Is this STEMI? No, it is one of the most common reasons for false cath lab activation.

This was contributed by Brooks Walsh, with a little editing and additions, plus a section of false positive cath lab activations added by me.  Brooks is a fine emergency physician from the Yale residency who has a keen and talented interest in ECGs and bedside cardiac echo.CaseA middle-aged man was sent to the ED from a primary care clinic, with “ECG changes” and worry for STEMI.The ECG shows ST elevation (STE) across the precordium, highest in V2 and V3. There are only minimal R waves in those leads [in fact, such tiny R-waves are technically considered Q-waves, and thus the patient has "QS"-waves (deep Q-waves without any R-wave at all], with markedly deep S waves.The ECG from the office that day, although not available here, was essentially identical to the above ECG. He had been at the clinic for a scheduled appointment. He denied having had any chest pain, SOB, nausea, or other ischemic symptoms at any point in the day. However, records sent from the clinic indicated he had had a STEMI treated with PCI at another hospital 4 months prior.Besides a new STEMI, what can account for the ST segment elevation?The T waves are dramatically biphasic, with a steep descent, suggesting a Wellen’s pattern. The poor R wave progression, however, rules out Wellen’s syndrome, which requires R-wave preservation. Additionally, the patient denies any recent symptoms. (A true Wellen’s syndrome is observed after ischemic symptoms have resolved.)The deep S waves and ST elevation ...

Source: Dr. Smith's ECG Blog - September 22, 2015 Category: Cardiology Authors: Steve Smith Source Type: blogs