What are the fascicles of heart?
Anatomy of the Heart’s Electrical Conduction System There is a single fascicle in the right ventricle referred to as the right bundle branch. There are two fascicles in the left ventricle: the left anterior fascicle and the left posterior fascicle of the left bundle branch.
What is the anterior fascicle?
The posterior fascicle supplies the posterior and inferoposterior walls of the LV, the anterior fascicle supplies the upper and anterior parts of the LV and the septal fascicle supplies the septal wall with innervation.
What are the three fascicles?
A trifascicular block is the combination of a right bundle branch block, left anterior or posterior fascicular block and a first-degree AV block (prolonged PR interval).
What is posterior fascicle?
A left posterior fascicular block (LPFB), also known as left posterior hemiblock (LPH), is a condition where the left posterior fascicle, which travels to the inferior and posterior portion of the left ventricle, does not conduct the electrical impulses from the atrioventricular node.
What is left anterior?
A left anterior fascicular block, also known as left anterior hemiblock, occurs when the anterior fascicle of the left bundle branch is no longer able to conduct action potentials. The criteria to diagnose a LAFB, or LAHB, on ECG include the following: Left axis deviation of at least -45 degrees.
Is LBBB a Bifascicular block?
LBBB alone is not considered bifascicular block (LAFB plus LPFB), although anatomically this may be the case. Bifascicular block occurs in 1% to 2% of the adult population.
Why is ECG abnormal?
An abnormal ECG can mean many things. Sometimes an ECG abnormality is a normal variation of a heart’s rhythm, which does not affect your health. Other times, an abnormal ECG can signal a medical emergency, such as a myocardial infarction /heart attack or a dangerous arrhythmia.
What is LPFB on ECG?
A left posterior fascicular block ― also known as a left posterior hemiblock, LPHB ― occurs on the ECG when the posterior fascicle of the left bundle branch is no longer able to conduct action potentials.
What is Bifascicular heart block?
Bifascicular block – The term bifascicular block most commonly refers to conduction disturbances below the atrioventricular (AV) node in which the right bundle branch and one of the two fascicles (anterior or posterior) of the left bundle branch are involved.
How is LPFB diagnosed?
The criteria to diagnose a LPFB on a 12-lead ECG include the following:
- Right axis deviation of 90-180 degrees.
- Presence of a qR complex in lead III and a rS complex in lead I.
- Absence of right atrial enlargement, or RAE, and/or right ventricular hypertrophy, and RVH.
What causes a left anterior fascicular block?
In the absence of manifest heart disease and in association with aging, left anterior fascicular block is attributed to degenerative disease of the conducting system,27 sclerosis of the left side of the cardiac skeleton,28 or myocardial fibrosis.
How serious is left posterior fascicular block?
There is no major clinical significance to the presence of a LPFB, except it indicates some degree of conduction system disease and thus a somewhat higher risk of progression to higher forms of heart block in the future.