Abstract
QRS deflection area vector (A^^→qrs), T deflection area vector (A^^→t) and ventricular gradient (G^^→) in right ventricular hypetrophy were studied in 53 subjects divided on the basis of cardiac catheterization data into four subgroups; normal controls, mild MS group, right ventricular pressure overload group and right ventricular volume overload group. A^^→qrs, A^^→t and G^^→ of the four subgroups were calculated using a microcomputer and compared. A^^→qrs in right ventricular pressure overload group and volume overload group was shifted to the right and slightly anteriorly from that in normal control group. A^^→t in right ventricular pressure overload group and volume overload group was shifted slightly upwards and significantly posteriorly from that in the normal control and mild MS groups. G^^→ in right ventricular pressure overload group and volume overload group was shifted to the right and significantly posteriorly from that in normal control and mild MS groups. Using multivariative analysis, we developed criteria for diagnosing right ventricular hypertrophy with A^^→t: 0.059At(Z) - 0.0145|A^^→t| - 0.2608 ⩽ 0. Application of this criteria achieved 82.4% (28 of 34) sensitivity in the patients with right ventricular hypertrophy and 90.9% (10 of 11) specificity in the normal control subjects.
