Severe involvement of the conduction system in a patient with sclerodermal heart disease. An electrophysiological study.

A case of progressive systemic sclerosis with syncopal symptoms is reported. The presenting ECG pattern was that of an anterior myocardial infarction. The clinical history and the coronary angiography excluded significant coronary atherosclerotic heart disease. The ECG pattern evolved from the infarctual pattern associated with right bundle branch block to probably major degree of right bundle branch block associated with left posterior fascicular block. M-mode echocardiography, heart catheterization and angiographic studies did not reveal significant mechanical impairment of the left or right ventricle function. His bundle electrogram documented a markedly prolonged H-V interval, confirming an advanced impairment of distal conducting system. This case supports the suggestion that intraventricular conduction disorders in sclerodermal heart disease are not always related to diffuse myocardial involvement. The risk of sudden death justifies accurate electrophysiological evaluation in selected patients with sclerodermal cardiopathy.