|
Pacemaker Failure
Pacemaker failure is the inability of an implanted artificial pacemaker to perform its intended function of regulating the beating of the heart. A pacemaker uses electrical impulses delivered by electrodes in order to contract the heart muscles. Failure of a pacemaker is defined by the requirement of repeat surgical pacemaker-related procedures after the initial implantation. Most implanted pacemakers are dual chambered and have two leads, causing the implantation time to take longer because of this more complicated pacemaker system. These factors can contribute to an increased rate of complications which can lead to pacemaker failure. Approximately 2.25 million pacemakers were implanted in the United States between 1990 and 2002, and of those pacemakers, about 8,834 were removed from patients because of device malfunction most commonly connected to generator abnormalities. In the 1970s, results of an Oregon study indicated that 10% of implanted pacemakers failed within the first mon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artificial Pacemaker
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 either the upper atria, or lower ventricles to cause the targeted chambers to contract and pump blood. By doing so, the pacemaker regulates the function of the electrical conduction system of the heart. The primary purpose of a pacemaker is to maintain an adequate heart rate, either because the heart's natural pacemaker is not fast enough, or because there is a block in the heart's electrical conduction system. Modern pacemakers are externally programmable and allow a cardiologist, particularly a cardiac electrophysiologist, to select the optimal pacing modes for individual patients. Most pacemakers are on demand, in which the stimulation of the heart is based on the dynamic demand of the circulatory system. Others send out a fixed rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the chest. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. Fish, in contrast, have two chambers, an atrium and a ventricle, while most reptiles have three chambers. In a healthy heart blood flows one way through the heart due to heart valves, which prevent backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a small amount of fluid. The wall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 period of time are referred to as an electrical storm. Short periods may occur without symptoms, or present with lightheadedness, palpitations, or chest pain. Ventricular tachycardia may result in ventricular fibrillation (VF) and turn into cardiac arrest. This conversion of the VT into VF is called the degeneration of the VT. It is found initially in about 7% of people in cardiac arrest. Ventricular tachycardia can occur due to coronary heart disease, aortic stenosis, cardiomyopathy, electrolyte problems, or a heart attack. Diagnosis is by an electrocardiogram (ECG) showing a rate of greater than 120 beats per minute and at least three wide QRS complexes in a row. It is classified as non-sustained versus sustained based on whether it lasts le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syncope (medicine)
Syncope, commonly known as fainting, or passing out, is a loss of consciousness and muscle strength characterized by a fast onset, short duration, and spontaneous recovery. It is caused by a decrease in blood flow to the brain, typically from low blood pressure. There are sometimes symptoms before the loss of consciousness such as lightheadedness, sweating, pale skin, blurred vision, nausea, vomiting, or feeling warm. Syncope may also be associated with a short episode of muscle twitching. Psychiatric causes can also be determined when a patient experiences fear, anxiety, or panic; particularly before a stressful event usually medical in nature. When consciousness and muscle strength are not completely lost, it is called presyncope. It is recommended that presyncope be treated the same as syncope. Causes range from non-serious to potentially fatal. There are three broad categories of causes: heart or blood vessel related; reflex, also known as neurally mediated; and orthos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpitations
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 rapid pulsation, an abnormally rapid or irregular beating of the heart. Palpitations are a sensory symptom and are often described as a skipped beat, rapid fluttering in the chest, pounding sensation in the chest or neck, or a flip-flopping in the chest. Palpitation can be associated with anxiety and does not necessarily indicate a structural or functional abnormality of the heart, but it can be a symptom arising from an objectively rapid or irregular heartbeat. Palpitation can be intermittent and of variable frequency and duration, or continuous. Associated symptoms include dizziness, shortness of breath, sweating, headaches and chest pain. Palpitation may be associated with coronary heart disease, hyperthyroidism, diseases affecting card ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hiccup
A hiccup (scientific name ''singultus'', from a Latin word meaning "to catch one's breath while sobbing"; also spelled hiccough) is an involuntary contraction (myoclonic jerk) of the diaphragm that may repeat several times per minute. The hiccup is an involuntary action involving a reflex arc. Once triggered, the reflex causes a strong contraction of the diaphragm followed about a quarter of a second later by closure of the vocal cords, which results in the "hic" sound. Hiccups may occur individually, or they may occur in bouts. The rhythm of the hiccup, or the time between hiccups, tends to be relatively constant. A bout of hiccups generally resolves itself without intervention, although many home remedies are often used to attempt to shorten the duration. Medical treatment is occasionally necessary in cases of chronic hiccups. Incidence Hiccups affect people of all ages, even being observed ''in utero''. They become less frequent with advancing age. Intractable hiccups, la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twiddler's Syndrome
