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Cardiac Arrhythmia Suppression Trial
The Cardiac Arrhythmia Suppression Trial (CAST) was a double-blind, randomized, controlled study designed to test the hypothesis that suppression of premature ventricular contraction, premature ventricular complexes (PVC) with class I antiarrhythmic agents after a myocardial infarction (MI) would reduce Mortality rate, mortality. It was conducted between 1986 and 1989 and included over 1700 patients in 27 centres. The study found that the tested drugs increased mortality instead of lowering it as was expected. The publication of these results in 1991/92, in combination with large follow-up studies for drugs that had not been tested in CAST, led to a paradigm shift in the treatment of MI patients. Class I and III antiarrhythmics are now only used with extreme caution after MI, or they are contraindicated completely. Heart Rhythm Society Distinguished Scientist D. George Wyse was a member of the CAST trial's steering and executive committees. Background The study was prompted by the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 tachycardia. Many attempts have been made to classify antiarrhythmic agents. Many of the antiarrhythmic agents have multiple modes of action, which makes any classification imprecise. Vaughan Williams classification The Vaughan Williams classification was introduced in 1970 by Miles Vaughan Williams.Vaughan Williams, EM (1970) "Classification of antiarrhythmic drugs". In ''Symposium on Cardiac Arrhythmias'' (Eds. Sandoe E; Flensted-Jensen E; Olsen KH). Astra, Elsinore. Denmark (1970) Vaughan Williams was a pharmacology tutor at Hertford College, Oxford. One of his students, Bramah N. Singh, contributed to the development of the classification system. The system is therefore sometimes known as the Singh-Vaughan Williams classification. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 travel into the shoulder, arm, back, neck or jaw. Often it occurs in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat or feeling tired. About 30% of people have atypical symptoms. Women more often present without chest pain and instead have neck pain, arm pain or feel tired. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock or cardiac arrest. Most MIs occur due to coronary artery disease. Risk factors include high blood pressure, smoking, diabetes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mortality Rate
Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of deaths per 1,000 individuals per year; thus, a mortality rate of 9.5 (out of 1,000) in a population of 1,000 would mean 9.5 deaths per year in that entire population, or 0.95% out of the total. It is distinct from "morbidity", which is either the prevalence or incidence of a disease, and also from the incidence rate (the number of newly appearing cases of the disease per unit of time). An important specific mortality rate measure is the crude death rate, which looks at mortality from all causes in a given time interval for a given population. , for instance, the CIA estimates that the crude death rate globally will be 7.7 deaths per 1,000 people in a population per year. In a generic form, mortality rates can be seen as calculated using (d/ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paradigm Shift
A paradigm shift, a concept brought into the common lexicon by the American physicist and philosopher Thomas Kuhn, is a fundamental change in the basic concepts and experimental practices of a scientific discipline. Even though Kuhn restricted the use of the term to the natural sciences, the concept of a paradigm shift has also been used in numerous non-scientific contexts to describe a profound change in a fundamental model or perception of events. Kuhn presented his notion of a paradigm shift in his influential book ''The Structure of Scientific Revolutions'' (1962). Kuhn contrasts paradigm shifts, which characterize a Scientific Revolution, to the activity of normal science, which he describes as scientific work done within a prevailing framework or paradigm. Paradigm shifts arise when the dominant paradigm under which normal science operates is rendered incompatible with new phenomena, facilitating the adoption of a new theory or paradigm. As one commentator summarizes: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Dysrhythmia
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 – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats. In more serious cases, there may be lightheadedness, passing out, shortness of breath or chest pain. While most cases of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death. Arrhythmias are often categorized into four groups: extra beats, supraventricular tachycardias, ventricular arrhythmias and bradyarrhythmias. Extra beats include premature atrial contractions, premature ventricular con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Heart, Lung, And Blood Institute
