Abstract 14005: Body Surface Potential Mapping Improves Diagnosis of ST-Elevation Myocardial Infarction in Patients With Significant Left Main Coronary Artery Stenosis Presenting With Acute Chest Pain
Non-invasive diagnosis of acute myocardial infarction (AMI) associated with significant left main coronary artery stenosis (LMCAS) is challenging, with characteristic 12-lead ECG abnormalities of ST elevation (STE) in lead aVR, precordial T wave inversion (TWI) and/or ST depression (STD) having low diagnostic sensitivity. Methods Consecutive patients presenting to our unit with acute ischaemic-type chest pain from 2000-10 were analyzed. Entry criteria: 12-lead ECG and BSPM at presentation, cardiac troponin T (cTnT) ≤ 12h and coronary angiography during admission. Peak cTnT ≥0.03µg/L defined AMI. ECG abnormalities assessed: STEMI by Minnesota criteria; STE in lead aVR ≥0.5mm; STD ≥0.5mm in ≥2 contiguous leads (CL); TWI ≥1mm in ≥2CL. BSPM STE was: ≥2mm in anterior; ≥1mm in lateral, inferior, right ventricular (RV) or high right anterior (HRA); and ≥0.5mm in posterior territories. Angiographic luminal narrowing ≥70% defined significant LMCAS. Results Enrolled were 2810 patients (age 67±10; 81% male). Of these, 116 (4.1%) had significant LMCAS. Mortality within 24-hrs of symptom-onset was significantly more likely in those with LMCAS (Adjusted Odds Ratio: 6.61; p<0.001). Diagnostic performance of BSPM STE and 12-lead ECG criteria for AMI are summarised in Table 1. Of those with BSPM STE, 62 (73%) had STE in either the HRA or RV territories not identified by the 12-lead ECG. Conclusion Of those with AMI and significant LMCAS stenosis, only 11% patients were classified as STEMI using 12-lead ECG. Early BSPM resulted in the reclassification of 86% of those patients classified as NSTEMI diagnosis to STEMI diagnosis by detection of STE beyond the territory of the 12-lead ECG. Thus, BSPM has the potential to reduce morbidity and improve survival in this high-risk patient group by facilitating emergent revascularization.
- Acute coronary syndromes
- Myocardial infarction, STEMI
- Myocardial infarction, NSTEMI
- Coronary artery disease
- © 2011 by American Heart Association, Inc.