Beneficial hemodynamic effects of nicorandil in a canine model of acute congestive heart failure: Comparison with nitroglycerin and cromakalim

Summary— Comparative hemodynamic effects of nicorandil (NCR), nitroglycerin (NTG) and cromakalim (CRM) were examined in a canine model of acute congestive heart failure (CHF). CHF was produced by injections of saponin into coronary arteries of anesthetized dogs followed by volume loading and continuous iv infusion of methoxamine. After the treatment, aortic blood flow (AoF), left ventricular d P /d t and myocardial segment shortening (SS) markedly decreased, while the left ventricular end-diastolic pressure (LVEDP), the right atrial pressure (RAP) and the systemic vascular resistance (SVR) increased. NCR ( n = 6), NTG ( n = 6) and CRM ( n = 8), which were administered iv after production of CHF, caused a comparable reduction in LVEDP. NCR and CRM profoundly increased AoF and SS but NTG did only slightly. On the other hand, NTG and NCR but not CRM significantly reduced RAP. Intracoronary NCR ( n = 8) exerted no or similar effects on SS as well as systemic hemodynamic indices to those observed with iv NCR despite distinct coronary vasodilation. These results indicate that NCR may exert beneficial hemodynamic effects in an experimental CHF mainly due to lessening both afterload and preload rather than the coronary vasodilating effect.