A bundle branch block is a blockage in either the right or left bundle of the conducting pathway (see above).
Because of the block, the electrical signals that stimulate the ventricles to contract together, are now out of sync.
Impulses on the side with the block will reach the respective ventricle more slowly than impulses traveling to
the unaffected side. As a result, contraction of one ventricle occurs later than the other. This process takes
longer than a normal contraction and therefore is measured wider on an EKG graph. Illustrated below, the conduction
is out of sync as it travels down the right ventricle and is delayed, and the left ventricle contracts on time.
Kind of like two separate (QRS) contractions overlapping out of sync (see below).
Bundle Branch Block can be caused by coronary artery disease, valve disease, or other conditions,
or can be present in an otherwise normal heart. By itself, bundle branch block may not require treatment.
However, in some instances, Bundle Branch Block may be associated with bradycardia and may require
treatment with pacemakers or cardiac resynchronization therapy to regulate the heartbeat.
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