Here is a classic ECG case not usually caught on a 12-lead ECG. Below, a progression of four ECGs helps to teach one of the most important ECG lessons any practicing health care professional needs ...

As always, this is a challenge to see if this wide-complex tachycardia is ventricular tachycardia or "SVT with aberrancy". There is indeed AV dissociation present best seen in lead V2 on this ECG ...

For many years, cardiologists and other experts have tried to find reliable methods of distinguishing between VT and SVT-AC on the basis of ECG criteria. Have we found one yet?