Increased susceptibility of the left lateral free wall to myocardial delayed enhancement in Duchenne Muscular Dystrophy: progressive systolic dysfunction demonstrable by CMR regional strain analysis
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KeywordsCardiac Magnetic Resonance Duchenne Muscular Dystrophy Duchenne Muscular Dystrophy Duchenne Muscular Dystrophy Patient Normal Ejection Fraction
Cardiac magnetic resonance imaging (CMR) has demonstrated reductions in peak LV myocardial circumferential strain (εcc) despite normal ejection fraction (EF) in Duchenne Muscular Dystrophy (DMD) patients. We hypothesized that the increased initial contractility of the lateral LV free wall makes that region more susceptible to myocardial injury with subsequent fibrosis than the septum in DMD patients.
We analyzed regional εcc from myocardial tagged CMR images on the mid-papillary level LV slice (using HARP™ software) from 14 DMD males with global cardiac dysfunction (LV EF < 55%) and myocardial delayed enhancement (MDE, a marker of myocardial fibrosis), as well as from 13 age-matched control males with normal cardiac function. Regions were assigned based on standard coronary perfusion regions. Regional Δεcc was computed as the difference between normal and DMD subject εcc per region.
Changes in εcc show that the regions with greatest contractility in control subjects (the lateral free wall) are the most susceptible to injury in DMD patients, as exemplified both by the greatest reduction in regional εcc and the development of MDE in those regions.
This article is published under license to BioMed Central Ltd.