Can We Trust Our Computer ECG Overlords?

If your practice is like my practice you see a lot of ECGs from triage. ECGs obtained for abdominal pain, dizziness, numbness, fatigue, rectal pain … and some, I assume, are for chest pain. Every one of these ECGs turns into an interruption for review to ensure no concerning evolving syndrome is missed.

But, a great number of these ECGs are read as “Normal” by the computer – and, anecdotally, are nearly universally correct.  This raises a very reasonable point as to question whether a human need be involved at all.

This simple study tries to examine the real-world performance of computer ECG reading, specifically, the Marquette 12SL software. Over a 16-week convenience sample period, 855 triage ECGs were performed, 222 of which were reported as “Normal” by the computer software. These 222 ECGs were all reviewed by a cardiologist, and 13 were ultimately assigned some pathology – of which all were mild, non-specific abnormalities. Two Emergency Physicians also then reviewed these 13 ECGs to determine what, if any, actions might be taken if presented to them in a real-world context. One of these ECGs was determined by one EP to be sufficient to put the patient in the next available bed from triage, while the remainder required no acute triage intervention. Retrospectively, the patient judged to have an actionable ECG was discharged from the ED and had a normal stress test the next day.

The authors conclude this negative predictive value for a “Normal” read of the ECG approaches 99%, and could potentially lead to changes in practice regarding immediate review of triage ECGs. While these findings have some limitations in generalizability regarding the specific ECG software and a relatively small sample, I think they’re on the right track. Interruptions in a multi-tasking setting lead to errors of task resumption, while the likelihood of significant time-sensitive pathology being missed is quite low. I tend to agree this could be a reasonable quality improvement intervention with prospective monitoring.

“Safety of Computer Interpretation of Normal Triage Electrocardiograms”

2 thoughts on “Can We Trust Our Computer ECG Overlords?”

  1. Really interesting post Ryan, thanks.

    The question must also be asked as to why these ECGs are performed when the patient seems to be under the test-threshold.

    The answer is probably that the ‘us’ that is being interrupted are actually the cause of the problem in the first place.

    The tendency for a clinician to ask for a urinalysis, ECG and BG on every single patient, irrespective of their presentation drives this. Thus leading our nursing colleagues into thinking their omission is somehow a mistake.

    A more rationalised a targeted work up by clinicians is needed for the burden of interpretation to really decrease.

    1. In my experience, ECGs are rarely ordered by clinicians – they’re part of triage protocols for all manner of chief complaints to ensure door-to-ECG time for STEMI meets an institutional “quality” goal, usually as part of a process for getting STEMI to the cath lab. Another example where the quixotic quest to shave a few non-meaningful minutes off a rare procedure generates a large burden on technical staff and physicians.

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