Correlation of Electrocardiogram and Regional Cardiac Magnetic Resonance Imaging Findings in ST‐Elevation Myocardial Infarction: A Literature Review

Abstract

Background:Patients with acute ST-elevation myocardial infarction (STEMI) benefit substantially from emergent coronary reperfusion. The principal mechanism is to open the occluded coronary artery to minimize myocardial injury. Thus the size of the area at risk is a critical determinant of the patient outcome, although other factors, such as reperfusion injury, have major impact on the final infarct size. Acute coronary occlusion almost immediately induces metabolic changes within the myocardium, which can be assessed with both the electrocardiogram (ECG) and cardiac magnetic resonance (CMR) imaging.Methods: The 12-lead ECG is the principal diagnostic method to detect and risk-stratify acute STEMI. However, to achieve a correct diagnosis, it is paramount to compare different ECG parameters with golden standards in imaging, such as CMR. In this review, we discuss aspects of ECG and CMR in the assessment of acute regional ischemic changes in the myocardium using the 17 segment model of the left ventricle presented by American Heart Association (AHA), and their relation to coronary artery anatomy.Results: Using the 17 segment model of AHA, the segments 12 and 16 remain controversial. There is an important overlap in myocardial blood supply at the antero-lateral region between LAD and LCx territories concerning these two segments.Conclusion: No all-encompassing correlation can be found between ECG and CMR findings in acute ischemia with respect to coronary anatomy.

Continuous ECG monitoring in hospital: part 2, practical issues

“…These leads view the left-hand side of the heart, and "see" the lateral wall of the left ventricle. The predominant artery supplying this region of the heart is the left circumflex artery (LCx) (Rinta-Kiikka et al, 2014). …”

Understanding the ECG. Part 8: myocardial ischaemia and infarction (part A)

“…The LAD runs down the front of the heart, giving off diagonal branches that supply the anterior wall of the LV, as well as perforators that penetrate and supply the interventricular septum (Tortora and Nielsen, 2014). Of the three major coronary arteries, the LAD provides the greatest proportion of blood to the LV (Rinta-Kiikka et al, 2014). Blockage of this vessel therefore has the greatest effect on LV function, and is associated with increased morbidity and mortality (Lee et al, 1995).…”

Understanding the ECG. Part 9: Myocardial ischaemia and infarction (part B)

“…Posterior infarction can therefore complicate either inferior or lateral STEMI, although it occasionally occurs in isolation (Somers et al, 2003). Where posterior STEMI is found in association with infarction of another cardiac territory, the greater infarct size results in higher mortality and a greater incidence of complications (Rinta-Kiikka et al, 2014). In studies of isolated posterior STEMI, the culprit lesion is most commonly in the LCx (Agarwal et al, 1999;Pride et al, 2010).…”

“…Acute rupture of this cap results in a thrombus that completely occludes the coronary artery, resulting in transmural ischaemia and ST elevation on the ECG (Wei et al, 2013). Unless the occluded artery is reopened swiftly, permanent myocardial damage occurs (Rinta-Kiikka et al, 2014). Immediate reperfusion is recommended in clinical guidelines because it limits infarct size, prevents complications, and improves patient outcomes (National Institute of Health and Care Excellence (NICE), 2013; Steg et al, 2012).…”