Some consider 2:1 AV block to be type II block, claiming that the PR interval doesn't lengthen. What they don't realize is that determining whether the PR interval lengthens requires at least 2 ...

In second degree type II AV nodal block (a.k.a. Mobitz Type II AV block), the AV node becomes completely refractory to conduction on an intermittent basis. For example, three consecutive P waves may ...

In figure 1, the 4th beat in tracing (a) suddenly has a longer PR interval than the others. The findings in tracing (b) suggest AV Wenckebach phenomenon (type I 2° AV block). The findings in tracing ...

A 68-year-old male with morbid obesity and no past medical history comes to the office complaining of fatigue and shortness of breath. He does not feel dizzy and has never passed out. He takes no ...