Comparison of multiple views for the evaluation of pulmonary arterial blood flow by Doppler echocardiography.

Forty adult patients underwent Doppler and two-dimensional echocardiographic examination of the pulmonary artery from multiple views to determine the variability in the magnitude of Doppler-determined flow velocity and pulmonary arterial diameter from various echocardiographic windows. Flows were recorded from two or more views in 32 patients (80%). Twelve of these patients (38%) had flow velocities recorded from two or more views that were within 6% of each other. Twenty of these patients (62%) had view-dependent differences in measured flow velocity ranging from 7% to 48%. The commonly used parasternal short-axis view yielded the highest pulmonary arterial flow velocity in only 35% of the patients studied. Determinations of pulmonary arterial blood flow can vary markedly when measured from different sites, and this is presumably due to varying ability to approximate a zero-degree Doppler angle from different views. Measurement of pulmonary arterial flow velocity should be attempted from multiple views, and the highest flow velocity should be selected as that obtained with the best zero-degree Doppler angle approximation.