Keywords: ECG, electrocardiogram, acute myocardial infarction (PubMed Search)
Just a reminder...an initially normal or non-specific ECG can certainly occur in patients that are actively having chest pain from acute MI. A 2001 study published in JAMA nicely pointed this out:
7.9% of patients having an acute MI had an initial normal ECG.
35.1% of patients having an acute MI had non-specific abnormalities on ECG.
57% of patients having an acute MI had diagnostic changes on ECG.
The greater the abnormality on the ECG, the worse the prognosis, but note that even when the ECG was normal, the in-hospital mortality in acute MI patients was 5.7%.
Although serial ECGs won't detect 100% of acute MIs, the diagnostic yield does certainly increase, and so whenever a patient has a concerning presentation, especially in the presence of on-going pain, make sure to get repeat ECGs!
[ref: Welch RD, et al, JAMA 2001]