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Acute coronary syndrome (ACS) is a
syndrome A syndrome is a set of medical signs and symptoms which are correlated with each other and often associated with a particular disease or disorder. The word derives from the Greek σύνδρομον, meaning "concurrence". When a syndrome is paired ...
(a set of
signs and symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormality showi ...
) due to decreased
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 continuousl ...
in the coronary arteries such that part of the
heart muscle Cardiac muscle (also called heart muscle, myocardium, cardiomyocytes and cardiac myocytes) is one of three types of vertebrate Muscle tissue, muscle tissues, with the other two being skeletal muscle and smooth muscle. It is an involuntary, striat ...
is unable to function properly or
dies Dies may refer to: * Dies (deity), the Roman counterpart of the Greek goddess Hemera, the personification of day, daughter of Nox (Night) and Erebus (Darkness). * Albert Christoph Dies (1755–1822), German painter, composer, and biographer * Jos ...
. The most common symptom is centrally located pressure-like
chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with ...
, often radiating to the left shoulder or angle of the jaw, and associated with
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 ...
and
sweating Perspiration, also known as sweating, is the production of fluids secreted by the sweat glands in the skin of mammals. Two types of sweat glands can be found in humans: eccrine glands and apocrine glands. The eccrine sweat glands are distri ...
. Many people with acute coronary syndromes present with symptoms other than chest pain, particularly women, older people, and people with
diabetes mellitus 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 ...
. Acute coronary syndrome is subdivided in three scenarios depending on the duration of symptoms, the presence of ECG changes and blood test results: ST elevation myocardial infarction (STEMI, 30%),
non-ST elevation 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 m ...
(NSTEMI, 25%), or unstable angina (38%). Generally, when symptoms occur for less than 30 minutes, it is unstable angina. When symptoms are prolonged for more than 30 minutes, the diagnosis is acute
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 ...
. ACS should be distinguished from ''stable'' angina, which develops during physical activity or stress and resolves at rest. In contrast with stable angina, unstable angina occurs suddenly, often at rest or with minimal exertion, or at lesser degrees of exertion than the individual's previous angina ("crescendo angina"). New-onset angina is also considered unstable angina, since it suggests a new problem in a coronary artery.


Signs and symptoms

The cardinal symptom of critically decreased blood flow to the heart is chest pain, experienced as tightness around or over the chest and (often, but not always) radiating to the left arm and the left angle of the jaw. This may be associated with diaphoresis (sweating),
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 ...
and
vomiting Vomiting (also known as emesis and throwing up) is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteri ...
, as well as
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 ...
. In many cases, the sensation is "atypical", with pain experienced in different ways or even being completely absent (which is more likely in female patients and those with
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 ...
). Some may report
palpitation Palpitations are perceived abnormalities of the heartbeat characterized by awareness of cardiac muscle contractions in the chest, which is further characterized by the hard, fast and/or irregular beatings of the heart. Symptoms include a rap ...
s, anxiety or a sense of impending doom (
angor animi Angor animi (also referred to as angina animi,Gairdner's disease. Online Medical Dictionary. ''CancerWeb. Centre for Cancer Education.'' Newcastle University. http://cancerweb.ncl.ac.uk/cgi-bin/omd?query=Gairdner%27s+disease (accessed: May 04, 200 ...
) and a feeling of being acutely ill. The description of the chest discomfort as a pressure has little utility in aiding a diagnosis as it is not
specific Specific may refer to: * Specificity (disambiguation) * Specific, a cure or therapy for a specific illness Law * Specific deterrence, focussed on an individual * Specific finding, intermediate verdict used by a jury in determining the final ...
for ACS. Though ACS is usually associated with
coronary thrombosis Coronary thrombosis is defined as the formation of a blood clot inside a blood vessel of the heart. This blood clot may then restrict blood flow within the heart, leading to heart tissue damage, or a myocardial infarction, also known as a heart at ...
, it can also be associated with
cocaine Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Am ...
use. Chest pain with features characteristic of cardiac origin (angina) can also be precipitated by profound
anemia Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, ...
, brady- or
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 ( ...
(excessively slow or rapid heart rate),
low Low or LOW or lows, may refer to: People * Low (surname), listing people surnamed Low Places * Low, Quebec, Canada * Low, Utah, United States * Lo Wu station (MTR code LOW), Hong Kong; a rail station * Salzburg Airport (ICAO airport code: LO ...
or
high blood pressure Hypertension (HTN or HT), also known as high blood pressure (HBP), is a long-term medical condition in which the blood pressure in the arteries is persistently elevated. High blood pressure usually does not cause symptoms. Long-term high b ...
, severe
aortic valve stenosis Aortic stenosis (AS or AoS) is the narrowing of the exit of the left ventricle of the heart (where the aorta begins), such that problems result. It may occur at the aortic valve as well as above and below this level. It typically gets worse ov ...
(narrowing of the valve at the beginning of the aorta), pulmonary artery hypertension and a number of other conditions.


