Spatial patterns of ventricular repolarization in arterial hypertension

Abstract

A study of the spatial electrocardiographic patterns has been performed in patients with arterial hypertension, using Frank''s corrected orthogonal system, and the results obtained have been compared to the patterns characteristic of normal subjects. Spatial QRS- and T-vector magnitude and direction, and the angle between the two (dA[degree]) have been measured preliminarily in normal subjects, and a definite correlation has been found to exist between spatial QRS and T magnitudes, and between dA[degree] and T magnitude. A multiple regression equation showing dependence of T magnitude on both QRS magnitude and dA[degree] has been calculated and the relation found highly significant. In hypertensive patients with no signs of altered repolarization on conventional electrocardiographic leads the most striking feature has been found to be a widening of dA[degree] and an absent correlation between dA[degree] and T magnitude. These phenomena are paralleled by a definite increase in ventricular gradient magnitude. Widening of dA[degree] has therefore been assumed to represent an early sign of altered repolarization which may not be evident from qualitative evaluation of conventional leads. In hypertensive patients with electrocardiographic signs of overload the direction of the T vector has been found to be completely upset, so that a further widening of dA[degree] results. Any correlation between QRS, T, and dA[degree] magnitude is completely lost.