Quantification of mitral regurgitation by automated integration of color Doppler data from left ventricular inflow and outflow

Automated cardiac output measurement (ACM) integrates digital color Doppler velocity in space and in time, but has not been used to compare LV inflow and outflow (MR). Methods: To compare ACM with standard Doppler-2D methods for quantification of MR, we studied 50 normal volunteers without MR or AR (44±5 years, 31 male) and 30 patients (59±16 years, 16 male) with isolated MR(no AR or VSD). ACM was performed across left ventricular outflow tract from apical long-axis view (ACMa), and mitral annulus from apical four-chamber view (ACMm). Cardiac output (CO) was also calculated by pulsed Doppler (PD) at the aortic valve and by 2D echo quantification of LV volume (2D) from the apical four chamber view. Results: 1. Normal volunteers: CO measured by ACMm correlated well with ACMa (r=0.90, p<0.0001, ΔCO-0.09±0.41 L/min), with PW (r=0.87, p<0.0001, ΔCO = 0.13 ± 0.46 L/min), and with 2D (r=0.85, p<0.0001, ΔCO=0.14±0.48 L/m). 2. Patients with MR: MR regurgitant volume (MRV) (stroke volume by ACMm - ACMa) correlated well with the 2-D - PD (r=0.93, y=0.87x+3.6, ΔMRV= - 1±11 ml) and jet size in LA: MR jet size (pts,n) 1+(5) 2+(9) 3+(10) 4+(6) ACM, MRV(ml) 10.8±5.6 21.7±6.7 30.0±14.9 47.8±24.5 2P-PD,MRV(ml) 8.9±6.8 22.9±12.6 26.4±18.5 52.9±22.2 Conclusions: 1) ACM is a feasible new method for quantifying outflow and inflow volume to measure the volume of mitral regurgitation. 2) ACM automatically performs calculations that are equivalent to more time consuming Doppler measurements derived from multiple windows.