Pathophysiology

In those who have ACS,
atheroma An atheroma, or atheromatous plaque, is an abnormal and reversible accumulation of material in the inner layer of an arterial wall. The material consists of mostly macrophage cells, or debris, containing lipids, calcium and a variable amount ...
rupture is most commonly found 60% when compared to atheroma erosion (30%), thus causes the formation of
thrombus A thrombus (plural thrombi), colloquially called a blood clot, is the final product of the blood coagulation step in hemostasis. There are two components to a thrombus: aggregated platelets and red blood cells that form a plug, and a mesh of cr ...
which block the coronary arteries. Plaque rupture is responsible for 60% in ST elevated
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 ...
(STEMI) while plaque erosion is responsible for 30% of the STEMI and vice versa for Non ST elevated myocardial infarction (NSTEMI). In plaque rupture, the content of the plaque are lipid rich, collagen poor, with abundant inflammation which is macrophage predominant, and covered with a thin fibrous cap. Meanwhile, in plaque erosion, the plaque is rich with
extracellular matrix In biology, the extracellular matrix (ECM), also called intercellular matrix, is a three-dimensional network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide struc ...
,
proteoglycan Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to w ...
, glycoaminoglycan, but without fibrous caps, no inflammatory cells, and no large lipid core. After the coronary arteries are unblocked, there is a risk of
reperfusion injury Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue ('' re-'' + '' perfusion'') after a period of ischemia or lack of oxygen (anoxia or ...
due spreading inflammatory mediators throughout the body. Investigations is still underway on the role of Cyclophilin D in reducing the reperfusion injury. Other, less common, causes of acute coronary syndrome include spontaneous coronary artery dissection, ischemia in the absence of obstructive coronary artery disease (INOCA), and myocardial infarction in the absence of obstructive coronary artery disease (MINOCA).


Diagnosis


Electrocardiogram

In the setting of acute chest pain, the electrocardiogram is the investigation that most reliably distinguishes between various causes. The ECG should be done as early as practicable, including in the ambulance if possible. If this indicates acute heart damage (elevation in the ''ST segment'', new left bundle branch block), treatment for a heart attack in the form of angioplasty or thrombolysis is indicated immediately (see below). In the absence of such changes, it is not possible to immediately distinguish between unstable angina and NSTEMI.


