ABSTRACT
<p><b>OBJECTIVE</b>To investigate the myocardial electrophysiological effect and its underlying mechanisms of atorvastatin (Ator) on isolated rat hearts injured by ischemia/reperfusion (I/R).</p><p><b>METHODS</b>Isolated SD rat hearts were mounted on Langendorff system, and a local I/R was induced by ligation (30 min) and release (15 min) of the left anterior descending artery. During the reperfusion period, the effect of Ator on diastolic excitation threshold (DET), effective refractory period (ERP) and ventricular fibrillation threshold (VFT) on rat heart were measured.</p><p><b>RESULT</b>Compared with the control group, medium concentration of Ator prolonged the ERP in normal rat hearts; low, medium and high concentration of Ator significantly inhibited the decrease of DET, ERP and VFT induced by I/R. However, pretreatment with L-NAME cancelled these cardiac electrophysiological effects of Ator.</p><p><b>CONCLUSION</b>Ator reduced electrophysiological alteration induced by I/R in isolated rat hearts, which may be mediated by activating nitric oxide pathway to enhance the myocardial electrophysiological stability.</p>