Effective regurgitant orifice area in tricuspid regurgitation: clinical implementation and follow-up study

Analysis of the flow-convergence zone proximal to a regurgitant orifice permits the noninvasive, quantitative measurement of clinically useful 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 effective 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 regurgitant orifice area by the flow-convergence method was tested in tricuspid regurgitation and then used to monitor patients noninvasively over time. The effective ROA was calculated in 45 patients with tricuspid regurgitation by means of the flow-convergence method and compared with 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 mm2). ROA also showed an excellent correlation with other indexes of valvular insufficiency such as regurgitant stroke volume (r = 0.89) and regurgitant fraction (r = 0.88). 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 its variability compared with that of other flow-based parameters obtainable from proximal acceleration. The variation between the two studies in regurgitant stroke volume and regurgitant flow rate was 5% +/- 20.6% and 5.2% +/- 35.7%, respectively. The effective ROA showed significantly less variability at 1.8% +/- 15%.(ABSTRACT TRUNCATED AT 250 WORDS)