Wide Complex Tachycardia with Huge ST Elevation. What is going on?

This 70-something woman with no significant past history (no previous ECGs or cardiac history) presented by EMS with fairly acute chest pressure and shortness of breath, with nausea and diaphoresis.  " Like an elephant sitting on my chest. "  She had no history of atrial fibrillation and was not on any anticoagulants.She stated that she had had a similar episode a couple weeks earlier, lasting 24 hours, with rapid heart beat but without chest pain, that spontaneously resolved.  She thought she was having a panic attack.  Since then she has had " little spurts " of the same thing lasting 1-2 hours.EMS EKG was recorded:The computer read " Atrial Fibrillation/STEMI Anterior Ischemia "Do you agree? Smith:  This is a wide complex tachycardia.  But it is an IRREGULAR wide complex tachycardia, so it is indeedatrial fibrillation with rapid ventricular response.  But it is impossible to say much about " STEMI " or " Occlusion MI " or " Ischemia " because the QRST goes off the page in both directions.  Moreover, whenever there is Atrial fibrillation with a rapid ventricular response, ESPECIALLY when there is LBBB, the ECG can mimic Occlusion when no Occlusion is present.EMS activated the cath lab prehospital.  When she arrived, an ED ECG was recorded:Irregularly Irregular Wide Complex Tachycardia at a rate of 132.So this is atrial fibrillation with rapid ventricular response.  Left Bundle Branch Block (LBBB) with large QR...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs