Guidant Defibrillators is one of the leading brands of ICDs or defibrillators in the United States. Implantable Cardioverter Defibrillators (ICD) are used to regulate heart rate in people who have been diagnosed with heart disease. This small computerized apparatus is surgically implanted in the heart patient's body to monitor the hearts functions and correct them if necessary. A pacemaker is used to treat patients who have a form of heart disease that puts them at risk for a certain type of heart arrhythmia, or abnormal heart rhythm, that is life threatening.

There are four heart therapies that the Guidant defibrillator can be programmed to treat. The physician must program the device and it monitors the heart rate and heart rhythm for any abnormal activity. When the ICD detects an abnormality, it sends an electrical impulse or a succession or impulses to particular area on the heart muscle. This shock is intended to return the heart's function to normal. This appliance is fully programmable to meet the needs of each individual. It is programmed by the physician to monitor and treat the patient according to his or her own specific heart condition. The four primary therapies include:

Anti-Tachycardia Pacing (ATP)

A tachycardia is a condition where the heart beats too fast. The ICD returns the heart to its normal rhythm and rate by providing a series of minor electrical impulses.

Cardioversion

Cardioversion is generally used if ATP is not proven to be effective. It is the next step in attempting to return the heart to its normal rate. It delivers a single low energy shock to the heart to return it to its normal rate and rhythm.

Defibrillation

When a heart is in fibrillation, the muscle fibers contract in a rapid, unsynchronized and irregular manner. The ICD provides a single high energy shock in an effort to restore the normal heart rhythm and rate. The shock is usually delivered to the ventricle.

Bradycardia Pacing

Bradycardia occurs when the heart beats too slowly. The ICD begins delivering a series of steady, constant electrical impulses in an attempt to increase the heart rate and restore normal rhythm. This process is known as bradycardia pacing. It is this function that is quite similar to the role of the pacemaker.

There are two ways that an ICD can be implanted. The most common method is the endocrinal. The device itself is implanted in an area that is not near the heart. The surgeon makes a small incision just under the collar bone. It is positioned just under the patient's skin and leads are attached to it. He or she then inserts the lead or leads into a vein and feeds them into the heart chamber or chambers.

The second method is more invasive because the Guidant defibrillator is placed directly on the outside of the heart, thus requiring open heart surgery. Referred to as epicardial, this method of implantation poses significantly more risks than the endocrinal method. The lead or leads are sewn into the heart tissue as opposed to being fed through a vein.