Is it possible to have first and second degree AV block, either type 1 or 2, on the same EKG strip? 

First, there is no such thing as first-degree AV block. A prolonged PR interval is caused by AV delay. In that context, it is more likely that a patient with a long AV nodal conduction time would develop decremental AV conduction or type 1 second-degree AV block. Type 2 second-degree AV block is usu...

The answer to the question is 'yes'. The two types of 2nd degree AV block are generally related to two cell types in the conduction system. Type 1 2nd degree AV block (aka: Wenckebach) is a decremental block of the Ca++ channel cells in the AV node, resulting in increasing PR intervals until conduct...