Presence of mechanical dyssynchrony in Duchenne muscular dystrophy.
Journal Article (Journal Article)
BACKGROUND: Cardiac 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. METHODS: DMD 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. RESULTS: There 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. CONCLUSION: Mechanical 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.
Full Text
Duke Authors
Cited Authors
- Hor, KN; Wansapura, JP; Al-Khalidi, HR; Gottliebson, WM; Taylor, MD; Czosek, RJ; Nagueh, SF; Akula, N; Chung, ES; Benson, WD; Mazur, W
Published Date
- February 2, 2011
Published In
Volume / Issue
- 13 / 1
Start / End Page
- 12 -
PubMed ID
- 21288342
Pubmed Central ID
- PMC3041675
Electronic International Standard Serial Number (EISSN)
- 1532-429X
Digital Object Identifier (DOI)
- 10.1186/1532-429X-13-12
Language
- eng
Conference Location
- England