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

Abstract

Delta-sarcoglycan (&#x3b4;-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&#xb1;5% vs. 66&#xb1;4%, p=0.014), lower RV ejection fraction (25&#xb1;2% vs. 51&#xb1;3%, p<0.001) lower myocardial circumferential strain, (15.0&#xb1;0.3% vs. 16.9&#xb1;0.3%, p=0.007) and RV dilatation (54&#xb1;3 &#x3bc;L vs. 40&#xb1;3 &#x3bc;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.