Can Lyme Disease Cause Atrial Fibrillation?
IRREGULAR HEARTBEAT WITH NO CLEAR CAUSE?
LYME DISEASE MAY AFFECT HEART RHYTHM
“My heart suddenly started racing—and no one knew why.”
Lyme disease is best known for joint pain and fatigue, but it can also affect the heart.
Quick Answer: Lyme disease may increase the risk of atrial fibrillation through inflammation of the heart, particularly in cases of Lyme carditis.
Clinical Insight: When patients develop unexplained arrhythmias—especially in endemic areas—Lyme disease should be considered as a potential cause.
Lyme carditis occurs when Borrelia burgdorferi affects the cardiac conduction system, leading to symptoms such as palpitations, dizziness, chest discomfort, and irregular heart rhythms.
Can Lyme disease cause atrial fibrillation?
Researchers have proposed that atrial fibrillation (AFib) may develop as a result of low-grade inflammation of the heart muscle.
“It is hypothesized that in some cases the AF might be a consequence of past low-grade myocarditis,” the authors explain.
Lyme disease is one potential source of this inflammation, particularly in cases of Lyme carditis.
What the study found
Researchers evaluated 113 patients with atrial fibrillation and compared them to 109 patients without AFib.
The average age was 75.8 years.
They found:
- 34.5% of AFib patients had evidence of Borrelia exposure
- Only 6.4% of patients in normal rhythm had positive results
The presence of anti-Borrelia antibodies was associated with a significantly higher risk of atrial fibrillation.
The reported odds ratio was 8.21, suggesting a strong association.
How Lyme disease affects the heart
Borrelia bacteria can affect multiple parts of the heart, including:
- The conduction system
- Heart muscle (myocardium)
- Heart valves and blood vessels
Inflammation in these areas may disrupt electrical signaling and lead to rhythm abnormalities.
This is most commonly seen as heart block—but other arrhythmias, including atrial fibrillation, may occur.
Why this connection may be missed
Lyme-related heart involvement is often under-recognized.
Many patients with atrial fibrillation already have risk factors such as:
- Hypertension
- Obesity
- Heart failure
- Chronic kidney disease
These conditions can overshadow a potential infectious cause.
In addition, direct evidence of Lyme infection in the heart is difficult to obtain, as cardiac biopsies are rarely performed.
Possible mechanisms
The authors propose two possible explanations for the association:
- Chronic low-grade inflammation leading to structural changes in the atria
- Autoimmune responses triggered by Borrelia, leading to tissue injury
Both mechanisms could contribute to the development of atrial fibrillation.
Clinical takeaway
Lyme disease may contribute to atrial fibrillation through inflammation of the heart.
While this study shows an association—not causation—it highlights the need to consider Lyme disease in patients with unexplained arrhythmias.
This is particularly important in endemic regions or in patients with a history of tick exposure.
Frequently Asked Questions
Can Lyme disease cause atrial fibrillation?
Possibly. Lyme disease may contribute to atrial fibrillation through inflammation of the heart.
What is Lyme carditis?
Lyme carditis occurs when Lyme disease affects the heart, often causing conduction abnormalities and arrhythmias.
What symptoms suggest Lyme carditis?
Palpitations, dizziness, chest discomfort, fainting, and irregular heart rhythms.
Is the connection between Lyme and AFib proven?
No. Current studies show an association, but more research is needed to confirm causation.
Related Reading
Dr. Daniel Cameron, MD, MPH
Lyme disease clinician with over 30 years of experience and past president of ILADS.
Symptoms • Testing • Coinfections • Recovery • Pediatric • Prevention
I was diagnosed with A Fib in 2017 after a bad reaction to Targretin and Levothyroxine, taken for NHL.
Only God knows if the Bb and Babesia, acquired in 1995, contributed to the pathology.
Are there Lyme cardiologists in the US…or at least cardiologists who understand Lyme Disease and the devastation it causes in the body?
I use cardiologist primarily to be sure I have not overlooked another illness.
I use cardiologist primarily to be sure I have not overlooked another illness.
