Effects of new calcium channel blocker of niludipine on the coronary hemodynamics, diastolic properties, and metabolic responses to tachycardia stress in patients with coronary disease.

A new calcium channel blocker, niludipine, was administered intravenously to nine patients with coronary artery disease in order to investigate its effects on left ventricular systolic and diastolic function, coronary sinus blood flow, and myocardial lactate metabolism. Coronary sinus pacing was performed in all patients and produced angina in six patients. Niludipine increased the resting heart rate from 75+/-3 beats/min (mean+/-SEM) to 82+/-3 (NS) and decreased the left ventricular systolic pressure from 155+/-4.7 mm Hg to 134+/-2.8 (p less than 0.05). Coronary sinus blood flow increased by 9%(NS). During pacing after niludipine, clinical improvement occurred in the six patients who had initially experienced angina. The extent of ischemic ST segment depression was decreased (-1.56+/-0.27 mm to -0.78+/-0.38, p less than 0.02) and myocardial lactate metabolism was improved. When pacing was terminated, niludipine suppressed the elevation of left ventricular end-diastolic pressure compared to pretreatment values (16.2+/-2.5 mm Hg vs 8.5+/-0.9, p less than 0.05) and decreased the left ventricular time constant T(26.4+/-3.6 msec to 20.2+/-2.4 p less than 0.05). The results suggest that niludipine appears to be beneficial in reducing systolic and diastolic work of the left ventricle during pacing induced angina without a significant change in total coronary sinus blood flow. Niludipine appears to have less of a hypotensive and reflex tachycardic effect than nifedipine.