Progress in arrhythmia therapy

Recent developments in classification and treatment of cardiac arrhythmias are reviewed. The advent of portable continuous ambulatory monitoring of electrocardiograms and of invasive catheterization techniques for electro-physiologically testing the heart has facilitated study of mechanisms and treatment of cardiac arrhythmias. A number of antiarrhythmic drugs are also in the final phases of clinical testing; some of these agents have unique properties that will affect therapeutic approaches. These recent studies and new techniques have led to a reassessment of the classification schemes for both arrhythmias and antiarrhythmic agents. The clinical importance of arrhythmias is also now better understood. Occasional supraventricular tachycardias in otherwise apparently healthy people are not associated with increased mortality. Sustained ventricular tachyarrhythmias, especially in patients with coronary-artery disease, are life-threatening and should be treated immediately and aggressively. Beta-adrenergic antagonists have proven valuable in the prevention of sudden death in patients who have had a myocardial infarction. Clinical trials documenting real advances in reducing mortality caused by electrical instability of the heart have been conducted in patients with recent myocardial infarction but are not yet available for most other patient types.