ARRHYTHMIAS AND CONDUCTION DEFECTS IN POL YMYOSITIS

The prevalence of cardiac complications of dermatomyositis and polymyo sitis is generally underestimated. The authors report the case of hear t block as the presenting symptom of the disease, situated in the atri oventricular node. Initially paroxysmal, it eventually became permanen t. It was associated with atrial (fibrillation and flutter) and ventri cular hyperexcitability (ventricular tachycardia in runs). Myocardial biopsy provided histological proof of the cardiac disease and the defi nitive link between the nodal conduction defect and the polymyositis.