Coronary flow characteristics of left coronary artery in aortic regurgitation before and after aortic valve replacement.

In 6 patients with pure aortic regurgitation, the velocity waveform in the left anterior descending coronary artery (LAD) was measured using an 80-channel 20-MHz-pulse Doppler velocimeter before and immediately after aortic valve replacement. All patients showed normal coronary angiograms. Flow velocity was analyzed by both zero-cross and fast Fourier transform methods in real time. The LAD flow in severe aortic regurgitation was characterized by an increase in the systolic flow component, a small and rapidly decreased diastolic flow, an irregular velocity profile across the vessel, and a wider velocity spectrum. After aortic valve replacement, systolic flow decreased by 36.3 +/- 21.7% (p less than 0.01), whereas diastolic flow increased by 81.4 +/- 51.8% (p less than 0.05). The ratio of diastolic flow to total LAD flow increased from 63 +/- 13% to 82 +/- 7% (p less than 0.05). The velocity profile became more parabolic and had a narrow spectrum. These results suggest that operation for aortic regurgitation induces beneficial effects on the myocardial inflow immediately after valve replacement.