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Mitral valve coaptation and its relationship to late diastolic flow: A color Doppler and vector flow map echocardiographic study in normal subjects
Author(s) -
Sherrid Mark V.,
Kushner Josef,
Yang Georgiana,
Ro Richard
Publication year - 2017
Publication title -
echocardiography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 62
eISSN - 1540-8175
pISSN - 0742-2822
DOI - 10.1111/echo.13480
Subject(s) - cardiology , mitral valve , diastole , vector flow , medicine , vortex , flow (mathematics) , doppler effect , doppler echocardiography , physics , mechanics , computer science , blood pressure , segmentation , astronomy , artificial intelligence , image segmentation
Background Three competing theories about the mechanism of mitral coaptation in normal subjects were evaluated by color Doppler and vector flow mapping ( VFM ): (1) beginning of ventricular ( LV ) ejection, (2) “breaking of the jet” of diastolic LV inflow, and (3) returning diastolic vortices impacting the leaflets on their LV surfaces. Methods and Results We analyzed 80 color Doppler frames and 320 VFM measurements. In all 20 normal subjects, coaptation occurred before LV ejection, 78±16 ms before onset. On color Doppler frames the larger anterior, and smaller posterior vortices circle back and, in all cases, strike the ventricular surfaces of the leaflets. On the first closing‐begins frame, for the first time, vortex velocity normal to the ventricular surface of the anterior leaflet ( AML ) is greater than that in the mitral orifice, and the angle of attack of LV vortical flow onto the AML is twice as high as the angle of flow onto the valve in orifice. Thus, at the moment coaptation begins, vortical flow strikes the mitral leaflet with higher velocity, and higher angle of attack than orifice flow, and thus with greater force. According to the “breaking of the jet” theory, one would expect to see de novo LV flow perpendicular to the leaflets beginning after transmitral flow terminates. Instead, the returning continuous LV vortical flow that impacts the valve builds continuously after the P‐wave. Conclusions Late diastolic vortices strike the ventricular surfaces of the mitral leaflets and contribute to valve coaptation, permitted by concomitant decline in transmitral flow.