Risk stratification in laminopathies and Emery Dreifuss muscular dystrophy

Acute heart failure and bradyarrhythmia in a young male—what hides beneath the surface?: a case report

Background

Muscular dystrophies (MDs) are characterized by early-onset muscular atrophy and weakness, with frequent cardiac involvement. Myocardial dysfunction and conduction system involvement are often rapidly progressive despite medical and device therapy, and may even precede muscular symptoms, posing a challenge to diagnosis.

Case summary

We report a case of a young male admitted to a cardiac intensive care unit due to ‘de novo’ acute heart failure (HF) and atrial flutter with a slow ventricular response. Careful evaluation of past medical history revealed the presence of neuromuscular symptoms since childhood, disregarded throughout adult age. Diagnostic workup allowed to establish a diagnosis of non-dilated hypokinetic cardiomyopathy secondary to Emery-Dreifuss MD, due to lamin A/C (LMNA) gene mutation. Our patient was treated with neurohormonal modulation therapy and a cardiac resynchronization therapy defibrillator (CRT-D) was implanted, but due to worsening advanced HF, cardiac transplantation was needed.

Discussion

Association of skeletal muscle and cardiac symptoms should always raise the suspicion for an underlying MD, since the consequences of a missed diagnosis are often dramatic. A timely diagnosis is crucial to prevent sudden death due to arrhythmias in these patients and to delay the progressive course of cardiomyopathy.

Cardiac diseases as a predictor warning of hereditary muscle diseases. The case of laminopathies

Mutations in the LMNA gene are associated with a wide spectrum of disease phenotypes, ranging from neuromuscular, cardiac and metabolic disorders to premature aging syndromes. Skeletal muscle involvement may present with different phenotypes: limb-girdle muscular dystrophy type 1B or LMNA-related dystrophy; autosomal dominant Emery-Dreifuss muscular dystrophy; and a congenital form of muscular dystrophy, frequently associated with early onset of arrhythmias. Heart involvement may occur as part of the muscle involvement or independently, regardless of the presence of the myopathy. Notably conduction defects and dilated cardiomyopathy may exist without a muscle disease. This paper will focus on cardiac diseases presenting as the first manifestation of skeletal muscle hereditary disorders such as laminopathies, inspired by two large families with cardiovascular problems long followed by conventional cardiologists who did not suspect a genetic muscle disorder underlying these events. Furthermore it underlines the need for a multidisciplinary approach in these disorders and how the figure of the cardio-myo-geneticist may play a key role in facilitating the diagnostic process, and addressing the adoption of appropriate prevention measures.