Intrapericardial Delivery of l-Arginine Reduces the Increased Severity of Ventricular Arrhythmias During Sympathetic Stimulation in Dogs With Acute Coronary Occlusion Nitric Oxide Modulates Sympathetic Effects on Ventricular Electrophysiological Properties

摘要: Background Nitric oxide (NO) modulates autonomic effects on myocardial contractility and sinus atrioventricular nodal function of the heart. Whether NO influences actions ventricular electrophysiological properties arrhythmogenesis is not known. Methods Results Four groups consisting 43 autonomically denervated dogs were studied. To “superfuse” sympathetic nerves innervating ventricles, test drugs introduced into pericardial sac for 30 minutes, their effective refractory period (ERP) arrhythmia development assessed before during stimulation (SS). In group 1 (n=12), ERPs showed no significant difference between control superfusion with l-arginine, a precursor (222±20 versus 222±19 ms, P=.485). However, l-arginine significantly reduced SS-induced ERP shortening compared (9±7 13±7 P<.001). Simultaneous administration NG-monomethyl-l-arginine (2 mg/mL) abolished inhibi...