Wide Complex Tachycardia -- VT, SVT, or A Fib with RVR? If SVT, is it AVNRT or AVRT?

A 69 y.o. male with pertinent past medical history including Atrial fibrillation, atrial flutter, cardiomyopathy, Pulmonary Embolism, and hypertension presented to the Emergency Department via ambulance for respiratory distress and tachycardia. Per EMS report, patient believes he has been in atrial fibrillation for 5 days, since coming down with flu-like illness with rhinorrhea, productive cough, SOB. Patient is on rivaroxaben, carvedilol, and dofetilide (to suppress atrial fib -- rhythm control).  He states that he maybe missed a dose or two during recent illness. On EMS arrival, patient ' s oxygen saturation was in the high 80s and improved on 4L O2 via nasal cannula. He was noted to have irregular heart rhythm with rates 120-170s. BG 248. Bedside ultrasound showed volume depletion and no pulmonary edema.Here is the prehospital ECG:First ED ECGWhat do you think?Description:Regular Wide Complex Tachycardia at a rate of about 160.  VT?  SVT with aberrancy?  If SVT, is it AVRT or AVNRT?  It appearstoo regular to be atrial fib with RVRI inspected this carefully and it is very regular.  Thus, it really cannot be atrial fibrillationIs it Ventricular Tachycardia, which is usually a regular rhythm?Smith opinion: I at first thought this was VT and would have electrically cardioverted.  But I changed my mind after seeing the old ECG (below)I later sent it to Ken Grauer, who annotated as below with the red Xs:The " Y " in lea...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs