minute is accepted as tachycardia in adults. Heart rates above the resting rate may be normal ( ...
and a heart rate that is too slow – below 60 beats per minute – is called bradycardia. Many types of arrhythmia have no symptoms. When symptoms are present these may include palpitations or feeling a pause between heartbeats. More seriously there may be lightheadedness
Lightheadedness is a common and typically unpleasant sensation of dizziness or a feeling that one may faint. The sensation of lightheadedness can be short-lived, prolonged, or, rarely, recurring. In addition to dizziness, the individual may feel ...
, passing out, shortness of breath
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...
, or chest pain. While most types of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in cardiac arrest
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and poss ...
.
There are four main types of arrhythmia: extra beats, supraventricular tachycardias, ventricular arrhythmias, and bradyarrhythmias. Extra beats include premature atrial contractions, premature ventricular contractions, and premature junctional contractions. Supraventricular tachycardias include atrial fibrillation, atrial flutter
Atrial flutter (AFL) is a common abnormal heart rhythm that starts in the atrial chambers of the heart. When it first occurs, it is usually associated with a fast heart rate and is classified as a type of supraventricular tachycardia. Atrial f ...
, and paroxysmal supraventricular tachycardia
Paroxysmal supraventricular tachycardia (PSVT) is a type of supraventricular tachycardia, named for its intermittent episodes of abrupt onset and termination. Often people have no symptoms. Otherwise symptoms may include palpitations, increased h ...
. Ventricular arrhythmias include ventricular fibrillation
Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and n ...
and ventricular tachycardia
Ventricular tachycardia (V-tach or VT) is a fast heart rate arising from the lower chambers of the heart. Although a few seconds of VT may not result in permanent problems, longer periods are dangerous; and multiple episodes over a short perio ...
. Arrhythmias are due to problems with the electrical conduction system of the heart
The cardiac conduction system (CCS) (also called the electrical conduction system of the heart) transmits the signals generated by the sinoatrial node – the heart's pacemaker, to cause the heart muscle to contract, and pump blood through ...
. Arrhythmias may occur in children; however, the normal range for the heart rate is different and depends on age. A number of tests can help with diagnosis including an electrocardiogram and Holter monitor
In medicine, a Holter monitor (often simply Holter) is a type of ambulatory electrocardiography device, a portable device for cardiac monitoring (the monitoring of the electrical activity of the cardiovascular system) for at least 24 hours.
...
.
Most arrhythmias can be effectively treated.[ Treatments may include medications, medical procedures such as a pacemaker, and surgery. Medications for a fast heart rate may include ]beta blockers
Beta blockers, also spelled β-blockers, are a class of medications that are predominantly used to manage abnormal heart rhythms, and to protect the heart from a second heart attack after a first heart attack ( secondary prevention). They are ...
or agents that attempt to restore a normal heart rhythm such as procainamide
Procainamide (PCA) is a medication of the antiarrhythmic class used for the treatment of cardiac arrhythmias. It is classified by the Vaughan Williams classification system as class Ia; thus it is a sodium channel blocker of cardiomyocytes. In add ...
. This later group may have more significant side effects especially if taken for a long period of time. Pacemakers are often used for slow heart rates. Those with an irregular heartbeat are often treated with blood thinner
Anticoagulants, commonly known as blood thinners, are chemical substances that prevent or reduce coagulation of blood, prolonging the clotting time. Some of them occur naturally in blood-eating animals such as leeches and mosquitoes, where th ...
s to reduce the risk of complications. Those who have severe symptoms from an arrhythmia may receive urgent treatment with a jolt of electricity in the form of cardioversion
Cardioversion is a medical procedure by which an abnormally fast heart rate ( tachycardia) or other cardiac arrhythmia is converted to a normal rhythm using electricity or drugs. Synchronized electrical cardioversion uses a therapeutic dose ...
or defibrillation.
Arrhythmia affects millions of people. In Europe and North America, as of 2014, atrial fibrillation affects about 2% to 3% of the population. Atrial fibrillation and atrial flutter resulted in 112,000 deaths in 2013, up from 29,000 in 1990. Sudden cardiac death
Cardiac arrest is when the heart suddenly and unexpectedly stops beating. It is a medical emergency that, without immediate medical intervention, will result in sudden cardiac death within minutes. Cardiopulmonary resuscitation (CPR) and possib ...
is the cause of about half of deaths due to cardiovascular disease or about 15% of all deaths globally. About 80% of sudden cardiac death is the result of ventricular arrhythmias.[ Arrhythmias may occur at any age but are more common among older people.][
]
Cardiac arrest
Cardiac arrest is a sudden stop in effective blood flow
Hemodynamics or haemodynamics are the dynamics of blood flow. The circulatory system is controlled by homeostatic mechanisms of autoregulation, just as hydraulic circuits are controlled by control systems. The hemodynamic response continuously m ...
due to the failure of the heart to contract effectively.[ Symptoms include loss of consciousness and abnormal or absent breathing.][ Some people may have chest pain, ]shortness of breath
Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing di ...
, or nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
before this occurs. If not treated within minutes, death
Death is the irreversible cessation of all biological functions that sustain an organism. For organisms with a brain, death can also be defined as the irreversible cessation of functioning of the whole brain, including brainstem, and brain ...
usually occurs.
The most common cause of cardiac arrest is coronary artery disease. Less common causes include major blood loss, lack of oxygen, very low potassium, heart failure, and intense physical exercise. A number of inherited disorders may also increase the risk including long QT syndrome. The initial heart rhythm is most often ventricular fibrillation
Ventricular fibrillation (V-fib or VF) is an abnormal heart rhythm in which the ventricles of the heart quiver. It is due to disorganized electrical activity. Ventricular fibrillation results in cardiac arrest with loss of consciousness and n ...
. The diagnosis is confirmed by finding no pulse.[ While a cardiac arrest may be caused by heart attack or heart failure these are not the same.][
Prevention includes not smoking, physical activity, and maintaining a healthy weight.][ Treatment for cardiac arrest is immediate ]cardiopulmonary resuscitation
Cardiopulmonary resuscitation (CPR) is an emergency procedure consisting of chest compressions often combined with artificial ventilation in an effort to manually preserve intact brain function until further measures are taken to restore spon ...
(CPR) and, if a shockable rhythm
Defibrillation is a treatment for life-threatening cardiac arrhythmias, specifically ventricular fibrillation (V-Fib) and non-perfusing ventricular tachycardia (V-Tach). A defibrillator delivers a dose of electric current (often called a ''coun ...
is present, defibrillation. Among those who survive targeted temperature management
Targeted temperature management (TTM) previously known as therapeutic hypothermia or protective hypothermia is an active treatment that tries to achieve and maintain a specific body temperature in a person for a specific duration of time in an e ...
may improve outcomes. An implantable cardiac defibrillator may be placed to reduce the chance of death from recurrence.
In the United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
, cardiac arrest outside of hospital occurs in about 13 per 10,000 people per year (326,000 cases). In hospital cardiac arrest occurs in an additional 209,000 Cardiac arrest becomes more common with age. It affects males more often than females. The percentage of people who survive with treatment is about 8%. Many who survive have significant disability
Disability is the experience of any condition that makes it more difficult for a person to do certain activities or have equitable access within a given society. Disabilities may be cognitive, developmental, intellectual, mental, physical, ...
. Many U.S. television shows, however, have portrayed unrealistically high survival rates of 67%.
Hypertension
Hypertension, also known as "high blood pressure", is a long term medical condition
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
in which the blood pressure in the arteries
An artery (plural arteries) () is a blood vessel in humans and most animals that takes blood away from the heart to one or more parts of the body (tissues, lungs, brain etc.). Most arteries carry oxygenated blood; the two exceptions are the pu ...
is persistently elevated. High blood pressure usually does not cause symptoms. Long term high blood pressure, however, is a major risk factor for coronary artery disease, stroke, heart failure, peripheral vascular disease
Peripheral artery disease (PAD) is an abnormal narrowing of arteries other than those that supply the heart or brain. When narrowing occurs in the heart, it is called coronary artery disease, and in the brain, it is called cerebrovascular dise ...
, vision loss, and chronic kidney disease.
