Abstract
Background/Objectives Limb girdle myopathies may have concurrent cardiomyopathy. The evaluation of biomarkers in this context, and appropriate screening with other cardiac investigations including electrocardiograms (ECG), transthoracic echocardiograms (TTE), and cardiac magnetic resonance imaging (cMRI), play an important role.
Methods In this case report, a patient presenting with proximal weakness without cardiac symptoms is described, for whom a Troponin I level provided a significant finding.
Results A 20-year-old male was reviewed in neurology outpatients with a 12-month history of progressive proximal upper and lower limb weakness. Background history revealed poor athletic performance and noted an arching of the back when running. There was no family history of neuromuscular disease. Physical examination demonstrated bilateral scapular winging, and mild hip extension weakness bilaterally. Previous investigations had demonstrated creatine kinase levels of ~5000 U/L, Troponin T 84, and dystrophic changes on muscle biopsy. Cardiac screening blood tests were requested. Subsequently the patient was recalled to hospital with a Troponin I 4,041 ng/L (normally < 54). Repeat Troponin T was 76. TTE demonstrated a left ventricular ejection fraction (LVEF) of 41% with global hypokinesis. cMRI demonstrated subpericardial late gadolinium enhancement of the basal to mid inferolateral and anterolateral segments, without evidence of myocardial oedema/inflammation. Heart failure with reduced ejection fraction was diagnosed, and guideline-directed medical therapy commenced. Subsequently, a dystrophin MPLA returned positive, consistent with a diagnosis of Becker’s muscular dystrophy.
Conclusion This case demonstrates the importance of screening cardiac function in patients with myopathy. Rationale, and indications, for specific cardiac investigations are discussed.
