American Heart Journal

HE electrocardiographic patterns of left ventricular hypertrophy or left T ventricular strain in standard limb lead records have received considerable attention from Less detailed attention has been paid to the pattern of left ventricular hypertrophy when using the unipolar limb and precordial leads. The typical pattern obtained by unipolar techniques has been described previously, 11-16 but the atypical ones and those showing lesser degrees of abnormalities have not been detailed adequately. The practical importance of the electrocardiographic position of the heart and of the time of onset of the intrinsic deflection of the ventricular complexes as an aid in diagnosis has been emphasized already.11J6 The purpose of the present investigation is to evaluate the criteria, using unipolar limb and precordipl leads, for the recognition of the atypical and early patterns of left ventricular hypertrophy; to determine the frequency of the characteristic changes noted by Wilson and his associatesll; and to study the diagnostic value of the electrocardiographic position of the heart and of the time of onset of the intrinsic deflection (ventricular activation time).