[Vectorcardiographic features of right ventricular dilatation].

Axial McFee-Parungao lead system vectorcardiograms were obtained in 55 patients with type atrial septal defect, aged 3-24 years, prior to and in average 3 years after surgical repair of the defect. Changes of the QRS loop observed after intervention led to the conclusion that the vectorcardiographic signs of right ventricular dilatation consist of a rightward shift of the posteriorly orientated horizontal plane vectors at 50-70 ms of QRS, decrease of the magnitude of vectors around the 40th ms, no changes in the magnitude and orientation of the initial (10-30 ms) QRS vectors as well abnormal departures of the spatial VCG loop from its preferential plane even in the absence of other signs of right ventricular conduction impairment. The above abnormalities vanished after normalization of hemodynamics.