This longtime firefighter could barely walk. Now, he's running a 5K a day.

Paul Dunwell was sitting in a town council meeting when he started feeling off. He was having trouble breathing and couldn't focus on the conversation.

He shook it off that night, assuming it wasn't a big deal. But he kept feeling worse over the next several weeks. His energy plummeted. He struggled to walk the mile and a half to work, a commute he'd been making for years without issue.

Dunwell was the fire and rescue chief in Shallotte, North Carolina. As a trained emergency medical technician who had worked in emergency fire services for over three decades, he knew how to identify the primary symptoms of many major health issues. Unable to connect the dots between his own symptoms and something serious, he didn't see a need to seek medical help right away.

But after a couple of months of feeling off, he finally went to his primary care doctor.

His doctor immediately knew something was wrong. Tests determined Dunwell was experiencing atrial fibrillation, or AFib, an irregular heartbeat that can lead to more serious complications.

Dunwell took home a heart monitor that would track his heartbeat, providing more information to determine the severity of his condition. That would also help set a treatment plan. Some people are able to control AFib through medication and lifestyle changes, while others need a medical procedure or surgical intervention.

The heart monitor revealed that Dunwell was experiencing an irregular heartbeat several times a day, often for more than an hour at a time. The doctor's verdict: It was serious. Dunwell needed a medical procedure.

Because he was diagnosed in July 2021, when the medical system was still stressed from the COVID-19 pandemic, Dunwell couldn't immediately get in to see a cardiologist, nor schedule the procedure he needed to improve his health.

He waited several weeks to see a specialist. His symptoms worsened during that time. He had extreme shortness of breath, dizziness, fatigue and cognitive difficulties. It took him an hour to walk a mile around his neighborhood. He couldn't drive. He could barely work. He went to the emergency room twice because his symptoms were so severe.

When he finally had his long-awaited appointment, his caseworker reviewed his medical information and told him, "You're probably going to have to quit your job as a firefighter."

Dunwell was devastated. He was 51 at the time and thought he had years left in his career.

"Firefighting was my life," he said. "I'd been doing it for 33 years and I couldn't just walk away from it."

He was determined to do whatever he could do to get well enough to keep working.

In November 2021, he got an ablation, a procedure that essentially zaps away abnormal tissue around the heart that's causing the irregular heartbeat. He also began a different regimen of medications.

"But I knew I didn't want to stay on medications forever," he said. Plus, the medications caused all sorts of side effects, including numb and tingling hands, dizziness and tremors, all of which impacted his ability to function. He seemed like a different person, his wife said.

Dunwell knew the pill regimen was unsustainable. "I told my doctor, 'I want to be a firefighter. How do I get healthy enough to do that?'"

His doctors helped him wean off the medication and gave him guidelines for the lifestyle he'd need to maintain for good heart health. Most of them, he'd already been doing. He'd always been active, eaten fairly well and didn't smoke or drink. The only risk factor he could identify was a family history of heart issues since his father experienced an abnormal heartbeat in his 70s.

Several months after his procedure, Dunwell went to see his doctor to check in on his progress. His doctor had him do a cardiac stress test, where they monitored his heart to see how it handled increased stress from exercise.

He got on the treadmill and started running. This feels great, he thought.

He had never been a runner before and had always thought of the sport as something that he couldn't do. But, as he ran on the treadmill, all he could think about was how good it felt to run and how he didn't want to stop.

"So, I just kept running," he said. "I've been running nearly every day ever since I got on that treadmill."

He met his goal of staying a firefighter. And he's set many new goals since then in the sport of running.

Since stepping on that treadmill just over two years ago, Dunwell has run almost 4,000 miles. He averages a 5K a day and has finished multiple half-marathons. He's training for Walt Disney World's Dopey Challenge, where he'll aim to complete a 5K, 10K, half-marathon and marathon over the course of four days in January.

"I've known Paul for over 18 years and never saw him run," said Justin Ward, deputy fire chief at Shallotte Fire and Rescue. "When he was at his worst, he could barely walk 100 feet without getting out of breath. But now he's blazing around, training for a marathon, inspiring all of us to take care of ourselves so we don't go through the same thing."

A big source of motivation for Dunwell is thinking about everything he's gone through and how he wants his life to be better on the other side of it – and how he wants to share his story to help others avoid their own heart challenges.

"When I'm running, I think a lot about how I'm here because of everyone in my life who took care of me," he said. "They never gave up on me. So, I can't give up on myself."

Stories From the Heart chronicles the inspiring journeys of heart disease and stroke survivors, caregivers and advocates.