What is atrioventricular (AV) block? continued...
Complete or third-degree block
third-degree heart block, all of the electrical impulses are completely blocked
between the upper and lower chambers of the heart. When this occurs, the atria and ventricles beat at completely different
Complete heart block is caused by the aging process,
medicines, heart attacks, infiltrative heart diseases (amyloidosis,
sarcoidosis), and infectious diseases (endocarditis, Chagas' disease). It may
also occur after heart surgery and can be present from birth
Complete heart block frequently causes symptoms of
lightheadedness or fainting and usually requires the placement of a permanent
pacemaker. People who are born with complete heart block (an uncommon
congenital condition) often have no symptoms and may not need treatment
initially. But eventually they almost always require pacemaker
What is bundle branch block?
Bundle branch block can affect the heart’s rhythm.
The heart has structures, like wires, that are called bundle branches. They are part of the heart's electrical pathway. When a branch is diseased, it is called "blocked," because the electrical signals can't travel down the branch.
Some people with bundle branch block don’t have any symptoms and don’t need treatment. But when a block causes the heart to beat too slowly, it can cause symptoms such as tiredness and fainting spells. A pacemaker may be used to get the heartbeat back to normal.