Imaging and blood tests

As it is only one of the many potential causes of
chest pain Chest pain is pain or discomfort in the chest, typically the front of the chest. It may be described as sharp, dull, pressure, heaviness or squeezing. Associated symptoms may include pain in the shoulder, arm, upper abdomen, or jaw, along with ...
, the patient usually has a number of tests in the emergency department, such as a
chest X-ray A chest radiograph, called a chest X-ray (CXR), or chest film, is a projection radiograph of the chest used to diagnose conditions affecting the chest, its contents, and nearby structures. Chest radiographs are the most common film taken in me ...
,
blood test A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a ch ...
s (including myocardial markers such as troponin I or T, and
H-FABP Heart-type fatty acid binding protein (hFABP) also known as mammary-derived growth inhibitor is a protein that in humans is encoded by the ''FABP3'' gene. Function Heart-type Fatty Acid-Binding Protein (H-FABP) is a small cytoplasmic protein ( ...
and/or a D-dimer if a
pulmonary embolism Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing ...
is suspected), and telemetry (monitoring of the heart rhythm). Combination of troponin levels (less than 5 ng/L) with low
TIMI The Thrombolysis In Myocardial Infarction, or TIMI Study Group, is an Academic Research Organization (ARO) affiliated with Brigham and Women's Hospital and Harvard Medical School dedicated to advancing the knowledge and care of patients with c ...
scores can help to predict those with low possibility of myocardial infarction and discharge them safely from the emergency department. Coronary CT angiography combined with Troponin levels is also helpful to
triage In medicine, triage () is a practice invoked when acute care cannot be provided for lack of resources. The process rations care towards those who are most in need of immediate care, and who benefit most from it. More generally it refers to pri ...
those who are susceptible to ACS. F-fluoride
positron emission tomography Positron emission tomography (PET) is a functional imaging technique that uses radioactive substances known as radiotracers to visualize and measure changes in metabolic processes, and in other physiological activities including blood flow, ...
is also helpful in identifying those with high risk, lipid-rich coronary plaques.


Prediction scores

The ACI-TIPI score can be used to aid diagnosis; using seven variables from the admission record, this score predicts crudely which patients are likely to have myocardial ischemia. For example, according to a
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 ...
, males having chest pain with normal or non-diagnostic ECG are at higher risk for having acute coronary syndrome than women. In this study, the
sensitivity Sensitivity may refer to: Science and technology Natural sciences * Sensitivity (physiology), the ability of an organism or organ to respond to external stimuli ** Sensory processing sensitivity in humans * Sensitivity and specificity, statisti ...
was 65.2% and specificity was 44%. This particular study had an 8.4% prevalence of acute coronary syndrome, which means the positive predictive value of being a male with chest pain and having coronary syndrome is 9.6% and negative predictive value is 93.2%
click here
to adjust these results for people at higher or lower risk of acute coronary syndrome). In a second
cohort study A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing ...
, exercise electrocardiography was similarly found to be a poor predictor of acute coronary syndrome at follow-up. Of the patients who had a coronary event at 6 years of follow up, 47% had a negative ECG at the start of the study. With an average follow up of 2.21 years the
receiver operating characteristic A receiver operating characteristic curve, or ROC curve, is a graphical plot that illustrates the diagnostic ability of a binary classifier system as its discrimination threshold is varied. The method was originally developed for operators of m ...
curves gave resting ECG a score of 0.72 and exercise ECG a score of 0.74. There are not only prediction scores for diagnosis of ACS, but also prognosis. Most notably, the GRACE ACS Risk and Mortality score helps diagnose, and based upon that score predicts mortality rate of a given patient. It takes into account both clinical (blood pressure, heart rate, EKG findings) and medical history in its scoring system.


Prevention

Acute coronary syndrome often reflects a degree of damage to the coronaries 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 ...
. Primary prevention of atherosclerosis is controlling the risk factors: healthy eating, exercise, treatment for hypertension and
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 ...
, avoiding
smoking Smoking is a practice in which a substance is burned and the resulting smoke is typically breathed in to be tasted and absorbed into the bloodstream. Most commonly, the substance used is the dried leaves of the tobacco plant, which have bee ...
and controlling
cholesterol Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell membr ...
levels; in patients with significant risk factors,
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 in ...
has been shown to reduce the risk of cardiovascular events. Secondary prevention is discussed in
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 ...
. After a ban on smoking in all enclosed public places was introduced in Scotland in March 2006, there was a 17% reduction in hospital admissions for acute coronary syndrome. 67% of the decrease occurred in non-smokers.


