Abstract
The incidence of a notch on the T wave, a T(N), was investigated in 5610 cardiovascular normals (Group 1), 100 cases with right bundle branch block (RBBB) (Group 2), 100 cases with congenital heart disease (Group 3), and 100 cases with left ventricular hypertrophy (LVH) (Group 4). A T (N) was observed at a rate of 7.5% in Group 1, 26% in Group 2, 21% in Group 3, and 15% in Group 4. In Group 1, a striking parallelism was observed in the incidence of a T (N) and an inverted T wave in V1 ("Juvenile T wave"). This indicates that a T (N) in normals may be associated with right ventricular preponderance. On the basis of the present study, it is suggested that RBBB and RVH may provide more suitable situations for the occurrence of a T (N) than LVH. Explanation of the genesis of a T (N) is provided on the assumption that a T (N) would be produced by a marked delay or marked inhomogeneity in the repolarization process of some part of the right or left ventricle.
