AICD (Automatic Implantable Cardioverter Defibrillator)- Cardiology

An implantable cardioverter-defibrillator is also one of the medical technologies designed to control irregular heart rate and rhythm. These types of medical devices are used to treat serious and life-threatening arrhythmias that can't be controlled by medicines or to prevent heart failure in people who are at major risk.

It is a battery-powered device that consists of thin wires known as lead and a battery. It is surgically implanted beneath the person's left upper chest. The device is used to monitor various heart problems. The battery of an AICD lasts about six to seven years. But you may need to get them checked every three to six months.

This article covers everything related to automatic implantable cardioverter defibrillators.

What Is an Automatic Implantable Cardioverter Defibrillator (AICD)?

An implantable cardioverter-defibrillator (ICD) is also known as an automated implantable cardioverter-defibrillator (AICD) or automatic cardioverter-defibrillator.

As the name indicates, the device is responsible for the defibrillation and pacing of the heart in patients who are at the risk of cardiac arrest or experiencing irregular heart rhythms. (Defibrillation is the administration of electric shock to the heart to restore abnormal rhythms.)

ICD monitors your heart rate and rhythm plus delivers an electric shock (defibrillation) when needed, for example, in case of arrhythmias (abnormal heart rate or rhythm).

What Is An Automated Implantable Cardioverter Defibrillator Made Of?

An implantable cardioverter-defibrillator is a medical device that is made up of the following components:

  1. An electric impulse generator that sends an electric shock to the heart.
  2. Electrode wire (lead) to sense the heart's rhythm and deliver an electric shock when needed.
  3. Batteries
  4. A mini computer chip that directs the AICD when to deliver an electric shock.

When Is Automated Implantable Cardioverter Defibrillator Given?

An AICD is indicated for the following cardiac conditions:

  • To correct arrhythmia (Irregular heart rate or rhythm).
  • To correct tachycardia (too fast heart rate).
  • To correct bradycardia (too slow heart rate).
  • It is given to patients who are at the risk of developing arrhythmias or irregular heart rate due to having inadequate blood flow to the heart (prophylactic therapy).
  • As a prophylactic treatment for patients at the risk of sudden cardiac death (heart failure).
  • It is also used to monitor heart rate to correct irregular rhythms when needed.
  • Hypertrophic Obstructive Cardiomyopathy (HOCM), A disease that results in abnormal thickening of your heart muscle wall (myocardium).
  • Ventricular tachycardia (Irregular heart rhythm in the lower chambers of your heart, i.e., ventricles).
  • Ventricular fibrillation.
  • To treat certain types of congenital diseases.
  • Long QT syndrome

Which Doctor To Consult?

It is evident that a cardiologist will deal with your heart problems and implant an ICD if needed.

Should You Get An AICD?

Your doctor or cardiologist can better diagnose if you need an AICD or not. AICD is usually recommended for people who are at high risk of developing abnormal heart rhythm that could be deadly, i.e., lead to heart failure or death. The risk can be identified through imaging or blood tests. Also, your doctor may identify the need for an AICD based on the amount of blood your heart pumps and your previous heart problems.

How Is ICD Done?

The procedure of an ICD implantation takes about 1 hour. Before the procedure, your doctor may ask you to avoid food and drink for at least 8 hours. Also, blood-thinning medications should be stopped a few days before the implantation. Depending on the condition of your heart, your doctor may implant a low-energy pacing or a high-energy pacing ICD.

In low-energy pacing, the ICD delivers a low-energy shock in which you will experience painless fluttering in the heart. In comparison, high-energy pacing delivers a higher-energy shock. It is commonly indicated for more severe heart rhythm problems. The high-energy pacing may be painful, but the pain lasts only a few seconds to two minutes till the end of the shock.

Note: Don't forget to tell your doctor about all the medications you take before the procedure and whether you should continue taking them after your implantation or not.

Also, inform your doctor about your disease history. For example, if you have any bleeding disorder, allergies, or any disease like asthma, kidney disease, diabetes, or any other medical conditions.

