“High grade AV nodal block,” a type of 3 rd degree heart block, occurs when there is AV dissociation similar to complete heart block, but occasional P waves do conduct through the AV node to ...

Also known as complete heart block, third-degree heart block is the most serious type of heart block ... to an emergency department right away. An ECG relies on electrodes placed on the skin ...

This ECG has both ... (second degree type I AV block), however at times P waves are randomly not conducted (2:1 AV block). Note the irregular R-R intervals making 3rd degree heart block unlikely.