What is an AICD

How does an implantable defibrillator (ICD) work?

If the heart has to be permanently protected from the consequences of severe cardiac arrhythmias, the ICD is inserted into the body in a small procedure. To do this, the disc-shaped device about five centimeters in diameter is pushed under the skin below the collarbone and sewn in there. Sometimes it is also placed under the pectoralis major. Two wire-shaped electrodes usually come off the device. The wires are threaded into an adjacent blood vessel and advanced into the heart. The device continuously monitors the heart's activity via the electrodes and - if necessary - emits several weaker current impulses or individual stronger current impulses.

Sometimes special devices are used under the skin or under the muscles that work without a cable connection to the heart.

If the heart suddenly beats too fast and the risk of complications increases, the device can deliver several electrical impulses in quick succession. In this way, the too fast heartbeat is "overtaken" (so-called overpacing). When the pulse delivery is over, the normal heart rhythm can resume.

Sometimes overpacing doesn't help - for example with. In such situations, the ICD delivers a single, more powerful surge of electricity. For a brief moment the heart is completely shut down by this "shock". This also allows the natural heart rhythm to start again. Sometimes it takes several shocks to get the heart to beat normally again.

An ICD contains batteries for power supply. They last up to ten years, depending on the model. Then the device is changed and reconnected to the electrodes left in the body. Some devices can record the heart's activity as an EKG curve, save it and transmit it directly to a doctor's office.