Ads
related to: what causes left bundle branch blocks
Search results
Results from the WOW.Com Content Network
Left bundle branch block (LBBB) is a conduction abnormality in the heart that can be seen on an electrocardiogram (ECG). [1] In this condition, activation of the left ventricle of the heart is delayed, which causes the left ventricle to contract later than the right ventricle .
A bundle branch block can be diagnosed when the duration of the QRS complex on the ECG exceeds 120 ms. A right bundle branch block typically causes prolongation of the last part of the QRS complex and may shift the heart's electrical axis slightly to the right.
And so the left ventricle contracts first . The signal then spreads from the purkinje fibers of the left ventricle over to the right ventricle, which contracts, but this happens after the left contracts. So with right bundle branch block, the right ventricle contracts late. If the block happened to be on the left side instead, a left bundle ...
Infra-Hisian blocks may occur at the left or right bundle branches ("bundle branch block") or the fascicles of the left bundle branch ("fascicular block" or "Hemiblock"). SA and AV node blocks are each divided into three degrees, with second-degree blocks being divided into two types (written either "type I or II" or "type 1 or 2").
Left anterior fascicular block (LAFB) is an abnormal condition of the left ventricle of the heart, [1] [2] related to, but distinguished from, left bundle branch block (LBBB). It is caused by only the left anterior fascicle – one half of the left bundle branch being defective. It is manifested on the ECG by left axis deviation.
Normal variation causing LAD is an age-related physiologic change. Conduction defects such as left bundle branch block or left anterior fascicular block can cause LAD on the ECG. Pre-excitation syndrome as well as congenital heart diseases such as atrial septal defect, endocardial cushion defects can also cause LAD on ECG.
There are two branches of the bundle of His: the left bundle branch and the right bundle branch, both of which are located along the interventricular septum. The left bundle branch further divides into the left anterior fascicle and the left posterior fascicle. These structures lead to a network of thin filaments known as Purkinje fibers.
As the Bundle of His divides into the right and left bundle branches, a block of the electrical impulse may result in a Right Bundle Branch Block or a Left Bundle Branch Block, respectively. Sinoatrial (SA) block may also result be a result of Lev's disease. During a SA block, the electrical impulse formed at the SA node is delayed or not ...
Ads
related to: what causes left bundle branch blocks