SURGICAL REVASCULARIZATION IN THE TREATMENT OF VENTRICULAR-TACHYCARDIA AND FIBRILLATION EXPOSED BY EXERCISE-INDUCED ISCHEMIA

The role of myocardial revascularization in the treatment of malignant ventricular arrhythmias is not well defined. Our hypothesis was that in patients with ventricular tachycardia or fibrillation exposed by exercise-induced ischaemia, the acute transient ischaemia plays a principal causal role, and that in these patients surgical myocardial revascularization alone might be an effective treatment. Among 1100 consecutive patients undergoing isolated coronary artery bypass surgery (CABG) 30 patients (2.7%) characterized by ventricular tachycardia or fibrillation at the symptom-limited exercise tests prior to revascularization were studied prospectively. All patients had exercise-induced angina pectoris or ischaemic ST-segment depression preceding at least one of the arrhythmic events. In addition, eight of these 30 patients had experienced syncope during out-of-hospital exertional activities. After surgical revascularization, the 28 patients surviving to hospital discharge were followed for 1.6 to 86 months (mean 29 ± 29 months) as outpatients and underwent between one to eight exercise tests (mean 2.6 ± 1-9). One of these patients died suddenly of unknown cause at 14 months, another from cancer at 53 months. Twenty-six patients experienced a total of 34 episodes of ventricular tachycardia before revascularization. Two of these patients, both having residual ischaemia, had arrhythmia recurrences during follow-up; odds ratio (OR) 84.5, 95% confidence interval (CI) 18.7-381.9; P=<0.001. Exercise-induced ventricular fibrillation occurred in eight patients pre-operatively. None of these had recurrences during follow-up (OR 21.5, 95% CI 2.0-228.8; P=<0.010), and none of the eight who experienced a total of 15 episodes of syncope on exertion out-of-hospital pre-operatively, had any recurrences during the follow-up period (OR 21.5, 95% CI 2.0-228.8; P<0.010). These results indicate that severe ventricular arrhythmias, including sustained monomorphic ventricular tachycardia, exposed by exercise-induced ischaemia, may effectively be abolished by surgical myocardial revascularization alone. The subjective maximal exercise test appears to be an effective means of identifying this subset of patients in which no additional antiarrhythmic treatment seems to be required. © 1993 The European Society of Cardiology.