Hemodynamic changes after subselective intracoronary administration of nisoldipine in humans

Hemodynamic changes after the subselective intracoronary administration of 50 micrograms of nisoldipine were analyzed in 24 nonstenotic coronary arteries using a randomized, placebo-controlled, double-blind protocol. The following hemodynamic parameters were studied: (a) epicardial coronary artery diameter, assessed by quantitative angiography; (b) coronary blood flow velocity, measured by an intracoronary Doppler probe; (c) coronary blood flow, calculated from the above parameters; (d) coronary flow velocity reserve, assessed after intracoronary administration of 10 mg of papaverine hydrochloride; and (e) heart rate and arterial blood pressure. Since 3 patients were excluded due to unreliable Doppler signals, a total of 21 patients was eligible for complete analysis (placebo: n = 9; nisoldipine: n = 12). In placebo-treated patients, all studied parameters proved to be very stable on repeat measurement and no significant changes were found. In nisoldipine-treated patients, a significant increase in epicardial diameter (+19%; p = 0.0001) and coronary blood flow (+47%; p = 0.003) was found. The coronary blood flow velocity transiently increased after nisoldipine, with a maximum (+80%) after 2 min and returning to baseline within 10 min. Finally, nisoldipine resulted in a significant decrease in the coronary flow velocity reserve by 20% (p = 0.001). All coronary hemodynamic effects were observed in the absence of changes in heart rate and arterial blood pressure. Therefore, the present data demonstrate that nisoldipine acts as a potent dilator of epicardial as well as resistance vessels in nonstenotic human coronary arteries.