Systemic, left ventricular and coronary hemodynamic effects of intravenous diltiazem in coronary artery disease.

Systemic and coronary hemodynamic effects of intravenous diltiazem, administered as a bolus of 250 micrograms/kg followed by an infusion of 1.4 micrograms/kg/min, were examined in 14 patients with effort angina. There was no change in heart rate despite significant decreases in systolic, diastolic and mean systemic pressures (13%, 10% and 11%, respectively, all p less than 0.01). The blood pressure decrease was closely correlated with the initial blood pressure (r = 0.81, p less than 0.05). Neither left ventricular end-diastolic pressure nor peak dP/dt changed significantly, but peripheral vascular resistance decreased 16% (p less than 0.001) and stroke volume index increased 10% (p less than 0.05). The pressure-rate product decreased 15% (p less than 0.005), but coronary blood flow was maintained as coronary resistance decreased 14% (p less than 0.025). Diltiazem increased regional coronary flow in some patients. Thus, intravenous diltiazem dilates coronary and systemic resistance vessels, without an increase in heart rate, favorably altering indexes of myocardial oxygen supply and demand.