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...