Here is how an ICD implantation takes place:

  1. Firstly, an IV (local or general anesthesia) will be injected into your arm to induce a sedative effect and numb the site.
  2. Your doctor will make small incisions under the skin of your chest. AICD is usually implanted under the left collarbone (A thin, long, slightly curved bone that joins your arms to your body).
  3. Next, your doctor will attach lead wires through the vein in your heart. One end of the lead wire is attached to your heart, while the other end is attached to the ICD (shock generator device) that is being implanted under your skin and below the collarbone.
  4. After implantation, your doctor will close the incision.
  5. After the ICD is implanted, your doctor may race your heart to check how well the ICD responds to normalize your heart rhythm.
  6. After the procedure, your doctor may recommend an overnight hospital stay to monitor for any signs of bleeding or swelling at the incision site.
  7. Commonly, one or two shocks may be required in 24 hours to normalize your heart functioning. Some people may need more than 3 shocks.

Is A Pacemaker And Implantable Cardioverter Defibrillator (ICD) the Same?

Many people confuse a pacemaker and an ICD by thinking they are the same. However, the two devices are different.

The process of ICD and pacemaker implantation is the same. But a pacemaker constantly works to maintain a normal heart rate, while ICD is used to monitor the heart rate and correct it when needed.

Side Effects Of ICD:

After your ICD implantation, the most common side effects you may experience include:

  • Fatigue
  • Sore at the site of incision
  • Pain, swelling, and tenderness.
  • Posttraumatic stress such as anxiety, depression, or anxiousness.

Soreness, pain, and swelling at the site of the incision are the most common effects after ICD implantation that may go away within a few days or weeks on their own. Your doctor will prescribe you OTC pain medications to relieve swelling and pain. Aspirin and ibuprofen increase the risk of bleeding; hence they are not recommended to use after ICD implantation.

Other more severe complications of ICD that require immediate attention include:

  • Infection at the site of implantation
  • Bleeding or bruising
  • Continuous pressure and pain in the chest.
  • Fever or chills
  • Nausea and vomiting

Life-threatening complications of AICD include:

  • Bleeding around the heart
  • Collapsed lungs
  • Blood clotting
  • Damage to the artery, veins, or nerves.

Essential Precautions To Consider With An AICD:

After your AICD implantation, you may need to follow some precautions for a few weeks and some precautions for the long term.

Necessary Precaution: It is crucial to consult your doctor immediately if you experience several shocks or remain unconscious for a few seconds to two minutes, or don't feel better after receiving a shock.

Avoid the following activities up to at least four weeks after your procedure:

  • Heavy lifting
  • Activities involving shoulder or chest exertion like swimming, vacuuming, tennis, golf, bowling, or cycling.
  • Driving

Precautions to follow for the long term after implantation include:

  • Keep your cell phones or any electrical devices six inches away from your chest.
  • Before taking any medications or going through any procedures like MRI, CT-Scan, MRA (magnetic resonance angiography), radiation, or chemotherapy, tell your doctor or healthcare professional that you have an ICD implantation.
  • Stand at least 2 feet away from high-voltage equipment or generators.
  • Stay at least 6 inches away from magnets, headphones, and wireless chargers. Magnets can affect the ICD, and headphones may have a magnetic substance. Hence it is good to take precautionary measures against these substances.


AICD or an ICD generator is a device that continuously monitors a person's heart rate and rhythm. Then if there is any irregular heart rhythm or an abnormal heart rate, the implantable cardioverter-defibrillator (ICD) delivers a shock. It is implanted under a person's chest and is used to correct life-threatening arrhythmias, tachycardia, and bradycardia.

After the implantation, it is necessary to tell all your health care professionals, i.e., doctors, dentists, physicians, pharmacists, and imaging technicians, that you have an ICD. Moreover, if you experience any unusual side effects like bleeding, excessive swelling, and infection at the incision site, consult your doctor immediately. Minor discomfort and pain are normal to happen after you receive a shock from ICD, but if the pain or rapid heartbeat lasts longer than two minutes, consider getting medical attention.

Admittedly, as AICD is a life-saving device, it should be closely monitored at all times, along with scheduling periodic appointments (every two to four weeks) with the cardiologist to ensure that the device is working properly and inaccurate shocks are minimized.


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About the Doctor:

Dr. Fatima Munir is a Doctor by profession, a freelance content writer, and a researcher. With a penchant for research, she diligently curates facts and the latest literature to guide readers on all matters of health.