Hemodynamic assessment of nicardipine alone and with atenolol in coronary artery disease using a modified echo-Doppler device

Abstract

We have used a modified noninvasive echo-Doppler cardiac output device, based on the principle of attenuated compensation volume flow, to assess the cardiovascular effects of the slow-calcium antagonist nicardipine in coronary disease. The dose-response effects of 2.5, 5.0 and 10.0 mg intravenous nicardipine were determined in 8 patients with angina. Dose-related decreases were seen in systemic mean arterial pressure (p less than 0.01) after administration of nicardipine. Cardiac pumping indexes were improved, as evident from linear increases in cardiac stroke volume (p less than 0.001), stroke length (p less than 0.01) and time-averaged mean velocity (p less than 0.01). The echo-Doppler device was also used to assess beta-blocking/nicardipine combination therapy in patients with angina. When nicardipine was given after the cardioselective beta blocker atenolol the reduction in heart rate and cardiac output after atenolol was reversed compared with a group that received atenolol followed by placebo. Cardiac performance improved and the 35% reduction in systemic vascular resistance was associated with markedly increased cardiac index (p less than 0.01), augmentation of time-averaged mean velocity (p less than 0.01) and cardiac stroke length (p less than 0.05). These data are consistent with previous invasive studies of nicardipine, either alone or when combined with beta blockade in coronary disease. The data also suggest that nicardipine/beta-blocking combination is safe in patients with coronary heart disease and that the echo-Doppler method of cardiovascular monitoring will prove useful in human pharmacodynamic studies.