[Arrhythmia behavior and sudden heart death in isolated stenoses or obstructions of the anterior interventricular branch].

The incidence and pattern of ventricular arrhythmias recorded with 24 h ambulatory monitoring were studied in 144 patients with angiographically documented stenoses (greater than or equal to 75%) or occlusions of the left anterior descending coronary artery (LAD) and were related to left ventricular wall motion abnormalities. Ambulatory monitoring was performed at the time of coronary angiography and mean follow-up ranged from less than 1 to 5.4 with a mean of 3.3 years. The incidence of sudden cardiac death (within 1 h after onset of symptoms) was significantly higher in patients with LAD occlusion than in patients with LAD obstructions (14/79, 17.7% versus 2/65, 3.1%); (p less than 0.05). One hundred and twenty-two patients had anterior myocardial infarctions documented with ECG and LV-angiograms. The incidence and size of infarctions were comparable in patients with LAD stenoses and LAD occlusions. There was no difference in wall motion abnormalities, LV end-diastolic pressure (LVEDP) and ejection fraction in both groups. The majority of patients in both groups showed complex ventricular arrhythmias of Lown classification IV during Holter monitoring. The incidence of sudden cardiac death in patients with ventricular arrhythmias of Lown class IV was significantly higher in patients with LAD occlusions than in patients with LAD stenoses (9/40, 22.5% versus 1/31, 3.2%); (p less than 0.05). Quantitative evaluation of the arrhythmias showed that there was no difference between patients with LAD occlusions and LAD stenoses so far as single PVC's is concerned, yet complex ventricular arrhythmias (pairs and/or salvos) were found significantly more often in patients with LAD occlusions than with LAD stenoses (means 9.8 versus 6.3); (p less than 0.05). We conclude therefore that complete occlusion of the LAD is accompanied by more complex ventricular arrhythmias and bears a higher risk for sudden cardiac death than mere LAD stenoses although both groups of patients have the same left ventricular wall motion abnormalities.