The association of right coronary artery conus branch size and course with ST segment elevation of right precordial leads and clinical outcome of acute anterior myocardial infarction

Abstract

Introduction: Coronary artery disease is the leading cause of death worldwide and electrocardiogram (ECG) is a reliable diagnostic tool to determine a myocardial infarction. The present study tried to compare the relationship between the ECG findings and angiographic findings in patients with acute anterior myocardial infarction. Methods: Seventy-four patients with acute anterior ST elevation myocardial infarction (Ant- STEMI) presenting to the emergency room in the first 12 hours after the onset of symptoms were studied. Upon admission, a full 14-lead ECG (including leads V3R and V4R) were performed. Angiographic and ECG findings, as well as clinical outcome were compared between two groups. The statistical tests including Chi-square and independent t-test were used for data analysis. Results: Small conus branch was seen in 52 (70.3%) and large conus in 22 ( 29.7%) patients. STE in right-sided leads and heart failure were significantly higher in small conus branch group versus large conus branch (88.6% vs 11.4%, P < 0.001 and 34.6% vs 9.1%, P = 0.02 respectively). There was no significant difference in mortality rate between the two groups (5.8% in small conous group vs 0% in large conus group, P = 0.55). There was a significant difference in major adverse cardiac events (MACE) between the two groups (51.9% in small conous group vs 18.2% in large conus group, P = 0.01). Conclusion: In patients with anterior MI, small conus branch was associated with higher rate of major adverse cardiac events mostly because of increased rate of acute heart failure.

An Important Concern for the Analysis of Culprit Artery

“…In the Figure, A, however, ST-segment elevation is absent in V 1 . There may be 3 plausible explanations: acute total LMT occlusion without collateral circulation, multiple blood supply in lead V 1 , and secondary ST-T wave changes . (1) In 2012, Fiol et al first reported the STEMI pattern with RBBB and left anterior fascicular block of proximal LAD without ST-segment elevation in lead V 1 , suggesting acute total occlusion of LMT without collateral circulation.…”

“…Therefore, reciprocal ST-segment depression in lead V 1 caused by left circumflex branch was excluded. (2) The basal portion of the interventricular septum may be supplied with blood by the septal branches and the conus branch of LAD and the conus branch of the right coronary artery . Accordingly, in patients with proximal LAD occlusion, the presence of the large conus branches may protect the interventricular septum, which manifests with absence of ST-segment elevation in lead V 1 .…”

The prognostic significance of early and late right precordial lead (V4R) ST‐segment elevation in patients with acute anterior myocardial infarction

“…Some recent studies demonstrated a relatively high incidence of concurrent RV infarction in patients with anterior STEMI (Barsheshet et al, 2011;Bodi et al, 2010;Pourafkari et al, 2016;Tusun et al, 2015). However, less data have been reported about the prognostic importance of STE in lead V 4 R in patients with anterior STEMI and authors are in conflict on how this STE has an impact on the prognosis (Barsheshet et al, 2011;Bodi et al, 2010;Ghaffari, Taban Sadeghi, & Sayyadi, 2017;Tusun et al, 2015). Additionally, RV infarction is considered as temporary and final infarct size is considered as small due to its thinner wall and subendocardial oxygenization (Bodi et al, 2010).…”