Match the following AV blocks with their characteristics. Question 8 options: P waves are completely blocked; the QRS complexes originate independently from below the Junction Occassionally a P wave is not followed by a QRS wave PR interval progressively lengthens and then is completely blocked PR interval >0.20 seconds 1. 1st degree AV block 2. 2nd degree AV block, type I 3. 2nd degree AV block, type II 4. 3rd degree AV block