[Cardiac deformity and dysfunction in facioscapulohumeral dystrophy--electrocardiogram, ECG gate cardiac MRI studies]

We studied the cardiac deformity and dysfunction in 8 patients with facio-scapulo-humeral (FSH) muscular dystrophy by electrocardiogram (ECG) and ECG gated cardiac magnetic resonance imaging (MRI). Two of the 8 FSH patients revealed elevated P waves and 3 of these patients revealed multifocal atrial premature contractions (APC) on ECG as reported previously. On ECG-gated MRI, the flattened thorax with anteriorly shifted vertebrae restricted the right ventricular movement. On the other hand, the right atrium is often enlarged. It is known that the patients suffering from severe "funnel chest" or "straight back syndrome" often develop similar ECG abnormalities and right atrial dysfunction resulting from restricted right ventricular dilatation. Although a possibility that the abnormal P waves or multifocal APC frequently observed in FSH are caused by myocardial degeneration selectively occurring in right atrium remains to be excluded, the characteristic thoracic deformity may play a primary role in the development of cardiac problems in this hereditary muscular disorder.