The epidemiological and prognostic significance of the R/S Ratio in DII derivation in patients with or without ST-segment elevation

Objective: The aim of this study was to evaluate the significance of R/S ratio (RSR) in the Lead II derivation of electrocardiography (ECG) in acute coronary syndrome (ACS) patients, in regards to the complications associated with myocardial infarction (MI), three-vessel coronary artery disease (TVCAD), and mortality. Method: This cross-sectional retrospective cohort study included a total of 1102 patients with ACS, who presented to our hospital's emergency department (ED) with chest pain and were admitted to the cardiology inpatient service between January 2014 and December 2017. The patients with an RSR value less than 1 were assigned to group I and the patients with RSR values greater than 1 were assigned to group II. These groups were compared in terms of age and gender; the presence of blocked major coronary arteries (BMCA), complications associated with MI, and TVCAD; Gensini Scores (GS), the levels of cardiac troponin I (cTnI), and mortality rates. Results: ST-segment elevation myocardial infarction (STEMI), unstable angina (UA), and non-ST segment elevation myocardial infarction (NSTEMI) were more frequent in group I in both genders. Ischemic heart failure (IHF), ventricular tachycardia (VT), acute pulmonary edema (APE), cardiac effusion (CE), and tamponade (CT) predominated in group I. However, atrioventricular (AV) block, TVCAD, and mortality was more frequent in group II. In men, STEMI, UA, NSTEMI, branch block (BB), complications, TVCAD, BMCA, and mortality were found to be high. Atrial fibrillation (AF) occurred more commonly in NSTEMI and BBB were more common in acute inferior MI (AIMI). IHF, VT, and APE were commonly seen in acute anterior MI (AAMI). AV block was more frequent in AIMI. TVCAD was more common and the mortality rate was higher in AAMI. The BMCA was identified to be the right coronary artery (RCA) in AIMI. The most commonly blocked vessels were the circumflex artery (Cx=L1) and the left anterior descending artery (LAD=L2) in AAMI. The most commonly blocked vessel was L2 in both UA and NSTEMI. Conclusions: The RSR value may become an adjunctive predictor for estimating the complications associated with MI, TVCAD, and mortality in ACS