Lifestyle factors can increase the risk of hypertension. These include excess salt in the diet, excess body weight, smoking, and alcohol consumption.[ Hypertension can also be caused by other diseases, or occur as a side-effect of drugs.
Blood pressure is expressed by two measurements, the systolic and ]diastolic
Diastole ( ) is the relaxed phase of the cardiac cycle when the chambers of the heart are re-filling with blood. The contrasting phase is systole when the heart chambers are contracting. Atrial diastole is the relaxing of the atria, and ventricu ...
pressures, which are the maximum and minimum pressures, respectively.[ Normal blood pressure when at rest is within the range of 100–140 millimeters mercury (mmHg) systolic and 60–90 mmHg diastolic.] High blood pressure is present if the resting blood pressure is persistently at or above 140/90 mmHg for most adults.[ Different numbers apply to children.] When diagnosing high blood pressure, ambulatory blood pressure monitoring over a 24-hour period appears to be more accurate than "in-office" blood pressure measurement
Arterial blood pressure is most commonly measured via a sphygmomanometer, which historically used the height of a column of mercury to reflect the circulating pressure. Blood pressure values are generally reported in millimetres of mercury (m ...
at a physician's office or other blood pressure screening location.
Lifestyle changes and medications can lower blood pressure and decrease the risk of health complications. Lifestyle changes include weight loss, decreased salt intake, physical exercise, and a healthy diet.[ If changes in lifestyle are insufficient, ]blood pressure medication
Antihypertensives are a class of drugs that are used to treat hypertension (high blood pressure). Antihypertensive therapy seeks to prevent the complications of high blood pressure, such as stroke and myocardial infarction. Evidence suggests that r ...
s may be used.[ A regimen of up to three medications effectively controls blood pressure in 90% of people.] The treatment of moderate to severe high arterial blood pressure (defined as >160/100 mmHg) with medication is associated with an improved life expectancy
Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...
and reduced morbidity
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
. The effect of treatment for blood pressure between 140/90 mmHg and 160/100 mmHg is less clear, with some studies finding benefits while others do not. High blood pressure affects between 16% and 37% of the population globally.[ In 2010, hypertension was believed to have been a factor in 18% (9.4 million) deaths.
]
Essential vs Secondary hypertension
Essential hypertension is the form of hypertension that by definition has no identifiable cause. It is the most common type of hypertension, affecting 95% of hypertensive patients, it tends to be familial and is likely to be the consequence of an interaction between environmental and genetic factors. Prevalence
In epidemiology, prevalence is the proportion of a particular population found to be affected by a medical condition (typically a disease or a risk factor such as smoking or seatbelt use) at a specific time. It is derived by comparing the number o ...
of essential hypertension increases with age, and individuals with relatively high blood pressure at younger ages are at increased risk for the subsequent development of hypertension.
Hypertension can increase the risk of cerebral, cardiac
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
, and renal
The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; bloo ...
events.
Secondary hypertension
Secondary hypertension (or, less commonly, inessential hypertension) is a type of hypertension which by definition is caused by an identifiable underlying primary cause. It is much less common than the other type, called essential hypertension, ...
is a type of hypertension which is caused by an identifiable underlying secondary cause. It is much less common than essential hypertension, affecting only 5% of hypertensive patients. It has many different causes including endocrine diseases, kidney diseases
Kidney disease, or renal disease, technically referred to as nephropathy, is damage to or disease of a kidney. Nephritis is an inflammatory kidney disease and has several types according to the location of the inflammation. Inflammation can b ...
, and tumors. It also can be a side effect
In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
of many medications.
Complications of hypertension
Complications of hypertension are clinical outcomes that result from persistent elevation of blood pressure. Hypertension is a risk factor for all clinical manifestations of atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no s ...
since it is a risk factor for atherosclerosis itself. It is an independent predisposing factor for heart failure, coronary artery disease, stroke, renal disease, and peripheral arterial disease. It is the most important risk factor
In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection.
Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often ...
for cardiovascular
The blood circulatory system is a system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascular system, tha ...
morbidity
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...
and mortality, in industrialized countries.
Congenital heart defects
A congenital heart defect, also known as a "congenital heart anomaly" or "congenital heart disease", is a problem in the structure of the heart that is present at birth
Birth is the act or process of bearing or bringing forth offspring, also referred to in technical contexts as parturition. In mammals, the process is initiated by hormones which cause the muscular walls of the uterus to contract, expelling the f ...
