EFFECT OF ADENOSINE-TRIPHOSPHATE ON HUMAN CORONARY CIRCULATION

We investigated in humans the effects of adenosine triphosphate (ATP), administered by intracoronary bolus (4-16 mu g) or intravenous infusi on (25-200 mu g/kg/min), on coronary and systemic hemodynamics and ele ctrocardiogram (ECG) variables. All patients had normal epicardial cor onary arteries. The maximal coronary blood flow velocity (CBFV) was de termined with intracoronary bolus of papaverine, A 12 mu g bolus of AT P (n=12) caused maximal coronary hyperemia similar to that caused by p apaverine. Intracoronary boluses caused a small brief decrease in arte rial pressure but no significant changes in HR or ECG variables. Intra venous infusion of ATP at 150 mu g/kg/min (n=15) caused a decrease in the coronary resistance index similar to that caused by papaverine, bu t the rate of increase in CBFV by ATP was smaller than that caused by papaverine. No patients had a significant change in ECG variables, but some patients (40 %) had a serious decrease in arterial pressure. The se studies suggest that maximal coronary vasodilation can be achieved safely with intracoronary ATP administration and that intravenous infu sions at 150 mu g/kg/min cause near-maximal coronary hyperemia in most patients.