These are two strips from the same patient during a pacemaker clinic visit. The first strip shows the patient's underlying rhythm. |

The second strip is with the DDD pacmaker turned on, with a long sensed PR interval of 300 ms. Note that in spite of Mobitz I conduction above with some conducted intervals less than 300 ms., even with a long sensed AV interval of 300 ms. the patient no longer conducts through the AV node. |
