Evaluation of effective aortic regurgitant orifice area and its effect on aortic regurgitant volume with Doppler echocardiography.

The authors measured the aortic regurgitant orifice area (ROA) using Doppler echocardiography and attempted to clarify how important the ROA is in determining the regurgitant volume (RV) in 22 patients with chronic aortic regurgitation (AR). The RV was calculated from the difference between the left ventricular ejection flow volume and transmitral inflow volume as measured by Doppler echocardiography. The ROA was obtained by two methods: RV/time velocity integral of AR jet measured by continuous wave Doppler (calculation method) and manual tracing of minimum cross-sectional area of short-axis color Doppler. The RV ranged from 10 to 90 mL/beat and the ROA by calculation method was from 0.05 to 0.35 cm2, which showed a strong correlation (r = 0.93, p < 0.001). The time velocity integral of aortic regurgitant jet showed a poor correlation with the RV (r = 0.45, p < 0.05). The values of ROA by the two methods showed a good correlation (r = 0.93, p < 0.001). Thus, the authors conclude that the ROA is a basic determinant of the RV in AR and that color Doppler can be employed to precisely assess the ROA.