AUTHOR=Li Jingchao , Yu Haijia , Cui Luqian , Song Huihui , Chu Yingjie , Dong Shujuan 

TITLE=The ratio of QRS/RV6-V1: a new electrocardiographic predictor of short- and long-term adverse clinical outcomes in patients with acute myocardial infarction combined with new-onset right bundle branch block

JOURNAL=Frontiers in Cardiovascular Medicine

VOLUME=Volume 10 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/cardiovascular-medicine/articles/10.3389/fcvm.2023.1129235

DOI=10.3389/fcvm.2023.1129235

ISSN=2297-055X

ABSTRACT=Background: Few studies have focused on electrocardiography (ECG) parameters correlated with clinic prognosis in acute myocardial infarction (AMI) patients combined with new onset right branch bundle block (RBBB).
Objectives: To assess the prognostic value of a new ECG parameter,ratio of QRS Duration/RV6-V1 interval, in AMI patients combined with new onset RBBB.
Methods: A total of 272 AMI patients combined with new onset RBBB treated with primary percutaneous coronary intervention(PCI) were retrospectively enrolled. Patients were divided into survival and death groups. Demographic, angiographic, and ECG characteristics were compared between the two groups. Receiver operating characteristic (ROC) curve was used to screen the best ECG parameters for indicting 1-year Mortality.The ratio of QRS Duration/RV6-V1 interval was converted to the high ratio group and low ratio group according to the optimal cut-off value point determined by X-tile software. We compared demographic, coronary, and ECG characteristics, in-hospital major adverse cardiac events (MACE), and 1-year mortality between the two groups. Multiple logistic and Cox regression were used to evaluate if the ratio of QRS Duration/RV6-V1 interval was an independent prognostic factor of in-hospital MACE and 1-year mortality.
Results: ROC curve showed that the ratio of QRS Duration/RV6-V1 interval had higher value for predicting 1-year mortality compared with QRS Duration, RV6-V1 interval, and RV1 interval. Patients in the high ratio group had a significantly higher CK-MB peak, ejection fraction (EF)%, and Killip, higher ratio of left anterior descending artery (LAD) as infarct-related artery (IRA), longer Total ischemia time (TIT) compared with the low ratio group. The in-hospital MACE rate (31.0% vs 93.3%, p<0.001) and 1-year mortality (13.2% vs 86.7%, p<0.001) in the high ratio group were higher than the low ratio group statistically.Higher ratio of QRS Duration/RV6-V1 interval was an independent predictor of in-hospital MACE (OR 8.546, 95%CI[1.395-52.367], p=0.02) and 1-year mortality (HR2.21, 95%CI[1.05-4.64],p=0.037) after adjusting other confounders.
Conclusion: According to our study, high ratio of QRS Duration/RV6-V1 interval was a valuable prediction of short and long-term adverse Clinical Outcomes in AMI patients combined with new onset RBBB.The implications of high ratio of QRS Duration/RV6-V1 were more serious ischemia and pseudo synchronization between bio-ventricle.