(CNN) John Fetterman's cardiologist said Friday that the Democratic Senate candidate suffers from both atrial fibrillation and cardiomyopathy, issuing a statement that provides more insight into what caused the Pennsylvania lieutenant governor's stroke in May.
Dr. Ramesh Chandra said he first saw Fetterman in 2017, when he reported having swollen feet. He said he diagnosed him with "atrial fibrillation, an irregular heart rhythm, along with a decreased heart pump." Although he advised him to follow up in the coming months, the doctor said Fetterman did not and "did not go to any doctor for 5 years and did not continue to take his medications."
Chandra said Fetterman is "well compensated and stable" after receiving a defibrillator that he said "is working perfectly." The doctor added that it was the cardiomyopathy, a condition that makes it harder for the heart to pump blood to the rest of the body, that was the reason the device needed to be implanted.
"The prognosis I can give for John's heart is this: If he takes his medications, eats healthy and exercises, he'll be fine," Chandra wrote. "If he does what I've told him, and I do believe that he is taking his recovery and his health very seriously this time, he should be able to campaign and serve in the U.S. Senate without a problem."
The letter comes weeks after Fetterman checked himself into a hospital in Lancaster, Pennsylvania, on May 13 as he was on his way to a campaign event. He was found to have suffered a stroke and doctors used a thrombectomy, a procedure where doctors enter the body through the groin and wind catheters up to the clot, to address it. Fetterman won the Democratic Senate primary on May 17 while in the hospital and underwent a nearly three-hour surgery that same day to implant the defibrillator. He was released from the hospital on May 22 after a nine-day stay.
Fetterman's race will be one of the most closely watched Senate contests in the country, with control of the evenly divided Senate hanging in the balance. The Democrat will face the winner of the GOP primary; the race between celebrity doctor Mehmet Oz and former hedge fund executive Dave McCormick has gone to a recount.
Despite multiple statements during and after his time in the hospital, Fetterman did not disclose previously that he had been diagnosed with atrial fibrillation diagnosed in 2017. And while the letter from Chandra provides insight into what led to Fetterman's stroke, the doctors that performed the procedure on the candidate in Lancaster last month have yet to speak publicly.
Fetterman, in a statement released Friday in conjunction with Chandra's letter, acknowledged that he "should have taken my health more seriously."
"The stroke I suffered on May 13 didn't come out of nowhere. Like so many others, and so many men in particular, I avoided going to the doctor, even though I knew I didn't feel well. As a result, I almost died," he said. "I want to encourage others to not make the same mistake."
Fetterman said he "didn't follow up" because he thought "losing weight and exercising would be enough" to address his heart issues. He admits he was wrong, saying that the stroke he suffered was "completely preventable" and that his doctors have told him that if he had "continued taking the blood thinners, I never would have had a stroke."
"It's not something I'm proud of, but it is something I hope that others can learn from," he said. "So please: listen to your body, and be aware of the signs. Because ignoring them -- and avoiding the doctor because you might not like what they have to tell you -- could cost you your life."
Fetterman said that his doctors have instructed him "to rest, eat healthy, exercise, and focus on my recovery" and, because of that, it will "take some more time to get back on the campaign trail like I was in the lead-up to the primary."
"It's frustrating -- all the more so because this is my own fault -- but bear with me, I need a little more time. I'm not quite back to 100% yet, but I'm getting closer every day," he said. "This race is so important for Pennsylvania and for the country. I'm going to be ready for it, and I can't wait to get back on the trail."
Fetterman had previously said that the stroke was "caused by a clot from my heart being in an A-fib rhythm for too long" and that his doctors were "able to quickly and completely remove the clot, reversing the stroke, they got my heart under control as well." Fetterman also said his doctors had told him he didn't suffer "any cognitive damage" and that he is "well on my way to a full recovery."
After that statement, Fetterman's campaign announced he had undergone the "standard procedure to implant a pacemaker with a defibrillator" and his wife, Gisele, told CNN on May 18 that the new implant would "make sure it's the strongest heart possible" after it was "weakened" by his irregular rhythm.
