Presence of mechanical dyssynchrony in duchenne muscular dystrophy

Journal of Cardiovascular Magnetic Resonance

Technical Notes

Janaka P Wansapura¹  Hussein R Al-Khalidi²  Sherif F Nagueh³  Richard J Czosek⁴  Nandakishore Akula⁴  Kan N Hor⁴  Michael D Taylor⁴  William M Gottliebson⁴  Woodrow D Benson⁴  Wojciech Mazur⁵  Eugene S Chung⁵ 

[1] Department of Radiology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA;Duke University School of Medicine, Durham, North Carolina, USA;Methodist Hospital, Houston, Texas, USA;The Heart Institute and Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA;The Heart and Vascular Center, The Christ Hospital, Cincinnati, Ohio, USA;

关键词: Cardiovascular Magnetic Resonance;    Cardiac Resynchronization Therapy;    Late Gadolinum Enhancement;    Duchenne Muscular Dystrophy;    Duchenne Muscular Dystrophy;   

DOI  :  10.1186/1532-429X-13-12

 received in 2010-09-21, accepted in 2011-02-02,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundCardiac dysfunction in boys with Duchenne muscular dystrophy (DMD) is a leading cause of death. Cardiac resynchronization therapy (CRT) has been shown to dramatically decrease mortality in eligible adult population with congestive heart failure. We hypothesized that mechanical dyssynchrony is present in DMD patients and that cardiovascular magnetic resonance (CMR) may predict CRT efficacy.MethodsDMD patients (n = 236) were stratified into 4 groups based on age, diagnosis of DMD, left ventricular (LV) ejection fraction (EF), and presence of myocardial fibrosis defined as positive late gadolinum enhancement (LGE) compared to normal controls (n = 77). Dyssynchrony indices were calculated based on timing of CMR derived circumferential strain (ecc). The calculated indices included cross-correlation delay (XCD), uniformity of strain (US), regional vector of variance (RVV), time to maximum strain (TTMS) and standard deviation (SD) of TTMS. Abnormal XCD value was defined as > normal + 2SD. US, RVV, TTMS and SD were calculated for patients with abnormal XCD.ResultsThere was overall low prevalence of circumferential dyssynchrony in the entire DMD population; it increased to 17.1% for patients with abnormal EF and to 31.2% in the most advanced stage (abnormal EF with fibrosis). All but one DMD patient with mechanical dyssynchrony exhibited normal QRS duration suggesting absence of electrical dyssynchrony. The calculated US and RVV values (0.91 ± 0.09, 1.34 ± 0.48) indicate disperse rather than clustered dyssynchrony.ConclusionMechanical dyssynchrony is frequent in boys with end stage DMD-associated cardiac dysfunction. It is associated with normal QRS complex as well as extensive lateral fibrosis. Based on these findings, it is unlikely that this patient population will benefit from CRT.

【 授权许可】

Unknown   
© Hor et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.