Female patient with proximal myotonic myopathy and ventricular tachycardia

Abstract

A 68-year-old woman with known proximal myotonic myopathy was transferred to our hospital for further diagnostic and therapeutic evaluation after successful termination of an episode of sustained ventricular tachycardia. In 2001, the myopathy was diagnosed after symptomatic weakness of the hip flexors. A cardiomyopathy with slight reduction of systolic left ventricular function was found in 2002. Coronary angiography excluded relevant coronary artery disease. The electrophysiologic examination could provoke atrial flutter, but neither a ventricular tachycardia nor a delay in the AV conduction was found. ECG and Holter ECG did not reveal any abnormalities. A reduction of the left ventricular systolic function (EF 45%) with normal size of cardiac chambers was demonstrated by echocardiography. It is known that in the patient group with myotonic dystrophies cardiac involvement manifests itself as cardiomyopathy, conduction disturbance or arrhythmia. However, only a small percentage of all patients with myotonic myopathy actually suffer from cardiac involvement. Among the different types of cardiac involvement, conduction disturbances requiring pacemaker implantation are most frequent. Only some patients develop ventricular tachycardias, and even cases of sudden cardiac death have been described. As a result of the case reports in the literature and the findings in our patient an ICD system was implanted on March 4, 2004.

Cardiac involvement in the muscular dystrophies

“…One study found that paroxysmal atrial fibrillation occurred in 16% of patients, mild left ventricular dysfunction occurred in 10%, and frank congestive heart failure occurred in 5% . Rare cases of SCD, presumably resulting from ventricular arrhythmias, have also been reported in DM2 …”

“…56 Rare cases of SCD, presumably resulting from ventricular arrhythmias, have also been reported in DM2. 58,59 Emery-Dreifuss Muscular Dystrophy. Emery-Dreifuss muscular dystrophy (EDMD) is a rare disorder with X-linked (EDMD1), autosomal dominant (AD; EDMD2) and, rarely, autosomal recessive (AR) inheritance.…”