Vectorcardiographic analysis of the QRS loop in hypertensive heart disease.

The authors made a quantitative and qualitative vectorcardiographic analysis (Frank lead system) in 47 patients with hypertensive heart disease compared with a control group of 16 normal subjects. The magnitude and the angle of the maximum QRS vector, the sense of rotation of the QRS loop, the magnitude of the maximum posterior deflection (Sz), of the anterior maximum one (Rz), of the maximum leftward one (Rx), and of the maximum rightward one (Qx), the length (L) and the width W) of the QRS loop, as well as the angle of the maximum T vector were measured. A significant difference, in all planes of the maximum QRS magnitude between the normals and the AHT was found, while the maximum QRS angle was not significantly different. The quantitative analysis of the veg made in the horizontal plane revealed significant differences for the Sz, Rx, L, and the relation Rz/Sz. The quantitative analysis made according to Varriale et al. (1966) revealed a prevalence of the cases of type I A (72.3%) and I B (21.3%).