Treatment

People with presumed ACS are typically treated with aspirin,
clopidogrel Clopidogrel — sold under the brand name Plavix, among others — is an antiplatelet medication used to reduce the risk of heart disease and stroke in those at high risk. It is also used together with aspirin in heart attacks and following ...
or ticagrelor,
nitroglycerin Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating g ...
, and if the chest discomfort persists
morphine Morphine is a strong opiate that is found naturally in opium, a dark brown resin in poppies ('' Papaver somniferum''). It is mainly used as a pain medication, and is also commonly used recreationally, or to make other illicit opioids. Ther ...
. Other
analgesics An analgesic drug, also called simply an analgesic (American English), analgaesic (British English), pain reliever, or painkiller, is any member of the group of Pharmaceutical drug, drugs used to achieve relief from pain (that is, analgesia or p ...
such as
nitrous oxide Nitrous oxide (dinitrogen oxide or dinitrogen monoxide), commonly known as laughing gas, nitrous, or nos, is a chemical compound, an oxide of nitrogen with the formula . At room temperature, it is a colourless non-flammable gas, and has ...
are of unknown benefit.
Angiography Angiography or arteriography is a medical imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body, with particular interest in the arteries, veins, and the heart chambers. Modern angiography is perfo ...
is recommended in those who have either new ST elevation or a new left or right
bundle branch block A bundle branch block is a defect in one the bundle branches in the electrical conduction system of the heart. Anatomy and physiology The heart's electrical activity begins in the sinoatrial node (the heart's natural pacemaker), which is situat ...
on their ECG. Unless the person has low oxygen levels additional oxygen does not appear to be useful.


STEMI

If the ECG confirms changes suggestive of
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 ...
(ST elevations in specific leads, a new left bundle branch block or a true posterior MI pattern), thrombolytics may be administered or primary coronary angioplasty may be performed. In the former, medication is injected that stimulates fibrinolysis, destroying blood clots obstructing the coronary arteries. In the latter, a flexible catheter is passed via the femoral or radial
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 pul ...
and advanced to the heart to identify blockages in the coronaries. When occlusions are found, they can be intervened upon mechanically with angioplasty and usually stent deployment if a lesion, termed the ''culprit'' lesion, is thought to be causing myocardial damage. Data suggest that rapid
triage In medicine, triage () is a practice invoked when acute care cannot be provided for lack of resources. The process rations care towards those who are most in need of immediate care, and who benefit most from it. More generally it refers to pri ...
, transfer and treatment is essential. The time frame for door-to-needle thrombolytic administration according to American College of Cardiology (ACC) guidelines should be within 30 minutes, whereas the door-to-balloon Percutaneous Coronary Intervention (PCI) time should be less than 90 minutes. It was found that thrombolysis is more likely to be delivered within the established ACC guidelines among patients with STEMI as compared to PCI according to a
case control Case or CASE may refer to: Containers * Case (goods), a package of related merchandise * Cartridge case or casing, a firearm cartridge component * Bookcase, a piece of furniture used to store books * Briefcase or attaché case, a narrow box to c ...
study.


NSTEMI and NSTE-ACS

If the ECG does not show typical changes, the term "non-ST segment elevation ACS" is applied. The patient may still have had a "non-ST elevation MI" (NSTEMI). The accepted management of unstable angina and acute coronary syndrome is therefore empirical treatment with aspirin, a second platelet inhibitor such as clopidogrel, prasugrel or ticagrelor, and heparin (usually a
low-molecular weight heparin Low-molecular-weight heparin (LMWH) is a class of anticoagulant medications. They are used in the prevention of blood clots and treatment of venous thromboembolism ( deep vein thrombosis and pulmonary embolism) and in the treatment of myocardia ...
), with intravenous
nitroglycerin Nitroglycerin (NG), (alternative spelling of nitroglycerine) also known as trinitroglycerin (TNG), nitro, glyceryl trinitrate (GTN), or 1,2,3-trinitroxypropane, is a dense, colorless, oily, explosive liquid most commonly produced by nitrating g ...
and
opioid Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioi ...
s if the pain persists. The heparin-like drug known as fondaparinux appears to be better than enoxaparin. A blood test is generally performed for cardiac troponins twelve hours after onset of the pain. If this is positive, coronary angiography is typically performed on an urgent basis, as this is highly predictive of a heart attack in the near-future. If the troponin is negative, a treadmill exercise test or a thallium scintigram may be requested. If there is no evidence of ST segment elevation on the electrocardiogram, delaying urgent angioplasty until the next morning is not inferior to doing so immediately. Using statins in the first 14 days after ACS reduces the risk of further ACS. In a
cohort study A cohort study is a particular form of longitudinal study that samples a cohort (a group of people who share a defining characteristic, typically those who experienced a common event in a selected period, such as birth or graduation), performing ...
comparing NSTEMI and STEMI, people with NSTEMI had a similar risk of death at one year after PCI as compared to people with STEMI (3.4% vs 4.4%). However, NSTEMI had significantly more "major cardiac events" (death,
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 ...
, disabling stroke, or requiring
revascularization In medical and surgical therapy, revascularization is the restoration of perfusion to a body part or organ that has had ischemia. It is typically accomplished by surgical means. Vascular bypass and angioplasty are the two primary means of ...
) at one year (24.0% vs 16.6%).
Cocaine Cocaine (from , from , ultimately from Quechua: ''kúka'') is a central nervous system (CNS) stimulant mainly used recreationally for its euphoric effects. It is primarily obtained from the leaves of two Coca species native to South Am ...
-associated ACS should be managed in a manner similar to other patients with acute coronary syndrome except
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 should not be used and
benzodiazepines Benzodiazepines (BZD, BDZ, BZs), sometimes called "benzos", are a class of depressant drugs whose core chemical structure is the fusion of a benzene ring and a diazepine ring. They are prescribed to treat conditions such as anxiety disorders, ...
should be administered early.


