Diagnosing an AMI in the ED
Typical history:
central, retrosternal chest pain, may be described as crushing, squeezing, tightness or pressure on the chest lasting > 30mins, unrelieved by nitrates.
May be associated with nausea, vomiting, sweating, dyspnoea
ECG changes:
ST segment elevation > 2mm in 2 or more of the precordial leads, or >1mm in the limb leads.
ST segment depression in leads V1-V3 (strongly suspicious of posterior MI) along with dominant R waves and upright tall T waves
Right sided ECG will show ST elevation in lead V4 – observing for right ventricular involvement.
Cardiac Enzyme elevation:
CK (Creatnine Kinase) greater than 180U/L from 6 hours of onset of chest pain
Troponin I greater than 2.5ng/ml after 8 hours of commencement of chest pain