Is mitral annular ascent useful in studying left ventricular function through left atrio-ventricular interactions?

Abstract

Background: The mitral annulus (MA) is a crucial structure that is in constant motion throughout the cardiac cycle. The main purpose of this study was to determine if M-mode evaluation of the longitudinal motion of the MA could be useful to examine atrio-ventricular interactions. Methods: Echocardiographic data obtained from 150 patients (mean age 56 ± 16; 82 males) from the University of Cincinnati College of Medicine was evaluated to examine if any relationship exists between MA motion and measures of atrio-ventricular interactions. Results: Even though left atrial size, left ventricular (LV) mass index, LV ejection fraction (LVEF) and degree of LV diastolic dysfunction (LVDD) were significant echocardiographic variables affecting MA motion; LVEF and the degree of LVDD were the main determinants of MA excursion during systole (MAPSE) and after atrial contraction (MAa). Our results confirm the surrogate value of MAPSE with regards to LVEF and also show that the extent of MA excursion during systole is the main determinant of MAa. The effect of LV diastolic function applies more strongly to MAPSE than to MAa. However, the maximal MAa amplitude varies in accordance to the type of LVDD. Conclusions: We have shown for the first time that M-mode interrogation of the MA longitudinal motion appears useful to assess atrio-ventricular interactions. Since LV systolic and diastolic functions are so closely related; additional studies are now required to examine how this longitudinal measure correlates with known circumferential rotational data obtained with other imaging modalities. Keywords: Atrio-ventricular interaction, Echocardiography, Left atria, Left ventricle, Mitral annulus, M-mode