Bifascicular block
Conduction abnormality in the heart
From Wikipedia, the free encyclopedia
Bifascicular block is characterized by right bundle branch block with left anterior fascicular block, or right bundle branch block with left posterior fascicular block on electrocardiography. Complete heart block could be the cause of syncope that is otherwise unexplained if bifascicular block is seen on electrocardiography.[1] It is estimated that less than 50% of patients with bifascicular block have high-degree atrioventricular block, although the exact incidence is unknown.[2]
| Bifascicular block | |
|---|---|
| |
| Two consecutive 12-lead ECGs recorded one minute apart on a symptomatic 82-year old male with Lev's disease. (Top) RBBB+LAFB. (Bottom) RBBB+LPFB+1°AVB. | |
| Specialty | Cardiology  |
The European Society of Cardiology (ESC) suggests using electrophysiology studies to look into it (EPS). When pharmacologic stress or incremental atrial pacing induces high-degree atrioventricular block, a permanent pacemaker (PPM) is recommended. If EPS is negative, long-term rhythm monitoring with an implantable loop recorder (ILR) is advised.[3]
Most commonly, it refers to a combination of right bundle branch block (RBBB) and either left anterior fascicular block (LAFB) or left posterior fascicular block (LPFB), with the former being more common.[4]