Assessment of the tilting properties of the human mitral valve during three main phases of the heart cycle: an echocardiographic study.
OBJECTIVE
In experimental models of the left heart, the mitral valve (MV) is commonly implanted perpendicular to a central axis of the apex/MV. To adapt this to a more correct anatomical model, as well as for further studies of the left ventricle, we created a database of implantation angles of the MV and annulus during three main phases of the heart cycle, based on standard cardiac ultrasound measurements.


METHODS
Twenty-eight patients were studied with the standard cardiac ultrasound equipment. From the apical echo window, an anteroposterior (AP) plane and a perpendicular commisure-commisure (CC) plane were generated during three critical moments in the heart cycle: systole (S); diastole early filling (E); and diastole late filling (A). In both planes, the angles between the annular plane and each mitral leaflet, as well as the angle between a theoretical longitudinal axis through the apex and center of the MV orifice and the mitral annulus plane, were measured with a custom-made application of Matlab R14.


RESULTS
We observed an inclination of the angle mitral annulus/central left ventricle axis, with its lowest point in the direction of the aortic valve (AP plane) of 85 degrees+/-7 degrees in systole (S), 88 degrees+/-8 degrees in early diastole (E), and 88 degrees+/-7 degrees in late diastole (A). In the CC plane, we observed an almost horizontal implantation of 91 degrees+/-5 degrees in systole (S), 91 degrees+/-8 degrees in early diastole (E), and 91 degrees+/-7 degrees in late diastole (A).
Vanhercke
Daniel
D
Department of Cardiovascular Diseases, General Hospital St. Lucas, and Hydraulics Laboratory, Cardiovascular Mechanics and Biofluid Dynamics Research Unit, Ghent University, Belgium. daniel.vanhercke@azstlucas.be
Claessens
Tom
T
Vandekerckhove
Hans
H
Van Tricht
Ilse
I
Segers
Patrick
P
Verdonck
Pascal
P
D000328:Adult; D004452:Echocardiography; D005260:Female; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008943:Mitral Valve / Q000033:anatomy & histology* / Q000000981:diagnostic imaging / Q000502:physiology; D009200:Myocardial Contraction / Q000502:physiology*