Relation between fragmented QRS and collateral circulation in patients with chronic total occlusion without prior myocardial infarction

Abstract

It has been shown that the fragmented QRS (fQRS) on electrocardiogram (ECG) signifies regional myocardial scar in patients with non-Q-wave myocardial infarction (MI). We hypothesized that presence of fQRS on ECG may be related with poorly-grown collateral coronary circulation (CCC) in patients with chronic total coronary occlusion (CTO) without prior MI. This retrospective observational study is included 56 patients (mean age 61.73±7.96 years; 67.9% men) with CTO in one of the major coronary arteries. Collateral circulation was graded according to Rentrop's classification. The fQRS was defined as the presence of an additional R wave or notching of R or S wave or the presence of fragmentation in two contiguous ECG leads corresponding to a major coronary artery territory. Patients with pathological Q-wave or history of MI, typical bundle brunch blocks (BBB) and incomplete right BBB were excluded from study. Statistical analysis was performed using Chi-square test, Student's t-test and logistic regression analysis. Fifteen patients had Rentrop grade 1, 15 patients had grade 2 and 26 patients had grade 3 CCC. Five (19%) of the patients who have grade 3 CCC, seven (47%) of the patients who had grade 2 CCC, ten (67%) of the patients who had grade 1 CCC had fQRS (p=0.002). Logistic regression analysis showed high predictive value of the presence of fQRS for Rentrop 1 CCC (OR=8.4, 95% CI 1.97-35.7; p=0.004). Results of our study may implicate the presence of fQRS on electrocardiogram as a predictor of a poorly grown CCC in patients with chronic total occlusion without prior MI.