There are data, which indicate that myocardial ischemia/reperfusion injury is a serious problem involved on cardiovascular diseases. Some naphtalen-derivatives have been used as cardioprotective drugs on myocardial ischemia-reperfusion injury; however, their activity and the molecular mechanism involved on myocardial ischemia-reperfusion injury are very confusing. Therefore, the aim of this study was to evaluate the activity of a naphtalen-oxirane derivative on myocardial ischemia/reperfusion injury using an isolated heart model. Additionally, molecular mechanism involved in the activity exerted by the naphtalen-oxirane derivative on perfusion pressure and coronary resistance was evaluated by measuring left ventricular pressure in absence or presence of following compounds; prazosin, metoprolol, indomethacin and nifedipine. The results showed that the naphtalen-oxirane derivative reduce infarct size compared with the control conditions. Other results showed that the naphtalen-oxirane derivative significantly increases the perfusion pressure and coronary resistance in isolated heart in comparison the control. Finally, other data indicate that the naphtalen-oxirane derivative increase left ventricular pressure in a dose-dependent manner; however, this phenomenon was significantly inhibited by nifedipine. In conclusion, all these data suggest that the naphtalen-oxirane derivative exert a cardioprotective effect through calcium channels activation and consequently induce changes in the left ventricular pressure levels. This phenomenon results in decrease of myocardial necrosis after ischemia and reperfusion.