AV Block, 1st, 2nd, 3rd block
First Degree PR : 0.20 sec (5 small boxes)
- 2nd Degree Block = P wave w/o QRS
- Progresses to 3rd degree block
- Frequently associated w/ BBB
- Type 1: Progressive prolongation of PR until dropped beat
- Type 2: Dropped beat w/o prolngation of PR interval.
3rd degree block = Complete absence of conduction of atrial impulses to ventricle. Most common cause of bradycardia (30-50).