Coronary blood flow in healthy neonates: effects of left ventricular function and mass

This study used transthoracic echocardiography, including pulsed-wave Doppler, to register coronary flow parameters in 55 healthy neonates. Intraobserver variability was tested in 20 neonates. A Doppler tracing of sufficient quality for analysis was obtained in the left anterior descending coronary artery (LAD) in 53 of 55 studies (96.4% feasibility) and in the right coronary artery (RCA) in 11 of 55 studies (20.0% feasibility). Estimation of intraobserver variability showed coefficients of variation of 7.5-8.0% for diastolic LAD Doppler flow parameters and volume flow but 17.5% for systolic peak flow velocity. Doppler flow parameters were significantly higher in the LAD than in the RCA. Correlation was found between LAD Doppler flow parameters and age, left ventricular (LV) mass, mitral peak early wave velocity as a measure of diastolic LV function, and the aortic velocity time integral/minute as a measure of systolic LV function. This study shows that diastolic LAD Doppler flow parameters and flow volume can be obtained in neonates by transthoracic echocardiography with acceptable reproducibility. In healthy neonates, left coronary flow parameters are linearly related to age, LV mass, and LV systolic and diastolic function. RCA flow parameters in neonates are lower than in the LAD.