The Quantitative Analysis of Vectorcardiograms of Normal Hearts and Left Ventricular Hypertrophy

(1) Measurement of various portions of vector loop obtained from 66 normal subjects and 42 patients with left ventricular hypertrophy was made. Vectorcardiograms were taken by the Frank method and by the Grishman method. In addition to normal values, differential quantitative features between two conditions not reported thus far were endeavoured to be sought.(2) In general anterior magnitude of initial forces and inferior and an-terior magnitude of body of QRSsÊ loop were smaller in left ventricular hypertrophy than in normal, and width of the body in frontal plane and posterior magnitude of the body were larger in the former than in the latter. These items constitute useful diagnostic differentiation between both conditions because of less overlapping.(3) The magnitude of the maximal vector of the QRSsÊ loop had tend-ency to be larger in cases with left ventricular hypertrophy than in normal hearts, but the overlapping between both values was too great for a good differential criterion.