Effects of Intracoronary Adenosine Triphosphate on Coronary Flow Velocity Dynamics in Children.

To assess the usefulness of adenosine triphosphate (ATP) as an alternative agent for functional determination of coronary circulation in children and to reveal the dose-response kinetics of intracoronary ATP, systemic hemodynamics and spectral coronary flow velocity dynamics using Doppler guide wire were measured during hyperemic responses to an intracoronary bolus injection of ATP (0.01μg/kg, 0.1μg/kg and 1.0μg/kg) in consecutive 40 Kawasaki disease patients (age: 8.4±5.1 years, 30 boys and 10 girls) without angiographic coronary lesions. ATP did not produce any significant change in heart rate, systolic blood pressure and mean blood pressure, but mildly decreased diastolic blood pressure. The coronary flow reserve (CFR) calculated as a ratio of hyperemic to basal averaged peak velocity (APV) for ATP was 2.05±0.31, 2.26±0.38 and 2.50±0.51 in LAD, and 2.24±0.28, 2.44±0.41 and 2.60±0.47 in RCA, respectively, for each of the three doses. There was no statistical significance between the mean values of GFR in LAD with ATP (1.0μg/kg: 2.39±0.16) and papaverine (0.15μg/kg: 2.43±0.16) in six patients without angiographic coronary lesions. The maximal coronary hyperemia was reached rapidly after intracoronary bolus injection of ATP in all doses (10, 10-15 and 15-20 seconds in both LAD and RCA, respectively, for each of the three doses). The time required for APV to return to basal levels (