Mitral valve motion after performing an edge-to-edge repair in an isolated swine heart.
OBJECTIVE
Mitral valve motion after performing an edge-to-edge repair is a major concern, but it has not yet been observed directly. Mitral valve motion was assessed by using a high-speed digital video camera and microsonometric analysis in an isolated swine heart, and any changes in the mitral valve area or the development of mitral stenosis symptoms were evaluated.


METHODS
A temporary edge-to-edge repair model was created. The mitral valve motion was assessed by using a high-speed digital video camera, and the motion of the mitral annulus was measured by means of sonomicrometric analysis with or without performing edge-to-edge repair (n = 5). The left ventricular volumetric measurements were also measured with a conductance catheter. One cardiac cycle was divided into 4 phases: the mitral valve open phase, the isovolumic contraction phase, the aortic valve open phase, and the isovolumic relaxation phase.


RESULTS
The mitral valve was divided into 2 orifices by using the edge-to-edge technique, and the mitral valve area decreased by approximately 30%. The ratio of mitral valve open phase significantly decreased (31.9% +/- 3.4% vs 41.4% +/- 3.7%, P = .04). There were no significant differences in the diameter and the changes of anteroposterior dimensions of the mitral annulus. The stroke volume and the peak positive and negative dp/dt values showed no obvious change, but dv/dt values increased slightly without significance after removing the edge-to-edge suture (118 +/- 25 vs 130 +/- 17 mL/s, P = .14).


CONCLUSIONS
The mitral valve area decreased slightly; however, edge-to-edge repair did not create symptomatic mitral stenosis and showed no adverse affects on cardiac function.
Hasegawa
Hiroki
H
Department of Cardiothoracic Surgery, Nagoya University Graduate School of Medicine, Nagoya, Japan. hirokih@med.nagoya-u.ac.jp
Araki
Yoshimori
Y
Usui
Akihiko
A
Yokote
Jun
J
Saito
Shunei
S
Oshima
Hideki
H
Ueda
Yuichi
Y
D000818:Animals; D006439:Hemodynamics / Q000502:physiology; D066298:In Vitro Techniques; D008943:Mitral Valve / Q000502:physiology* / Q000601:surgery*; D008946:Mitral Valve Stenosis / Q000209:etiology; D013536:Suture Techniques; D013552:Swine; D014741:Video Recording