. Signs and symptoms depend on the specific type of problem.[ Symptoms can vary from none to life-threatening.][ When present they may include rapid breathing, bluish skin, poor weight gain, and feeling tired.][ It does not cause chest pain.] Most congenital heart problems do not occur with other diseases. Complications that can result from heart defects include heart failure.[
The cause of a congenital heart defect is often unknown. Certain cases may be due to infections during ]pregnancy
Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occur ...
such as rubella, use of certain medications or drugs such as alcohol or tobacco
Tobacco is the common name of several plants in the genus '' Nicotiana'' of the family Solanaceae, and the general term for any product prepared from the cured leaves of these plants. More than 70 species of tobacco are known, but the ...
, parents being closely related, or poor nutritional status or obesity
Obesity is a medical condition, sometimes considered a disease, in which excess body fat has accumulated to such an extent that it may negatively affect health. People are classified as obese when their body mass index (BMI)—a person's ...
in the mother. Having a parent with a congenital heart defect is also a risk factor.[ A number of genetic conditions are associated with heart defects including ]Down syndrome
Down syndrome or Down's syndrome, also known as trisomy 21, is a genetic disorder caused by the presence of all or part of a third copy of chromosome 21. It is usually associated with physical growth delays, mild to moderate intellectual dis ...
, Turner syndrome, and Marfan syndrome.[ Congenital heart defects are divided into two main groups: cyanotic heart defects and non-cyanotic heart defects, depending on whether the child has the potential to turn bluish in color.][ The problems may involve the interior walls of the heart, the ]heart valves
A heart valve is a one-way valve that allows blood to flow in one direction through the chambers of the heart. Four valves are usually present in a mammalian heart and together they determine the pathway of blood flow through the heart. A heart v ...
, or the large blood vessels that lead to and from the heart.[
Congenital heart defects are partly preventable through ]rubella vaccination
Rubella vaccine is a vaccine used to prevent rubella. Effectiveness begins about two weeks after a single dose and around 95% of people become immune. Countries with high rates of immunization no longer see cases of rubella or congenital rubell ...
, the adding of iodine to salt, and the adding of folic acid to certain food products.[ Some defects do not need treatment.][ Other may be effectively treated with catheter based procedures or heart surgery.][ Occasionally a number of operations may be needed.] Occasionally heart transplantation
A heart transplant, or a cardiac transplant, is a surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease when other medical or surgical treatments have failed. , the most common procedu ...
is required.[ With appropriate treatment outcomes, even with complex problems, are generally good.][
Heart defects are the most common birth defect.][ In 2013 they were present in 34.3 million people globally.] They affect between 4 and 75 per 1,000 live births depending upon how they are diagnosed. About 6 to 19 per 1,000 cause a moderate to severe degree of problems.[ Congenital heart defects are the leading cause of birth defect-related deaths.][ In 2013 they resulted in 323,000 deaths down from 366,000 deaths in 1990.]
Tetralogy of Fallot
Tetralogy of Fallot
Tetralogy of Fallot (TOF), formerly known as Steno-Fallot tetralogy, is a congenital heart defect characterized by four specific cardiac defects. Classically, the four defects are:
*pulmonary stenosis, which is narrowing of the exit from the r ...
is the most common congenital heart disease arising in 1–3 cases per 1,000 births. The cause of this defect is a ventricular septal defect
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one ...
(VSD) and an overriding aorta. These two defects combined causes deoxygenated blood to bypass the lungs and going right back into the circulatory system. The modified Blalock-Taussig shunt is usually used to fix the circulation. This procedure is done by placing a graft between the subclavian artery and the ipsilateral pulmonary artery to restore the correct blood flow.
Pulmonary atresia
Pulmonary atresia happens in 7–8 per 100,000 births and is characterized by the aorta branching out of the right ventricle. This causes the deoxygenated blood to bypass the lungs and enter the circulatory system. Surgeries can fix this by redirecting the aorta and fixing the right ventricle and pulmonary artery connection.
