Therapeutic considerations in the treatment of common cardiac arrhythmias.

Atrial and ventricular premature extrasystoles are common in the normal population. In most cases, reassurance and instructions regarding the avoidance of cardiac stimulants will be the only therapy necessary. As a rule, cardiac arrhythmias do not present as isolated events. The clinical setting dictates the choice of therapy for supraventricular tachyarrhythmias. Infrequent, self-limiting supraventricular tachycardias seldom require therapy. On the other hand, supraventricular tachycardias producing serious hemodynamic alternations should have immediate restoration of sinus rhythm with electric cardioversion. The prevention of ventricular arrhythmias with prophylactic lidocaine is advocated for patients with suspected acute myocardial infarction. Ventricular arrhythmias occurring in acute myocardial infarction require aggressive therapy. The use of potent antiarrhythmic agents demands thorough understanding of the drug's pharmacokinetics, side effects and toxic manifestations. Potential benefit should always be carefully weighed against possible risks. Drug cost and patient inconvenience must also enter the decision making process.