EFFECTS OF THE INTRACORONARY INFUSION OF COCAINE ON CORONARY ARTERIALDIMENSIONS AND BLOOD-FLOW IN HUMANS

This study was done to assess the influence of large concentrations of cocaine (infused into the left coronary artery) on coronary arterial dimensions and blood flow in humans. In 20 subjects undergoing cardiac catheterization, incrementally increasing doses of (1) saline solutio n (n = 10, controls) or (2) cocaine hydrochloride (n = 10) were infuse d into the left coronary artery, and the effects on heart rate, system ic arterial pressure, coronary sinus blood flow, and coronary arterial dimensions were measured. Saline solution induced no change in any va riable. With the infusion of cocaine, there wets an incremental increa se in its concentration in the systemic (femoral arterial) and coronar y (coronary sinus) circulations (maximal concentrations, 0.14 +/- 0.06 [mean +/- SD] and 3.50 +/- 0.70 mg/L, respectively). At the maximal c ocaine infusion rate, heart rate and diastolic arterial pressure incre ased slightly, but coronary sinus blood flow and the dimensions of non diseased and diseased coronary arterial segments did not change. Thus, intracoronary infusion of cocaine in an amount sufficient to achieve a high concentration in the coronary circulation does not induce epica rdial coronary arterial vasoconstriction or alter blood flow.