• Texas Medical Center, 6560 Fannin St. #1680, Houston, TX 77030
  • Heights Office, 427 W 20th St Houston, TX 77008
  • Texas Medical Center, 6560 Fannin St. #1680, Houston, TX 77030
  • Heights Office, 427 W 20th St Houston, TX 77008

Implantable Cardioverter Defibrillator (ICD)

Implantable Cardioverter Defibrillators (ICD) in Houston, TX

What Is an Implantable Cardioverter Defibrillator (ICD)?


Certain heart conditions can cause life-threatening, abnormal heartbeats (arrhythmias) that start in the lower chambers of the heart (ventricles). These can manifest as an unusually rapid heartbeat (ventricular tachycardia or VT) or as a disorganized heartbeat that causes the lower chambers of the heart to quiver instead of beating normally (ventricular fibrillation or VF).

Such abnormal heartbeats prevent the heart from working properly, which can disrupt the delivery of oxygen-rich blood to the brain and other vital organs. They can also cause the heart to stop working (sudden cardiac death).

An implantable cardioverter-defibrillator (ICD) is a heart device that is implanted under the skin on your chest to continuously monitor your heart rhythm. If the device detects a life-threatening arrhythmia, it will first send small, painless electrical signals to correct your heart rhythm. If the arrhythmia continues, the defibrillator will deliver a powerful electrical pulse (shock) to restore your heart’s normal rhythm.

The ICD system includes a defibrillator (also called ICD generator or battery) and one or multiple special wires (leads).

  • The ICD monitors the heart rhythm continuously and delivers therapies automatically to correct arrhythmias when necessary. In addition to delivering electrical shocks to your heart, the ICD can function as a pacemaker.
  • The ICD leads are thin insulated wires about the size of spaghetti noodles. The leads carry the electrical impulses from the defibrillator to your heart and transmit information about the heart’s activity back to the defibrillator.

You may need an ICD if the cause of your arrhythmia cannot be corrected or if you are at high risk for sudden cardiac death. Some health conditions can cause arrhythmias that increase the risk for sudden cardiac death. These include heart failure, heart attack, history of life-threatening arrhythmias, electrolyte abnormalities, and certain hereditary heart diseases. Taking certain medications and over-the-counter supplements can also increase the risk of sudden cardiac death.

If you have been newly diagnosed with heart failure, you may have an increased risk of developing ventricular arrhythmias. Your doctor may prescribe certain medications or open up blockages in the arteries that supply blood to your heart, to improve your heart function.

In this situation, your physician may ask you to temporarily wear a cardiac defibrillator known as LifeVest® until he or she determines if you need an ICD.

Types of Implantable Cardioverter Defibrillator (ICD)

icd devices

Percutaneous Implantable Cardioverter Defibrillator (ICD)

The traditional ICD, also called percutaneous ICD, is a type of device with leads that run through the veins underneath your collarbone and connect to your heart muscle. The ICD can be connected to the heart through one (single chamber ICD), two (dual chamber ICD), or three (biventricular ICD or CRT-D) wires.

An external computer called a programmer is used to program your ICD at your doctor’s office or at the clinic where your ICD is implanted. This computer can retrieve information that will assist your doctor in treating your arrhythmia or heart failure. You will also receive a home monitoring device that allows the electrophysiologist (EP) to monitor your ICD remotely.

Getting an ICD

What to expect

The risk for complications related to the surgery performed to insert your implantable cardioverter defibrillator (ICD) is low. Your doctor will explain the risks and possible complications of the procedure before the implantation.

The procedure

The ICD implantation procedure usually takes a few hours. After the medical staff prepares you for the procedure, you will be transferred to a room with special X-ray equipment, known as an electrophysiology (EP) lab or catheterization (cath) lab.

For most ICD implantations, local anesthesia is used to numb the area of the incision and other medications are administered through your arm vein to help you relax. Your doctor will make a small incision in the upper part of your chest and will guide one or several leads (thin insulated wires) through a vein into the heart.

One end of each lead is connected to a certain area in your heart, while the other end is connected to the ICD generator/battery. The ICD is then inserted into a pouch beneath the skin. The incision is closed and covered with a special dressing.

At the end of the procedure, the electrophysiologist (EP) will test the ICD to ensure that it is working correctly and program it to meet your specific needs. After the procedure, you will typically spend the night in the hospital and go home the next day.

Before you leave the hospital
  • You will receive instructions about self-care after your procedure and about follow-up visits with your doctor.
  • You will receive a home monitoring device and will be instructed on how to set it up. The home monitoring device will communicate your ICD information to your doctor’s office, so that the doctor can monitor you remotely. Make sure that your home monitor is always working properly.
  • You will also receive an ICD wallet identification card, which contains essential information about your ICD. Always carry the card or a copy with you.
  • Follow your doctor’s instructions and contact the doctor’s office if you have any questions or concerns about your ICD.

Subcutaneous Implantable Cardioverter Defibrillator (S-ICD)

The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a new type of ICD that has only one lead, which is placed under the skin on your chest close to the heart instead of directly connecting to the heart through the veins.

This electrode senses life-threatening arrhythmias and delivers therapy when necessary. The defibrillator generator is implanted just below the armpit. The S-ICD system delivers the energy (through the electrode) to the heart without the electrode touching the heart or any neighboring vessels.

The placement of the S-ICD generator under the armpit reduces the visible scarring of the incision. Additionally, because the electrode does not come into contact with the bloodstream, the chance of having serious infections is much lower than with traditional ICDs.

Patients who are at high risk for infection, such as those with kidney disease who are getting dialysis, those who have had ICD-related infections, and those who do not want visible scars, may benefit from an S-ICD.

