Electrocardiographic diagnosis of left ventricular hypertrophy.

Abstract

Eletrocardiographic changes observed in 141 cases of left ventricular hypertrophyare related. These findings were distributed in two groups: 1) Cases with suggestive electrocardiographic signs of left hypertrophy; 2) Cases with undoutable signs of left ventricular hypertrophy. The A.A. classify the electrocardiographic changes found in the above mentioned cases in two groups: fundamental changes and secondary ones. The fundamental electrocardiographic changes are: 1) R waye in V5 with more than 15 mm. of amplitude; 2) flattened,negative or diphasic T wave in V5; 3) late appearance of the intrinsic deflexion; 4) flattened, negative or diphasic T wave in D1; 5) widened, QRS complex in the classic derivations (0,10 of a second or more). The secondary eletrocardiographic changes are: 1) unleveling of the RS-T segment in V5;2) unleveling of the RS-T segment in V3; 3) flattened, negative or diphasic T wave in V3; 4) highvoltage QRS complex in the classic derivations; 5) left shift of the electric axis. Undoutable diagnosis of left ventricular hypertrophy was established whenever all five fundamental changes were found,or five fundamental changes plus one of the secondary changes, or three fundamental changes plus one of the secondary changes, or three fundamental changes plus three or more of these condary changes. Suggestive diagnosis of left ventricular hypertrophy was established when one of the fundamental changes plus one or more of the secondary changes were present. In 68(48.22 per cent) of the 141 cases, undoubtable electrocardiographic diagnosis of left ventricular hypertrophy was established. In 73 cases (51.78 per cent) a suggestive electrocardiographic diagnosis of left ventricular hypertrophy was made. The electric position of the heart was determined in every case.