Implantable Cardioverter Defibrillator (ICD) or AICD

ICD stands for Implantable Cardioverter Defibrillator. Implantable Cardioverter Defibrillator is a small electronic device that is implanted under the skin of the chest to monitor and regulate the heart’s rhythm. An ICD is typically used to treat patients who are at high risk for sudden cardiac arrest (SCA), which occurs when the heart’s electrical system malfunctions and causes life threatening arrhythmia.
Fig 52 ICD implant Converted
The Implantable Cardioverter Defibrillator is similar to a pacemaker in that it has leads that are threaded through veins to the heart. The device continuously monitors the heart’s rhythm and delivers electrical shocks to restore normal heart rhythm if it detects a dangerous heart rhythm. The ICD can also act as a pacemaker to treat slow heart rhythms. ICDs may also have additional features such as the ability to record the heart’s electrical activity, monitor fluid levels in the body.
ICDs are typically recommended for patients who have survived sudden cardiac arrest or sustained ventricular tachycardia (secondary prevention). These patients have already had a life-threatening arrhythmia and are at high risk of experiencing further episodes of it. Primary prevention use of an ICD, on the other hand, refers to the use of an ICD prophylactically in patients who have not experienced a life-threatening arrhythmia but are considered at high risk of developing one. This includes for example, patients with a history of heart failure, or certain genetic conditions such dilated cardiomyopathy or hypertrophic cardiomyopathy, who are considered at high risk for sudden cardiac arrhythmia in the future.
An ICD continuously monitors the heart’s electrical activity and if the device detects a dangerous arrhythmia, such as ventricular tachycardia or ventricular fibrillation, the Implantable Cardioverter Defibrillator can treat it by delivering an electrical shock to the heart to restore a normal rhythm. The shock is delivered through the leads and is timed to the patient’s heartbeat to ensure that it is delivered at the most effective time essentially “rebooting” the heart and returning it to a normal rhythm. In other words, it causes the heart to stop beating for a brief moment to resynchronize all heart cells. When the heart restarts, it often resumes a normal rhythm. Another way the ICD can terminate a dangerous tachycardia is by anti-tachycardia pacing (ATP). During an ATP therapy, the ICD sends rapid pacing pulses to the heart to interrupt the fast arrhythmia. The pacing pulses are delivered through the ICD leads, and the pacing rate and intensity are customized based on the patient’s individual needs and the specific arrhythmia being treated. The biggest advantage of ATP is that it is painless and uses less energy compared to shocks. In addition to treating fast heart rates, ICDs can also pace the heart to treat slow heart rhythms. This is achieved by sending small electrical impulses to the heart through the leads to stimulate the heart muscle and maintain normal heart speed.

There are several types of ICDs available, each designed to meet the specific needs of different patients. The main types of ICDs include:

Fig 64 Sub Cutaneous ICD بطارية ازالة الرجفان البطيني تحت الجلد1

Subcutaneous ICD

A subcutaneous ICD (S-ICD) is implanted under the skin of the chest and does not require leads to be placed inside the heart. Instead, the device delivers electrical shocks through a lead that runs along the outside of the chest wall.

Fig 66 Biventricular ICD بطارية تنسيق عمل البطينين1

Biventricular ICD

A biventricular ICD has three leads that are placed in the right atrium, right ventricle, and left ventricle of the heart. This type of ICD is used to treat patients with heart failure and lack of synchrony between the ventricles (the heart's lower chambers beat out of sync with each other).

Fig 32 ICD

Dual-chamber ICD

A dual-chamber ICD has two leads that are placed in the right atrium and right ventricle of the heart. This type of ICD is used to treat patients with ventricular arrhythmia who also require significant pacing for slow heart rate.

Fig 62 ICD Implantable Cardioverter Defibrillator ICD1

Single-chamber ICD

A single-chamber ICD has one lead that is placed in the right ventricle.

The type of Implantable Cardioverter Defibrillator that is best for a patient depends on several factors, including the underlying heart condition, base line ECG, the patient’s medical history, and their individual needs and preferences. The decision on which ICD to use should be made by the patient’s electrophysiologist based on a comprehensive evaluation.

The procedure to implant an Implantable Cardioverter Defibrillator typically takes 1-2 hours and is performed under local anesthesia, with the patient awake but sedated. Here are the general steps involved:

The patient is prepared for the procedure by having an IV line inserted and being connected to monitors to track their heart rate, blood pressure, and oxygen levels. The skin is sterilised and the patient is covered with sterile drapes.

A small incision is made in the chest near the collarbone, and the electrophysiologist creates a pocket under the skin for the ICD device.

One or more leads are inserted through a vein in the chest and guided to the heart. The leads are then attached to the pacemaker device and tested to make sure they are working properly.

The ICD and leads are then inserted into the pocket created earlier under the skin. The device is then tested to ensure that it is functioning properly and delivering the correct electrical impulses.

The incision is closed using sutures or surgical staples.

The electrophysiologist will use a special programmer to communicate with the ICD and program the parameters depending on the case.

After the procedure, the patient is taken to a recovery room and monitored for a few hours. They will need to avoid strenuous activity and heavy lifting for several weeks while the incision heals.

The patient will need to have regular check-ups with their doctor to ensure that the ICD is functioning properly and to make any necessary adjustments to the device’s programming.

The effectiveness of ICD therapy in treating arrhythmias and saving lives has been well-established through numerous clinical trials and real-world experience. In general, Implantable Cardioverter Defibrillator therapy has been shown to be highly effective in preventing sudden cardiac death and improving survival in patients with arrhythmias. However, like all medical devices, there are small potential risks and complications associated with ICD therapy that should be discussed with the patient prior to implantation.