EMS Continuing Education
Pollak P and Brady W: Electrographic Patterns Mimicking STEMIs. Cardiol Clin 30 (2012) 601-615.
This is a GREAT paper – it is very readable for both advanced EMS providers, emergency physicians, and advanced practice providers (APPs), and the best part is that it shows you, for every STEMI mimic they talk about, an EKG of the mimic right beside the EKG of a STEMI to make their point that there is a difference you can see in the field. The paper discusses the common STEMI mimics: myocarditis and pericarditis; benign early repolarization; a previous MI, now with a ventricular aneurysm (rare); coronary vasospasm (Prinzmetal’s variant angina); Takosubo cardiomyopathy; Brugada syndrome; hyperkalemia, LBBB; LV hypertrophy; and ventricular paced pattern. There is a discussion of Sgarbossa’s criteria (suggestive of AMI in the presence of LBBB). The only mimic that they don’t discuss is the neurogenic changes that look like a STEMI from a subarachnoid hemorrhage (see Chatterjee, S: ECG Changes in Subarachnoid Haemorrhage: A Synopsis. Neth Heart J. Jan 2011; 19(1): 31–34.)
The bottom line is the best part of the paper – the EKG needs to be examined in context of the patient presentation: the patient with ST elevation but without a convincing picture should prompt the provider to suspect a non-AMI presentation. At times, these diagnoses are very challenging – this understandably impacts the rapid application of reperfusion therapy and likely increases the door-to-therapy time. The EKG is an imperfect tool. The cardiologists know that their evaluation of equivocal EKGs may result in them not taking the patient to the cath lab despite our thinking that this was a clear STEMI. A certain fraction of “overcalls” is completely acceptable, and they are NOT distressed that we brought them patient with a worrisome history, concerning symptoms, and an EKG that looks alarming.
Look at this carefully – next month, we start looking at real EKGs of patients brought in to Methodist’s ED – we’ll play “STEMI or Mimic” – and we’ll have fun!