Hello, thank you for your input. I believe the CRT-P are fairly new from Biotronik. My ventricles were not insync so resyncrination was what was called for in my condition. As I understand, since my AV Node ablation caused my ventricles to handle the workload, they needed to be more efficient to carry the load, thus a different pacemaker with an additional lead was needed. I feel much better but still somewhat limited in what I can do. So thankful for my excellent Cardiologist from Mayo.