Cardiac involvement in patients with limb-girdle muscular dystrophy type 2 and Becker muscular dystrophy

Objective: To investigate the extent of cardiac involvement in patients with 1 of the 12 groups of recessively inherited limb-girdle muscular dystrophy type 2 (LGMD2A-L) and Becker muscular dystrophy (BMD). Design: Prospective screening. Setting: Neuromuscular Clinic and Department of Cardiology at Rigshospitalet. Patients: One hundred one patients with LGMD2A-I and BMD and 29 patients with LGMD2 and no molecular diagnosis. Main Outcome Measures: Clinical investigation, echocardiography, and electrocardiographic findings. Results: Cardiac involvement was present in 24 of 100 patients (24%) with LGMD2A-I and in 14 of 30 patients (47%) with BMD. Only a few patients with LGMD2A and unclassified LGMD2 had mild cardiac involvement, whereas 29% and 67% of patients with LGMD2I and LGMD2E, respectively, had cardiac involvement. Cardiac involvement was not correlated with age, muscle strength, or the level of dystrophic changes on muscle biopsy. Conclusions: This study demonstrates a high prevalence of cardiac involvement in patients with LGMD2I, LGMD2E, and BMD. Patients with LGMD2A, LGMD2D, and unclassified LGMD2 have a much lower and milder prevalence of cardiac involvement.