Vasomotor function of endothelium in patients with coronary artery disease and ventricular arrhythmias occurring during myocardial ischemia

Purpose: To compare vasomotor endothelial function in patients with coronary artery disease (CAD) with and without VA occurring during myocardial ischemia. Methods: We studied 48 patients with CAD who had electrocardiographic signs of ischemia during ergometer exercise testing. All patients were divided into 2 equal groups: group I with VA occurred at peak exercise or during recovery and group II without VA. Exercise test duration was similar in the groups I and II. None of the patients had severe arterial hypertension, diabetes mellitus or signs of heart failure. Assessment of endothelial-dependent flow-mediated vasodilation (FMD) and endothelial-independent nitroglycerin-mediated vasodilation of brachial artery (BA) was performed using high-resolution ultrasound. Plasma endothelin-1 levels were measured by immunoassay method. Results: FMD of BA was lower and duration of ischemic changes of ECG during recovery was greater in the group I compared with group II. There were no significant differences in plasma ET-1 levels among the groups I and II. Conclusions: The patients with CAD and VA occurring during ischemia have FMD impaired to a greater degree and duration of ischemic changes of ECG in recovery longer compared with ones without VA.