World's Smallest Leadless Pacemaker!

World's Smallest Leadless Pacemaker!

Meet Micra™

Out of sight. Out of mind. Micra™ is the world’s smallest pacemaker — leaving no bump under the skin, no chest scar and requiring no lead. Micra™ is completely self-contained within the heart and provides the therapy needed without a visible or physical reminder of a medical device.

What heart condition would warrant the Micra™ Leadless Pacemaker?

Bradycardia is a condition in which the heart beats too slowly. A healthy heart beats 60 to 100 times per minute, pumping about 284 liters of blood every hour. When you have bradycardia, the heart beats fewer than 60 times per minute. At that rate, the heart may not be able to pump enough oxygen-rich blood to the body during activity or exercise. As a result, you might feel dizzy, tired, short of breath or have fainting spells.

How do Pacemakers Work?

A pacemaker is designed to mimic the heart’s natural rhythm when there are disturbances, such as pauses, in the natural rhythm. The pacemaker has two main purposes — pacing and sensing.

Pacing: A pacemaker will send an electrical impulse to the heart when the heart’s own rhythm is too slow or interrupted.

Sensing: A pacemaker will also “sense” (monitor) the heart’s natural electrical activity. When the pacemaker senses a natural heartbeat, it will not deliver a pacing pulse.


Most pacemakers require a device (size of tea bag) to be surgically implanted under your skin in the upper chest. The system also requires a lead to be connected to the pacemaker and is threaded into the heart. The lead carries electrical signals from the pacemaker to your heart to help it beat regularly.


Micra™ is 93% smaller than traditional pacemakers. It is the size of a large vitamin capsule, and has a battery that lasts as long as a traditional pacemaker. Unlike a standard pacemaker, it is implanted into the heart through a vein in your leg and does not require a lead. Micra’s miniaturized size and minimally invasive approach leaves no visible sign of a medical device under the skin. This can mean fewer post-implant activity restrictions and no obstructions to shoulder movement.

How is Micra™ implanted?

  • Your doctor will insert a “straw-like” catheter system into a vein, typically near the upper thigh area of your leg
  • The catheter system moves the Micra™ into the right ventricle of the heart
  • The Micra™ is placed against the heart wall and secured with flexible tines (see image at the far right below)
  • Your doctor tests the Micra™ to ensure it is working properly
  • The catheter system is then removed
Can I use a mobile phone?

Yes. When talking on a mobile phone keep the phone’s antenna about 6 inches away from an implanted Micra™. We also recommend avoiding placing the mobile phone in a shirt or jacket pocket of the chest.

Are household appliances safe to use?

Yes. Most household appliances are safe to use as long as they are properly maintained and in good working order. This includes microwave ovens, major appliances, electric blankets and heating pads.

Will magnets affect my Micra™?

Items that contain magnets, such as magnetic therapy products, stereo speakers and hand-held massagers can temporarily affect the operation of a pacemaker. Therefore, it is recommended keeping items containing magnets at least 6 inches away from an implanted pacemaker. We do not recommend the use of magnetic mattress pads and pillows because it is difficult to maintain a 6-inch distance when using these items.

How long will my Micra™ last?

A new Micra™ is needed when battery power falls to a low level. Battery power is affected by many factors, including the nature of the heart condition. The estimated average battery life for Micra™ is 12 years after it is implanted2; individual patient experience may vary.

The battery power is checked at each Micra™ follow-up appointment. The doctor or nurse will notify you when you need a new pacemaker.

Micra™ is designed to provide options when a new device is needed. It may be turned off and a new Micra™ or a traditional system may be implanted or it may be retrieved and a new system implanted. Your doctor will determine what is best for you.

Can I exercise? Can I go about my regular activities?

You should be able to return to your usual activities, as long as those activities do not exceed current fitness levels. Questions about specific exercises should be discussed with your physician.

Cardiovascular Services