Prognostic significance ofprogrammed ventricular stimulation insurvivors ofacutemyocardial infarction

SUMMARY Theprognostic significance oftheresponse toprogrammed ventricular stimulation was studied in75stable survivors ofacutemyocardial infarction. Programmedventricular stimulation induced sustained ventricular arrhythmias in33(44%)patients anddidnot induce these arrhythmias in42(56%)patients. During a mean follow up of18months, fourpatients died suddenly andthree developed spontaneoussustained ventricular tachycardia. Theoccurrence of arrhythmic eventswas notsignificantly different inpatients withinducible sustained arrhythmias andthose without, butsucheventswere predicted bythepresenceofmildcongestive heart failure. Although theinducibility ofsustained ventricular tachycardia (butnot ventricular fibrillation) seemed toidentify ahighrisk subset with anarrhythmic eventrateof21% compared with55% in others, ithadalowsensitivity (57%)andalowpositive predictive accuracy (21%)forarrhythmic events. Programmed ventricular stimulation isnothelpful inidentifying asubset ofpatients athighrisk after an uncomplicated acutemyocardial infarction. Insurvivors ofacutemyocardial infarction mortality inthefirst yearafter discharge fromhospital varies from7to11%.'-' Suddencardiac death accounts for abouthalf ofthedeaths andisprobably caused by ventricular tachycardia orfibrillation. Inrecent years several investigators haveexamined thevalueof programmed ventricular stimulation inidentifying a subset atanincreased risk ofsuddendeath,"' butthe results havebeenconflicting. Moreover, noneofthe reported studies usedastandard stimulation protocol ofthreeextrastimuli orcompared theprognostic significance ofinducible ventricular arrhythmias withthatofother prognostic variables. We assessed theprognostic value oftheinduced response toprogrammed ventricular stimulation ina prospective study ofclinically stable survivors of acutemyocardial infarction. We also usedastepwise