Familial neuromuscular cardiomyopathy: A review and pooled analysis of pathophysiology, diagnosis and clinical management

The role of genetic mutation in the pathogenesis of cardiomyopathies (CM) has been long-established. In contrast, the involvement of familial (hereditary) neuromuscular diseases (NDs) in the development of CM remains under-researched. Little attention has been paid to better characterize and understand myocardial involvement in NDs. There is evidence that early diagnosis may improve therapeutic response in ND patients with CM. However, diagnosis can be easily missed because signs and symptoms of cardiac dysfunction are non-specific or can overlap with that of muscular wasting (reduced physical activity) and respiratory failure due to the underlying ND. Diagnosis can also be delayed because of the late manifestations of the traditional non-invasive imaging markers of cardiac dysfunction particularly left ventricular (LV) systolic function and LV volumes or dimensions on echocardiography and late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMRI). For these reasons, a better understanding of longitudinal progress, cardiac complications and long-term cardiac outcomes is warranted. The clinician should also be familiar with the therapeutic options in CM associated with NDs. Thus, this review discusses important clinical and diagnostic features of CM in patients with NDs as well as emerging diagnostic and therapeutic options.