Heart Blocks as Relationships 1st degree AV block - Not as close as they used to be... 2nd degree Mobitz I - They slowly drift apart, get back together, and drift apart again 2nd degree Mobitz II - They're on. They're off... They're on, they re off. 3rd degree - It's over. Dr. Robert Buttner @rob_buttner #Heart #Blocks #cardiology #diagnosis #comparison #types