Mitral anulus motion. Relation to pulmonary venous and transmitral flows in normal subjects and in patients with dilated cardiomyopathy

The dynamics between mitral anulus motion, and, thus, motion of the base of the heart, and filling of the left atrium and ventricle were studied by Doppler echocardiography in 12 normal subjects and 28 patients with dilated cardiomyopathy. The normal motion of the mitral anulus is associated with two phases of inflow from the pulmonary veins. The first phase (J) of pulmonary venous inflow occurs during ventricular systole, concomitant with the descent of the mitral anulus toward the ventricle apex, the extent of which is 12.8 ± 1.4 mm. The end of the descent of the anulus occurs at the cessation of aortic ejection. About 100 msec later, a rapid recoil of the mitral anulus toward the atrium coincides with the onset of transmitral filling. This rapid recoil contributes to the displacement of blood from the atria into the ventricles in early diastole. The second phase (K) of pulmonary venous flow begins in early diastole, with its peak occurring about 50 msec after the peak of transmitral flow. During atrial contraction, the mitral anulus moves slightly (2.4 ± 0.7 mm) toward the atrium and then returns toward its initial position within 120 msec. This motion coincides with the A wave of transmitral flow. In patients with dilated cardiomyopathy, pulmonary venous flow and mitral anulus motion are markedly altered in comparison with normal subjects. In all patients, motion of the mitral anulus is either reduced or absent. In 10 patients with some residual motion of the mitral anulus and a competent mitral valve, who were in sinus rhythm, the profile of pulmonary venous flow maintained a normal biphasic pattern. In the remaining 18 patients, the systolic (J) phase of pulmonary blood flow was either reduced or absent. This abnormal pattern of pulmonary venous flow was associated with either absence of mitral anulus motion, atrial fibrillation, or significant mitral regurgitation. In patients with severe mitral regurgitation, a systolic regurgitation flow was observed in the pulmonary veins. Thus, both atrial contraction and normal motion of the mitral anulus that is produced by left ventricular systolic function contribute to the normal biphasic filling from the pulmonary veins into the atria. Dysfunction of either atrial or ventricular systolic emptying results in abnormal filling from the pulmonary veins during ventricular systole and leaves one major phase of pulmonary venous flow in late diastole.