What is heart block?
Heart block is a disorder of the heartbeat. It occurs when electrical impulses can't pass from the atria (upper chambers of the heart) to the ventricles (the heart's lower chambers). This may keep the contractions of the atria from coordinating with
the contractions of the ventricles , and may cause a very slow heart rate.
The muscles of the heart contract in a rhythmic order for each heart beat, because electrical impulses travel along a specific route called the conduction system. The main junction of this system is called the atrioventricular node (AV node). Just as on a highway, there are occasionally some delays getting the impulse from one point to another. These delays are classified according to their severity.
In first-degree heart block, the signal is just slowed down a little as it travels along the defective part of the conduction system so that it arrives late traveling from the atrium to the ventricle. In second-degree heart block, not every impulse reaches its destination. The block may affect every other beat, every second or third beat, or be very rare. If the blockage is frequent, it results in an overall slowing of the heart called bradycardia. Third-degree block, also called complete heart block, is the most serious. When no signals can travel through the AV node, the heart uses its backup impulse generator in the lower portion of the heart. Though this impulse usually keeps the heart from stopping entirely, it is too slow to be an effective pump.
Heart block is common in elderly people as their hearts have undergone degenerative (wear and tear) changes. However, it may also be cogenital (at birth), or a result of some other heart disease such as Myocarditis (inflammation of the muscle in the wall of the heart), Coronary thrombosis (sudden blockage in the heart vessels), Cardiomyopathy (disease of heart muscle), and Valvular heart disease (disease of the heart valves). The result of compromised heart beat is decreased blood supply to the vital body organs such as the brain,kidny and liver.
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