Evaluation of postextrasystolic T wave alterations in identification of patients with coronary artery disease or left...

This study was performed (1) to assess the value of postextrasystolic T wave alterations in identification of patients with cardiac disease and (2) to determine if their frequency depends on length of compensatory pause. In 52 patients a pacing catheter was placed in the right ventricular (RV) apex, and premature beats were programmed to occur 30 msec beyond RV refractory period. Postextrasystolic T wave alterations occurred in 32 patients, 13 with an 19 without coronary artery disease (CAD) (NS). Such alterations were also not related to presence of abnormal left ventricular (LV) ejection fraction (less than 0.55) or end-diastolic pressure (greater than 12 mm Hg). In 33 patients, premature beats were also introduced 330 msec beyond the RV refractory period to compare effects of long and short compensatory pauses on frequency of postextrasystolic T wave alterations. When the pause was near maximal, 18 patients had alterations in 60 ECG leads; when it was shorter, seven patients had alterations in 10 leads (p less than 0.001). Thus, judging from provoked postextrasystolic T wave alterations, such spontaneous changes appear neither sensitive nor specific in the identification of patients with cardiac disease. The frequency of postextrasystolic T wave changes depends on the length of the compensatory pause.