The mitral valve opening phenomenon
Since the late 1970s, irregularities have been described in the
descriptions of the opening and closing times of the mitral valve by
various echocardiography modalities, and findings of the start of
transmitral flow by Doppler have been described before showing a loss of
coaptation of the mitral valves leaflets during diastolic
suction36, an early mitral valve opening suggests a
shorter duration of isovolumetric contraction37. More
recently, MRI has documented, as previously discussed, that the start of
elongation and detorsion by AS determines the opening of the mitral
valve approximately 27 ms before the coaptations of the aortic
valve24, this muscular action potentially triggering
diastolic dysfunction, coinciding in experimental studies with the LV
negative dP/dt pressure curve due to (Figure 4: 3A) AS
contraction, which is the key point to identify the unwinding and
elongation process19,20,27.
As we have seen, the BL causes clockwise recoil by rotating the apex
with its subendocardial fibers and papillary muscles that connect the
leaflets to the mitral annulus, (Figure 2: 4A) when it
rotates counterclockwise due to DS contraction during ejection, it
allows closure the mitral annulus, (Figure 2: 1A-B)
(Figure 4: 3B-3C) to subsequently open again with the contraction of
the AS that elongates and untwists the LV38(Figure 2: 3A-B) (Figure 4: 2C-3A) . Therefore, the
mechanical explanation of mitral valve opening with LV elongation as a
consequence of AS contraction poses a mechanical explanation for
understanding diastolic dysfunction.