Interatrial block during exercise tolerance tests as an additional parameter for the diagnosis of ischemic heart disease.

摘要

INTRODUCTION: Interatrial block (IAB; P-wave duration, >/=120 milliseconds) is associated with increases of left atrial pressure. We studied the use of IAB during exercise tolerance test (ETT) in diagnosis of ischemic heart disease. METHOD: Exercise tolerance tests were performed in 149 patients (mean age, 50 years; male, 60.4%). P-wave duration was measured at rest, at each stage of exercise using the Bruce protocol, and in recovery. As clinically indicated, 71 patients subsequently underwent nuclear stress test and/or catheterization. The evidence of ischemia (EOI) was considered present according to the more definite test, that is, catheterization over nuclear stress test over ETT. RESULTS: Among patients who did not have IAB at rest (n = 115), 63 patients (54.7%) developed IAB during the ETT. The incidence of IAB during the ETT was higher in patients with EOI than patients without EOI (88.9% vs 51.9%, P = .03). When IAB during the ETT and positive ETT were used together to detect EOI, they were more accurate (86.1% vs 81.7%) than the ETT alone. Among patients with IAB at rest (n = 34), patients with EOI had a higher incidence of P-wave duration increase of more than 20 milliseconds during the recovery period than patients without EOI (100% vs 21.8%, P = .015). When using P-wave duration increase of more than 20 milliseconds during the recovery period in conjunction with positive ETT, the sensitivity in detecting EOI was higher than using the ETT alone (100% vs 0%), but the specificity was worsened (68.8% vs 84.4%). CONCLUSION: New IAB and worsening of IAB during ETT appeared in patients with ischemic heart disease and may be used as additional parameters for the ETT interpretation.