Implantable Cardioverter Defibrillator
What is an implantable cardioverter defibrillator?
An implantable cardioverter-defibrillator (ICD) is a small, lightweight cardiac device that is implanted under the skin. It is connected to wires that are placed in the heart. An ICD detects heart arrhythmia and sends out electrical signals to correct this issue.
What is it used for?
Heart defibrillators are often used to treat patients with a heart rhythm that is too fast.
Cardiologists determine the eligibility of the candidate for ICD when their condition is life-threatening, and other possible causes have been ruled out. These heart conditions include:
- Heart attack
- Ischemia (Restricted blood flow to the heart)
- Imbalance of electrolytes
How does it work?
ICDs are able to detect when the heart is beating too fast. When the heartbeat is too fast, the generator in the cardiac device sends an electrical pulse through the wires to the heart, which restores a regular heartbeat. ICDs also contain a built-in pacemaker, which the cardiologist can activate as necessary. The pacemaker element of the device prevents the heart from slowing down too much and constantly monitors the heart rate. Read more information about pacemakers and how they work.
New ICD models allow the cardiologist to view images of the patient’s heart. This allows him to accurately confirm diagnoses and make judgments about treatment options. These models provide a variety of treatments, depending on the patient’s heart condition.
What are the treatment options?
When it comes to treating a fast heartbeat, there are two treatment options. These are:
- Low-energy treatment
Low-energy treatment, or anti-tachycardia pacing, is a very gentle method of treatment used to treat fast heartbeat. A pacemaker in the ICD controls the heart rate, and in some cases, the cardiologist can program the machine to send very low-energy shocks to restore proper heart rhythm. - Maximum-energy shocks
In this form of treatment, the cardiologist programs the cardiac device to send maximum-energy shocks in order to provide effective therapy for a fast heartbeat.
What happens at a pacemaker/ICD implantation procedure?
A battery-powered device is placed inside a pouch under the surface of the abdomen or chest. The wires attached travel to the heart’s surface but can run through the blood vessels. As a result, there is no need for open-chest surgery to install the device.
Dr Thomas carries out the following when implanting an ICD:
- He injects an anaesthetic to numb the site
- He makes tiny incisions in the chest where he inserts a lead through the vein and positions it onto the heart with the assistance of fluoroscopy.
- The lead's tip connects to the heart, whereas the other end attaches to a pulse generator.
Dr Thomas may carry out a (i) an endocardial, transvenous approach or (ii) an epicardial approach. With an epicardial approach, the patient is placed under general anaesthesia. They remain asleep while the procedure takes place. The generator is inserted beneath the skin of the abdomen. Overall, recovery from this procedure involves a hospital stay over five days, but surgeons may utilise less invasive techniques to shorten a patient’s recovery time.