Significance of QRS Duration Changes in the Evaluation of ST‐Segment Depression Presenting Exclusively During the Postexercise Recovery Period

Abstract

The aim of this study was to evaluate the contribution of QRS prolongation in the diagnosis of coronary artery disease (CAD) in patients with exercise-induced ST-segment depression exclusively during the recovery period. The study population consisted of 107 patients (90 males and 17 females) aged 39-70 (mean 59 +/- 7) years who underwent a treadmill exercise test using Bruce protocol and presented ST-segment depression limited to the recovery period. Angiographic data were available for all studied patients. Among studied patients, 74 (69%) were found to have hemodynamically significant CAD, while the remaining 33 (31%) had normal coronary arteries. Concomitant QRS prolongation was revealed in 61 (82%) of the patients with angiographically documented CAD, while in 13 (18%) patients QRS duration remained unchanged. On the contrary, only 4 (12%) of the 33 patients with normal coronary arteries showed prolonged QRS duration during ST depression, while in the remaining 29 (88%) QRS duration remained unchanged. The evaluation of the concomitant QRS duration changes may discriminate patients with truly ischemia-induced ST-segment depression limited to the recovery period.