CLINICAL AND ELECTROPHYSIOLOGIC DETERMINANTS, TREATMENT AND SURVIVAL OF PATIENTS WITH SUSTAINED MALIGNANT VENTRICULAR TACHYARRHYTHMIAS OCCURRING LATE AFTER MYOCARDIAL-INFARCTION

[摘要] To assess the clinical and electrophysiologic determinants, treatment and survival of patients with sustained malignant ventricular tachyarrhythmias late after myocardial infarction, a total of 108 patients (mean age 61 +/- 10 years) were studied. Thirty-two patients (Group 1) had sustained ventricular tachyarrhythmias 8 to 60 days (mean 13 +/- 9) after acute myocardial infarction. The remaining 76 patients (Group II), who served as a control group, had no sustained ventricular tachyarrhythmias less-than-or-equal-to 60 days after infarction. The most significant independent determinants of sustained ventricular tachyarrhythmias late after infarction were the presence of late potentials (chi square = 16.07, p = 0.0001), defined as an abnormal signal-averaged QRS complex in association with an abnormal root-mean-square voltage in the terminal 40 ms of the QRS complex, and an abnormal ejection fraction of < 40% (chi square = 10.09, p = 0.001). Sustained ventricular tachycardia was induced in 27 (96%) of 28 Group I patients. Among the 32 patients in Group I, antitachycardia therapy included antiarrhythmic drug therapy as the sole preventive measure in 14 (44%); map-guided surgery or coronary artery bypass surgery, or both, in 14 (44%) and the automatic cardioverter-defibrillator in 4 (12%). The arrhythmias were rendered noninducible in 83% of patients after map-guided surgery and in 41% after drug therapy. During a follow-up period of 20 +/- 14 months, five Group I patients (15%) had an arrhythmic event and four (9.3%) had a cardiac-related death. All five patients who had an arrhythmic event were receiving antiarrhythmic drug therapy. None of the patients who had successful map-guided surgery had an arrhythmic event. The long-term 2-year arrhythmia-free survival (0.83 versus 0.92) and total survival (0.87 versus 0.92) were not significantly different between Group I and Group II. Conclusions: 1) Sustained ventricular tachycardia/ventricular fibrillation late (8 to 60 days) after myocardial infarction is usually due to the presence of a well formed substrate rather than the occurrence of acute myocardial ischemia. 2) A marked improvement in survival not significantly different from that of a control group of patients with no sustained ventricular tachyarrhythmias and better left ventricular function was observed with an aggressive approach consisting of electrophysiologically guided therapy inclusive of map-guided surgery, coronary revascularization, drug therapy and the automatic implantable cardioverter-defibrillator. 3) Patients with more than two episodes of drug-resistant sustained ventricular tachyarrhythmias do better with early surgery than with antiarrhythmic therapy.

[发布日期] 1991-02-01