Response of Functional Mitral Regurgitation during Dobutamine Infusion in Relation to Changes in Left Ventricular Dyssynchrony and Mitral Valve Geometry.
10.3349/ymj.2014.55.3.592
- Author:
Woong Gil CHOI
1
;
Soo Hyun KIM
;
Soo Han KIM
;
Sang Don PARK
;
Young Soo BAEK
;
Sung Hee SHIN
;
Sung Il WOO
;
Dae Hyeok KIM
;
Keum Soo PARK
;
Jun KWAN
Author Information
1. Division of Cardiology, Department of Internal Medicine, Konkuk University College of Medicine, Chungju, Korea.
- Publication Type:Original Article ; Clinical Trial
- Keywords:
Mitral regurgitation;
dyssynchrony;
dobutamine
- MeSH:
Aged;
Dobutamine/administration & dosage/*pharmacology;
Echocardiography;
Female;
Humans;
Male;
Middle Aged;
Mitral Valve/*anatomy & histology/drug effects/*physiopathology;
Mitral Valve Insufficiency/*physiopathology;
Ventricular Dysfunction, Left/*physiopathology
- From:Yonsei Medical Journal
2014;55(3):592-598
- CountryRepublic of Korea
- Language:English
-
Abstract:
PURPOSE: Functional mitral regurgitation (FMR) and myocardial dyssynchrony commonly occur in patients with dilated cardiomyopathy (DCM). The aim of this study was to elucidate changes in FMR in relation to those in left ventricular (LV) dyssynchrony as well as geometric parameters of the mitral valve (MV) in DCM patients during dobutamine infusion. MATERIALS AND METHODS: Twenty-nine DCM patients (M:F=15:14; age: 62+/-15 yrs) with FMR underwent echocardiography at baseline and during peak dose (30 or 40 ug/min) of dobutamine infusion. Using 2D echocardiography, LV end-diastolic volume, end-systolic volume (LVESV), ejection fraction (EF), and effective regurgitant orifice area (ERO) were estimated. Dyssynchrony indices (DIs), defined as the standard deviation of time interval-to-peak myocardial systolic contraction of eight LV segments, were measured. Using the multi-planar reconstructive mode from commercially available 3D image analysis software, MV tenting area (MVTa) was measured. All geometrical measurements were corrected (c) by the height of each patient. RESULTS: During dobutamine infusion, EF (28+/-8% vs. 39+/-11%, p=0.001) improved along with significant decrease in cLVESV (80.1+/-35.2 mm3/m vs. 60.4+/-31.1 mm3/m, p=0.001); cMVTa (1.28+/-0.48 cm2/m vs. 0.79+/-0.33 cm2/m, p=0.001) was significantly reduced; and DI (1.31+/-0.51 vs. 1.58+/-0.68, p=0.025) showed significant increase. Despite significant deterioration of LV dyssynchrony during dobutamine infusion, ERO (0.16+/-0.09 cm2 vs. 0.09+/-0.08 cm2, p=0.001) significantly improved. On multivariate analysis, DeltacMVTa and DeltaEF were found to be the strongest independent determinants of DeltaERO (R2=0.443, p=0.001). CONCLUSION: Rather than LV dyssynchrony, MV geometry determined by LV geometry and systolic pressure, which represents the MV closing force, may be the primary determinant of MR severity.
