Toothache, incidental Wide Complex Tachycardia

Discussion by our ElectrophysiologistSmith: “I thought that the wide complex tachy (WCT) could be AVRT or VT” EP: " Antidromic AVRT morphology would essentially be the same as “VT” originating from ventricular the insertion site of the accessory pathway. Therefore, traditional criteria for SVT with aberrancy do not apply to antidromic AVRT (except, that negative concordance can never be AVRT!) "  Smith: “But then when the patient converted and had PVCs of exactly the same morphology as the WCT, that it must be VT and not AVRT ” EP: " In cases of intermittent pre-excitation, you could potentially see wide and narrow QRS complex on the same EKG – but those of course will be preceded by P-wave (albeit with short PR interval) " Smith: “Is this logic supported by evidence? Or is it still likely to be ARVT? ” EP: " Not sure, but PVC ’s from RVOT and the wide complex tachycardia of same morphology is highly suggestive of it to be VT.Another observation on the EKG is that presumably the retrograde atrial activity is quite far out from the next wide complex beat. In other words, if this was AVRT, then you ’re assuming that the “PR” interval is very long and is conducting down the accessory pathway. Although there are slowly conducting accessory pathways, I believe they tend to cause Orthodromic AVRT more often. One example is “PJRT” that you might have come across. On occasion, if someone has “fully pre-...
Source: Dr. Smith's ECG Blog - Category: Cardiology Authors: Source Type: blogs