The National Heart, Lung, and Blood Institute (NHLBI) is the third largest Institute of the National Institutes of Health, located in Bethesda, Maryland, United States. It is tasked with allocating about $3.6 billion in FY 2020 in tax revenue to advancing the understanding of the following issues: development and progression of disease, diagnosis of disease, treatment of disease, disease prevention, reduction of health care disparities within the American population, and advancing the effectiveness of the US medical system. NHLBI's Director is Gary H. Gibbons (2012–present). Operation In 1948, the National Heart Act established the National Heart Institute and the National Advisory Heart Council. The intramural research program was established a year later in 1949. In 1969, the National Heart Institute was renamed the National Heart and Lung Institute, and the scope of the institute was expanded. In 1976, it was given its current name, the National Heart, Lung, and Blood Insti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 techniques, medical devices, diagnostic procedures or other medical treatments. Participants who enroll in RCTs differ from one another in known and unknown ways that can influence study outcomes, and yet cannot be directly controlled. By Random assignment, randomly allocating participants among compared treatments, an RCT enables ''statistical control'' over these influences. Provided it is designed well, conducted properly, and enrolls enough participants, an RCT may achieve sufficient control over these confounding factors to deliver a useful comparison of the treatments studied. Definition and examples An RCT in clinical research typically compares a proposed new treatment against an existing Standard of care#Medical standard of care, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. The Holter's most common use is for monitoring ECG heart activity (electrocardiography or ECG). Its extended recording period is sometimes useful for observing occasional cardiac arrhythmias which would be difficult to identify in a shorter period. For patients having more transient symptoms, a cardiac event monitor which can be worn for a month or more can be used. The Holter monitor was developed at the Holter Research Laboratory in Helena, Montana, US by experimental physicists Norman J. Holter and Bill Glasscock, who started work on radio telemetry in 1949. Inspired by a suggestion from cardiologist Paul Dudley White in the early 1950s, they redirected their efforts toward development of a wearable cardiac monitoring device. The Holter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encainide
Encainide (trade name Enkaid) is a class Ic antiarrhythmic agent. It is no longer used because of its frequent proarrhythmic side effects. Synthesis See also * Iferanserin * Cardiac Arrhythmia Suppression Trial The Cardiac Arrhythmia Suppression Trial (CAST) was a double-blind, randomized, controlled study designed to test the hypothesis that suppression of premature ventricular complexes (PVC) with class I antiarrhythmic agents after a myocardial infarc ... References Antiarrhythmic agents Benzanilides Phenol ethers Piperidines Sodium channel blockers Withdrawn drugs {{cardiovascular-drug-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flecainide
Flecainide is a medication used to prevent and treat abnormally fast heart rates. This includes ventricular and supraventricular tachycardias. Its use is only recommended in those with dangerous arrhythmias or when significant symptoms cannot be managed with other treatments. Its use does not decrease a person's risk of death. It is taken by mouth or injection into a vein. Common side effects include dizziness, problems seeing, shortness of breath, chest pain, and tiredness. Serious side effects may include cardiac arrest, arrhythmias, and heart failure. It may be used in pregnancy, but has not been well studied in this population. Use is not recommended in those with structural heart disease or ischemic heart disease. Flecainide is a class Ic antiarrhythmic agent. It works by decreasing the entry of sodium in heart cells, causing prolongation of the cardiac action potential. Flecainide was approved for medical use in the United States in 1985. It is available as a generic me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moracizine
Moracizine or moricizine, sold under the trade name Ethmozine, is an antiarrhythmic of class IC. It was used for the prophylaxis and treatment of serious and life-threatening ventricular arrhythmias, but was withdrawn in 2007 for commercial reasons. Pharmacology Moracizine, a phenothiazine derivative, undergoes extensive first-pass metabolism and is also extensively metabolized after it has entered the circulation. It may have pharmacologically active metabolites. A clinical study has shown that moracizine is slightly less effective than encainide or flecainide in suppressing ventricular premature depolarizations. Compared with disopyramide and quinidine, moracizine was equally or more effective in suppressing premature ventricular contractions, couplets, and nonsustained ventricular tachycardia. In the Cardiac Arrhythmia Suppression Trial (CAST), a large study testing the influence of antiarrhythmics on mortality, showed a statistically non-significant increase of mortality fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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