Fetterman was the favorite to win Pennsylvania's Democratic Senate nomination months before he suffered the stroke. And the stint in the hospital didn't dim those chances: Fetterman, from his hospital bed, easily defeated US Rep. Conor Lamb in the commonwealth's Democratic Senate primary.
Days after the primary, Fetterman announced he was leaving the hospital and "feeling great," but would "continue to rest and recover" so that he could "go full speed soon" and win in November.
The lieutenant governor has not held a public event since May 12.
Dr. Jonathan Reiner, a CNN medical analyst and interventional cardiologist who has treated several high-profile politicians, said there were several anomalies with Fetterman's hospital stay, including its length. He delivered a blistering critique of the letter released Friday by the Fetterman campaign as a "horrible note."
"First of all, it's not from the doctors who treated him during his stroke. It's from a doctor that he saw in 2017," said Reiner, who has called on Fetterman to be more transparent about his condition and recovery.
"The note doesn't say why the patient had a defibrillator implanted during that admission, doesn't mention his ejection fraction or residual neurologic deficits, doesn't describe a timetable for returning to the campaign trail," Reiner said. "Horrible note. Totally insufficient. The campaign should make available the docs who treated him during the stroke. Why are they hiding them?"
Reiner and other experts on cardiology and vascular neurology previously had told CNN that the time and scope of Fetterman's recent stay in the hospital for his recent stroke spoke to a more complicated health prognosis than one acknowledged by the Democratic Senate nominee, a belief confirmed by Chandra's letter and the revelation of cardiomyopathy and the earlier diagnosis.
Reiner and the other doctors said although the procedure Fetterman underwent is common in the United States, the uses of a thrombectomy to combat the stroke and the implantation of a defibrillator spoke to a more complicated health profile.
The use of a defibrillator, Reiner said, spoke "to something decidedly more ominous in terms of his status" because it could mean there is a cardiac structural issue that needed to be addressed before he could go home. In a less worrying moment, Reiner said, a doctor may use less drastic measures to address a heart issue before jumping to a defibrillator.
Dr. Donald Lloyd-Jones, president of the American Heart Association, said that while life with a defibrillator is "very manageable" and Fetterman's prognosis should be good with it, "a pacemaker and defibrillator is not standard treatment for atrial fibrillation."
Lloyd-Jones, who, like Reiner, has not treated Fetterman, added that "people with atrial fibrillation do not routinely require a pacemaker unless there's something also potentially happening with the conduction system -- the electrical connections of the heart -- separate from the atrial fibrillation."
Fetterman's health scare -- coupled with the recount on the Republican side -- has effectively frozen the Senate race in time.
Fetterman and his team had not offered details about the lieutenant governor's prognosis until Friday. The remarkably limited information from the campaign raised alarms among top Democrats in Pennsylvania and in Washington, officials said, and has prompted party lawyers to study the steps it would take to replace Fetterman on the ballot should that ultimately be necessary. State law sets an August timeline for doing so.
"Everyone hopes that isn't necessary and he remains on the ballot, but the stakes are too high not to prepare for every scenario," a senior party official told CNN, speaking on condition of anonymity to discuss the delicate nature of Fetterman's recovery.
There are also concerns about how Republicans may use Fetterman's health in a general election. While both Oz and McCormick have wished Fetterman well as he recovers from the stroke, some Democrats are worried that the broader universe of Republican groups and super PACs could attempt to use Fetterman's health scare against him.
Reiner and other doctors told CNN that they believed Fetterman could make a full recovery from the stroke but added that any suggestion that the stroke was small would be incorrect, especially because doctors in Lancaster opted to use thrombectomy to remove the clot.
Dr. Shazam Hussain, director of the Cerebrovascular Center at the Cleveland Clinic, said a thrombectomy is mostly used to address "bigger clots that can cause really bad stroke."
Lloyd-Jones echoed that suggestion, telling CNN that the use of a thrombectomy suggested the stroke stemmed from a "larger blood clot" in "a larger artery that is blocked" because the catheters used in the procedure cannot get into smaller areas.
And Dr. Michelle Johansen, an assistant professor of neurology and attending physician in the cerebrovascular division at the Johns Hopkins Hospital, said that "patients who are eligible for thrombectomy normally are in the process of having a bigger stroke."