Comparable Analysis Of Treadmill Exercise Test After Acute Myocardial Infarction And Coronary Angiography

Objective The symptom-limited treadmill exercise test was performed in patients at recovery phase of acute myocardial infarction to detect metabolic equivalents (METS), exercise timing and maximum heart rate of the patients.meanwhile. ST segment fluctuations and various arrhythmias were monitored by 12 leads electrocardiogram.The patients underwent coronary angiography and left ventriculography at appropriate time to investigate the extent of coronary artery disease and left ventricular ejection fraction. We can evaluate the significance of performing treadmill exercise test at early stage of acute myocardial infarction.Methods The symptom-limited treadmill exercise test was carried out in 60 patients with acute myocardial infarction before coronary angiography . The average timing of the treadmill exercise test was 32 days (10-53days). The coronary angiography and left ventriculography were performed to determine the extent of coronary artery disease (single vessel disease, two vessel disease, three vessel disease) and left ventricular ejection fraction. Some related parameters were evaluated.Results The sensitivity specificity positive predictive value and negative predictive value in predicting multivessel disease by exercise -induced ST segment depression >0.1 mv was 62% , 67% , 76%. 50% respectively. The sensitivity specificity positive predictive value and negative predictive value in predicting multivessel disease by METS<6.0 was 46% 86% 85% 52%. However, the sensitivity specificity positive predictive value and negative predictive value in predicting multivessel disease by exercise -induced ST segment depression >0.2mv was 35% 91% 86% 55% respectively .By combining low workload and ST segment depression was 76% 62% 77% 40% respectively. METS maximum heart rate and exercise timing were not statistically significant between the single vessel disease and two vessel disease(p>0.05). Whereas, the three parameters mentioned above were statistically significant between single vessel disease and three vessel disease as well as two vessel disease and three vessel disease (P<0.05). No significantly comparable relations between the location of coronary artery disease and leads with positive ST segment changes were found out simultaneously. The leads with higher distributing frequencies were II III aVF V2 V3 V4 V5 V6 . ST segment elevation correlates with the location of myocardial infarction and aneurysm. The incidence of the aneurysm in 12 patients withexercise-induced ST segment elevation was 66%. ST segment elevation induced by exercise test was more prevalent in patients with anterior myocardial infarction than in patients with other infarct locations (P<0.05). In addition, the incidence of ventricular arrhythmias in 60 patients undergoing exercise test was 31 %. The incidence of atrial arrhythmias was 3.3%. No correlation between METS and left ventricular ejection fraction was found.Conclusions (1)Treadmill exercise test is both safe and reliable in patients at early phase of acute myocardial infarction . No cardiac event occurs in our study. (2)Treadmill exercise test has definite value in predicting coronary multivessel disease . The location of coronary artery disease can be primarily determined so as to provide valuable reference for coronary angiography. The sensitivity, specificity , positive predictive value and negative predictive value in predicting multivessel disease varies respectively with the selective parameters .(3) ST segment elevation induced by exercise test is significantly indicative of the location of myocardial infarction and aneurysm.