PROGRAMMED VENTRICULAR STIMULATION IN SURVIVORS OF ACUTE MYOCARDIAL-INFARCTION - LONG-TERM FOLLOW-UP

The prognostic significance of ventricular tachyarrhythmias induced by programmed ventricular stimulation was evaluated in 492 consecutive s urvivors of acute myocardial infarction (AMI). Holter monitoring, sign al-averaged electrocardiogram (EGG) and measurement of left ventricula r ejection fraction (EF) were also performed. The protocol used up to 3 extrastimuli. Sustained monomorphic ventricular tachycardia (VT) < 2 70 beats/min, > 270 beats/min (ventricular flutter) (VF1), and ventric ular fibrillation (VF) were induced in 99, 66 and 52 patients, respect ively. Long term follow-up (mean 3.7 +/- 2.2 years) showed that most e pisodes of VT occurred during the first months following AMI (n = 14), but some patients (n = 6) could develop VT as]ate as 4 years after AM I. Sudden death (SD) (n = 22) always occurred during the first year fo llowing AMI. Multivariate analysis demonstrated that EF < 30% and indu ction of a VT < 270 beats/min were the only predictors for total cardi ac death (P < 0.001). EF < 30%, induction of a VT < 270 beats/min and also of VF1 (P < 0.05) were predictors for VT and SD: the risk was 4% in patients without inducible VT, 12% in those with inducible VF1, and 21% in those with inducible VT < 270 beats/min. In conclusion, induct ion of a sustained monomorphic VT < 270 beats/min or > 270 beats/min i s a predictor of arrhythmic events during the first year as well as 4 years after myocardial infarction. However the risk of arrhythmic sudd en death decreases after the first year, while the risk of VT persists . Because of the low positive predictive value of programmed stimulati on (respectively 21% and 12% for the induction of a sustained VT and V F1), we recommend the indication of programmed stimulation in only the patients with one abnormal non-invasive investigation.