WASHINGTON - Tiny, new pacemakers are making headway around the world. One type, the Micra, is keeping 15,000 people’s hearts beating in 40 countries, according to manufacturer Medtronic. One of those people is Mary Lou Trejo, a senior citizen who lives in Ohio.
A healthy heart has its own pacemaker that establishes its rhythm, but people like Trejo need the help of an artificial device.
Trejo comes from a family with a history of heart disease. Her heart skipped beats, and she could feel it going out of rhythm. Trejo wanted to do something to advance heart health, so in 2014, she volunteered to participate in a clinical trial for the Micra pacemaker. The device is 24 millimeters long implanted, one-tenth the size of traditional pacemakers.
Most pacemakers rely on batteries placed under the skin, usually just below the collarbone. Sometimes patients get infections after the surgery or have difficulty healing from the incision.
Traditional pacemakers use leads with electrodes on one end that are threaded through blood vessels to connect to the heart. There can be problems with the leads as well.
Dr. Ralph Augostini at Ohio State’s Wexner Medical Center says a tiny pacemaker like the Micra avoids all of these problems.
“The electrodes are part of the can, and therefore it eliminates the lead,” he said. There’s no incision in the chest to become infected and no chance of complications with the leads.
Small and self-contained
Augostini implanted Trejo’s pacemaker in 2014. He threaded the entire device thorough an artery in her leg up to her heart. The pacemaker has small, flexible tines that anchor it into the folds of the heart muscle. Once it’s in place, the doctor gives it a tug to make sure the pacemaker is stable before removing the catheter used to place it in the heart.
The Wexner Medical Center was one of the sites that participated in the Micra clinical trial. Since the Micra received FDA approval in 2016, Medtronic has been training more physicians on the procedure. A company spokesman told VOA that this device is becoming available at other centers across the U.S. and countries throughout the world.
Dr. John Hummell, a cardiologist at the Wexner Medical Center, has studied the effectiveness of this new generation of pacemakers.
“We don’t leave any wires behind and the pacemaker, the battery, the wire is all just a tiny little piece of metal sitting down in the heart,” he said. Medtronic said the results of the clinical trial showed a success rate of 99.6 percent.
Dr. Richard Weachter, with the University of Missouri Health Care, says the leadless pacemakers’ complication rates are about half the rate of traditional pacemakers.
The battery lasts for 14 years and after that, Weachter said, doctors can implant another one in the same chamber of the heart. They can repeat the procedure a third time if needed.
The pacemaker activates only when necessary to keep the heart beating normally. Studies show that the Micra and other leadless pacemakers are safe and effective.
These tiny pacemakers are not right for all patients, but as the technology develops, more people will be able to benefit from the procedure. Four years after her implant, Trejo’s doctors say she is doing fine.