Standing along the creased, snow-covered spine of a thin trail leading to the top of Mount Denali in Alaska last year, Dave Ohlson — a physician, mountain climber, photographer, and filmmaker — had everything he needed to summit the highest peak in North America.

Experience? Check.

He had summited the two tallest mountains in the world: K2 (28,251 feet) and Mount Everest (29,029 feet) in previous years.

For the Denali expedition last May, Ohlson joined five climbers with U.S. Expeditions and Explorations (USX), a nonprofit organization comprised of active and veteran military personnel who travel the world to combine outdoor adventure trips with scientific research, to summit the snow-caked face of the 20,310-foot-tall peak.

Equipment? Check.

The harnesses, ropes, crampons, helmets, and hiking poles protected Ohlson and his fellow climbers from a potentially fatal slide down the mountain face. Goggles, hardshell jackets and pants, and gloves shielded the team from the freezing elements. And the brightly colored tents pitched thousands of feet below offered respite during downtime.

But one item was a new addition to the team’s gear: All climbers were equipped with Cardea SOLO medical devices.

Lightweight and wing-shaped, Cardea SOLO — the product of Bellevue-based Cardiac Insight — is a wearable, wire-free electrocardiogram (ECG) sensor that records and stores a patient’s every heartbeat for up to seven days. It detects arrhythmias and other cardiac abnormalities, all while providing physicians access to ECG data through the company’s proprietary analysis software.

Cardea SOLO

Photo by Jeff Hobson

For Ohlson, cardiac health in high-altitude settings has interested him since he was a child growing up in the Bay Area of California. On weekends, Ohlson and his father would drive high into the Sierra Nevadas to camp and hike.

“I remember waking up gasping for breath on those first nights,” Ohlson recalled. “As I got older, I learned more about why that happened to me, and why so many people experience Acute Mountain Sickness when they travel to high altitudes. The more I’ve learned, the more particular my questions get. Now, I’m finally in a position to answer questions for myself.”

Credible researchers report a higher risk of sudden cardiac death exists specifically for older men unaccustomed to intense physical exertion and with certain risk factors. Heart attacks are the most common cause of non-traumatic death in men over age 34 while skiing or hiking at high altitude because, according to researchers, high altitude increases the likelihood of cardiac arrhythmias.

“That exposure to high altitudes causes abnormalities in the rhythm of the heart is not controversial, but it is not well-characterized,” Ohlson, a doctor specializing in internal medicine at Bingham Memorial Hospital in Idaho, explained. “The medical device market is making it easier to gather data in situations that previously were not amenable to it. I was excited to carry out this project because I thought it would be an opportunity to demonstrate that a cardiac monitoring patch would be an excellent way to gather large amounts of data.”

To that end, Ohlson approached Cardiac Insight to inquire about fitting his quintet of climbers with Cardea SOLO devices. In the end, Cardiac Insight donated nearly three dozen of the patch-like adhesive devices, which were worn by climbers during their 28-day expedition to climb Denali, reach the summit, and return to base camp.

Ohlson is still compiling the data recorded on Denali, but he’s already discovered some telling bits of information. For example, one climber experienced 15 skipped heartbeats per night at the highest elevation, of a duration of about three seconds each.

Ohlson plans to publish a research paper in the next year and a half.

And although he is clear to point out that a study pool of five climbers is hardly definitive, Ohlson believes the data captured on the trip will help provide new insights into how frequently abnormal heart rhythms occur in healthy individuals at high altitude and also provide a model for larger studies in the future.

Cardiac Insight’s path from biotech startup to the manufacturer of a medical device worn by adventurous mountaineers is about as circuitous as any route up one of the world’s tallest peaks.

In 2008, Dr. David Linker, a cardiologist at the University of Washington, and Brad Harlow, a veteran in the medical device field, partnered to begin to develop lightweight and inexpensive sensors that could be worn by patients to monitor cardiac health and abnormalities, such as the early diagnosis of atrial fibrillation, which could lead to increased risks of stroke and cardiovascular disease.

Meanwhile, Cardea Associates in Woodinville was developing CardeaScreen, a handheld ECG device that identified cardiovascular abnormalities that increase the risk of sudden cardiac arrest in high school, college, and professional athletes.

It’s a serious issue, especially considering that sudden cardiac arrest is the number one medical cause of death in athletes, according to the American Heart Association, and it is estimated an athlete dies of sudden cardiac arrest in the U.S. every 72 hours.

Dave Hadley

Dave Hadley, Cardiac Insight senior VP of research and development. Photo by Jeff Hobson.

What’s more, the industry standard ECG tests for identifying risks were flawed, according to Dave Hadley, the former president of Cardea Associates.

“ECG devices that were being used for screening kids or young athletes were really more attuned for identifying heart attacks in older people,” said Hadley. “They didn’t really account for the adaptation that a heart undergoes during athletic participation.”

As a result, according to Hadley, tests for cardiac abnormalities in young athletes were producing false positive results 25 percent of the time, worrying athletes and their families into thinking they had serious medical ailments. The expense of follow-up testing made cardiac screening cost-prohibitive.

“They just weren’t real issues,” Hadley added. “They were things that are normal in young athletes, but look abnormal in an older person who isn’t undergoing athletic training.”

In 2011, Hadley joined a group of cardiologists (including Jonathan Drezner at the University of Washington Center for Sports Cardiology) to co-author a research paper that set new criteria for screening young athletes, and it was published in a leading medical journal. From there, Hadley set out to develop what would become the CardeaScreen, which received FDA approval in 2013, and dropped the false-positive rate down to about two percent.

