BACKGROUND: Mitral valve (MV) annular dynamics have been well described in animal models of functional mitral regurgitation (FMR). Despite this, little if any data exist regarding the dynamic MV annular geometry in humans with FMR. In the current study we hypothesized that 3-dimensional (3D) echocardiography, in conjunction with commercially available software, could be used to quantify the dynamic changes in MV annular geometry associated with FMR. METHODS: Intraoperative 3D transesophageal echocardiographic data obtained from 34 patients with FMR and 15 controls undergoing cardiac operations were dynamically analyzed for differences in mitral annular geometry with TomTec 4D MV Assessment 2.0 software (TomTec Imaging Systems GmbH, Munich, Germany). RESULTS: In patients with FMR, the mean mitral annular area (14.6 cm(2) versus 9.6 cm(2)), circumference (14.1 cm versus 11.4 cm), anteroposterior (4.0 cm versus 3.0 cm) and anterolateral-posteromedial (4.3 cm versus 3.6 cm) diameters, tenting volume (6.2 mm(3) versus 3.5 mm(3)) and nonplanarity angle (NPA) (154 degrees +/- 15 versus 136 degrees +/- 11) were greater at all points during systole compared with controls (p < 0.01). Vertical mitral annular displacement (5.8 mm versus 8.3 mm) was reduced in FMR compared with controls (p < 0.01). CONCLUSIONS: There are significant differences in dynamic mitral annular geometry between patients with FMR and those without. We were able to analyze these changes in a clinically feasible fashion. Ready availability of this information has the potential to aid comprehensive quantification of mitral annular function and possibly assist in both clinical decision making and annuloplasty ring selection.
The impact of aortic valve replacement (AVR) on the dynamic geometry and motion of the mitral annulus remains unknown. We analyzed the effects of AVR on the dynamic geometry and motion of the mitral annulus. We used 3-dimensional transesophageal echocardiography to analyze 39 consecutive patients undergoing elective surgical AVR for aortic stenosis. Intraoperative 3-dimensional transesophageal echocardiography was performed immediately before and after AVR. Volumetric data sets were analyzed using a software package capable of dynamically tracking the mitral annulus and leaflets during the entire systolic ejection phase. After AVR, there were significant decreases (p <0.01) in annular dimensions such as anteroposterior (3.5 +/- 0.1 vs 3.2 +/- 0.1 cm), anterolateral-posteromedial (3.7 +/- 0.1 vs 3.5 +/- 0.1 cm), and commissural diameters (3.7 +/- 0.1 vs 3.3 +/- 0.1 cm), as well as annular circumference (12.0 +/- 0.30 vs 11.1 +/- 0.2 cm) and 3-dimensional mitral annular area (mean 10.9 +/- 0.6 vs 9.3 +/- 0.3 cm(3)). Vertical mitral annular displacement was also reduced (6.2 +/- 3.1 vs 4.3 +/- 2.2 mm). Mitral annular nonplanarity angle (154 +/- 1.5 degrees vs 161 +/- 1.6 degrees ) and aorto-mitral angle (133 +/- 3.3 degrees vs 142 +/- 2.0 degrees ) were both increased after AVR, suggesting reduced nonplanar shape of the mitral annulus and reduced aorto-mitral flexion. In conclusion, these data demonstrate that mitral annular size is reduced immediately after AVR and that the dynamic motion of the mitral annulus is restricted. These findings may have important clinical implications for patients undergoing AVR with concurrent mitral regurgitation.
Warraich H. Fishing for Yeti. Journal of the American Medical Association. 2013;310(4):373.