Twiddler's syndrome is a malfunction of a pacemaker due to manipulation of the device and the consequent dislodging of the leads from their intended location. As the leads move, they stop pacing the heart and can cause strange symptoms such as phrenic nerve stimulation resulting in abdominal pulsing or brachial plexus The brachial plexus is a network () of nerves formed by the anterior rami of the lower four cervical nerves and first thoracic nerve ( C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in th ... stimulation resulting in rhythmic arm twitching. Twiddler´s syndrome in patients with an implanted defibrilator may lead to inadequate, painful defibrillation-shocks. References External links {{Medical resources , DiseasesDB = , ICD10 = {{ICD10, T82.198 , ICD9 = , ICDO = , OMIM = , MedlinePlus = , eMedicineSubj = , eMedicineTopic = , MeshID ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Federal Communications Commission
The Federal Communications Commission (FCC) is an independent agency of the United States federal government that regulates communications by radio, television, wire, satellite, and cable across the United States. The FCC maintains jurisdiction over the areas of broadband access, fair competition, radio frequency use, media responsibility, public safety, and homeland security. The FCC was formed by the Communications Act of 1934 to replace the radio regulation functions of the Federal Radio Commission. The FCC took over wire communication regulation from the Interstate Commerce Commission. The FCC's mandated jurisdiction covers the 50 states, the District of Columbia, and the territories of the United States. The FCC also provides varied degrees of cooperation, oversight, and leadership for similar communications bodies in other countries of North America. The FCC is funded entirely by regulatory fees. It has an estimated fiscal-2022 budget of US $388 million. It has 1,482 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetic Resonance Imaging
Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body. MRI does not involve X-rays or the use of ionizing radiation, which distinguishes it from CT and PET scans. MRI is a medical application of nuclear magnetic resonance (NMR) which can also be used for imaging in other NMR applications, such as NMR spectroscopy. MRI is widely used in hospitals and clinics for medical diagnosis, staging and follow-up of disease. Compared to CT, MRI provides better contrast in images of soft-tissues, e.g. in the brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, though "Open" MRI designs mostly relieve this. Additionally, implants and oth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X-ray
An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz ( to ) and energies in the range 145 eV to 124 keV. X-ray wavelengths are shorter than those of UV rays and typically longer than those of gamma rays. In many languages, X-radiation is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it on November 8, 1895. He named it ''X-radiation'' to signify an unknown type of radiation.Novelline, Robert (1997). ''Squire's Fundamentals of Radiology''. Harvard University Press. 5th edition. . Spellings of ''X-ray(s)'' in English include the variants ''x-ray(s)'', ''xray(s)'', and ''X ray(s)''. The most familiar use of X-rays is checking for fractures (broken bones), but X-rays are also used in other ways. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Therapeutic Radiation
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill Malignancy, malignant cell (biology), cells and normally delivered by a Linear particle accelerator, linear accelerator. Radiation therapy may be curative in a number of types of cancer if they are localized to one area of the body. It may also be used as part of adjuvant therapy, to prevent tumor recurrence after surgery to remove a primary malignant tumor (for example, early stages of breast cancer). Radiation therapy is synergistic with chemotherapy, and has been used before, during, and after chemotherapy in susceptible cancers. The subspecialty of oncology concerned with radiotherapy is called radiation oncology. A physician who practices in this subspecialty is a radiation oncologist. Radiation therapy is commonly applied to the cancerous tumor because of its ability to control cell growth. Ionizing ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tumors
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists in growing abnormally, even if the original trigger is removed. This abnormal growth usually forms a mass, when it may be called a tumor. ICD-10 classifies neoplasms into four main groups: benign neoplasms, in situ neoplasms, malignant neoplasms, and neoplasms of uncertain or unknown behavior. Malignant neoplasms are also simply known as cancers and are the focus of oncology. Prior to the abnormal growth of tissue, as neoplasia, cells often undergo an abnormal pattern of growth, such as metaplasia or dysplasia. However, metaplasia or dysplasia does not always progress to neoplasia and can occur in other conditions as well. The word is from Ancient Greek 'new' and 'formation, creation'. Types A neoplasm can be benign, potential ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
