| Bifascicular block | |
|---|---|
 | |
| Bifascicular block on an electrocardiogram. | |
| Specialty | Cardiology  |
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]
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]
- ^ Shabbir, Muhammad Asim; Shaukat, Muhammad Hamza Saad; Ehtesham, Moiz; Murawski, Shannon; Singh, Sukhraj; Alimohammad, Rizwan (2022). "Bifascicular block in unexplained syncope is underrecognized and under-evaluated: A single-center audit of ESC guidelines adherence". PLOS ONE. 17 (2). PLOS: e0263727. Bibcode:2022PLoSO..1763727S. doi:10.1371/journal.pone.0263727. PMC 8884493. PMID 35226666.
- ^ M, Brignole; C, Menozzi; A, Moya; R, Garcia-Civera; L, Mont; M, Alvarez; F, Errazquin; J, Beiras; N, Bottoni; P, Donateo (2001). "Mechanism of syncope in patients with bundle branch block and negative electrophysiological test". Circulation. 104 (17): 2045–2050. doi:10.1161/hc4201.097837. ISSN 1524-4539. PMID 11673344. S2CID 8442192. Retrieved December 30, 2023.
- ^ M, Brignole; A, Moya; FJ, de Lange; JC, Deharo; PM, Elliott; A, Fanciulli; A, Fedorowski; R, Furlan; RA, Kenny; A, Martín; V, Probst; MJ, Reed; CP, Rice; R, Sutton; A, Ungar; JG, van Dijk (August 28, 2018). "2018 ESC Guidelines for the diagnosis and management of syncope". European Heart Journal. 39 (21). Eur Heart J: 1883–1948. doi:10.1093/eurheartj/ehy037. hdl:2262/89469. ISSN 1522-9645. PMID 29562304.
- ^ "Lesson VI — ECG Conduction Abnormalities". Archived from the original on 16 January 2009. Retrieved 2009-01-07.