Also known as<unk> -degree heart block
Defined as prolongation of the PR interval on an electrocardiogram (ECG) to more than 200 msec (5 small squares on the ECG tracing)
Considered “marked” when the PR interval exceeds 300 msec (more than 7 small squares on the ECG tracing)
First degree AV block
Third degree AV block
Second degree AV block type I 
Left bundle branch block
Second degree AV block type II
Wide-complex tachycardia
Narrow-complex tachycardia
AV dissociation without complete heart block