Kyle Lee’s heart raced for the first time last September. Six days later, it happened again.

But the 30-year-old husband and father from Ham Lake didn’t think much about it — the rapid heartbeat lasted about 15 minutes and went away.

Then, two weeks ago while Lee was at his job installing flooring, it hit him again, this time lasting two hours.

Despite a battery of tests, Lee and his doctor still aren’t sure what’s going on in his heart. So they’ve turned to a tiny, wireless implanted cardiac monitor to get answers.

On Friday, Lee was implanted with the Reveal Linq by Medtronic Inc., a device about the size of two matchsticks stuck together. Positioned just beneath the skin of his chest, the monitor will record heart data for up to three years.

Lee is among the first patients in the country to receive it, in the hope that some of the mysteries of their hearts may soon be solved. The Reveal Linq is for people who experience dizziness, palpitation, fainting or chest pain that may suggest a problem with the heart’s electrical system.

“They are still kind of unsure of what’s causing it, from what I gather,” said Lee, whose rapid heartbeat was accompanied with tingly arms and a tight jaw. But the new monitor is “supposed to monitor nonstop. We will see what happens.”

Linq is the next generation of an earlier, larger implantable heart monitor from Fridley-based Medtronic called the Reveal XT. The new version, which is about one-third the size of a AAA battery, is inserted in minutes just beneath the skin with a syringe-like device. It is 80 percent smaller than similar devices on the market.

Medtronic recently received regulatory approval to sell it in the United States and Europe. Mercy Hospital in Coon Rapids was the first in Minnesota to implant it.

Linq is one of a number of ever-shrinking devices being introduced by Medtronic and ­Little Canada-based St. Jude Medical Inc. with the expectation that they will appeal to younger patients because they are harder to see.

Almost invisible to the naked eye, Linq continuously monitors a patient’s heart and beams data readings to the doctor. It is expected to do a better detective job than many current monitoring methods, which track a patient for days or weeks.

Doctors say episodes often happen unexpectedly and outside the time a patient is being monitored. The Linq is never off.

Linq patients also carry a small, mouse-like device they can hold over the monitor when they are having an episode. By pressing a button during an event, data about that episode is immediately transmitted.

Dr. Stephen Remole, a heart rhythm specialist with Metropolitan Heart and Vascular Institute at Mercy Hospital, installed the first one a couple weeks ago. Remole said he expects doctors in his practice to implant 25 to 30 a year.

“This is so much easier for patients,” Remole said. “Sometimes people have a hard time with electronic gadgets because they’re required to do things with them. But with this, it’s all automatic and self-contained, so it’s very simple to use.”

Steven Byboth, like Lee, has had heart rhythm issues that doctors have been hard-pressed to explain — or catch in action. The 37-year-old from Coon Rapids became the first patient in the state with the device after five years of scary, unpredictable episodes of rapid heartbeat.

“I go to the ER, they can never catch it, it’s too late,” he said. “It could happen now, or a week from today. It’s frustrating.”

His doctor suggested the Linq after Byboth’s most-recent episode, when he almost passed out while shopping. “It scares me. It feels like my heart is going to jump out of my chest.”

The implant wasn’t painful, he said, “like a stretching feel when they put it in. I still feel the bump there, but if I don’t see it, I don’t know it’s there.”

Until now, Remole said, the standard way to diagnose what was happening for many patients was to have them carry around a tiny monitor in their pocket, attached by wires to sticky electrodes on the skin of their chest. The monitor records heart rhythms for a day or two. Others can record for up to a month. But problems are missed. The Linq works constantly.

“The real beauty of this is that it works by itself,” he said.

Recent data that suggest continuous monitoring may better detect atrial fibrillation in patients who have had a stroke may also increase the number of patients who are recommended for the device, Remole said. Last month, results were released of a Medtronic-sponsored study that showed that the Reveal XT — or the Linq — may help doctors prevent those patients from having a second stroke.

The idea, Remole said, is to find answers. “People come to you, they want to know what’s going on,” he said. “What this does is it makes me more confident we are going to get an answer. It lessens the hand of chance.”