Abstract 14876: Enlarged Distance Between Posterior Papillary Muscle Heads in Patients With Functional Mitral Regurgitation
Purpose: Both papillary muscles (PMs) have independent heads. Each tip supports the anterior, posterior, or commissural leaflets via chordae tendineae. PM heads come closer to each other in systole, and move away in diastole. The purpose of this study was to investigate the relationship between the distance of PM tips, left ventricular (LV) function and mitral regurgitation.
Methods and Results: In 42 consecutive patients without structural mitral valve lesions, the distance between the posterior PM (PPM) heads of the anterior and posterior mitral valve leaflet at end-diastole (D’) and end-systole(S), LV Ejection fraction (EF) and LV end-diastolic dimension (LVDd) were measured using MDCT. The severity of MR was quantitated as (0=none, 1=trivial, 2=mild, 3=moderate, 4=severe) using echocardiography. Patients were divided into 2 groups: Group I (10 patients with EF<50%) and Group II (32 patients with EF≥50%). Standardized values of D’ (=D/LVDd) and S’ (=S/LVDd) were also calculated. Results were shown in the figure.
Conclusion: The results indicate that that the distance between the PPM heads was enlarged in both systole and diastole in patients with poor LVEF and MR compared to normal subjects. Enlarged head distances between the papillary muscles may cause leaflet tethering. The results provide anatomical support to a strategy of mitral repair surgery which connects both anterior and posterior PM heads together.
- © 2013 by American Heart Association, Inc.