Evaluation of Coronary Perfusion Using Pulsed-Wave Doppler in Hypoplastic Right Heart Syndrome with Right Ventricle-Dependent Coronary Circulation Before and After Aorta-To-Right Ventricle Shunt

Abstract

We present a male infant diagnosed with pulmonary atresia, hypoplastic right ventricle, ventricular septal defect, atresia of the orifice of the left coronary artery, and right ventricle-dependent coronary circulation. We assessed the blood flow in the sinusoidal communication (SC) utilizing pulsed-wave Doppler echocardiography to calculate coronary perfusion during the clinical course. At the time of delivery, the SC blood flow had a biphasic pattern; antegrade from the right ventricle (RV) to the left ventricle (LV) intramyocardium during systole and retrograde from the LV intramyocardium to the RV during diastole. The patient received a Blalock–Taussig (BT) shunt method at the age of 1 month. Following the BTS method, myocardial ischemia developed, and the SC blood flow showed a triphasic pattern; antegrade from the RV to the LV intramyocardium during systole, retrograde from the LV intramyocardium to the RV during early diastole, and antegrade from the RV to the LV intramyocardium during late diastole. The increase in diastolic RV pressure after the BTS method caused a reversal of the late diastolic blood pressure between the RV and LV myocardium, which was considered to induce a flow of non-oxygenated flow through the SC, leading to LV myocardial ischemia. An aorta-to-right ventricle (Ao-RV) shunt method was conducted at the age of 2 months. The SC blood flow revealed the same triphasic pattern, but the myocardial ischemia vanished. We hypothesize that the increased oxygenation of the SC blood flow during late diastole from the Ao-RV shunt enhanced the coronary circulation. Evaluation of SC blood flow patterns is effective for predicting myocardial ischemia.