Mobitz type 2: Type 2 second-degree heart block is more severe and causes irregular, slowed, or skipped heartbeats. This type impacts the heart's ability to supply the body with blood.

There are three types of second degree heart block, also called atrioventricular (AV) block. In type I the signal sometimes does not reach the ventricles, causing skipped beats.

When 2:1 AV block is present, the rhythm may be second-degree type I or second-degree type II AV block. Exercising the patient will increase AV nodal conduction and help distinguish these two.

Mobitz type 1 heart block is a subtype of second degree heart block. The electrical signals that control the heart beat become disrupted. Learn more here.

There does appear to be a prolonging PR interval before some dropped beats (second degree type I AV block), however at times P waves are randomly not conducted (2:1 AV block).