Coronary Hyperemic Dose Responses of Intracoronary Sodium Nitroprusside

Background— Sodium nitroprusside is one of several agents considered effective for treating the no-reflow phenomenon during acute coronary interventions. However, the coronary hyperemic dose responses and systemic hemodynamic effects of intracoronary nitroprusside have yet to be determined in humans. The purpose of this study was to compare the hyperemic and hemodynamic responses of intracoronary nitroprusside to intracoronary adenosine in patients during cardiac catheterization with angiographically normal anterior descending arteries. Methods and Results— In 21 patients, coronary blood flow velocity (0.014-inch Doppler flow wire), heart rate, and blood pressure were measured in unobstructed left anterior descending coronary arteries at rest, after intracoronary adenosine (30- to 50-μg boluses), and after 3 serial doses (0.3-, 0.6-, and 0.9-μg/kg boluses) of intracoronary nitroprusside. Coronary reserve was calculated as hyperemia/basal coronary flow velocity. In an additional 9 patients with intermediat...