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All about heart block first degree heart block second degree heart block third degree or complete heart block causes of heart block symptoms of heart block diagnosis of heart block treatments for heart block arrhythmias (abnormal heart rhythms) {bundle branch block cardiac arrhythmia atrial fibrillation atrial flutter supraventricular tachycardia sick sinus syndrome ventricular arrhythmias ventricular tachycardia ventricular fibrillation heart block Brugada syndrome long QT syndrome short QT syndrome Wolff-Parkinson-White syndrome (WPW syndrome)}

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.

More information on heart block

What is heart block? - Heart block is a disorder of the heartbeat. Heart block is common in elderly people as their hearts have undergone degenerative changes.
What's first degree heart block? - First-degree heart block, or first-degree AV block, is when the electrical impulse moves through the AV node more slowly than normal.
What's second degree heart block? - Second degree heart block is a disease of the electrical conduction system of the heart. There are two distinct types of second degree heart block.
What's third degree or complete heart block? - Third degree heart block, also known as complete heart block, is a disease of the electrical system of the heart.
What causes heart block? - Heart block has a variety of causes. It can sometimes be a result of a congenital defect. It can also occur after a heart attack or as a result of myocarditis.
What are the symptoms of heart block? - The main symptom associated with heart block is fainting (syncope). Second degree heart block may not cause symptoms.
How is heart block diagnosed? - Heart blocks can be diagnosed with a test called an electrocardiogram (ECG), which measures the heart's electrical activity.
What're the treatments for heart block? - First-degree heart block requires no treatment even when it is caused by heart disease. A temporary pacemaker may be used in an emergency.
Heart & cardiovascular disorders Mainpage

Topics in heart disease and cardiovascular disorders

Coronary circulation disorders
Myocardium disorders
Heart valve disorders
Arrhythmias (abnormal heart rhythms)
Heart inflammation and infection
Congenital heart disease
Valvular disease (blood vessels disorders)
Procedures done for coronary artery disease
Devices used in cardiology
Diagnostic tests and procedures for heart diseases
Heart transplant

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All information is intended for reference only. Please consult your physician for accurate medical advices and treatment. Copyright 2005,, all rights reserved. Last update: July 18, 2005