Abnormal Heart Rhythm

Heart Block

Signs and Symptoms
Diagnosis
Treatment

Signs and Symptoms

Complete heart block occurs when the electrical signal can't pass normally from the atria, the heart's upper chambers, to the ventricles, or lower chambers. If the atrioventricular (AV) node is damaged during surgery, complete heart block may result. Sometimes complete heart block occurs spontaneously without surgery. An artificial pacemaker can restore a normal heart rate and rhythm.

Heart block occurs when the electrical impulses that make the heart beat do not transmit normally. These impulses travel from the hearts upper chambers the atria to the lower chambers the ventricles through the atrioventricular (AV) node. In heart block, the AV node may be damaged from surgery, medications or congenital heart conditions. Heart block affects the hearts ability to pump blood and the bodys blood pressure.

Heart block causes an abnormally slow heart rhythm called bradycardia.

Heart block may cause the following symptoms:

• Palpitations, which can be skipping, fluttering or pounding in the chest
• Fatigue
• Chest pressure or pain
• Shortness of breath
• Fainting, also known as syncope, or near-syncope
• Lightheadedness or dizziness

It is important to note that during a period of heart block, children may not know how to describe what they are feeling. They may have trouble keeping up with other children or realize they are having "spells" and want to sit down and rest.

Reviewed by health care specialists at UCSF Children's Hospital.
Last updated May 8, 2007