BRATTLEBORO -- Art Magnaghi Jr. doesn’t know whose heart beats inside his chest, but he knows how lucky he is.

The Brattleboro man received more than a transplanted organ on Aug. 24, 2007. He got a second chance at life -- a chance to see a daughter’s wedding day, and a chance to see his grandchildren come into the world.

The way Magnaghi sees it, he was also given a new, highly personal mission to promote the growth of organ donation in Vermont, in New England and nationwide.

"We’ve got a lot more work to do," he said. "I really want to get the donation rate up."

Magnaghi’s experiences have led him directly to that spokesman’s role. He had his first heart attack in 2003 and another in 2007, when he was stricken in March while preparing to ski at Mt. Snow.

He recalls being transported to Dartmouth-Hitchcock in Lebanon, N.H., where he had trouble breathing and passed out. "The next thing I remember was waking up six days later at Tufts Medical Center (in Boston)," Magnaghi said. "I was in a coma for six days."

He later learned that he had "flat-lined" twice after landing at Tufts and owed his life to crews who had worked for hours to save him.

"Somebody was looking out for me, believe me," he said. "It was a miracle."

Magnaghi’s struggles were far from over, however. After renting an apartment in Boston for about a month so that he could visit Tufts daily, Magnaghi returned to Brattleboro, where his condition worsened.

"It was pretty rough, because I only had 20 to 25 percent (heart) function, so I had all kinds of problems," he said. "I went into congestive heart failure around June."

That same month, he was listed as a candidate for a heart transplant. On Aug. 24 -- exactly five months after his heart attack -- Magnaghi received a 3 a.m. phone call notifying him that a heart was available; he credits his wife, Wendy, with getting him to Tufts in just 90 minutes.

Magnaghi was hospitalized for less than two weeks, but it was a long road to recovery after the transplant. Intensive monitoring followed the operation, with doctors watching for signs that his body would reject the new heart.

"You’re immediately put on anti-rejection medications, which I’m on for the rest of my life," Magnaghi said.

Those medications compromise his immune system, meaning Magnaghi must take constant precautions to avoid even the common cold. Even though recovery is "a work in progress all the time," he can live a relatively normal life today.

"I exercise daily on the treadmill. I take walks. I can ski, I can play tennis, I can do anything that I want to do," Magnaghi said.

One of the things he did almost immediately was to get involved with organ-donation causes. Magnaghi volunteered his help to the New England Organ Bank, which is the federally designated organ-procurement organization for all or part of six states.

Magnaghi has made speaking appearances to promote the cause and tell his story. He also became involved in an urgent effort to fix what had been a disconnect in Vermont’s donation system: Residents could sign up as organ donors, but their names were not making it into a donor registry, recalled Matt Boger, a spokesman for New England Organ Bank.

"Now, Vermont does have a thriving donor registry," Boger said. "Vermont went from a few hundred (registered donors) to a few thousand to over 120,000 today."

Boger credits Gov. Peter Shumlin, state Health Commissioner Harry Chen and Department of Motor Vehicles Commissioner Robert Ide with coordinating to fix the glitch. Legislation that passed in 2011 also played a role by creating an Organ and Tissue Donation Work Group; Magnaghi was named as a member of that group, which helped to address the registry problem.

"We’re still in existence," Magnaghi said. "We meet probably four times a year, and we’re working on all kinds of things."

The focus of that work is advocating for more organ donors. Even though studies show that more than 90 percent of Americans support organ donation, "only about 40 percent of the American population is registered," Boger said.

While Vermont has made great strides in recent years, state Department of Health officials say less than half of those renewing their driver’s licenses this year have agreed to be donors. Registering through the DMV is critical, as that is how the vast majority of donors sign up; residents also can register via www.DonateLifeVT.org.

"We’re trying to work on improving the number of donors significantly," Magnaghi said.

At the same time, the number of people in need of transplants is growing, both in New England and nationally: The organ bank says more than 121,000 men, women and children in the U.S. await "life-saving organ transplants," a list that has more than doubled in size in a decade’s time.

Boger acknowledges that registration as an organ donor is a "voluntary decision, and we respect that." But he believes misconceptions play a major role in keeping the number of registered donors down.

Organ-donation advocates say prominent myths include:

* Some believe doctors and nurses won’t work as hard to save the life of an organ donor. Nothing could be further from the truth, Boger said.

"Their only job is to save your life," he said. "Additionally, they do not have access to information on whether you a donor or not" until making a check after death.

* Illnesses do not necessarily make a person ineligible for organ donation.

The New England Organ Bank says eligibility is based on a case-by-case medical review: "Even if you have had a serious health problem like diabetes, high blood pressure, heart disease, certain types of cancer or even hepatitis, you may still be able to donate at the time of death," administrators said.

* Likewise, advanced age is not a disqualifier. "You can donate your organs at any age," Boger said.

* Organ donation is a commonly accepted practice among most religious faiths, officials say. "All major organized religions approve of organ and tissue donation and consider it an act of charity or leave it up to the decision of the individual," the organ bank says.

* Identities of donors are not disclosed unless a donor’s family requests that the information is released, administrators say.

Magnaghi knows that his heart came from a young person and from the state of Pennsylvania, but that’s all he knows. He was able, however, to write an anonymous thank-you letter to the donor’s family.

"I really felt so blessed and so fortunate to have been able to get this heart," he said. "I saw my second daughter married. I saw all my grandkids being born. I wouldn’t ever have been able to do that."

When it comes to aiding the public-education effort for organ donation, Boger said there is no substitute for organ recipients and the families of donors detailing their experiences.

"It’s a way of giving back," Boger said. "The most compelling stories come from those individuals who have been personally touched."

Magnaghi’s feelings about organ donation -- and about his own experiences following his transplant -- were summed up in a newspaper piece he wrote a few years ago.

"There is not a day or night that has passed since then that I don’t pray to God to bless the donor and donor family for their gift of the heart that beats within me," he wrote. "I never refer to the heart within me as mine, because it is not. It comes to be within me as a very precious gift that has given me a second chance to live a longer and healthy life."