Maintenance of increased coronary blood flow in excess of demand by nisoldipine administered as an intravenous infusion

Systemic and hemodynamic effects of nisoldipine, administered as a 4.5-micrograms/kg intravenous bolus over 3 minutes followed immediately by an infusion of 0.2 microgram/kg/min over 30 minutes, were studied in 13 patients undergoing diagnostic catheterization for suspected coronary artery disease or follow-up catheterization after coronary angioplasty. Responses to the drug tended to be exaggerated in the first 8 minutes of the infusion, but thereafter produced a steady state, with heart rate increased by 14 +/- 3% at 16 minutes and by 15 +/- 3% at 24 minutes (p less than 0.05), mean aortic pressure decreased 12 +/- 2% and 13 +/- 3% at the same times (p less than 0.05) and coronary venous blood flow increased by 31 +/- 5% and 34 +/- 6% (p less than 0.05). Myocardial oxygen consumption and the heart rate-systolic aortic pressure product were unchanged and cardiac output and stroke volume were significantly increased. Study during matched coronary sinus pacing produced similar trends. Nisoldipine is a potent coronary and peripheral vasodilator that maintains an increase in myocardial oxygen supply in excess of demand when given as an intravenous infusion.