The effects of the intravenous administration of the antianginal drug, nicorandil, 50 micrograms/kg administered over 2 minutes, were investigated during pacing-induced ischemia in 8 patients with coronary artery disease. Hemodynamic parameters were measured and single-plane left ventriculograms were obtained in control and postpacing periods both before and after pretreatment with nicorandil. Regional wall motion of the left ventricle was assessed by measuring shortening of the radial axes originating from the center of gravity of the end-diastolic silhouette. Heart rate, left ventricular (LV) systolic pressure and end-diastolic volume index did not change in the immediate postpacing period with or without medication. LV end-diastolic pressure decreased with nicorandil, from 22.0 +/- 3.4 to 17.0 +/- 2.3 mm Hg (mean +/- standard error of the mean) (p less than 0.05), and LV systolic volume index, from 39.6 +/- 8.0 to 30.4 +/- 6.8 ml/m2 (p less than 0.05). Ejection fraction increased from 55.2 +/- 5.0 to 64.3 +/- 3.8% (p less than 0.05). Stroke index and cardiac index (calculated from heart rate and stroke index) did not change significantly. Rapid right ventricular pacing increased the extent and degree of dyskinesia of the left ventricle, but premedication with nicorandil improved the wall motion. Thus, nicorandil has salutary effects on ventricular contractile and hemodynamic responses to transient ischemia induced by pacing stress.