Restrictive cardiomyopathy as a cardiac manifestation of myofibrillar myopathy

ObjectivesRestrictive cardiomyopathy (RCM) has been repeatedly reported as a cardiac manifestation of certain neuromuscular disorders, but only in single patients with myofibrillar myopathy (MFMP).Case ReportIn a 19-year-old woman with a history of short stature, tiptoe-walking since childhood, fixed joint contractures, severe scoliosis requiring surgical correction, elevated levels of creatine kinase, and RCM, MFMP was diagnosed based on her clinical presentation, her elevated muscle enzymes and a muscle biopsy. An electrocardiogram showed an atrioventricular-block I, paroxysmal sinus-tachycardia, biphasic P-waves, right-axis deviation, abnormal repolarization, and episodes of supraventricular tachycardia. Echocardiography confirmed her RCM. Her respiratory function was markedly reduced, despite surgical correction of her severe scoliosis at age 14 years. After an aggravation of heart failure because of atrial flutter, the patient profited from successful cardioversion and diuretics.ConclusionElectrocardiographic abnormalities such as atrial flutter and RCM represent cardiac manifestations of MFMP. Cardioversion can be successful, and oral anticoagulation may prevent cardioembolic events.