INDUCTION OF VENTRICULAR-FIBRILLATION PREDICTS SUDDEN-DEATH IN PATIENTS TREATED WITH AMIODARONE BECAUSE OF VENTRICULAR TACHYARRHYTHMIAS AFTER A MYOCARDIAL-INFARCTION

Objective-To examine the value of programmed electrical stimulation of the heart in predicting sudden death in patients receiving amiodarone to treat ventricular tachyarrhythmias after myocardial infarction. De sign-Consecutive patients; retrospective study. Setting-Referral centr e for cardiology, academic hospital. Patients-106 patients with ventri cular tachycardia (n = 77) or ventricular fibrillation (n = 29) late a fter myocardial infarction. Interventions-Programmed electrical stimul ation was performed while on amiodarone treatment for at least one mon th. Measurements and main results-In 80/106 patients either ventricula r fibrillation (n = 15) or sustained monomorphic ventricular tachycard ia (n = 65) was induced. After a mean follow up of 50 (SD 40) months ( 1-144), 11 patients died suddenly and two used their implantable cardi overter defibrillator. By multivariate analysis two predictors for sud den death were found: (1) inducibility of ventricular fibrillation und er amiodarone treatment (P much less than 0.001), and (2) a left ventr icular ejection fraction of < 40% (P < 0.05). The survival rate at one , two, three, and five years was 70%, 62%, 62%, and 40% respectively f or patients in whom ventricular fibrillation was induced, and 98%, 96% , 94%, 94% for patients with induced sustained monomorphic ventricular tachycardia. Where there was no sustained arrhythmia, five year survi val was 100%. Conclusions-In patients receiving amiodarone because of life threatening ventricular arrhythmias after myocardial infarction, inducibility of ventricular fibrillation, but not of sustained monomor phic ventricular tachycardia, indicates a high risk of sudden death.