BACKGROUND: Coronary perfusion pressure(CPP) is the most important factor for the success of cardiopulmonary resuscitation(CPR). Therefore, CPP must be optimized during the resuscitation. The purpose of this study is to investigate the effects of isosorbide dinitrate(Isoket(R)) on CPP during CPR. METHODS: 10 Korean dogs were divided into two groups: Group I(N=5) was resuscitated with infusion of isosorbide dinitrate(1 microgram /kg/min) and Group II(N=5) was resuscitated without using isosorbide dinitrate. Following CPR, the heart rate(HR), blood pressure(BP), pulmonary capillary wedge pressure, cardiac output(CO), CPP and endocardial viability ratio(EVR) were measured repeatedly. RESULTS: The changes in HR were not significantly different between the two groups but systolic and diastolic BP, CO, CPP and EVR were well maintained in group 1. CONCLUSIONS: These results suggest that the usual dosage of isosorbide dinitrate is effective in improving CPP and EVR on CPR after impending cardiac arrest.