There are two subtypes of second-degree heart block: Mobitz type 1 (also called a Wenckebach block), which may or may not cause symptoms, and Mobitz type 2, which can cause problems pumping blood ...

In second-degree atrioventricular nodal block — also known as Wenckebach block or Mobitz Type I AV block — varying failure of conduction through the AV node occurs, such that some P waves may ...

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 ...