- A defibrillator is a device that sends an electric shock through the heart muscle to halt an arrhythmia and restore a normal heartbeat.
- An automatic implantable cardiac defibrillator, or ICD, is a small device that is implanted under the skin in the upper chest and connected to the heart with wires called leads. The ICD constantly monitors the heart rate and, when it detects an irregularity, the ICD electrically shocks the heart to normalize its rhythm.
- People who have experienced cardiac arrest and certain people with a high risk of developing an arrhythmia called ventricular fibrillation are generally considered candidates for an ICD.
The implantable cardiac defibrillator is similar to a pacemaker. Pacemakers are commonly advised for patients with unhealthy, slow heartbeats.
The implantable defibrillator is a bigger device and is placed in the body to help people who have life-threatening arrhythmias (heartbeat irregularities). It can deliver a low energy shock that can convert an abnormal rhythm back to a normal heartbeat, and it can send a high energy shock that is delivered only if the condition is so severe that the heart is quivering instead of beating (ventricular fibrillation).
The implantable defibrillator consists of a generator and a system of leads, or wires, which connects the generator to the heart. The generator is a smooth, lightweight metal case containing a tiny computer and a battery. The implantable defibrillator can:
- Keep track of heart rhythms,
- Send out electrical pulses and shocks when needed,
- Record heart rhythm, and
- Record the pulses and shocks the defibrillation device sends out.
The titanium implantable defibrillator is smaller than a cigarette lighter and is placed under the collarbone. The wire lead runs through a vein and into the heart, and the device tracks the heart's rhythm, activating when needed.