Left Bundle Branch Block

[pal1234]

Would like to know how serious a Left Bundle Branch Block is?  Are there symtoms to watch for regarding heart complications from the Branch Block? There is family history of heart disease.  Person also has a mild mitral valve leak. This is regarding a woman.

[kenkeith]

There are conductive pathways for electrical impulses to follow from the source at the right atrium  down the setum (wall separating left and right sides of the heart) and then into left and right ventricle to contract at the same time. Left bundle branch block (LBBB) is a conduction abnormality seen on the electrocardiogram. In this condition, activation of the left ventricle is delayed, which results in the left ventricle contracting later than the right ventricle. This condition in itself is not of any major concern, but the underlying cause should be diagnosed but it could be primary.

Secondary condtions that can cause LBBB:
Aortic stenosis (aorta valve opening narrowed)
Dilated cardiomyopathy (enlarged left ventricle)
Acute myocardial infarction (having a heart attack)
Extensive cases of coronary artery disease (vessel occlusions, blockage)
Long standing hypertension leading to aortic root dilation and subsequent aortic regurgitation.

I don't believe a mild MVR is of any medical significance, but individuals with LBBB require complete cardiac evaluation, and those with LBBB and syncope (fainting)  or near-syncope may require a pacemaker. Some patients with LBBB, a markedly prolonged QRS (time interval for lower chamber contractions), and congestive heart failure may benefit from a pacemaker (provides a stable, faster than normal electrical impulse) increasing left ventricular contractions.

Hope this provides some insight to your questions, and if you have any further questions or comments you are welcome to respond.  Thanks for your questions, take care.

Ken