[Beta blockers in arrhythmias].

Beta blockers are effective antiarrhythmic agents. In this survey we discuss the indications of beta blockers in supraventricular tachycardias as well as in ventricular tachyarrhythmias. Clinical studies of beta blockers in myocardial infarction are reviewed. In patients with suspected infarction and without contraindications, early treatment with an intravenous dose is of paramount importance. Oral therapy should be continued for at least a year or two. Although only few data are available on the effects of beta blockers in preventing sudden death in patients who have not suffered a myocardial infarction, it may be reasonable to treat all patients with cardiac arrest due to ventricular fibrillation--irrespective of etiology--unless there is a strong contraindication. Nevertheless, the favorable results of treatment with cardioversion defibrillators must be considered.