Intraventricular Dyssynchrony May Play a Role in the Development of Mitral Regurgitation in Dilated Cardiomyopathy

• Published in: Journal of cardiac failure Vol. 11; no. 8; pp. 631 - 637
• Main Authors: Soyama, Akiko, Kono, Tatsuji, Mishima, Takayuki, Morita, Hideaki, Ito, Takahide, Suwa, Michihiro, Kitaura, Yasushi
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-10-2005
• Subjects: Adult; Aged; Cardiomyopathy; Cardiomyopathy, Dilated - complications; Cardiomyopathy, Dilated - diagnostic imaging; Cardiomyopathy, Dilated - physiopathology; Dyssynchrony; Echocardiography, Doppler, Color; Female; Humans; Male; Middle Aged; Mitral regurgitation; Mitral Valve Insufficiency - diagnostic imaging; Mitral Valve Insufficiency - etiology; Mitral Valve Insufficiency - physiopathology; Myocardial Contraction; Papillary muscle; Papillary Muscles - diagnostic imaging; Papillary Muscles - physiopathology; Regression Analysis; Severity of Illness Index; Stroke Volume; Ventricular Dysfunction, Left - complications; Ventricular Dysfunction, Left - diagnostic imaging; Ventricular Dysfunction, Left - physiopathology; Mitral regurgitation; Dyssynchrony; Cardiomyopathy; Papillary muscle
• ISSN: 1071-9164; 1532-8414
• DOI: 10.1016/j.cardfail.2005.06.438

The development of functional mitral regurgitation (MR) in dilated cardiomyopathy (DCM) has been attributed to altered left ventricular (LV) geometry and annular dilatation. We propose the hypothesis that intraventricular dyssynchrony may play a role in the development of MR in DCM.
Tissue Doppler echocardiography was performed in 32 DCM patients to assess the time from the onset of the QRS complex to the peak systolic myocardial strain (Ts) at 2 segments adjacent to the anterolateral and posteromedial papillary muscles from a short axis view. The time difference corrected by the RR interval (ΔTs/√RR) was used to evaluate dyssynchrony of these segments. There was no difference in the QRS duration (103 ± 29 ms versus 95 ± 22 ms,
P = .38) or the presence of left bundle branch block (39% versus 14 %,
P = .25) between 18 patients with MR and 14 patients without MR. However, ΔTs/√RR was significantly increased in the patients with MR, compared with those without MR (104 ± 67 ms versus 5 ± 16 ms,
P < .0001). Stepwise multiple regression analysis showed that ΔTs/√RR was independent contributing factor of MR.
Dyssynchrony of myocardial segments adjacent to the papillary muscles may disturb synchronized closure of the mitral leaflets and cause MR in DCM.