Are there Lyme cardiologists in the US…or at least cardiologists who understand Lyme Disease and the devastation it causes in the body?
We are in Michigan and I just had the family practice tell me my husbands joint quick onset and AFIB and my joints also Lyme (my test is positive) infected have nothing to do with Lyme. My gosh we need Kennedy to step in for this.
There are so many causes of a fib. In some cases the cause has never been identified. I have included Lyme disease in my evaluation particularly if there are other issues including joint pain.
In 2008 I was taking a shower and notice the right calf of my leg was swollen and had a big bullseye redness on it. I did not see a tick but we live in the on a mountain in PA and often get tick bites. I went to the doctor who said she thought it was a tick bite and gave me 3 antibiotics pills to take. Since then I have large knees that are painful and hot and I am very tried a lot. My hands are sore mostly my thumbs. I see floating color spots and my eye site blurry. I did get checked about 5 years after the bite again for limes and it came back all but one marker was positive for limes so I was told o do not have limes disease. I now have AFib. And I often wonder did they miss diagnose me?
I have not found the laboratory tests all that reliable. I have had to treat some of my patients based on clinical judgement rather than relying solely on the test. I have always encouraged someone who has bee ill for years after a tick and rash to be reevaluated by a doctor experienced in treating Lyme disease. BTW I would not be comfortable with “3” doxycycline after a tick bite.
During the summer of 1998 I was walking home in a pair of shorts due to hot weather, when I returned home I noticed a slight itching on the shin of my leg, I went to bed and when I awoke the next morning my leg had swelled up considerably and there was a red bullseye mark. I went to see my GP and he told me to go straight to the emergency dept. I was kept in hospital for 3 nights to treat the bite and returned home. Approx 3 years later I began having palpations which eventually was diagnosed as atrial fibrillation (lone afib). Could there be a link to the bite and the afib?
There are so many causes of atrial fibrillation. I reported on a published case in my blog to encourage doctors to look a second time for Lyme disease.
I had Lyme disease in 2008 treated with 3 months of iv rocephin. I have had afib not crontrolled well for several years. This winter had heart failure due to the afib. They tried to do electro cardoiversion which worked for a few days but returned to afib. I am on metoprolol, jardiance, lasix, xarelto and losartan. The electrocardiologiat said abblation will likely not work and rec to do a pacemaker. Want to be sure this is the right approach .
There are so many causes of atrial fibrillation to consider. I still look for evidence of a tick borne illness.
I had a cardiac ablation at John’s Hopkins less than two years ago for SVT (Holter Monitor captured 230 bpm for 23 mins). I’d been previously diagnosed twice (2 different strains) with Lyme disease. I asked then if the Lyme had produced this, since I’d not had heart issues before infection. It was unknown. Since the procedure, I have not had an episode of tachycardia. I’ve learned that about 30% of the population seems to have chronic Lyme symptoms, and I was being treated with pulse doses of antibiotics for continuing symptoms. I guess I’m wondering if I’d be a candidate for an atrial biopsy at any point. Thank you for your dedication to this.
I prescribe daily treatment in my practice.
I have had palpitations on and off for some years. A few months ago I experienced them again and the next day noticed a tick on my leg. The palpitations lasted about a week. Could a tick bite cause palpitations in isolation or should I be checked for Lymes disease?
Palpitation can occur in isolation. Palpitations can indicate POTS, a condition seen in Lyme disease. I also have had patients with both a history of Lyme and palpitations.
I developed afib in 2019, not long after I had found an embedded tick. I was not evaluated or treated for Lyme disease at the time. After a difficult year with increasingly severe afib symptoms that resisted other treatments, I had a cardiac ablation in July 2020 and the afib stopped. Three weeks ago, I found another tick on my leg, in February 2024. I have been diagnosed with Lyme disease this time . My afib has returned, unfortunately, despite two weeks of antibiotic treatment with doxycycline.
I included my understanding of the cardiac cases to encourage my colleagues to discuss the topic. I hope you resolve your issues.
Why are doctors so illiterate in treating diseases that have been around since the
70’s in the USA Really no excuse for this uneducated population. Lay people understand it better living with it. May god save us all.