Cardiac MRI for early detection of subclinical cardiac dysfunction in dysferlinopathy

Dysferlinopathy [Limb Girdle Muscular Dystrophy (LGMD) R2] is due to deficient expression of the dysferlin protein in the sarcolemma. As dysferlin is expressed in skeletal and cardiac muscles, dysferlinopathy may affect the heart in addition to skeletal muscle. We aimed to detect cardiac abnormalities using Cardiac Magnetic Resonance (CMR) imaging and to investigate its association with clinical, biochemical, and genetic parameters in patients with genetically confirmed dysferlinopathy. Cardiac involvement was defined as abnormalities in ventricular volumes, systolic function or wall motion, myocardial oedema, late gadolinium enhancement, or valvular regurgitation on CMR. All 30 patients (43.3 % females) recruited were asymptomatic for cardiac involvement. The mean age of onset was 21.50 ± 6.29 years, and the mean duration of illness was 7.1 ± 3.89 years. 11 (36.7 %) had one or more cardiac abnormalities on CMR. 5 (16.7 %) had left ventricular systolic dysfunction, and 5 (16.7 %) had myocardial fibrosis. We found significant correlations between left ventricular end-diastolic volume (LVEDV) and indexed left ventricular end-systolic volume (LVESVi) with the Muscular Dystrophy Functional Rating Score (MDFRS); and between left ventricular ejection fraction (LVEF) and the Medical Research Council (MRC) sum score. To conclude, More than a third of dysferlinopathy patients had subclinical cardiac involvement.