The relationship between fragmented QRS complexes and syntax II scores in patients with ST-segment elevation myocardial infarction

Background: Even though the relationship between syntax score (SS) and fragmented QRS (fQRS) has been studied, the relation between syntax score II (SS II) and fQRS in patients with ST elevation myocardial infarction (STEMI) is undefined. We aimed to define the relationship between fQRS and SS II for the evaluation of extension and complexity of coronary artery disease.

Material and methods: This study enrolled 167 patients undergoing primary percutaneous coronary intervention (pPCI) for STEMI. The standard 12-lead electrocardiograms (ECGs) were obtained from all patients before and after PCI. SS and SS II were calculated in all patients. Transthoracic echocardiography was performed to all patients.

Results: Thirty-nine patients (23.4%) had fQRS on their ECGs. The median SS II was 27 (22.9-33.9). SS II values in the fQRS(+) group were statistically significantly higher than that of the fQRS(-) group (35.2 (26.4-47.2) vs. 25.7 (22.1-30.7), p < 0.001). Also, in patients with higher SS II, there was significantly higher number of ECG derivations with fQRS.

Conclusions: The presence of fQRS and high number of derivations with fQRS on ECG may be associated with high SS II in patients undergoing pPCI for STEMI.