Prognosis


TIMI score

The
TIMI The Thrombolysis In Myocardial Infarction, or TIMI Study Group, is an Academic Research Organization (ARO) affiliated with Brigham and Women's Hospital and Harvard Medical School dedicated to advancing the knowledge and care of patients with c ...
risk score can identify high risk patients in non-ST segment elevation MI ACS and has been independently validated.


Global Registry of Acute Coronary Events (GRACE) score

Based on a global registry of 102,341 patients, the GRACE Risk Score estimates in-hospital, 6 months, 1 year, and 3-year mortality risk after a heart attack
GRACE Score 2.0 Calculator


Killip class

The Killip classification consists of 4 classes based on clinical symptoms. It predicts 30-day mortality after myocardial infarction.


Biomarkers for diagnosis

The aim of diagnostic markers is to identify patients with ACS even when there is no evidence of heart muscle damage. * Ischemia-Modified Albumin (IMA) – In cases of Ischemia – Albumin undergoes a conformational change and loses its ability to bind transitional metals (copper or cobalt). IMA can be used to assess the proportion of modified albumin in ischemia. Its use is limited to ruling out ischemia rather than a diagnostic test for the occurrence of ischemia. * Myeloperoxidase (MPO) – The levels of circulating MPO, a leukocyte enzyme, elevate early after ACS and can be used as an early marker for the condition. * Glycogen Phosphorylase Isoenzyme BB-(
GPBB Glycogen phosphorylase isoenzyme BB (abbreviation: GPBB) is an isoenzyme of glycogen phosphorylase. This isoform of the enzyme exists in cardiac (heart) and brain tissue. The enzyme is one of the "new cardiac markers" which are discussed to impr ...
) is an early marker of cardiac ischemia and is one of three
isoenzyme In biochemistry, isozymes (also known as isoenzymes or more generally as multiple forms of enzymes) are enzymes that differ in amino acid sequence but catalyze the same chemical reaction. Isozymes usually have different kinetic parameters (e.g. dif ...
of Glycogen Phosphorylase. * Troponin is a late cardiac marker of ACS


Biomarkers for risk determination

The aim of prognostic markers is to reflect different components of pathophysiology of ACS. For example: * Natriuretic peptide – Both B-type natriuretic peptide (BNP) and N-terminal Pro BNP can be applied to predict the risk of death and heart failure following ACS. * Monocyte chemo attractive protein (MCP)-1 – has been shown in a number of studies to identify patients with a higher risk of adverse outcomes after ACS.


Day of admission

Studies have shown that for ACS patients, weekend admission is associated with higher mortality and lower utilization of invasive cardiac procedures, and those who did undergo these interventions had higher rates of mortality and complications than their weekday counterparts. This data leads to the possible conclusion that access to diagnostic/interventional procedures may be contingent upon the day of admission, which may impact mortality. This phenomenon is described as weekend effect.


