[An electro- and vectorcardiographic study of ventricular activation in scleroderma]

Electrical ventricular activation was studied by means of electrocardiogram and vectorcardiogram in 62 patients, 55 women and 7 men, affected by systemic sclerosis of average disease duration of 10.3 years. 45% of the patients showed the "diffused form" of the disease and 55% the "limited form". The vectorcardiogram showed some alterations of the ventricular activation in 55% of the recorded cases. The previous electrocardiogram found only 18%. The alterations, which are more frequent in the diffuse form than in the limited one, are the presence of loss of forces in septal, lateral or inferior or combined areas and intraventricular conduction disorders as complete and incomplete right bundle branch block, left anterior subdivision block, left posterior subdivision block, or combination between incomplete right bundle branch block and left anterior or posterior subdivision block. The vectorcardiogram was more sensitive than the electrocardiogram in showing loss of forces, also in patients with the limited form of systemic sclerosis, when the electrocardiogram was normal. Moreover the vectorcardiogram is helpful to identify left posterior subdivision block. The vectorcardiographic investigation seems to be a useful complement of the electrocardiogram especially for the identification of cases with myocardial involvement that is clinically silent.