The expression of normal ventricular repolarization in the body surface distribution of T potentials.

Isopotential maps from 120 normal subjects were obtained from 192 simultaneously recorded electrocardiographic leads. Maps were plotted at 1 msec intervals during the QRS and 5 msec intervals during the ST-T deflection. Repetition of QRS features was evident during all but the first few msec of the initial half of serial T maps. This suggests similarities of the normal sequence of ventricular excitation and recovery. Such similarities have been demonstrated by direct studies but are not evident from other electrocardiographic examinations. Serial maps during later portions of the T wave showed decreasing intensity of potentials with little change of body surface locations. This also correlates with an established feature of ventricular repolarization, namely that potential difference boundaries with stable locations are widely distributed during part of that process. Findings suggest isopotential maps show features of ventricular recovery not apparent from less extensive examinations.