Valvular heart disease

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 ...
is characterized by damage to or defective in one of the four
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: the mitral, aortic, tricuspid or pulmonary. Some types of valvular heart disease include valvular stenosis, valvular prolapse and regurgitation.


Oral manifestations

Oral infections may pose risk during postoperative period of heart valve surgery. Oral health in patients scheduled for heart valve surgery is poorer than in individuals without valve disease. Most of them experience periodontitis due to high
dental plaque Dental plaque is a biofilm of microorganisms (mostly bacteria, but also fungi) that grows on surfaces within the mouth. It is a sticky colorless deposit at first, but when it forms tartar, it is often brown or pale yellow. It is commonly found be ...
scores, reflecting poorer dental hygiene. This situation could favour the appearance of bacteremia following tooth brushing in these individuals. Bacteremia secondary to periodontal infection is known to be one of the primary causes of infectious endocarditis, particularly in patient with heart valve disorders. Therefore, treatment of dental disease should be done prior to performing heart surgery. Periodontal treatment is advised in patients with advanced
periodontitis Periodontal disease, also known as gum disease, is a set of inflammatory conditions affecting the tissues surrounding the teeth. In its early stage, called gingivitis, the gums become swollen and red and may bleed. It is considered the main cau ...
, followed by
root planing Scaling and root planing, also known as conventional periodontal therapy, non-surgical periodontal therapy or deep cleaning, is a procedure involving removal of dental plaque and calculus (scaling or debridement) and then smoothing, or planing, o ...
and
ultrasound Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is not different from "normal" (audible) sound in its physical properties, except that humans cannot hear it. This limit varies fr ...
treatment. Those teeth not amenable to treatment and with poor prognosis should be removed as pre-surgical preventive measures.


Dental management

The two main concerns during dental treatment for people of patient with valvular heart disease are the risk of infective endocarditis and bleeding in anti coagulated patients.
Endocarditis Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves. Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or the ...
is more likely to occur in patients who have previously had endocarditis and those with certain cardiac lesions. Risk of a normally functioning prosthesis being infected after a dental procedure is probably no higher than risk in patient with damaged native valves. However, mortality and
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 ...
is much higher should prosthesis become infected. Patient with native valve disease can often stop or reduce their anticoagulants, but those with prosthetic valves should not discontinue anticoagulants without cardiological advice. Mechanical mitral valves are prone to
thrombosis Thrombosis (from Ancient Greek "clotting") is the formation of a blood clot inside a blood vessel, obstructing the flow of blood through the circulatory system. When a blood vessel (a vein or an artery) is injured, the body uses platelets (thr ...
, which cause emboli if adequate anti-coagulation is not maintained, although short term modification may be possible.


Heart failure

Heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome, a group of signs and symptoms caused by an impairment of the heart's blood pumping function. Symptoms typically include shortness of breath, excessive fatigue, ...
(HF) is defined as the incapacity of the heart to function properly, pumping insufficient blood towards the tissues and leading to fluid accumulation within the lungs, liver and peripheral tissues.


Oral manifestations

    Most if not all patients with heart failure will be undergoing drug treatments for their condition and these drugs can produce a series of oral manifestation. In this context, angiotensin-converting enzyme (ACE) inhibitors such as captopril and enalapril can produce burning mouth sensation lichenoid reactions and a loss of taste sensation, while
diuretic A diuretic () is any substance that promotes diuresis, the increased production of urine. This includes forced diuresis. A diuretic tablet is sometimes colloquially called a water tablet. There are several categories of diuretics. All diuretics in ...
s like furosemide can produce xerostomia.


