Implantable Medical Devices

For Rhythm Control

  • Implantable cardioverter defibrillator (Also known as ICD) — An ICD is a battery-powered device placed under the skin that keeps track of your heart rate. If an ICD detects a heart rhythm that is chaotic or much faster than normal, it will send an electrical shock to the heart to bring the rhythm back to normal.   
  • Pacemaker (Also known as Artificial Pacemaker) — A small battery-operated device that helps the heart beat in a regular rhythm. 

To Support the Heart and Circulation

Left Ventricular Assist Device (Also known as LVAD) — The left ventricle is the large, muscular chamber of the heart that pumps blood out to the body. When the left ventricle isn’t able to pump enough blood to the body on its own, an LVAD helps with that function.

Implantable Cardioverter Defibrillator

What the device does

An ICD detects the rhythm of the heart and has wires which are implanted into the heart tissue which can deliver electrical shocks, to correct the heart's rhythms, as needed.

Reason for the device 

  • Used in people at risk for recurrent, sustained ventricular tachycardia or ventricular fibrillation.
  • Restores the heart to normal rhythm. 
  • Helps prevent sudden cardiac death.

Learn more about ICDs.


A temporary pacemaker may be needed in the hospital after a heart attack if you have a heart rhythm that is too slow. A pacemaker may not be indicated long term unless damage to the heart's electrical conduction system from the heart attack will impact being able to have a normal heart rhythm and rate.

What the device does

A small device that has wires which are implanted in the heart tissue to send electrical impulses that help the heart beat in a regular rhythm. The device is powered by a battery.

Reason for the device

When the heart's "natural pacemaker" is defective and causes the heart to beat too fast, too slow or irregularly, a pacemaker helps the heart beat in a regular rhythm.

What is a pacemaker Answers by Heart sheet 

Left Ventricular Assist Device

The left ventricle is the large, muscular chamber of the heart that pumps blood out to the body. The LVAD is a battery-operated, mechanical pump-type device that's surgically implanted. It helps maintain the pumping ability of a heart when it can't effectively work on its own.

These devices are available in most heart transplant centers.

Reason for the device

This device is sometimes called a "bridge to transplant," but is also used in long-term therapy. People often must wait a long time before a suitable heart becomes available for transplant. During this time, the person's already-weakened heart may deteriorate and become unable to pump enough blood to sustain life. An LVAD can help the person while they are waiting for the heart transplant or even eliminate the need for the transplant. LVADs are also being used longer-term as ‘destination therapy’ in people with end-stage heart failure when heart transplantation is not an option.

What the device does

The LVAD has a tube that pulls blood from the left ventricle into a pump. The pump then sends blood into the aorta (the large blood vessel leaving the left ventricle). The pump is placed at the bottom of the heart inside the chest. Another tube attached to the pump is brought out of the abdominal wall to the outside of the body and attached to the pump's battery and control system. LVADs are portable and are often used for weeks to months. People with LVADs can be discharged from the hospital and have an acceptable quality of life while waiting for a donor heart to become available.

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