[Malignant ventricular arrhythmias in the subacute and late phases of myocardial infarction. Clinical arrhythmological characteristics and prognostic value].

The purposes of this study are as follows: 1) to describe the clinical and arrhythmological characteristics of 30 patients (23 male, 7 female, mean age: 61 years) who suffered from episodes of ventricular tachycardia and/or ventricular fibrillation between the 7th and the 90th day following acute myocardial infarction; 2) to evaluate the effectiveness of treatment with amiodarone also taking into account the results of electrophysiologic study; 3) to correlate our results with data from previous studies. The site of the acute myocardial infarction was anterior in 16 patients, inferior in 12, and anterior and inferior in 2. Twenty patients had early post-acute myocardial infarction complications (67%) such as cardiac failure (16), bundle branch blocks (9) and ventricular fibrillation in the first 48 hours (6). The mean ejection fraction was 33 +/- 8% and a left ventricular aneurysmatic evolution was observed in 13 patients (43%). The first episodes of spontaneous ventricular arrhythmias occurred after a mean interval of 32 +/- 24 days following acute myocardial infarction. These occurred in the form of ventricular fibrillation in 19 patients (63%) and of ventricular tachycardia in the other 11 (37%). The patients experienced 5.6 +/- 5 episodes of ventricular fibrillation or ventricular tachycardia. Of the 30 patients, 28 received amiodarone, 1 procainamide and 1 propafenone. Five of the 28 patients treated with amiodarone were also given either procainamide or propafenone due to the early recurrence of ventricular tachycardia or fibrillation. One patient underwent early left ventricular aneurysmatic resection due to refractory ventricular fibrillation. Two groups of patients were distinguished on the basis of the electrophysiologic study results obtained during anti-arrhythmic treatment: group A consisted of 17 cases in which a sustained ventricular tachycardia was inducible (57%), group B consisted of 13 cases in which a sustained ventricular tachycardia was not inducible (43%). During a mean follow-up period of 31.6 +/- 26 months the total mortality rate was 23% in group A and 46% in group B (p = ns), the incidence of sudden death was 17% in group A and 23% in group B (p = ns), the incidence of non fatal ventricular tachycardia or ventricular fibrillation recurrences was 24% in group A and 0% in group B (0.05 less than p less than 0.1). One group A patient successfully underwent a heart transplant. The negative predictive value of ventricular stimulation in relation to sudden death and to non-fatal arrhythmic recurrences was 77% and 100%; the positive predictive value was 17 and 28%.(ABSTRACT TRUNCATED AT 400 WORDS)