A mismatch index based on the difference between measured left ventricular ejection fraction and that estimated by infarct size at three months following reperfused acute myocardial infarction

J Electrocardiol. 2014 Mar-Apr;47(2):191-6. doi: 10.1016/j.jelectrocard.2013.10.009. Epub 2013 Oct 31.

Abstract

Background and aim: The reduction of left ventricular ejection fraction (LVEF) following ST-segment elevation myocardial infarction (STEMI) is a result of infarcted myocardium and may involve dysfunctional but viable myocardium. An index that may quantitatively determine whether LVEF is reduced beyond the expected value when considering only infarct size (IS) has previously been presented based on cardiac magnetic resonance (CMR). The purpose of this study was to introduce the index based on the electrocardiogram (ECG) and compare indices based on ECG and CMR.

Method and results: In 55 patients ECG and CMR were obtained 3 months after STEMI treated with primary percutaneous coronary intervention. Significant, however moderate inverse relationships were found between measured LVEF and IS. Based on IS and LVEF an IS estimated LVEF was derived and an MI-LVEF mismatch index was calculated as the difference between measured LVEF and IS estimated LVEF. In 41 (74.5%) of the patients there was agreement between the ECG and CMR indices in regards to categorizing indices as >10 or ≤ 10 and generally no significant difference was detected, mean difference of 1.26 percentage points (p = 0.53).

Conclusion: The study found an overall good agreement between MI-LVEF mismatch indices based on ECG and CMR. The MI-LVEF mismatch index may serve as a tool to identify patients with potentially reversible dysfunctional but viable myocardium, but future studies including both ECG and CMR are needed.

Keywords: Cardiac Magnetic Resonance; Electrocardiography; Infarct size; Infarct size estimated left ventricular ejection fraction; Left ventricular ejection fraction; MI–LVEF mismatch index; Selvester QRS score.

Publication types

  • Comparative Study

MeSH terms

  • Electrocardiography / methods*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Myocardial Infarction / complications
  • Myocardial Infarction / pathology
  • Myocardial Infarction / physiopathology*
  • Myocardial Infarction / therapy
  • Percutaneous Coronary Intervention
  • Retrospective Studies
  • Time Factors
  • Ventricular Dysfunction, Left / etiology
  • Ventricular Dysfunction, Left / physiopathology*