Abstract 13929: Body Surface Potential Mapping identifies Acute Coronary Occlusion and Myocardial Infarction in Patients Presenting with Acute Chest Pain and ST-Segment Depression on 12-Lead ECG
Prompt diagnosis and early reperfusion therapy in patients with STEMI are associated with a reduction in morbidity and mortality and relies on the principle that early reperfusion of an occluded coronary artery improves outcomes. However, ∼30% of STEMI are missed at the time of presentation. Aim We hypothesized that 80-lead body surface potential mapping (BSPM) would improve detection of acute myocardial infarction (AMI) and occluded culprit artery in patients presenting with ST-segment depression (STD) only on 12-lead ECG. Methods From our database, consecutive patients presenting pre- and in-hospital between 2000-6 with acute ischaemic-type chest pain and an initial 12-lead ECG with STD only of ≥0.05mV in ≥2 contiguous leads were analyzed. Patients were included if they had a BSPM recorded at presentation, cTnT ≤ 12-hours after chest pain and coronary angiography during the index admission. Patients with ST-segment elevation (STE), left bundle branch block and/or left ventricular hypertrophy on 12-lead ECG were excluded. AMI was defined as peak cTnT ≥0.03µg/L. STE on BSPM was: ≥0.2mV in the anterior territory; ≥0.1mV in the lateral, inferior, right ventricular or high right anterior territories; and ≥0.05mV in the posterior territory. Flow in the culprit artery at angiography was graded according to the TIMI flow grade (TFG) criteria. Results Enrolled were 410 patients: of these, 240 (59%) had an occluded culprit artery (TFG 0/1) with AMI, 80 (19%) had a patent culprit artery (TFG 2/3) with AMI, 67 (16%) had TFG 2/3 with cTnT<0.03µg/L and 23 (6%) had TFG 0/1 with cTnT<0.03µg/L. Among patients with an occluded artery, the culprit was most often the left circumflex artery (47%). BSPM STE occurred in 267 (65%) patients: sensitivity 91%, specificity 72%, positive predictive value 82% and negative predictive value 85% for the diagnosis of TFG 0/1 in the culprit artery and AMI, i.e. STEMI ‘missed’ by 12-lead ECG. Moreover, BSPM STE occurred most commonly in the posterior territory (60%), with right ventricular involvement in 58%. Conclusion Among ACS patients presenting with only STD, BSPM identifies STE beyond the territory of the 12-lead ECG in 65% patients, with sensitivity 91% and specificity 72% for the diagnosis of an occluded culprit artery with cTnT elevation.
- Acute coronary syndromes
- Myocardial infarction, NSTEMI
- Myocardial infarction, STEMI
- ST segments
- Coronary artery disease
- © 2011 by American Heart Association, Inc.