ECG Interpretation of STEMI: Who's the Expert?

Amal Mattu, MD


March 21, 2012


This study is reminiscent of a 2009 publication by Jayroe and colleagues[1] in which researchers asked 15 experienced cardiologists to interpret 116 ECGs for evidence of STEMI. In that study, only 8 patients (7% of the total) had true STEMI. The researchers once again found large variations in the sensitivity (50% to 100%; mean 75%) and specificity (71% to 97%; mean 85%) in detecting the true STEMIs. The researchers concluded, "If experienced readers using the current criteria and guidelines cannot accurately and consistently distinguish between STEMI and [non-STEMI], less experienced readers cannot be expected to do so." Perhaps there really are no true gold standards for ECG interpretation.

There's no doubt that the accuracy of ECG interpretation is improved when more clinical information than "appropriate corresponding symptoms" is available. The interpretation of any test is best when you can look at the patient, get a good history, and in many cases even watch the patient for a period of time. However, when it comes to diagnosis of STEMI and activation of the catheterization lab, we all are under the proverbial gun to make decisions as quickly as possible, primarily based on the ECG interpretation. In regard to the clinical information, we all are familiar with the inconsistencies in histories and the frequency of atypical presentations of true acute coronary syndromes. So we have an imperfect test and interpretation combined with an imperfect history combined with time pressure to make decisions as quickly as possible. Furthermore, we live in a medical society that implicitly encourages blame and "Monday-morning quarterbacking." As emergency physicians we play a lot of games on Saturday and Sunday.

So what do you do with this information? I recommend the following: (1) As I tell my own residents, we need to be the BEST in our respective houses of medicine at reading ECGs. If you think there's another specialist who has all the answers, someone else who's going to bail you out of trouble every time you have a question about ECGs, you are mistaken. That person may just as likely be wrong, so YOU must strive to become THE expert; (2) We all have to drop the veil of pretention, ego, and blame that is so prevalent in our medical culture. As these studies point out, even the "experts" are far from perfect. When you see someone make a mistake, try to troubleshoot rather than castigate; and (3) Keep articles like this close at hand because, unfortunately, too many people will not make it past #2. I wish I'd had these articles during that legal case. Maybe the emergency physician would have won.



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