EFFECTS OF NICORANDIL ON REGIONAL PERFUSION AND LEFT-VENTRICULAR FUNCTION

Left ventricular function and regional perfusion were evaluated by two study designs in patient groups with stable ischemic coronary artery disease (CAD): (1) using conventional left ventricular angiographies a nd (2) applying myocardial contrast echocardiography. The aim of the s tudies was to establish the effects of sublingually or orally applied nicorandil (N) on pacing-induced myocardial ischemia (MIS). In the fir st angiographic study, in nine patients with ischemic CAD and with pac ing-inducible MIS, the effect of N, 29 mg sublingually, on hemodynamic s and regional wall motion (RWM) were studied. There were no parameter changes without MIS being induced when comparing measurements at the 7th and 14th minute after N application to control values (p > 0.05). In the 15th and 16th minutes after N, pacing-induced MIS could no long er be elicited but left ventricular pump function improved; comparing MIS with N versus MIS without N: ejection fraction improved by 21%, ca rdiac index by 37%, and RWM by 21%, while filling pressure fell by 41% and systemic vascular resistance fell by 29%. Thus, N-mediated ''prot ection from ischemia'' with rather improved hemodynamics and RWM corre sponds with alterations that theoretically could have been expected af ter nitroglycerin given under the above conditions. In the second echo cardiographic study, regional perfusion was assessed in 10 patients by intracoronary injection of a newly developed echo contrast medium (EC M) and measurement of ECM washout halftime (t(1/2)) over opacified myo cardial regions of interest, which displayed wall motion abnormalities already at rest. Echocardiographic evaluations were performed at rest and during MIS with and without the effects of 20 mg of oral N. The t (1/2) shortened significantly by 60% and was accompanied by a decrease in filling pressure from 18 +/- 9 to 7 +/- 3 mmHg. The perfused myoca rdial area increased by 75%, displaying a partially regained wall moti on in previously hypokinetic areas, which resulted in an augmentation of regional ejection fraction. Concomitantly, the degree of coronary s tenoses was reduced by 21% (p < 0.05). The antiischemic effects of the drug demonstrated were not accompanied by side effects.