THE DETERMINATION OF VENTRICULAR PREDOMINANCE FROM THE ELECTROCARDIOGRAM

Abstract

Two recent articles containing much speculation and few facts have directed my attention to the necessity for a review of the subject of the electrocardiographic diagnosis of hypertrophy of one or the other ventricle of the heart. The original observations on this subject were that cases in which hypertrophy of the left ventricle might be expected showed a relatively tall R wave in Lead 1, with absence of an S wave in this lead, while Lead 3 shows a relatively small or absent R wave and a deep S wave. In like manner, cases in which hypertrophy of the right ventricle might be expected showed a relatively small R wave in Lead 1 and a deep S, while the S wave was absent in Lead 3 and the R wave relatively tall.¹ Einthoven demonstrated the fact that if the actual values of the largest waves of the Q R S