M-mode echocardiogram of the normal mitral valve

The position of the beam relative to the long axis precordial plane anatomy is shown in panel A; a diagram of the M-mode pattern of the mitral valve echo is seen in panel B. During diastole the movement of the anterior leaflet (AL) of the valve has an M-shape pattern, while the posterior mitral valve leaflet (PML) moves in the opposite direction (panels C and D). The initial opening, the D-point, reaches a peak at the E point; this represents maximal opening of the valve associated with rapid filling after which there is temporary equilization of pressure and the valve leaflets move back to or near their closed position at the F-point. The speed with which the leaflets close from E to F is known as the E to F slope. The A wave is the peak opening during atrial contraction after which the valve closes (C-point). If the PR interval is prolonged and atrial contraction delayed, the leaflets may "float" back to an opened position (GH in panel D). During systole the segment between C and D represents the coapted leaflets and their migration from posterior to anterior with the descent of the base and the torsion of the longitudinal myocardial segments (panels E and F). Panel E is from a patient with cardiomyopathy; the reduced E to F slope and B notch in diastole indicate elevated left ventricular filling pressure and diastolic dysfunction. Panel F is recorded from a normal individual.