Polymyositis presenting as sick sinus syndrome.

Introduction Myocardial involvement in polymyositis has been increasingly recognized since it was first reported by Oppenheim (1899). Cardiac manifestations include congestive cardiac failure (Lynch, 1971; Bohan et al., 1977; Denbow et al., 1979), pericarditis (Lynch, 1971), atrioventricular and bundle branch block (Lynch, 1971, Schaumburg, Nielsen and Yurchak, 1971; Henderson et al., 1980) and atrial and ventricular arrhythmias (Devere and Bradley, 1975; Bohan et al., 1977; Sharratt, Danta and Carson, 1977; Denbow et al., 1979). Polymyositis however is not a well recognized cause of the tachycardiabradycardia form of the sick sinus syndrome.