A study of 100 subjects with LGMD2A to 2I used echocardiographic and electrocardiographic criteria to define cardiac involvement (CI): EF <50%, intraventricular septum greater than 1.2 cm, left bundle branch block, atrial fibrillation/flutter, or atrioventricular conduction block[15]. Here, CAPN3 is linked to Left bundle branch block.