Magnetic resonance imaging assessment of cardiac dysfunction in δ-sarcoglycan null mice

Delta-sarcoglycan (delta-sarcoglycan) null, Scgd(-/-), mice develop cardiac and skeletal muscle histopathological alterations similar to those in humans with limb-girdle muscular dystrophy. The objective of this study was to assess the feasibility of using MRI to investigate cardiac dysfunction in Scgd(-/-) mice. Cardiac MRI of 8 month old Scgd(-/-) and wild type (WT) mice was performed. Compared to WT, Scgd(-/-) mice had significantly lower LV ejection fraction (44 +/- 5% vs. 66 +/- 4%, p = 0.014), lower RV ejection fraction (25 +/- 2% vs. 51 +/- 3%, p < 0.001) lower myocardial circumferential strain, (15.0 +/- 0.3% vs. 16.9 +/- 0.3%, p = 0.007) and RV dilatation (54 +/- 3 mu L vs. 40 +/- 3 mu L, p = 0.007). The regional circumferential strain also demonstrated significant temporal dyssynchrony between opposing regions of the Scgd(-/-) LV. Our results demonstrate severe cardiac dysfunction in Scgd(-/-) mice at 8 months. The study identifies a set of non-invasive markers that could be used to study efficacy of novel therapeutic agents in dystrophic mice. (C) 2010 Elsevier B.V. All rights reserved.