Cardiogenic shock with wide complex tachycardia and poor LV function in a young woman

A 30-something woman presented with CP and SOB. She was hypoxic and intubated. She had very poor LV systolic function on bedside echo. There were no B-lines and the RV was normal.The following ECG was recorded:Wide complex regular tachycardia at a rate of 140, no P-wavesWhat do you think?What do you want to do?This ECG was texted to me on my iPhonewithout any clinical information, with the question: " VT or SVT with aberrancy? "Here was my response:" Tough one, as they always are. Looks like SVT with LBBB (LBBB morphology strongly supports SVT).  Lead  aVR is all negative. I am going to say SVT and I would try adenosine. "Alternatively, it is sinus tachycardia with LBBB and P-waves are not visible. Always considerLewis leads when this is a possibility, as they are likely to exaggerate and uncover otherwise hidden P-waves.Further analysis, with magnification of V2 and V3:This is typical LBBB morphology.When VT has its origin in the RV, it can have an LBBB-like morphology, but there are differences.  Except in the case of fascicular VT, VT starts in the myocardium (not in conducting tissue) and therefore the initial part of the QRS is not rapid (it is slow).  Thus, when it is VT with LBBB morphology, the onset of the LBBB-like QRS is more prolonged. Thus, if it were VT: 1) the R-wave in right precordial leads would typically be greater than 30 ms.Here it is about 20 ms2) the onset of the R-wave to the nadir o...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs