A heart must beat with a regular rate and rhythm, not too slow or too fast, to keep blood pumping and keep you healthy. These rhythms are controlled by special electrical spots in your heart tissue.
Sometimes, things go wrong in the heart's electrical pathways. An electrical signal may be sent from a part of the heart that should not be sending signals. This is called an arrhythmia. This can cause too many electrical impulses and result in too many heartbeats. These fast arrhythmias, also called tachyarrhythmias, can occur in the upper or lower parts of the heart. They can be very mild to very severe. A person might have abnormal beats once in a while, for many years and have no symptoms. Other times, symptoms such as a rapid heart rate, pounding in the chest, dizziness, lightheadedness, fainting or near fainting can occur.
The treatment will vary depending on the type of fast heartbeat and what is making it happen. Sometimes a medicine can be prescribed that returns the abnormal heart rhythm to a normal rhythm. Other medications may be used to control how fast the heart beats or how thin the blood is.
If arrhythmias happen in the lower part of the heart, or ventricles, they can be life-threatening. One type is called ventricular tachycardia. When ventricular tachycardia happens, less blood is pumped to the body and brain. If ventricular tachycardia isn't treated properly, it can worsen into a condition called ventricular fibrillation. During ventricular fibrillation, the heart quivers, and no blood is pumped to the body or brain. A person with ventricular fibrillation usually passes out very quickly, and without immediate medical care, ventricular fibrillation can cause death.
An implantable defibrillator, or ICD, is a device that can constantly monitors heartbeats and detects when they are abnormal. It will then send small shocks to the heart to stop the abnormal beats before they become serious.