A Comparison Of Different Exercise Electrocardiogram Testing Criterions To Diagnose Coronary Artery Disease

Background and aimsExercise electrocardiogram testing is a non-invasive, economical, easy operating, and widely-used method to diagnose coronary artery disease, especially in hospitals where coronary angiography can not be performed. The traditional diagnostic criterion of exercise electrocardiogram testing is the depression of the ST segment during or after exercise. While the sensitivity and specificity of this criterion are relatively low, this influences the clinical application of exercise electrocardiogram testing. Someone uses ST/HR slope, ST/HR index, and QRS score to improve the effect of exercise electrocardiogram testing, but the actual application value has not been generally accepted.This study aims to compare the values of ST segment depression, ST/HR index, and QRS score in diagnosing coronary artery disease.MethodsOne hundred and seventy-seven subjects were involved between January, 2007 and February, 2008. All of them underwent coronary agiography within 3 weeks after undergoing exercise electrocardiogram testing. Exercise electrocardiogram testing was performed according to the Bruce protocol and the values of ST depression, ST/HR indexes and QRS scores were measured. Based on the results of coronary angiography, the values of ST segment depression, ST/HR index, and QRS score in diagnosing coronary artery disease were compared.Results1. ST/HR index has the highest sensitivity, specificity and accuracy in diagnosing coronary artery disease (86.8%, 77.2%, and 81.4%), then QRS (78.9%, 71.3%, and 74.6%) sore and ST depression (73.4%, 54.5%, and 62.7%). The sensitivity, specificity and accuracy of ST/HR index was significantly higher when compared with ST depression (P<0.05). There was no significant difference between the sensitivity, specificity and accuracy of ST/HR index and QRS score. The specificity and accuracy of QRS score were significantly higher when compared with ST depression, while there was no significantly difference in sensitivity.2. The ST/HR index increased with the number of vessels suffered increasing (P<0.05). The QRS scores decreased with the number of vessels suffered increasing (P<0.05).Conclusions1. The sensitivity, specificity and accuracy of ST depression to diagnose coronary artery disease are relatively low. In clinical application, overall analyses are needed when false-positive and false-negative occurs.2. The sensitivity, specificity and accuracy can be increased when using ST/HR index as the diagnostic criterion. But it was not so convenient when evaluted with the ST depression. Meanwhile, ST/HR index can predict the severity of coronary artery lesions.3. The diagnostic value of QRS score is not better than ST/HR index, but it is also a good choice when there are some facts interfering the change of ST segment.