SIGNIFICANCE OF THE CHANGES IN QRS LOOP DURATION AFTER THE TREADMILL EXERCISE TEST IN THE DIAGNOSIS OF CORONARY HEART DISEASE

Objective To assess the significance of changes in QRS loop duration after the treadmill exercise test with continuous vectorcardiogram monitoring in the diagnosis of coronary heart disease.MethodsTreadmill exercise tests were conducted on patients with coronary heart disease(group A) and suspected cases(group B;total n=91) for two days,followed by coronary arteriography.Continuous monitoring of the vector-cardiogram was performed during the exercise,and changes in the duration of QRS loop were measured and compared with the results of the arteriography.ResultsAfter the test,the duration of QRS loop was prolonged in group A,but shortened in group B,the corresponding changes were most obvious just after the exercise.The QRS loop duration corrected with BAZETT formula(QRSc) was also prolonged both in groups A and B,furthermore,the prolongation of QRSc in group A was more prominent than that in group B(t=20.2,P0.01).ConclusionMeasurement of the changes in QRS loop duration after the treadmill exercise test can increase the accuracy in the diagnosis of coronary heart(disease);which is easy-doing and repetitive and worth of the clinical promotion.