There are two types of pulmonary atresia, classified by whether or not the baby also has a ventricular septal defect
A ventricular septal defect (VSD) is a defect in the ventricular septum, the wall dividing the left and right ventricles of the heart. The extent of the opening may vary from pin size to complete absence of the ventricular septum, creating one ...
.
* Pulmonary atresia with an intact ventricular septum: This type of pulmonary atresia is associated with complete and intact septum between the ventricles.
* Pulmonary atresia with a ventricular septal defect: This type of pulmonary atresia happens when a ventricular septal defect allows blood to flow into and out of the right ventricle.
Double outlet right ventricle
Double outlet right ventricle
Double outlet right ventricle (DORV) is a form of congenital heart disease where both of the great arteries connect (in whole or in part) to the right ventricle (RV). In some cases it is found that this occurs on the left side of the heart rather ...
(DORV) is when both great arteries, the pulmonary artery and the aorta, are connected to the right ventricle. There is usually a VSD in different particular places depending on the variations of DORV, typically 50% are subaortic and 30%. The surgeries that can be done to fix this defect can vary due to the different physiology and blood flow in the defected heart. One way it can be cured is by a VSD closure and placing conduits to restart the blood flow between the left ventricle and the aorta and between the right ventricle and the pulmonary artery. Another way is systemic-to-pulmonary artery shunt in cases associated with pulmonary stenosis. Also, a balloon atrial septostomy can be done to relieve hypoxemia caused by DORV with the Taussig-Bing anomaly while surgical correction is awaited.
Transposition of great arteries
There are two different types of transposition of the great arteries
Transposition of the great vessels (TGV) is a group of congenital heart defects involving an abnormal spatial arrangement of any of the great vessels: superior and/or inferior venae cavae, pulmonary artery, pulmonary veins, and aorta. Congenital ...
, Dextro-transposition of the great arteries and Levo-transposition of the great arteries
Levo-Transposition of the great arteries is an acyanotic congenital heart defect in which the primary arteries (the aorta and the pulmonary artery) are transposed, with the aorta anterior and to the left of the pulmonary artery; the morphological ...
, depending on where the chambers and vessels connect. Dextro-transposition happens in about 1 in 4,000 newborns and is when the right ventricle pumps blood into the aorta and deoxygenated blood enters the bloodstream. The temporary procedure is to create an atrial septal defect
Atrial septal defect (ASD) is a congenital heart defect in which blood flows between the atria (upper chambers) of the heart. Some flow is a normal condition both pre-birth and immediately post-birth via the foramen ovale; however, when this d ...
. A permanent fix is more complicated and involves redirecting the pulmonary return to the right atrium and the systemic return to the left atrium, which is known as the Senning procedure
The Senning procedure is an atrial switch heart operation performed to treat transposition of the great arteries. It is named after its inventor, the Swedish cardiac surgeon Åke Senning (1915–2000), also known for implanting the first permanent ...
. The Rastelli procedure can also be done by rerouting the left ventricular outflow, dividing the pulmonary trunk, and placing a conduit in between the right ventricle and pulmonary trunk. Levo-transposition happens in about 1 in 13,000 newborns and is characterized by the left ventricle pumping blood into the lungs and the right ventricle pumping the blood into the aorta. This may not produce problems at the beginning, but will eventually due to the different pressures each ventricle uses to pump blood. Switching the left ventricle to be the systemic ventricle and the right ventricle to pump blood into the pulmonary artery can repair levo-transposition.
Persistent truncus arteriosus
Persistent truncus arteriosus is when the truncus arteriosus
The truncus arteriosus is a structure that is present during embryonic development. It is an arterial trunk that originates from both ventricles of the heart that later divides into the aorta and the pulmonary trunk.
Structure
The truncus arterio ...
fails to split into the aorta and pulmonary trunk. This occurs in about 1 in 11,000 live births and allows both oxygenated and deoxygenated blood into the body. The repair consists of a VSD closure and the Rastelli procedure.
Ebstein anomaly
Ebstein's anomaly
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart. It is classified as a critical congenital heart defect accounting ...
is characterized by a right atrium that is significantly enlarged and a heart that is shaped like a box. This is very rare and happens in less than 1% of congenital heart disease cases. The surgical repair varies depending on the severity of the disease.
