Left posterior fascicular block causes

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Ayokunle Olubaniyi, M.B,B.S [2]

Overview

Isolated left posterior fascicular block is often an uncommon finding^[1] owing to the fact that the left posterior fascicle has a dual blood supply, and it is exposed to lower pressures and turbulence, hence, it is rarely damaged. It usually accompanies right bundle branch block (RBBB) or in the setting of arteriosclerotic heart diseases such as myocardial infarction. Other less common causes include: infectious (e.g. diphteritic myocarditis, Chagas disease); genetic (e.g. myotonic dystrophy).

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

Cardiovascular	Cardiomyopathy, coronary artery disease, diphteritic myocarditis, hypertensive heart disease, myocardial infarction
Chemical/Poisoning	No underlying causes
Dental	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	No underlying causes
Ear Nose Throat	No underlying causes
Endocrine	No underlying causes
Environmental	No underlying causes
Gastroenterologic	No underlying causes
Genetic	Kearns-Sayre syndrome, limb-girdle muscular dystrophy, myotonic dystrophy
Hematologic	No underlying causes
Iatrogenic	No underlying causes
Infectious Disease	Chagas disease, diphteritic myocarditis
Musculoskeletal/Orthopedic	Limb-girdle muscular dystrophy, myotonic dystrophy
Neurologic	Kearns-Sayre syndrome
Nutritional/Metabolic	No underlying causes
Obstetric/Gynecologic	No underlying causes
Oncologic	No underlying causes
Ophthalmologic	No underlying causes
Overdose/Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	Cor pulmonale
Renal/Electrolyte	Hyperkalemia
Rheumatology/Immunology/Allergy	No underlying causes
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Miscellaneous	No underlying causes

↑ Godat, FJ.; Gertsch, M. (1993). “Isolated left posterior fascicular block: a reliable marker for inferior myocardial infarction and associated severe coronary artery disease”. Clin Cardiol. 16 (3): 220–6. PMID 8443995. Unknown parameter |month= ignored (help)