Dental management

    Consultation with the supervising physician is highly advised in order to understand the patient's current condition and the medication prescribed. The patient should be receiving medical care, and heart failure should be compensated. Dental treatment is to be limited to patients who are in stable condition, since these people are at a high risk of developing questionable arrhythmias and even sudden death secondary to cardiopulmonary arrest. Stress and
anxiety Anxiety is an emotion which is characterized by an unpleasant state of inner turmoil Turmoil may refer to: * ''Turmoil'' (1984 video game), a 1984 video game released by Bug-Byte * ''Turmoil'' (2016 video game), a 2016 indie oil tycoon video ...
are to be avoided during the visits, which in turn should be brief (< 30 minutes) and are to be scheduled for the morning sessions. The patient should be seated on the chair in a semi-supine position, with control of body movements (which should be slow), to avoid orthostatic hypotension. In patients who has been administered with digitalis agents (digoxin, methyl-digoxin), the vasoconstrictor dose should be limited to two anaesthetic carpules, since this drug combination can cause arrhythmias.
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 in ...
(acetylsalicylic acid) can lead to fluid and sodium retention, and therefore should not be prescribed in patients with heart failure. In emergency (i.e., lung edema), after contacting the emergency service, the patient should be seated with the legs lowered, and receiving nasal oxygen at a rate of 4–6 liters/minute. Sublingual nitroglycerin tablets are indicated (0.4-0.8 mg), and the dose may be repeated every 5 or 10 minutes if blood pressure is maintained.


Arrhythmia

Arrhythmia Arrhythmias, also known as cardiac arrhythmias, heart arrhythmias, or dysrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. A resting heart rate that is too fast – above 100 beats per minute in adults ...
s are variations in normal heart rate due to cardiac rhythm, frequency or contraction disorders. The most common type of cardiac arrhythmia is atrial fibrillation.


Oral manifestations

Many anti-arrhythmic drugs have side effects such as gingival hyperplasia or
xerostomia Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause. This symptom is very common and is often seen as a side ef ...
.


Dental management

Consultation with the supervising physician is also advised in order to understand the patient's current condition and the type of arrhythmia involved, as well as the medication prescribed. It must be checked that the patient uses the medication correctly. Stress and anxiety can be reduced with
anxiolytic An anxiolytic (; also antipanic or antianxiety agent) is a medication or other intervention that reduces anxiety. This effect is in contrast to anxiogenic agents which increase anxiety. Anxiolytic medications are used for the treatment of anxie ...
s. Short visits in the morning are to be preferred. Patient monitoring, with recording of the pulse, is indicated before treatment. It is very important to limit the use of vasoconstrictor in
local anesthesia Local anesthesia is any technique to induce the absence of sensation in a specific part of the body, generally for the aim of inducing local analgesia, that is, local insensitivity to pain, although other local senses may be affected as well. I ...
, with no more than two carpules. The treatment planned should not be too long or complicated. Although modern
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 ei ...
are more resistant to electromagnetic interferences, caution is required when using electrical devices like ultrasound and electric scalpels that might interfere with pacemakers – especially the older models, since such devices developed in the last 30 years are bipolar and are generally not affected by the small electromagnetic fields generated by dental equipment. It is therefore important to know the type of pacemaker, the degree of electromagnetic protection of the generator, and the nature of the arrhythmia. If arrhythmia develops during dental treatment, the procedure should be suspended, oxygen is to be given, and the patient vital signs are to be assessed: body temperature (normal values: 35.5-37oC), pulse (normal values: 60-100 bpm), respiratory frequency (normal values in adults: 14-20 cycles or respirations per minute), blood pressure (normal values: systolic blood pressure under 140 mmHg and diastolic blood pressure under 90 mmHg). Sublingual nitrites are to be administered if there is chest pain. The patient should be placed in the Trendelenburg position, with vagal maneuvering where necessary (
valsalva maneuver The Valsalva maneuver is performed by a forceful attempt of exhalation against a closed airway, usually done by closing one's mouth and pinching one's nose shut while expelling air out as if blowing up a balloon. Variations of the maneuver can ...
, massage in the carotid pulse region). The dental team should be prepared for basic
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 ...
and initiation of the emergency procedure for evacuation to a hospital centre, if necessary.


See also

*
Allergic acute coronary syndrome Kounis syndrome is defined as acute coronary syndrome (symptoms such as chest pain relating to reduced blood flow to the heart) caused by an allergic reaction or a strong immune reaction to a drug or other substance. It is a rare syndrome with au ...
(Kounis syndrome)


References


External links

{{DEFAULTSORT:Acute Coronary Syndrome Medical emergencies Ischemic heart diseases Syndromes affecting the heart