Pediatric cardiology is a sub-specialty of pediatrics. To become a pediatric cardiologist in the U.S., one must complete a three-year residency in pediatrics, followed by a three-year fellowship in pediatric cardiology. Per doximity, pediatric cardiologists make an average of $303,917 in the U.S.
Diagnostic tests in cardiology
Diagnostic tests in cardiology
The diagnostic tests in cardiology are methods of identifying heart conditions associated with healthy vs. unhealthy, pathologic heart function.
Bedside
History
Obtaining a medical history is always the first "test", part of understanding the l ...
are the methods of identifying heart conditions associated with healthy vs. unhealthy, pathologic heart function. The starting point is obtaining a medical history, followed by Auscultation. Then blood tests, electrophysiological procedures, and cardiac imaging can be ordered for further analysis. Electrophysiological procedures include electrocardiogram, cardiac monitoring
Cardiac monitoring generally refers to continuous or intermittent monitoring of heart activity to assess a patient's condition relative to their cardiac rhythm. Cardiac monitoring is usually carried out using electrocardiography, which is a noninva ...
, cardiac stress testing, and the electrophysiology study.
Trials
Cardiology is known for randomized controlled trial
A randomized controlled trial (or randomized control trial; RCT) is a form of scientific experiment used to control factors not under direct experimental control. Examples of RCTs are clinical trials that compare the effects of drugs, surgical te ...
s that guide clinical treatment of cardiac diseases. While dozens are published every year, there are landmark trials that shift treatment significantly. Trials often have an acronym of the trial name, and this acronym is used to reference the trial and its results. Some of these landmark trials include:
* V-HeFT (1986) — use of vasodilators (hydralazine & isosorbide dinitrate) in heart failure
* ISIS-2 (1988) — use of aspirin in myocardial infarction
* CASE I (1991) — use of antiarrhythmic agent
Antiarrhythmic agents, also known as cardiac dysrhythmia medications, are a group of pharmaceuticals that are used to suppress abnormally fast rhythms ( tachycardias), such as atrial fibrillation, supraventricular tachycardia and ventricular ta ...
s after a heart attack increases mortality
* SOLVD (1991) — use of ACE inhibitors in heart failure
* 4S (1994) — statin
Statins, also known as HMG-CoA reductase inhibitors, are a class of lipid-lowering medications that reduce illness and mortality in those who are at high risk of cardiovascular disease. They are the most common cholesterol-lowering drugs.
Low ...
s reduce risk of heart disease
* CURE (1991) — use of dual antiplatelet therapy in NSTEMI
A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may tra ...
* MIRACLE (2002) — use of cardiac resynchronization therapy in heart failure
* SCD-HeFT (2005) — the use of implantable cardioverter-defibrillator in heart failure
* RELY (2009), ROCKET-AF (2011), ARISTOTLE (2011) — use of DOACs in atrial fibrillation instead of warfarin
* ISCHEMIA (2020) — medical therapy is as good as coronary stent
A coronary stent is a tube-shaped device placed in the coronary arteries that supply blood to the heart, to keep the arteries open in the treatment of coronary heart disease. It is used in a procedure called percutaneous coronary intervention (PC ...
s in stable heart disease
Cardiology community
Associations
* American College of Cardiology
The American College of Cardiology (ACC), based in Washington, D.C., is a nonprofit medical association established in 1949. It bestows credentials upon cardiovascular specialists who meet its qualifications. Education is a core component of the ...
* American Heart Association
* European Society of Cardiology
* Heart Rhythm Society
* Canadian Cardiovascular Society
The Canadian Cardiovascular Society (CCS) is the national voice for cardiovascular physicians and scientists in Canada. The CCS is a membership organization that represents more than 1,800 professionals in the cardiovascular field. Its mission is ...
* Indian Heart Association
* National Heart Foundation of Australia
The National Heart Foundation of Australia (known as the Heart Foundation) is a charity established in 1959. Its activities have been funding cardiovascular research, supporting health professionals in their practice, developing health promotion ...
