Prevalence of junctional ST-depression with tall symmetrical T-waves in a pre-hospital field triage system for STEMI patients

Introduction: The prevalence of the junctional ST-depression with tall symmetrical T-waves in a field triage system for ST-Elevation Myocardial Infarction (STEMI) is unknown. Material and methods: We prospectively collected all transmitted 12-lead electrocardiograms (ECGs) from the STEMI field triage system in Amsterdam from 2011 to 2013. Electrocardiograms with junctional ST-depression with tall symmetrical T-waves were recognized and angiographic documentation and clinical follow up were collected. Results: A total of 5588 patients with at least 1 transmitted field ECG were identified from the database. ST-elevation infarction was present on the field ECG in 1864 patients (33%) and 701 ECGs (12,5%) showed anterior infarction. In 11 patients, junctional ST-depression with tall symmetrical T-waves was identified (0,2% of total transmitted ECGs and 1,6% of anterior infarctions). The 11 angiograms invariably showed involvement of the proximal Left Anterior Descending (LAD) artery (segment 5,6 and 7). Mortality was 27% within the first week. Conclusions: An ECG with junctional ST-depression with tall symmetrical T-waves is an infrequent finding. Because this pattern of STEMI equivalent is associated with LAD occlusions, it is important to recognize this pattern, so patients can be transported to the catheterization laboratory without delay.