[Deterioration in ventricular arrhythmia caused by anti-arrhythmia preparations]

Study of the efficacy of some antiarrhythmic drugs in 92 patients with frequently occurring ventricular premature heart beat including high grades has demonstrated that in an insignificant number of patients these drugs produce an arrhythmogenic action. Such an action is observed after intake of the common therapeutic drug dose and is not accompanied by subjective symptoms pointing to the drug intolerance. The arrhythmogenic action of the drugs results in a dramatic increase in the number of ventricular premature heart beats and in the appearance of high grades of such beats including the development of ventricular flutter.