AV Block: 2nd degree, Mobitz II (Hay block) • LITFL
Patients typically have a pre-existing LBBB or bifascicular block, and the 2nd degree AV block is produced by intermittent failure of the remaining fascicle ("bilateral bundle-branch block") In around 75% of cases, the conduction block is located distal to the Bundle of His, producing broad QRS complexes. In the remaining 25% of cases, the ...