Your heart functions to pump blood to your other body organs.
The pumping action, or contraction, is coordinated by your heart's own electrical
circuit. The steady rhythmic beat of a normal heart plays a major role in the
heart's ability to pump and circulate blood efficiently to the body. An irregularity
in this electrical circuit is called an arrhythmia, or heart rhythm disorder.
Arrhythmias are very common, affecting millions of people worldwide, and can
show up as heart rates that are too slow or too fast. These abnormal heart rhythms
may be unnoticed, or may result in palpitations (awareness of the heartbeat
or a rapid heartbeat), dizziness or fainting.
An arrhythmia can cause:
- Rapid heartbeat (Tachycardia)
- Slow heartbeat (Bradycardia)
- Delayed or asynchronous heartbeat (dyssynchrony)
Most arrhythmias are harmless, but some can be serious and can cause sudden
cardiac death. Recent advances in medical technology have resulted in treatments
that can control or eliminate many arrhythmias. New treatments also can significantly
prolong the lives of people at high risk for fatal arrhythmias.
Life-Threatening Arrhythmias Include:
The fast and chaotic rhythms of VT and VF reduce the heart's effectiveness
as a pump. During VF, the heart beats very fast and chaotically and loses its
ability to pump and circulate blood throughout the body and the brain. Without
immediate emergency help, VF will result in sudden cardiac arrest (SCA) and
death within minutes.
Last updated: 20 January 2005
