Skeletal muscle involvement in cardiomyopathies

Abstract

The link between heart and skeletal muscle disorders is based on similar molecular, anatomical and clinical features, which are shared by the 'primary' cardiomyopathies and 'primary' neuromuscular disorders. There are, however, some peculiarities that are typical of cardiac and skeletal muscle disorders. Skeletal muscle weakness presenting at any age may indicate a primary neuromuscular disorder (associated with creatine kinase elevation as in dystrophinopathies), a mitochondrial disease (particularly if encephalopathy, ocular myopathy, retinitis, neurosensorineural deafness, lactic acidosis are present), a storage disorder (progressive exercise intolerance, cognitive impairment and retinitis pigmentosa, as in Danon disease), or metabolic disorders (hypoglycaemia, metabolic acidosis, hyperammonaemia or other specific biochemical abnormalities). In such patients, skeletal muscle weakness usually precedes the cardiomyopathy and dominates the clinical picture. Nevertheless, skeletal involvement may be subtle, and the first clinical manifestation of a neuromuscular disorder may be the occurrence of heart failure, conduction disorders or ventricular arrhythmias due to cardiomyopathy. ECG and echocardiogram, and eventually, a more detailed cardiovascular evaluation may be required to identify early cardiac involvement. Paediatric and adult cardiologists should be proactive in screening for neuromuscular and related disorders to enable diagnosis in probands and evaluation of families with a focus on the identification of those at risk of cardiac arrhythmia and emboli who may require specific prophylactic treatments, for example, pacemaker, implantable cardioverter-defibrillator and anticoagulation.

A mutation update for the FLNC gene in myopathies and cardiomyopathies

“…Cardiac involvement is a common clinical manifestation in hereditary muscular dystrophies (Hermans et al, 2010). Conversely, muscular problems in cardiomyopathy patients have also been described (Limongelli et al, 2013), showing the strong molecular link between hereditary muscular dystrophies and cardiomyopathies. In line with this, cardiac involvement is not uncommon in FLNC-associated myopathy ( Figure 5), but muscle involvement has not been described (yet) at the moment of diagnosis in FLNC-associated cardiomyopathy (Ader et al, 2019).…”

Diagnostic clues for the diagnosis of nonsarcomeric hypertrophic cardiomyopathy (Phenocopies): Amyloidosis, fabry disease, and mitochondrial disease

“…Another 10%–15% of the patients can be affected by systemic diseases mimicking HCM and including genetic syndromes,[ 9 ] metabolic/storage,[ 10 ] mitochondrial,[ 11 ] or neuromuscular diseases. [ 12 ]…”

Diagnosis of Cardiomyopathies: Tips and Tricks for Internists and General Practitioners

“…55 A recent history of unknown fever and travels in foreign countries could suggest an infective myocarditis, while a personal history of autoimmune diseases or signs and symptoms of systemic inflammatory disorders can suggest a non-infective myocardi- tis. Some symptoms and signs may suggest a specific cause of DCM (Table 2): the presence of intellectual disability may suggest a mitochondrial cause 17 and dystrophinopathies; 56 sensorineural deafness in mitochondriopathies; 17 gait disturbance and muscle weakness in neuromuscular diseases; 57 pigmentation of skin and scars is a specific sign of hemochromatosis. 58 The ECG in DCM shows usually less clues than other cardiomyopathies (Table 2).…”