The relationship between terminal QRS distortion on initial ECG and final infarct size at 4 months in conventional ST- segment elevation myocardial infarct patients

M.E.C.J Hassell,R Delewi,C.P.H Lexis,M.W Smulders,A Hirsch,G Wagner,S.C.A.M Bekkers,I.C.C Van Der Horst,F Zijlstra,A.C Van Rossum,J.J Piek,P Van Der Harst,R Nijveldt

doi:10.1016/j.jelectrocard.2016.03.009

Abstract

BackgroundIn the Sclarovsky-Birnbaum Ischemia Severity Grading System for patients with ST-segment elevation myocardial infarction (STEMI), “Terminal QRS distortion” is considered as “Grade III”. This evidence for most severe ischemia is associated with cardiovascular magnetic resonance imaging (CMR) markers of myocardial damage in the subacute phase. Our aim was to assess whether terminal QRS distortions on the initial electrocardiogram (ECG) is predictive for infarct size (IS) and left ventricular ejection fraction (LVEF) at 4months in anterior versus infarct locations. MethodsPatient data of the HEBE, GIPS III and MAST, were pooled. ECGs of 411 STEMI patients were classified as absence (Grade II) or presence (Grade III) of terminal QRS distortion according to Sclarovsky-Birnbaum grading. CMR was performed at approximately 4months and included IS and LVEF. ResultsGrade III ischemia was present in 142 of 411 (35%) patients and was more frequently observed with inferior STEMI (P=0.01). In the total cohort and in anterior STEMI, no difference in LVEF or IS was observed between the two Grades. Whereas, in inferior STEMI Grade III was associated with a larger IS (P<0.01) and also, a trend towards a lower LVEF was observed (P=0.09). ConclusionIn inferior STEMI, terminal QRS distortion on the initial ECG is associated with a larger IS at approximately 4months, and can be used to identify a high-risk population in the acute phase. Also, a Grade III was associated with a trend towards a lower LVEF.

Highlights

The introduction of primary percutaneous coronary intervention (PPCI) has resulted in an improved survival in ST-segment elevation myocardial infarct (STEMI) patients, and has resulted in smaller infarct size (IS), less remodeling, less impaired left ventricular ejection fraction (LVEF) and less heart failure [1,2]
Previous studies have assessed its predictive value for Cardiovascular Magnetic Resonance imaging (CMR) markers of myocardial infarction assessed in the subacute phase
Time from symptom onset to PPCI did not differ between the Grade II and Grade III ischemia (P = 0.21)

Summary

Introduction

The introduction of primary percutaneous coronary intervention (PPCI) has resulted in an improved survival in ST-segment elevation myocardial infarct (STEMI) patients, and has resulted in smaller infarct size (IS), less remodeling, less impaired LVEF and less heart failure [1,2]. The electrocardiogram (ECG) remains a cornerstone diagnostic modality in STEMI patients and identifying a prognostic ECG marker as a risk-stratifying tool is both feasible and clinically applicable. There are different criteria for application in the ECG leads revealing the acute changes in anterior versus inferior STEMI locations: the “disappearing S wave criterion” for anterior and the “small R wave to ST ratio” for inferior STEMI. This grading system was initially developed in the thrombolysis era, several studies have shown its prognostic value in PPCI treated STEMI. Its predictive value on long term IS and left ventricular ejection fraction (LVEF) has not yet been investigated

Objectives

Methods

Results

Conclusion