AVNRT on the 12-lead

Typical AV nodal re-entrant tachycardia in twelve leads: regular, narrow and fast, near 180 per minute, with no P wave before the QRS. The retrograde P lands on the end of the QRS as a pseudo-S in the inferior leads. Turn on Study to count the beats, measure the R-R, and find the pseudo-S, and use Normal to see what sinus rhythm leaves out.