Ischemicst-segment changes on electrocardiogram in acute myocardial infarction-still common
Al-Darzi W, Nowak R, Hudson M, Moyer ML, Jacobsen G, McCord J. Ischemicst-segment changes on electrocardiogram in acute myocardial infarction-still common? J Gen Intern Med. 2017;32(2):S235-S236.
BACKGROUND: Prior studies report ischemic ST-segment changes on electrocardiogram (ECG) in 40-60% of patients with acute myocardial infarction (AMI) with important diagnostic and prognostic implications. Additionally, 1 to 6% of AMI patients had normal ECG on prior studies. These findings may have changed on the era of more sensitive cardiac troponin (cTn) assays. METHODS: In a single-center we prospectively studied 569 patients who were evaluated for possible AMI in the emergency department from May 2013 to April 2015. Diagnosis of AMI was adjudicated by 2 independent physicians in accordance with the universal definition of AMI using all clinical information and required cTnI > 0.04 ng/ml (Siemens Ultra-cTnI). In situations where there was disagreement between the adjudicators, a third Cardiology adjudicator reviewed the case for final determination. Patients with ECG findings that led to immediate reperfusion therapy were excluded. RESULTS: There were 45 (8%) patients with a diagnosis of AMI. Among AMI patients, the most common ECG findings were T-wave inversion 13 (29%) and normal 13 (29%) while 6 (13%) ECGs demonstrated ST Depression ≥ 1 mm. Comparing patients with and without ST-segment elevation or depression, there was non-significantly higher cTnI levels (13.2 ± 28.3 vs. 5.9 ± 15.6 ng/ml; p = 0.355). CONCLUSIONS: ST-segment changeson ECG are becoming less common in AMI. This may relate to smaller AMIs identified by more sensitive cTn assays which should be verified in larger trials. (Table Presented).