The significance of QTpd, QRS duration and frontal plane QRS axis during treadmill exercise test in patients with coronary artery disease

Objective:To investigate the clinical significance of QTpd?QRS duration and frontal plane QRS axis during treadmill exercise test in patients with or without coronary artery disease.Methods:Sixty six patients who underwent coronary angiography and treadmill exercise test were divided into two groups: with or without coronary artery disease, QTpd and QRS duration were assessed during treadmill exercise test. The patients with coronary artery disease were subdivided into subgroup 1(with left anterior descending artery lesion±left circumflex artery lesion) subgroup 2(with right coronary artery lesion±left circumflex artery lesion) and subgroup 3(with three vessels lesions or with left anterior descending artery lession±right coronary artery lesion). The frontal plane QRS axis was assessed during treadmill exercise test.Results:1 Before exercise, QTpd and QRS duration were no significant difference between two groups(P 0.05 ). 2 In patients without CAH, QTpd were no significant difference (P 0.05 ), and QRS duration were significantly shortened (P 0.01 ) after exercise. In patients with CAD, Qtpd and QRS duration were significantly prolonged (P 0.01 ). 3 After exercise, there was no significant axis shift in patients without coronary artery disease(P 0.05 ); In subgroup 1, the frontal plane QRS axis was shifted to the left (P 0.01 ); In subgroup 2,the frontal plane QRS axis was shifted to the right(P 0.01 ); In subgroup 3, no siginificant axis shift was observed(P 0.05 ).Conclusion:For diagnosis of coronang artery disease, it is useful to exercise induced QTpd, and QRS prologation and frontal plane QRS deviation.