Quantification of Mitral Regurgitation by the Proximal Convergence Method Using Transesophageal Echocardiography

Abstract

A simple geometric correction factor largely eliminates overestimation caused by flow constraint with the proximal convergence method and should extend the clinical utility of this technique.

Quantification of Mitral Regurgitation by the Proximal Flow Convergence Method—Comparison of Transthoracic and Transesophageal Echocardiography

“…8,20 In four of the five patients, in whom a geometric correction had to be applied in our study, a prolapse of the mitral valve with a grade III or IV mitral regurgitation was present. It can be inferred from previously published data that the flow convergence method overestimated the regurgitant volume, especially in patients with mitral valve prolapse and severe regurgitation.…”

“…An eccentric proximal flow convergence region was defined as one that was constrained by an adjacent ventricular wall in at least one transthoracic or transesophageal plane. 8 Otherwise, the proximal flow convergence region was classified as central. In the case of an eccentric proximal flow convergence region, regurgitant volume was corrected by (1) RV ϫ ␣/180 (assuming a one-dimensional flow constraint) and (2) RV ϫ [1-cos(␣/2)] (assuming a funnel-like constraint).…”

“…␣ was determined as the minimum angle between the two sides of the proximal flow convergence region derived from the two transthoracic and from the transesophageal view(s). Determination of ␣ was described in detail by Pu et al 8 To determine intraobserver variability, the proximal isovelocity surface area radii from TTE and TEE were reexamined by the same investigator in 15 randomly selected study patients from video tapes more than 6 months after the first echocardiographic examination. Data from TTE and TEE were analyzed independently on two different occasions.…”

Quantification of flow volume with a new digital three‐dimensional color Doppler flow approach: an in vitro study.

“…Abbreviations ACM, automated cardiac output measurement; MRI, magnetic resonance imaging; SEE, standard error of the estimate; TEE, transesophageal echo; 3D, three-dimensional; 2D, two-dimensional ccurate, noninvasive measurement of blood flow in the inflow and outflow tracts of the heart and great arteries continues to be an important clinical goal in the assessment of cardiac function, shunt flows in congenital cardiac defects, and regurgitation in the presence of valvular disease. [1][2][3][4][5][6][7][8][9][10][11][12] Noninvasive methods for the quantification of blood flow include magnetic resonance imaging (MRI) and combinations of M-mode and two-dimensional (2D) echocardiography and spectral Doppler flow. 13 Phase-encoded MRI velocity methods have been used for quantifying flow across…”

“…[1][2][3][4][5][6][7][8][9][10][11][12] Noninvasive methods for the quantification of blood flow include magnetic resonance imaging (MRI) and combinations of M-mode and two-dimensional (2D) echocardiography and spectral Doppler flow. 13 Phase-encoded MRI velocity methods have been used for quantifying flow across semilunar and atrioventricular valves and do not have the inherent angle dependency, window restrictions, or attenuation limitations that exist for Doppler ultrasonography.…”