The echocardiogram of the anterior leaflet of the mitral valve. Correlation with hemodynamic and cineroentgenographic studies in dogs.

Abstract

The echocardiogram of the anterior leaflet of the mitral valve (ECHO) was compared to hemodynamic and cineroentgenographic data to evaluate its accuracy in timing mitral valve (MV) opening and closure, and to validate it as an indicator of MV motion. The ECHO, high speed cineroentgenography at 250 frames/sec, and/or measurement of intracardiac pressures allowed accurate timing of the events of MV motion in dogs on right heart bypass. The intersection of left ventricular and left atrial pressures in early diastole preceded the onset of rapid anterior motion of ECHO (D' point) by 17 to 33 plus or minus 7.6 msec; r equals 0.98. The onset of left ventricular systole occurred before the termination of final rapid posterior motion of the ECHO in end diastole (Co point) by 25 plus or minus 10 msec; r equals 0.96. Radiopaque clips were attached to the free edges of both leaflets of the MV. Cineroentgenographically determined plots of clip distance from the ultrasound transducer were morphologically similar to the simultaneously recorded ECHO. A delay of 23 plus or minus 3 (0 to 40) msec was observed in the ECHO peaks of diastolic anterior excursion compared to clip motion. Contrast medium advances beyond the free edges of MV leaflets mixing with left ventricular blood 43 plus or minus 3 msec after initial separation. These cineroentgenographic studies elucidate nonuniformity of leaflet motion responsible for ECHO delays. Thus, ECHO D' and Co correlate well with hemodynamic indicators of MV opening and closure. However, ECHO motion, although qualitatively similar, is unpredictably delayed compared to cineroentgenography of clips on the MV free edge. Since the ECHO correlates well with hemodynamic indices of MV opening and closure, this noninvasive technique can be used as a reference in the timing of intracardiac events and in the determination of systolic and diastolic time intervals.

Mitral valve motion assessed by high-speed video camera in isolated swine heart

“…Some speculations had been made on the site where leaflet separation first occurs [2,4,6]. This has been clearly elucidated through the present study.…”

“…Pohost et al [2] indicated through cineangiographic study with contrast medium injection that the leading edge preceded the remainder of the leaflet during valve opening. In contrast, Karlsson et al [6] mentioned that the leading edge followed the other part of the leaflet.…”

“…The motion of the mitral valve has been studied using various modalities including cineangiography, cinefluoroscopy with radiopaque marker implantation, and twodimensional echocardiography [1][2][3][4][5]. In recent years, accurate measurements of the mitral leaflet and annular motion by use of three-dimensional analysis of implanted markers are vigorously reported [6][7][8][9][10].…”

“…By use of this modality, the present study aimed (1) to delineate the motion of the mitral leaflets, chords and annulus throughout the cardiac cycle, and (2) to elucidate the influence of alterations in loading conditions on leaflet excursion.…”

Increasing temporal resolution of 3D transesophageal ultrasound by rigid body registration of sequential, temporally offset sequences

“…Mitral valve modeling as a method to improve and assist mitral valve repair surgeries has been pursued for over 30 years [1]. The complex 3D anatomy of the mitral valve apparatus and the rapid motion of the leaflets make it difficult to understand the abnormal structural relationships of a dysfunctional mitral valve from standard 2D echocardiographic images [2].…”