ABSTRACT
The incidence of AF, the most common sustained arrhythmia in clinical practice, increases with age and coronary artery disease, hypertension and valvular heart disease are common underlying substrates; however, occasionally, AF may occur without any underlying heart disease. The most widely accepted theory of its mechanism is Moe's multiple wavelet hypothesis, although recent studies are helping to shed light on other mechanisms, including the focal origin of AF in some patients. Most patients experience palpitations, but fatigue, dyspnoea, and dizziness may also occur. Therapy includes prevention of thromboembolism, control of rate, and restoration and maintenance of sinus rhythm. The risks and benefits of each treatment modality need to be assessed according to each patient's circumstances. Unlike other arrhythmias, there is still no highly successful therapy for treating AF. However, significant advances are being made using non-pharmacological approaches to either prevent or cure this troublesome arrhythmia.
Subject(s)
Amiodarone/therapeutic use , Anti-Arrhythmia Agents/therapeutic use , Anticoagulants/therapeutic use , Atrial Fibrillation/drug therapy , Clinical Trials as Topic , Defibrillators, Implantable , Humans , Prognosis , Risk Assessment , Risk Factors , Sports , Treatment OutcomeSubject(s)
Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Anti-Arrhythmia Agents/therapeutic use , Arrhythmias, Cardiac/complications , Cardiomyopathy, Dilated/complications , Death, Sudden, Cardiac/epidemiology , Defibrillators, Implantable , Cardiac Catheterization , Heart Conduction System/physiopathology , Humans , Myocardial Revascularization , Physical Examination , Risk Assessment , Risk FactorsABSTRACT
Over 50 percent of deaths in patients who survive an acute myocardial infarction (MI) are due to fatal ventricular tachyarrhythmias. Patients who survive an episode of sustained ventricular arrhythmia are at highest risk of recurrent cardiac arrest. Electrophysiological studies have been found to be useful in guiding therapy and reducing mortality in these patients. However, evaluation and treatment of nonsustained ventricular tachycardia following MI remains controversial. Asymptomatic patients at high risk after MI include those who have significant left ventricular dysfunction, positive late potentials on signal-averaged electrocardiogram (SAECG), high grade ventricular ectopy and abnormal heart rate variability. These tests, however, have a low positive predictive accuracy and are not helpful to guide therapy with antiarrhythmic drugs which are usually ineffective and can frequently harm these patients. Beta-adrenoreceptor blocking agents, however, have been shown to reduce mortality after an acute myocardial infarction.