EFFECTIVE REGURGITANT ORIFICE AREA IN TRICUSPID REGURGITATION - CLINICAL IMPLEMENTATION AND FOLLOW-UP-STUDY

Analysis of the flow-convergence zone proximal to a regurgitant orific e permits the noninvasive, quantitative measurement of clinically usef ul parameters of valvular insufficiency. However, many indexes such as flow rate reflect not only the size of the regurgitant lesion but are also highly dependent on the hemodynamic loading conditions. The effe ctive regurgitant orifice area (ROA) in contrast is a more fundamental parameter, less dependent on hemodynamics and more reflective of real changes in the geometry of the valve, making it a promising index for serial assessment of patients. In this study, the measurement of regu rgitant orifice area by the flow-convergence method was tested in tric uspid regurgitation and then used to monitor patients noninvasively ov er time. The effective ROA was calculated in 45 patients with tricuspi d regurgitation by means of the flow-convergence method and compared w ith the ROA obtained with pulsed Doppler echocardiographic methods. An excellent correlation was obtained between the two assessments of ROA (r = 0.96, Delta ROA = -0.09 +/- 6.5 mm(2)). ROA also showed an excel lent correlation with other indexes of valvular insufficiency such as regurgitant stroke volume (r = 0.89) and regurgitant fraction (r = 0.8 8). In a subgroup of 22 patients thought to be clinically stable, ROA was calculated serially over a mean follow-up period of 2 months and i ts variability compared with that of other flow-based parameters obtai nable from proximal acceleration. The variation between the two studie s in regurgitant stroke volume end regurgitant flow rate was 5% +/- 20 .6% and 5.2% +/- 35.7%, respectively. The effective ROA showed signifi cantly less variability at 1.8% +/- 15%. It is concluded that the effe ctive ROA is an excellent parameter to monitor in the serial assessmen t of valvular insufficiency because it is less dependent on hemodynami c conditions and correlates well with traditional indexes of regurgita tion.