Pattern of coronary artery disease in patients with ventricular tachycardia and fibrillation exposed by exercise-induced ischemia

Abstract

The majority of patients with serious exercise-induced ventricular arrhythmias have extensive coronary artery disease. These arrhythmias develop, however, only in a minority of patients with angina pectoris. The purpose of the present study was therefore to investigate whether these arrhythmia patients are characterized by any specific “arrhythmogenic” pattern of coronary artery disease. Among 1100 consecutive patients undergoing coronary artery bypass grafting, 30 (2.7%) patients had ventricular tachycardia or fibrillation during preoperative exercise testing. For each of these patients, two matched controls with angina pectoris but no ventricular arrhythmia were selected. All patients underwent angiocardiography by standard techniques. The recordings were blinded and interpreted in random order by an experienced invasive cardiologist. Significant stenosis (≥50%) of the main left coronary artery was found in 27% of the case patients compared to 12% of the matched controls ( p = 0.069, two-tailed t test); promximal left anterior descending artery stenoses were more frequent in the arrhythmia patients. Although stenosis ≥75% was only moderately more frequent in the case patients, the difference was highly significant for stenosis ≥95%, which was seen in 47% of the case patients compared to 22% of the controls ( p = 0.015). The difference was even more pronounced for the combination of main left coronary artery stenosis and/or high-grade stenosis (>-95%) of the left anterior descending artery. This pattern was seen in 60% of the case patients compared to 28% of the matched controls ( p = 0.004). In addition, concurrent stenosis of the right coronary artery was seeen in 14 (47%) of these case patients compared to 12 (20%) in the matched controls ( p = 0.009). These results suggest that exercise-induced ventricular tachycardia and fibrillation are associated with a specific arrhythmogenic pattern of coronary artery obstruction consisting of the main left coronary artery or the proximal left anterior descending artery. The additional effect of concurrent right coronary artery involvement may be through an impaired collateral supply to the left anterior descending territory.