A Modesto man had a very slow heart rate. The answer was a device the size of a pill

James Souza of Modesto was introduced to a leadless pacemaker after an exam showed his heart rate was only 32 beats per minute.

Cyclist Lance Armstrong might have impressed the world with his reported 32 bpm resting pulse, but it’s a serious health concern for an octogenarian like Souza. (A normal resting heart rate is 60 to 90 beats a minute.)

“The doctor said when it’s below 40 beats a minute they usually do something about it,” said Souza, a former underground electrician for Modesto Irrigation District.

In a procedure last month at Memorial Medical Center in Modesto, Dr. Kent Wong attached a small pacemaker that is not much larger than a multivitamin to the lower chamber of Souza’s heart.

Souza said last week he does not notice when his heart rate slows down, but if it does, the pacemaker kicks in to restore the normal heartbeat.

The Micra Transcatheter Pacing System recently made its debut in Modesto and hospitals in Sacramento after the device received approval last year from the Food and Drug Administration..

While a conventional pacemaker is embedded under the skin of a patient’s chest, the Micra device is inserted through an incision in the groin, directed through blood vessels to the heart and then anchored in the muscle of the lower, right ventricle.

Rather than using lead wires to jolt the heart, tines protruding from the Micra pacemaker serve to stimulate the heart.

Souza, who suffers from Parkinson’s disease, was a candidate for the leadless pacemaker for a second reason. The retiree has a brain stimulator housed in a pocket under the skin of his chest to relieve the symptoms of Parkinson’s disease.

Wong said there is not much room on Souza’s chest for a cardiac pacemaker. Doctors were concerned about a possible interaction between a traditional pacemaker and the patient’s brain stimulator.

Roughly 200,000 people a year receive pacemakers in the United States, but only about 10 percent of that population would likely qualify for a single-chamber pacemaker like the Micra.

Souza is among patients whose irregular heartbeats can be treated by stimulating just one chamber of the heart. The vast majority of pacemaker candidates need wire leads in the upper and lower chambers of the heart.

The Micra device was developed by Medtronic, a company that makes other pacemakers which are about the size of a credit card. “With a traditional device, the leads can fracture. They can pull out,” said Dr. Mark Bowers of Sacramento, who specializes in cardiac electrophysiology.

With traditional pacemakers, the pocket in the chest can become infected. Patients who receive a traditional pacemaker must wait six weeks before they can go back to full activities. The Micra’s recovery period is days, not weeks.

Wong said some patients with a common irregular heartbeat called atrial fibrillation may eventually need a Micra pacemaker. The disease by itself does not require a pacemaker but medicine to treat the rapid heartbeat may result in bradycardia or a very slow heart rate.

The patient may become dizzy or pass out. But electric stimulation to the lower chamber of the heart often corrects the problem. Wong expects to handle about 30 of the procedures each year.

A Micra pacemaker is projected to last for 12 years. Wong said the device is so small that a new one can be placed next to an old one that has run out of juice.

The procedure to attach the pacemaker may take as little as 20 minutes, said Wong, one of the interventional cardiologists doing the procedure at Memorial. The patient is put under conscious sedation for the procedure.

“We watch them overnight in the hospital,” Wong said. “The next day, they get up and walk and go home if there is no bleeding in the access point (in the groin).”

In one of the known complications, the tines may occasionally cause bleeding by perforating the heart, but that is avoided by proper placement of the device.

In an international study considered by the Food and Drug Administration, about 96 percent of patients who received the Micra pacemaker had no major complications after six months. The study found that 25 of the 725 patients had complications, including 11 with perforations or fluid around the heart.

The technology was accepted for use in Europe years before the FDA approved the Micra pacemaker in April 2016.

“I am supposed to go back (Monday) to see if it is working well,” Souza said.

This story was originally published September 20, 2017 at 1:30 PM with the headline "A Modesto man had a very slow heart rate. The answer was a device the size of a pill."