Evaluation of collateral circulation with clinical, electrocardiographic, and angiographic parameters in patients with acute myocardial infarction

Objectives: We investigated the presence of collateral circulation (CC) during early period of acute myocardial infarction (AMI) and evaluated its relationship with clinical, electrocardiographic, and angiographic parameters.
Study design: İn 79 patients (63 men, 16 vvomen; mean age 57 years) who presented within the first six hours of AMİ, coro-nary angiography was performed before primary angioplasty to determine the infarct-related artery (IRA), the number of arteries with significant stenosis (≥50%), localization of stenosis (proxi-mal, middle, or distal), and the presence of CC. The presence of Q waves and reciprocal ST-segment changes were evaluated on initial electrocardiograms. Collateral circulation to the IRA was graded according to the Rentrop scoring system.
Results: Collateral circulation to the IRA was detected in 31 patients (39.2%). İnfarct-related artery was the left anterior descending (LAD) coronary artery in 43 patients (54.4%), circumflex (Cx) artery in 11 patients (13.9%), and the right coronary artery (RCA) in 25 patients (31.7%). On initial electrocardiograms, Q wave was absent in 34 patients (43%) and reciprocal ST-segment depression was present in 53 patients (67.1%). Collateral circulation was more common in RCA occlusions than those involving the LAD and Cx arteries (60%, 32.6%, and 18.2%, respectively; p=0.012). The presence of CC was significantly correlated with hypertension (r=0.226, p=0.045) and RCA occlusion (r=0.309, p=0.006). In multiple regression analysis, only RCA occlusion was found to be an independent predictor for CC (r=0.377, p<0.001).
Conclusion: In the early period of AMİ, collateral circulation becomes functional in a considerable number of patients who have hypertension and RCA occlusion. This may be helpful in choosing between conservative and invasive treatments.

Keywords: Electrocardiography, collateral circulation; angiography; coronary circulation; hypertension; myocardial infarction.