An irregularly irregular wide complex tachycardia

This was written by Pendell Meyers, a G2 of the Stony Brook residency who has a keen interest in ECGs and who is going to start to help edit this blog. It was edited by me (Smith).Below is a common and important ECG that somehow hasn ' t made it onto this blog yet!CaseA middle aged man presented with acute shortness of breath. He was hemodynamically stable but in mild respiratory distress, with diffuse B-lines and requiring BIPAP.Here is his initial ECG:What is your interpretation? What is the rhythm? Are there signs of acute coronary occlusion?This shows an irregularly irregular wide complex tachycardia at a rate of about 120. Of course, whenever confronted with a wide complex tachycardia, one must consider ventricular tachycardia. However, unless it is polymorphic VT (which has multiform QRS complexes), VT is never this irregular. An irregularly irregular rhythm must put atrial fibrillation (AF) at the top of the differential.The QRS complex is classic for LBBB except that V1 and V2 do not show a large, predominant S-wave. It is possible that lead misplacement may account for these two leads, but the rest of the precordial leads and high lateral leads have morphology diagnostic of LBBB. Thus, this is most likely AF with LBBB. Is there coronary occlusion? If there is, it is not evident on this ECG: it does not meet either the original or modified Sgarbossa criteria. The differential diagnosis of irregularly irregular wide complex tachycardia is an importa...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs