Congestive heart failure induced by six of the newer antiarrhythmic drugs

Abstract The incidence of drug-induced congestive heart failure with several newer antiarrhythmic agents including encainide, ethmozine, lorcainide, mexiletine, propafenone and tocainide was determined in a group of 407 patients who underwent 1,133 drug tests. The incidence rate ranged from 0.7% with lorcainide to 4.7% with propafenone. Congestive heart failure was present in 167 patients (41%) who underwent 491 drug trials. Congestive failure was induced in 15 (9%) of these 167 patients and involved 19 (3.9%) of the 491 tests. Left ventricular ejection fraction was 20 ± 8% in patients who developed congestive failure, in contrast to 39 ± 19% in those who did not (p It is concluded that each of the six antiarrhythmic drugs examined has the potential to aggravate congestive heart failure in patients with reduced left ventricular ejection fraction or a history of congestive heart failure, but the incidence rate is low and its occurrence unpredictable.