Relation between recovery sequence estimated from body surface potentials and T wave shape in patients with negative T waves and normal subjects.

Abstract

BACKGROUND Advances in analytical methods of the epicardial electrical potentials allowed us to demonstrate spatial distributions of local recovery. Because local recovery will be reflected in events on body surface ECG mapping, abnormalities in recovery sequence that may be responsible for the origin of negative T waves can be detected from body surface potentials. METHODS AND RESULTS Eighty-seven unipolar ECGs were recorded simultaneously from the entire thorax in patients having negative T waves on left anterior precordial leads and in normal subjects. These included 40 patients with anterior myocardial infarction (MI), 21 patients with left ventricular hypertrophy (LVH), and 44 male volunteers. We measured Tmax time, defined as the instant of maximal first derivative of the T wave as the index of local recovery (Wyatt's method). Parameters related to T wave potentials were positive T wave amplitude, negative T wave amplitude, and T integral. Significant correlations were observed between the Tmax time and each of the T wave potentials. The T wave potentials were dependent on Tmax times. In the anterior MI, the late Tmax times were located on the upper left anterior chest and early Tmax times on the lower right lateral chest. In the LVH, the area showing a delayed recovery was displaced in a left downward direction compared with anterior MI. CONCLUSIONS Body surface Tmax time distributions clearly separate two negative T wave groups, i.e., anterior MI and LVH. Appearance of the negative T waves correlates well with the presence of the area with delayed Tmax time on the spatial distribution.