Chest pain, ST Elevation, and tachycardia in a 40-something woman

A prehospital cath lab activation for STEMI came through with the information that the 40-something woman had chest pain and a pulse of140.We were immediately skeptical that the patient had a STEMI because of the high heart rate.  She would have to be in cardiogenic shock with a massive STEMI for that.  Certainly possible, but when the heart rate is so high, be skeptical.The patient arrived with this ECG:Here the heart rate is obviously no longer 140What do you think?ECG: it certainly appears to be an anterior STEMI, but it is important to realize that right ventricular ischemia from either inferior and RV STEMI or from pulmonary embolism can manifest with STE in V1-V3.On arrival, she immediately lost pulses. Due to body habitus, an adequate transthoracic echo could not be done.  There was no ventricular fibrillation recorded, but in the rush of action, she did get defibrillated.  Most involved agree there was never any ventricular fibrillation.  This turned out to be a pulmonary embolism (on autopsy).  Massive PE can have Right Ventricular ischemia resulting in RV ST Elevation.  When there is sudden loss of pulse butno ventricular fibrillation, then STEMI is an unlikely etiology of arrest.  In this series of 1246 cardiac arrests, 60 of which were from PE, only 3 had ventricular fibrillation.In contrast, the vast majority of initial rhythms in cardiac arrest from acute coronary syndrome are shockable rhythms, and the vast...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs