A left posterior fascicular block (LPFB), also known as left posterior hemiblock (LPH), is a condition where the
left posterior fascicle
The bundle branches, or Tawara branches, are offshoots of the bundle of His in the heart's Ventricle (heart), ventricle. They play an integral role in the electrical conduction system of the heart by transmitting cardiac action potentials from the ...
, which travels to the inferior and posterior portion of the left ventricle, does not
conduct the electrical impulses from the
atrioventricular node
The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of t ...
. The wave-front instead moves more quickly through the
left anterior fascicle
The bundle branches, or Tawara branches, are offshoots of the bundle of His in the heart's ventricle. They play an integral role in the electrical conduction system of the heart by transmitting cardiac action potentials from the bundle of His to ...
and right bundle branch, leading to a right axis deviation seen on the
ECG
Electrocardiography is the process of producing an electrocardiogram (ECG or EKG), a recording of the heart's electrical activity. It is an electrogram of the heart which is a graph of voltage versus time of the electrical activity of the hear ...
.
Definition
The
American Heart Association
The American Heart Association (AHA) is a nonprofit organization in the United States that funds cardiovascular medical research, educates consumers on healthy living and fosters appropriate cardiac care in an effort to reduce disability and death ...
has defined a LPFB as:
* Frontal plane axis between 90° and 180° in adults
* rS pattern in leads I and aVL
* qR pattern in leads III and aVF
* QRS duration less than 120 ms
The broad nature of the posterior bundle as well as its dual blood supply makes isolated LPFB rare.
See also
*
Left bundle branch block
Left bundle branch block (LBBB) is a conduction abnormality in the heart that can be seen on an electrocardiogram (ECG). In this condition, activation of the left ventricle of the heart is delayed, which causes the left ventricle to contract late ...
*
Left anterior fascicular block
Left anterior fascicular block (LAFB) is an abnormal condition of the left ventricle of the heart, related to, but distinguished from, left bundle branch block (LBBB).
It is caused by only the left anterior fascicle – one half of the left bundl ...
References
Further reading
*
External links
Cardiac arrhythmia
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