How can my doctor be sure my wide complex tachycardia is svt instead of vt?

Svt vs VT: sometimes it is not easy to differentiate between SVT with aberration and VT. VT is likely to become symptomatic sooner and sometimes the presence of buried p wave within the QRS that occurs in a rhythmic manner (measure the p-p interval) may be a clue. Other times , the changes in the direction of the QRS may be a clue that it is VT.

Svt vt : There are several ways, ultimate way is doing an Ep study, you can consult us if you have Ecg strips