* Cardiology Society of India
Journals
* Acta Cardiologica
* American Journal of Cardiology
* Annals of Cardiac Anaesthesia
* Current Research: Cardiology
* Cardiology in Review
* Circulation
* Circulation Research
* Clinical and Experimental Hypertension
* Clinical Cardiology
* EP – Europace
* European Heart Journal
* Heart
The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide to t ...
* Heart Rhythm
The cardiac conduction system (CCS) (also called the electrical conduction system of the heart) transmits the signals generated by the sinoatrial node – the heart's pacemaker, to cause the heart muscle to contract, and pump blood through the ...
* International Journal of Cardiology
* Journal of the American College of Cardiology
The ''Journal of the American College of Cardiology'' is a peer-reviewed medical journal covering all aspects of cardiovascular disease, including original clinical studies, translational investigations with clear clinical relevance, state-of-the-a ...
* Pacing and Clinical Electrophysiology
* Indian Heart Journal
Cardiologists
* Robert Atkins (1930–2003), known for the Atkins diet
* Eugene Braunwald
Eugene Braunwald (born August 15, 1929 in Vienna, Austria) is an Austrian-born American cardiologist.
Early life
Braunwald was born to Jewish parents Wilhelm Braunwald and Clara Wallach in Vienna. He obtained his A.B. and M.D. at New York Univer ...
(born 1929), editor of ''Braunwald's Heart Disease'' and 1000+ publications
* Wallace Brigden (1916–2008), identified cardiomyopathy
* Manoj Durairaj (1971– ), cardiologist from Pune, India who received Pro Ecclesia et Pontifice
''Pro Ecclesia et Pontifice'' ("For Church and Pope" in Latin) is a decoration of the Holy See. It is currently conferred for distinguished service to the Catholic Church by lay people and clergy.
History
The medal was established by Leo XIII o ...
* Willem Einthoven
Willem Einthoven (21 May 1860 – 29 September 1927) was a Dutch doctor and physiologist. He invented the first practical electrocardiograph (ECG or EKG) in 1895 and received the Nobel Prize in Physiology or Medicine in 1924 for it ("for the di ...
(1860–1927), a physiologist who built the first practical ECG and won the 1924 Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
("for the discovery of the mechanism of the electrocardiogram")
* Werner Forssmann (1904–1979), who infamously performed the first human catheterization on himself that led to him being let go from Berliner Charité Hospital, quitting cardiology as a speciality, and then winning the 1956 Nobel Prize in Physiology or Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, accord ...
("for their discoveries concerning heart catheterization and pathological changes in the circulatory system")
* Andreas Gruentzig (1939–1985), first developed balloon angioplasty
* William Harvey
William Harvey (1 April 1578 – 3 June 1657) was an English physician who made influential contributions in anatomy and physiology. He was the first known physician to describe completely, and in detail, the systemic circulation and propert ...
(1578–1657), wrote '' Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus'' that first described the closed circulatory system and whom Forssmann described as founding cardiology in his Nobel lecture
* Murray S. Hoffman (born 1924) As president of the Colorado Heart Association, he initiated one of the first jogging programs promoting cardiac health
* Max Holzmann
Max Holzmann (31 March 1899 – 27 January 1994) was a Swiss cardiology, cardiologist.
Early life
Max Holzmann was born on 31 March 1899 in Zurich, the son of physician Moritz Holzmann and Anna Helena Lerch. Holzmann took a degree in medici ...
(1899–1994), co-founder of the Swiss Society of Cardiology, president from 1952 to 1955
* Samuel A. Levine
Samuel Albert Levine (January 1, 1891 – March 31, 1966) was an American cardiologist. The Levine scale, Levine's sign and Lown–Ganong–Levine syndrome are named after him. The Samuel Albert Levine Cardiac Unit at Brigham and Women's Hospita ...
(1891–1966), recognized the sign known as Levine's sign as well as the current grading of the intensity of heart murmurs
Heart murmurs are unique heart sounds produced when blood flows across a heart valve or blood vessel. This occurs when turbulent blood flow creates a sound loud enough to hear with a stethoscope. Turbulent blood flow is not smooth. The sound dif ...
, known as the Levine scale
In cardiac physiology, the Levine grading scale is a numeric scoring system to characterize the intensity or the loudness of a heart murmur. The eponym is from researcher Samuel A. Levine who studied the significance of systolic heart murmurs. The ...
