Dynamism of the Mitral Annulus: A Spatial and Temporal Analysis

Objective In this study, the authors sought to investigate the extent and timing of changes in mitral annular area during the cardiac cycle. Particularly, the authors assessed whether these changes were limited to the posterior part of the annulus or were more global in nature. Design Prospective, observational study Setting Tertiary care university hospital Participants Twenty three patients undergoing non-valvular cardiac surgery and 3 patients undergoing vascular procedures. Interventions Intraoperative 3-dimensional transesophageal echocardiographic data obtained from patients with normal mitral valves undergoing non-valvular cardiac surgery were analyzed geometrically. Annular areas and diameters were measured during various stages of the cardiac cycle. Intertrigonal distance also was measured using 3D data. Measurements and Main Results Both anterior and posterior portions of the mitral annulus demonstrated dynamism throughout the cardiac cycle. The expansion phase ranged from mid-systole to early-diastole, whereas mid-diastole to early-systole was characterized by an annular contraction phase. Area changes were contributed equally by anterior and posterior parts of the annulus. Annular dimensions increased in accordance with mitral annular area (p