Effects of Balloon Valvuloplasty on Coronary Blood Flow in Neonates With Critical Pulmonary Valve Stenosis Assessed With Transthoracic Doppler Echocardiography

Background: Treating pulmonary valve stenosis with balloon valvuloplasty (BV) is a good model to study the effect of right ventricular (RV) pressures on coronary flow. Methods: Transthoracic Doppler echocardiography was used to register coronary flow in 10 age-matched healthy controls and 7 neonates before and 1 day after BV. Results: Left ventricular fractional shortening and cardiac output increased significantly after BV. Right coronary artery diameter decreased from 1.2 ± 0.2 to 1.1 ± 0.1 mm (P < .02). Posterior descending coronary artery flow parameters decreased significantly, with blood flow decreasing from 8.4 to 5.7 ± 1.9 mL/s (P < .003). RV end-diastolic pressure and RV systolic pressure explained almost totally the variation in coronary flow (r² = 0.87). Conclusions: RV end-diastolic pressure and RV systolic pressure determined coronary flow in neonates with critical pulmonary valve stenosis. Cardiac output and left ventricular fractional shortening increased after pulmonary valve BV.