* Henry Joseph Llewellyn "Barney" Marriott (1917–2007), ECG interpretation and ''Practical Electrocardiography''
* Bernard Lown
Bernard Lown (June 7, 1921February 16, 2021) was a Lithuanian-American cardiologist and inventor. Lown was the original developer of the direct current defibrillator for cardiac resuscitation, and the cardioverter for correcting rapid disordered h ...
(born 1921), original developer of the defibrillator
* Woldemar Mobitz
Woldemar Mobitz (31 May 1889 – 11 April 1951) was a Russian-German physician. The forms of second degree AV block are named after him for him.
Mobitz was born on May 31, 1889 in St. Petersburg, Russia. He attended the local high school in Meinin ...
(1889–1951), described and classified the two types of second-degree atrioventricular block
Second-degree atrioventricular block (AV block) is a disease of the electrical conduction system of the heart. It is a conduction block between the atria and ventricles. The presence of second-degree AV block is diagnosed when one or more (but n ...
often called "Mobitz Type I" and "Mobitz Type II"
* Jacqueline Noonan
Jacqueline Anne Noonan (October 28, 1928 – July 23, 2020) was an American pediatric cardiologist best known for her characterization of a genetic disorder now called Noonan syndrome. She was also the original describer of hypoplastic left heart ...
(born 1928), discoverer of Noonan syndrome
Noonan syndrome (NS) is a genetic disorder that may present with mildly unusual facial features, short height, congenital heart disease, bleeding problems, and skeletal malformations. Facial features include widely spaced eyes, light-colored ...
that is the top syndromic cause of congenital heart disease
* John Parkinson (1885–1976), known for Wolff–Parkinson–White syndrome
Wolff–Parkinson–White syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, ...
* Helen B. Taussig (1898–1986), founder of pediatric cardiology and extensively worked on blue baby syndrome
Blue baby syndrome can refer to conditions that cause cyanosis, or blueness of the skin, in babies as a result of low oxygen levels in the blood. This term has traditionally been applied to cyanosis as a result of:
#Cyanotic heart disease, whi ...
* Paul Dudley White
Paul Dudley White (June 6, 1886 – October 31, 1973), was an American physician and cardiologist. He was considered one of the leading cardiologists of his day, and a prominent advocate of preventive medicine.
Early life and education
White wa ...
(1886–1973), known for Wolff–Parkinson–White syndrome
Wolff–Parkinson–White syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, ...
* Louis Wolff Louis may refer to:
* Louis (coin)
* Louis (given name), origin and several individuals with this name
* Louis (surname)
* Louis (singer), Serbian singer
* HMS ''Louis'', two ships of the Royal Navy
See also
Derived or associated terms
* Lewis (d ...
(1898–1972), known for Wolff–Parkinson–White syndrome
Wolff–Parkinson–White syndrome (WPWS) is a disorder due to a specific type of problem with the electrical system of the heart. About 60% of people with the electrical problem developed symptoms, which may include an abnormally fast heartbeat, ...
* Karel Frederik Wenckebach
Karel Frederik Wenckebach (; March 24, 1864 – November 11, 1940) was a Dutch anatomist who was a native of the Hague.
He studied medicine in Utrecht, and in 1901 become a professor of medicine at the University of Groningen. Later he was a profe ...
(1864–1940), first described what is now called type I second-degree atrioventricular block
Second-degree atrioventricular block (AV block) is a disease of the electrical conduction system of the heart. It is a conduction block between the atria and ventricles. The presence of second-degree AV block is diagnosed when one or more (but n ...
in 1898
See also
* Glossary of medicine
This glossary of medical terms is a list of definitions about medicine, its sub-disciplines, and related fields.
A
* Aarskog–Scott syndrome – (AAS) A rare, inherited (X-linked) disease characterized by short stature, facial abnormalities ...
* List of cardiac pharmaceutical agents
The following are medications commonly prescribed cardiac pharmaceutical agents.
The specificity of the following medications is highly variable, and often are not particularly specific to a given class.
As such, they are listed as are commonly acc ...
* Outline of cardiology
References
Sources
*
*
External links
American Heart Association
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