Cardiac Insight acquired Cardea Associates two years later.

Brad Harlow

Brad Harlow, Cardiac Insight CEO. Photo by Jeff Hobson.

“I needed to put a couple of million dollars into the company to build a sales and marketing team,” explained Hadley, who is Cardiac Insight’s senior vice president of research and development. “I have known (Cardiac Insight CEO) Brad (Harlow) for ages. Brad had a sales and marketing team, and I had electronics and software. It seemed like a marriage made in heaven.”

Following the acquisition, CardeaScreen was rebranded as the Cardea 20/20 ECG. Today, many teams within the National Football League, National Basketball Association, Major League Baseball, National Hockey League, and the PAC-12 Conference are among the many organizations that have incorporated Cardea 20/20 ECG on scouting trips to check the heart health of athletes.

“One of my very first customers were the (Milwaukee) Brewers baseball team,” said Hadley. “They love it because they can put it in a suitcase when they go to South America to recruit. The kid doesn’t get a contract until they do an ECG. They are buying a high-value asset. They want to know what they are buying.”

For some medical device companies, creating a product that helps save the lives of young people is enough of an accomplishment. But Cardiac Insight acquired Cardea Associates to help bring to market its innovative and wearable cardiac monitor.

For decades, bulky and cumbersome Holter monitors were the industry standard for cardiac monitoring. Boxy, battery-powered devices rigged with wires, Holter monitors worked for 24 to 48 hours, patients couldn’t shower with them, and some hospital emergency rooms didn’t allow patients to take these expensive devices home. Not that it mattered. Most patients didn’t want to wear such an obtrusive device, which, with new technology over the years, went from being about the size of a Walkman and was clipped to one’s belt, to about the size of an iPhone but still wired and uncomfortable to wear.

Cardiac Insight saw an opportunity to improve upon the device through Cardea SOLO.

Data downloading from Cardiac Insight Device

A physician downloads data recorded by Cardiac Insight’s medical devices directly to a computer. Photo by Randell Walton Photography.

Disposable and water-resistant, Cardea SOLO, which received FDA clearance in March 2017, is a wing-shaped device that houses a small CPU module, or uProcessor, and ECG chip integrated with two adhesive-backed electrodes. Once the single-channel device is applied to a patient’s chest and activated, the electronics go to work recording 250 samples of the heart every second, detecting arrhythmias and other cardiac abnormalities.

If a patient experiences a bout of dizziness, lightheadedness, or chest pain, he or she can touch a button on the device, which will flag the incident for the doctor to review once the data are downloaded. Otherwise, patients can go about their day exercising, working, and even showering while wearing the device.

At the end of the prescribed wear period, the patient returns to his or her physician, who removes the Cardea SOLO and accesses the electronics module under the protective cover, and separates it from the electrodes. The module is plugged into a smart cable connected to a PC, and the data are downloaded directly to the doctor’s computer. Within five minutes, a comprehensive ambulatory ECG report is produced.

Today, the U.S. market for mobile cardiac rhythm monitors is estimated to be $1.7 billion, and Cardiac Insight isn’t without its competitors. Some hospitals still use Holter monitors, for example. And the company’s closest competitor is San Francisco-based iRhythm Technologies, a publicly traded company with a market cap of $1.8 billion, and that produces a cardiac monitor called Zio, which can be worn longer than Cardea SOLO.

Still, Cardiac Insight believes it has an edge over its competitor — namely, in the immediacy of its data.

Data gathered by the Zio patch are sent to an outside agency for the analysis required to generate reports, adding days or weeks before the doctor receives the results, makes a diagnosis, and prescribes a treatment plan.

Woman with Patch

Lightweight and wireless, Cardea SOLO is a wearable ECG sensor. Photo courtesy Cardiac Insight.

“With the Cardea SOLO, we do our interpretation,” said Dr. Mohammed Abuzahra, a cardiologist at Baltimore Heart Associates who uses Cardiac Insight’s device in his daily practice. “We download the data, and the physician goes through it. With the Zio patch, it goes back to the company, and the company does a preliminary interpretation. With the Cardea SOLO, the patients bring it back directly to our office, and from there it is interpreted by us.”

Currently, Cardea SOLO is approved for use only in the United States. But Harlow and his team plan to seek regulatory authorization in Europe and Asia over the next 18 months. Although Harlow would not share revenue information, he said Cardiac Insight, which has raised more than $20 million from investors, is profitable and exceeds sales expectations.

The company has approximately 20 employees, and it recently moved from its headquarters in Kirkland’s Carillon Point to a larger space in Bellevue.

“It’s exciting,” Harlow said. “We are changing the way athletes are screened for sudden cardiac death, and we are changing the way patients are found to have atrial fibrillation. They are advances on technology that have been around for years, but really have been put into faster and newer, if you will, capabilities.”


7 Financial Facts

  • $749 Billion
    Estimated total direct medical costs of cardiovascular disease by 2035.
  • $220.9 Billion
    The projected total direct costs of high blood pressure by 2035.
  • $9 Billion
    Cost of treating coronary heart disease in U.S. hospitals.
  • $1.7 Billion
    The estimated value of the U.S. market for mobile cardiac rhythm monitoring.
  • $329.7 Billion
    Estimated total direct and indirect costs of total cardiovascular diseases and strokes.
  • $12.1 Billion
    Cost of treating heart attacks in U.S. hospitals.
  • $6 Billion
    The estimated annual cost of U. S. healthcare related to atrial fibrillation.

SOURCE: American Heart Association; Cardiac Insight