The Role of Beta-Blockers in the Treatment of Patients after Infarction

Secondary prevention after myocardial infarction: effects of beta blocking agents and calcium antagonists

Therapeutic interventions in patients with myocardial infarction, whether during the first hours after coronary occlusion or several days later, aim to reduce mortality and morbidity by several mechanisms: Prevention of fatal ventricular fibrillation, limitation of infarct size, and inhibition of platelet aggregation are some examples of such mechanisms. Results from early intervention trials with beta blocking agents, particularly from ISIS-I, suggest that 1-year mortality is significantly lower in selected patients randomized to active treatment. Late intervention studies also suggest a significant reduction in coronary mortality and morbidity with beta blockade, particularly when data are pooled. Studies with the calcium channel blockers nifedipine and verapamil were unable to demonstrate any beneficial effects of these drugs on mortality or reinfarction. In this review article, attention will be directed to the most recent information about the preventive value of beta adrenergic blocking drugs and slow calcium channel inhibitors.

Ventricular arrhythmias in elderly patients. Evaluation and management

In evaluating and managing ventricular arrhythmias in elderly patients, the clinician must first decide which patients are appropriate candidates for therapy. Arrhythmias can be categorized as to their potential for causing sudden cardiac death as benign, potentially malignant, or malignant by considering their type and the underlying structural cardiac disease present. Factors that may aggravate the arrhythmias should be identified and corrected. The ventricular arrhythmias should be well characterized using ambulatory monitoring or electrophysiologic studies to gauge the efficacy of subsequent therapy. If pharmacologic therapy is to be initiated, the most appropriate antiarrhythmic drug should be chosen with consideration of potential efficacy, potential adverse cardiovascular and systemic side effects, pharmacokinetics, and drug interactions. In selected patients with malignant ventricular arrhythmias, the failure of antiarrhythmic medication may lead the clinician to consider nonpharmacologic therapy such as surgical endocardial resection or the automatic implantable cardioverter-defibrillator.