Implantable Cardioverter Defibrillator (ICD)


The implantable cardioverter defibrillator (ICD) is a device utilized for medical purposes. An ICD is surgically put under the skin on the patient’s chest that contains batteries and wires (leads). The battery of the ICD is almost the size of the stopwatch. Moreover, the leads in the ICD go into the patient’s heart chambers to manage the heart rhythm. 

The ICD continuously records the rhythm and heart rate. It helps prevent unexpected cardiac arrests, manage arrhythmia, and collect information about the patient’s heart.

The ICD was introduced by Dr. Michel Mirowski in 1980. In the beginning, physicians did not acknowledge the ICD widely; it was viewed as an unethical therapy. Currently, this therapy is generally chosen for patients who are at risk for life-threatening arrhythmias. 

Implanted Cardiovascular Defibrillator vs. Pacemaker:

A pacemaker and an implanted cardioverter defibrillator (ICD) share some similarities, though the pacemaker is larger in size than the ICD. The pacemaker aids in normalizing a slow heartbeat. Whereas an ICD is suggested for the patient who is at risk of fatal ventricular arrhythmias. The pacemaker combines many devices, and the ICD consists of one unit for individuals who require both functions. The ICD and the pacemaker (both) are injected in the electrophysiology or cardiac catheterization labs, requiring a tiny incision right under the collarbone. The ICD batteries last for almost seven years; the patient must visit the healthcare advisor every three to six months for a battery check and overall examination. 

Who requires an Implantable Cardioverter Defibrillator (ICD)?

Individuals with the following heart problems are most likely to have ICD:

  • Brugada Syndrome: This condition refers to irregular heart rhythm in the individual’s lower heart chamber, known as the ventricles. This syndrome can lead to (syncope) fainting, and sudden cardiac death (SCD). 
  • Congenital Heart Disease (CHD): CHD is a fault in the structure of an individual’s heart from birth.
  • Hypertrophic Cardiomyopathy (HCM): This illness causes the enlargement of an individual’s heart muscles. 

Before the Implantation of ICD: The healthcare advisor will guide the patient on the following measures before the ICD:

  • The patient will have to fast for several hours before the implantation.
  • The healthcare advisor will ask for specific blood tests, electrocardiograms, and urine tests for healthy implantation.
  • It’s vital to inform the consultant if you are on any medication like blood thinners or allergic to dyes, bee stings, iodine, shellfish, or have any bleeding disorders. 
  • The individual must inform the healthcare adviser about any disorders they have, such as asthma, kidney disorder, or diabetes.  

What happens when an automatic Implantable Cardioverter Defibrillator (ICD) is implanted?

The ICD is performed in a clinic or hospital, which takes a few hours. The selection of devices, procedures, and other surgical intervention depends upon the patient’s condition. The most typical procedure is the transvenous approach, in which the consultant threads the leads through veins and accesses the patient’s heart. In some cases, the implantation will require open-heart surgery. The procedure of ICD includes;

  1. Injecting anesthesia to relax and put the patient to sleep.
  2. Further, numbing the skin’s location with a local anesthetic. 
  3. After that, the consultant will make an incision near the chest, collarbone, or belly (abdomen).
  4. Then, locate the subclavian vein and insert it into the heart chambers.
  5. Plug the ICD into a pouch under the skin of the patient.
  6. The ICD pouch lead will be connected to the patient’s heart.
  7. After the implantation of the ICD, the consultant will test the wires and devices to confirm that they are connected correctly and working well.
  8. After confirming the ICD, the healthcare provider will close the incision.
  9. Lastly, test the ICD working again and send the patient for recovery.

After the implantation of ICD: After the process of ICD, the patient might feel sore and tired, especially near the incision area. For which, the healthcare advisor will prescribe some painkillers to relax the discomforted area. Most individuals are allowed to go home the day after the surgery, depending upon the ICD procedure and the patient’s health condition. 

How many shocks will an ICD deliver?

The shocks will depend upon an individual’s health condition; most patients require only one shock to restore normal heart rhythm; the healthcare advisor will set the intensity and frequency of the shocks. 

If an individual requires almost three or more shocks in a short period, then it is vital to seek immediate medical guidance. This condition is known as an arrhythmia storm or electrical storm. It indicates that either the patient’s ICD is not functioning correctly or the patient has a cardiac emergency.  

What does an Implantable Cardioverter Defibrillator (ICD) feel like?

The ICD can be programmed to give a high-energy shock (in severe situations) that causes discomfort for a while; it may feel similar to a blow to the chest. Furthermore, low-energy shocks might feel like a thump or flutter in the patient’s chest. 

What is the life acceptancy of individuals with ICD?

The life acceptancy of individuals with ICD is almost five years. The life threat increases for the elder patient receiving an ICD at about seventy-five years of age. 

Possible risk factors for ICD: The implantable cardioverter defibrillator is a safe process; however, the following risk factors are associated with it;

  • Damaged blood vessels from the leads
  • Swelling, inflammation
  • Malfunction
  • Pneumothorax, also known as a ‘collapsed lung’
  • Bruising and bleeding
  • Infection on the incision site



  • https://my.clevelandclinic.org/health/treatments/17123-implantable-cardioverter-defibrillator-icd
  • https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=85&contentid=p00234#:~:text=An%20implantable%20cardioverter%20defibrillator%20(ICD)%20looks%20similar%20to%20a%20pacemaker,people%20who%20need%20both%20functions 
  • https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021193/
  • https://my.clevelandclinic.org/health/diseases/16813-brugada-syndrome 
  • https://my.clevelandclinic.org/health/diseases/21674-congenital-heart-disease 
  • https://my.clevelandclinic.org/health/diseases/17116-hypertrophic-cardiomyopathy 
  • https://my.clevelandclinic.org/health/treatments/17123-implantable-cardioverter-defibrillator-icd 
  • https://medlineplus.gov/ency/article/007370.htm 
  • https://www.mayoclinic.org/tests-procedures/implantable-cardioverter-defibrillators/about/pac-20384692https://www.mayoclinic.org/tests-procedures/implantable-cardioverter-defibrillators/about/pac-20384692
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