For years, pacemakers have been about the size of two stacked silver dollars and require a 2-inch incision below the collarbone to implant. Tiny wires called leads connect the battery-powered device to the heart. When it detects an abnormal rhythm, the pacemaker sends a signal to help control and normalize the heartbeat. Millions of Americans have pacemakers; thousands are implanted each year.
And for some of them, the procedure just got a lot simpler.
Doctors are buzzing about technological advances that have resulted in devices so small they can be implanted inside the heart — without leads that can cause problems, or incisions or the bulkiness patients feel under their skin.
One of the newest pacemakers on the market, the Micra Transcatheter Pacing System made by Medtronic, was approved by the Food and Drug Administration in April and is billed as the world's smallest minimally invasive pacemaker. A similar lead-less product, Nanostim, is made by St. Jude Medical and is expected to receive FDA approval any day.
Both have been sold in Europe for more than a year.
The Micra is about the size of a large vitamin pill or smaller than a AAA battery. It is placed directly in the right ventricle of the heart through a catheter in the groin, not a chest incision. Small hooks anchor it in place but also allow for repositioning if needed.
Some early pacemakers weighed about a half-pound; the Micra weighs about as much as a penny.
"This is almost unbelievable," said Dr. Jose Gallastegui, a cardiac electrophysiologist and director of the electrophysiology program at Morton Plant Hospital in Clearwater. Gallastegui has been implanting pacemakers for more than 30 years.
"They were so big at first," he said. "To think of where we are now is amazing. This mini pacemaker makes the procedure and recovery easier for doctors and for patients."
This summer, James Schrader of Clearwater became one of the first Floridians to receive a Micra outside a clinical trial. The retired owner of a landscaping company, he started having heart problems about nine years ago while living in New Jersey.
He eventually moved to Florida and was referred to Gallastegui, who found that, despite trying medications and several other procedures, Schrader's problems weren't going away. His heartbeat was slower than normal and his heart could no longer pump enough blood to his body, leaving it without enough oxygen. The condition, known as bradycardia, causes extreme fatigue, fainting spells, dizziness and shortness of breath.
"I would fall asleep just sitting at the table during meals," said Schrader, 73. Gallastegui implanted him with the Micra on June 7 at Morton Plant and he was sent home the next day. Eventually, doctors say, most patients will go home the same day.
"I'm nowhere near as tired as before," Schrader said. "I'm enjoying life more, happy to be able to get out and get going again."
The earliest pacemakers of the 1950s were about the size of a textbook, had to be plugged into a wall and were reserved for use in hospital emergency rooms. Later models were portable and either taped to the chest or hung on a lanyard and worn around the neck.
By the 1960s, pacemakers were small enough to implant in the body, but it still took a large incision to place them in the chest. Patients not only had to contend with a long hospital stay, but also had a sizable surgical scar and could often feel the edges of the device through their skin.
A lot of that has changed as technology advanced and surgical techniques improved, but one ongoing problem with pacemakers has been with the leads that attach to the heart. Because they constantly respond to the beating heart and a person's upper body movement, leads can break, wear out, fail to work properly or cause infections, and sometimes need to be replaced.
"It's almost always the leads and rarely the pacemaker itself that gives us problems," Gallastegui said.
As good as it may sound, the new Micra isn't for everyone who needs a pacemaker. Most people need help with pacing in two or more chambers of the heart. The Micra is for only 10 percent to 15 percent of pacemaker patients — those who need single-chamber pacing or pacing in the right ventricle.
"That's a very limited population," said Dr. Sanders Chae, a cardiac electrophysiologist and associate professor in the department of cardiovascular sciences at the USF Health Morsani College of Medicine.
Chae was not involved in clinical trials for the Micra and does not currently work with the device, but has met with Medtronic about possibly bringing it to Tampa General Hospital.
"Right now, it's a niche product, but having an extra option is always helpful," said Chae, who looks forward to the next generation of mini pacemakers, which are expected to be dual-chamber devices.
"When we get there," he said, "then these devices could eventually replace standard pacemakers."
Dr. Gordon Tomaselli, a spokesman for and past president of the American Heart Association, also looks forward to the dual-chamber mini pacemaker of the future but is impressed with the small size of the current version and its battery life.
"It's quite respectable," said Tomaselli, a professor of medicine and chief of the division of cardiology at Johns Hopkins University School of Medicine in Baltimore. He has followed the Micra's development but hasn't worked with the device.
"The expectation and the manufacturer's claim is that it will last up to 10 to 12 years," he said. "That's as good or better than most standard pacemakers."
Locally, availability of the Micra mini pacemaker is limited to two BayCare hospitals, Morton Plant and St. Joseph's in Tampa. Florida Hospital Tampa says it expects to begin offering the Nanostim mini pacemaker early next year, after it is approved.
Most insurance plans, including Medicare, do not cover lead-less pacemakers, but manufacturers are working to change that. Medicare is evaluating the devices and expects to issue a decision in February.
The industry publication Modern Healthcare recently reported that the Micra is estimated to cost $10,000.
Medtronic declined to provide a cost figure for the Micra, but company spokesman Ryan Mathre said in an email that it is more expensive than a standard single-chamber pacemaker, which averages about $2,500 to $3,500, just for the device.
Contact Irene Maher at email@example.com.