Ask your doctor if you are a candidate for an S-ICD instead of a traditional ICD.


Living with an Implantable Cardioverter Defibrillator (ICD)

  • Life with an ICD. Many people with ICDs resume their normal daily activities after they recover from the implantation procedure. Your doctor may recommend avoiding certain activities or situations. You can discuss your activity and lifestyle goals with your doctor, who will help you develop a plan that works best for you.
  • ICD shocks. When your device detects a life-threatening abnormal rhythm (arrhythmia), it will automatically deliver a treatment “shock” to restore your normal heart rhythm. This usually feels like a sudden jolt or thump to the chest. Some people describe it as a sensation of being hit in the back.

On occasions, the shock may be delivered during sleep, when you may not feel it. You could pass out from the shock. If you experience a shock or feel like you may receive a shock, contact your doctor immediately, OR go straight to the emergency room if someone can drive you, OR call 911.

  • Driving with an ICD. Ask your doctor about any driving restrictions you may have after receiving the ICD.
  • ICD identification card. You will receive an ICD wallet identification card (ID card). This card contains essential information about your device, including its model, make, type, and the name of your doctor. Always carry the card or a copy with you.
  • Working with an ICD. It is critical to discuss the type of tools, machinery, and equipment that you use or plan to use at work with your doctor, because some of these may interfere with the function of your ICD. Talk to your doctor if you have any questions about the safety of using certain tools or equipment at home or at work.
  • Home monitoring. Make sure that your ICD home monitoring device is active and is functioning properly.
  • ICD battery life and replacement. ICD batteries last between 5 and 15 years (6 to 7 years on average), depending on how active the ICD/S-ICD is and how often it is being used to regulate your heart rhythm. Your electrophysiologist (EP) will replace the generator along with the battery before the battery starts to run down.
  • Cell phones. Keep the antennas of your cell phone 6 inches away from your ICD and hold the phone to the opposite ear from your device. It is also recommended to avoid carrying the cell phone in a pocket near your ICD.
  • Household appliances. You can safely use most appliances, as long as they are properly maintained and in good working order. This includes microwave ovens and other major home appliances, electric blankets, and heating pads. Do not use magnetic mattress pads, pillows, or chairs, or body fat measuring scales. Talk to your doctor if you have any questions about the safety of using any tools or equipment at home or at work while using an ICD.
  • Travel and security screening. Passing through a metal detector or a full body scanner in an airport will not interfere with your ICD, although it may trigger the security alarm. Avoid lingering near or leaning against a metal-detection system.

To avoid potential problems, carry your ID card to show that you have an ICD. If the security personnel insist on using a hand-held metal detector, ask them not to hold the device near your ICD any longer than necessary, or ask for an alternative form of body search.

  • Medical and dental procedures. Some medical and dental equipment can interfere with the normal function of your ICD. If a doctor recommends a medical/dental procedure or test, let them know that you have an ICD. Before you undergo a procedure or test, discuss it with your EP to check whether it is safe for you.

LifeVest® Wearable Cardioverter Defibrillator

life vest

The wearable cardioverter defibrillator (WCD) is temporarily worn by patients who are at risk for sudden cardiac death (death that occurs when your heart suddenly stops) while they are waiting to receive an implantable cardioverter-defibrillator (ICD). The WCD, which is currently available in the United States, is called LifeVest® (Zoll Medical Corporation, Pittsburgh, PA).

The LifeVest® device consists of two main components: a garment and a monitor. It is lightweight and easy to wear. The garment, which is worn under clothing, detects abnormal heart rhythms (arrhythmias) and delivers shocks to correct them. The monitor, which is worn around the waist or attached to a shoulder strap, records the arrhythmias.

Your doctor may ask you to wear a LifeVest® while you are waiting to receive an ICD or while you are undergoing treatments that may improve your heart condition.

Some patients with heart failure are at a high risk for sudden cardiac death and will benefit from an ICD. However, if you are newly diagnosed with heart failure, specific treatments, such as medications or the removal of blockages in the heart arteries, may improve your heart function and heart failure. This may lower the risk for sudden cardiac death to such an extent that you no longer need an ICD.

While your doctor is assessing your response to the treatment, you will remain at high risk for sudden cardiac death. In this situation, your doctor may recommend that you temporarily wear a LifeVest®, which can detect life-threatening arrhythmias and automatically deliver treatment shocks to restore your normal rhythm.

If you receive a LifeVest®, it is crucial to wear it at all times. At the end of the monitoring period (usually 90 days), your doctor will reevaluate your heart failure and your risk for sudden cardiac death to decide if you need an ICD.

Can You Have an MRI Test if You Have an ICD or an S-ICD?

Magnetic resonance imaging (MRI) utilizes a magnetic field and radio waves to obtain detailed images of the organs and tissues within the body.

Depending on the make and model, some ICDs or S-ICDs are safe for use in the MRI environment.

Before you schedule your MRI test, make sure to tell the staff at the MRI center about your cardiac device and show them your ICD or S-ICD identification card. The MRI staff will consult your doctor, directly or through you, to confirm that your ICD is working correctly and is safe to use during the MRI.

On the day of your MRI test, your ICD/S-ICD will be reprogrammed to ensure that it works appropriately in the MRI environment. After the MRI, your device will be restored to its original settings.

If you experience any heart issues after your MRI scan, contact your cardiologist immediately.

Cardiologist and Cardiac Electrophysiologist in Houston, TX

Are you a candidate for an implantable cardioverter-defibrillator to treat an arrhythmia? To learn more about ICD and other treatment options, schedule an evaluation with Dr. Alireza Nazeri in Houston, Texas, just a short drive from Pearlman and Pasadena. Call (713) 909-3166 today or Request an Appointment online.

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