What is Arrhythmia?
The steady beating of the heart results from the regular transmission of electrical impulses through the heart. When these electrical impulses are mistimed or uncoordinated, the heart fails to beat properly. This irregular heartbeat, otherwise known as arrhythmia (ah-RITH-me-ah), can result in complications that can range from fatigue to stroke or death. More than five million people in the United States currently suffer from the resulting abnormal heart rhythms.
A heartbeat that is too fast is called tachycardia (TAK-ih-KAR-de-ah).
A heartbeat that is too slow is called bradycardia (bray-de-KAR-de-ah).
Most arrhythmias are harmless, but some can be serious or even life threatening. During an arrhythmia, the heart may be unable to pump enough blood to the body. Lack of blood flow can damage the brain, heart and other organs.
The Heart's Internal Electrical System
To understand arrhythmias better, it helps to understand the heart's electrical system. The heart's electrical system controls the rate and rhythm of the heartbeat. An electrical signal spreads from the top of the heart to the bottom. As the signal travels, it causes the heart to contract and pump blood.
Each electrical signal begins in a group of cells called the sinus node or sinoatrial (SA) node. The SA node is located in the heart's upper right chamber, the right atrium (AY-tree-um). In a healthy adult heart at rest, the SA node fires off an electrical signal to begin a new heartbeat 60 to 100 times a minute.
A problem with any part of this process can cause an arrhythmia. For example, in atrial fibrillation (A-tre-al fi-bri-LA-shun), a common type of arrhythmia, electrical signals travel through the atria in a fast and disorganized way. This causes the atria to quiver instead of contract. Without powerful heart muscle contractions, the blood does not flow and the body cannot get the oxygen it needs.
Fortunately, doctors who specialize in treating problems with the heart’s internal electrical system (electrophysiologists) can now diagnose and treat these problems with advanced technology that reduces risks of complications and speeds recovery.