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Can Lyme disease cause heart problems? Learn the symptoms of Lyme carditis, palpitations, tachycardia, dizziness, fainting, and when to seek evaluation.
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Can Lyme Disease Cause Heart Problems? Understanding Lyme Carditis Symptoms
Lyme disease can affect the heart
Palpitations, dizziness, and fainting deserve evaluation
Many cases of Lyme carditis improve with treatment
Lyme disease can affect the heart and cause symptoms ranging from mild palpitations to serious rhythm disturbances. Patients may report chest discomfort, dizziness, fainting, shortness of breath, or an unusually slow or rapid heartbeat. These symptoms may develop weeks after infection and may occur even when a tick bite or rash was never noticed.
Although heart involvement is less common than joint or neurologic symptoms, recognizing Lyme-related cardiac complications early is important because many cases improve with appropriate treatment.
What Is Lyme Carditis?
Lyme carditis occurs when Lyme disease affects the electrical conduction system of the heart. Cardiac involvement most commonly presents during the early disseminated stage of infection and may lead to fluctuating conduction abnormalities, including atrioventricular (AV) block.
Although AV block is the hallmark of Lyme carditis, some patients may also experience other rhythm disturbances, including bradycardia (slow heart rate), tachycardia (fast heart rate), or an irregular heartbeat (arrhythmia). Symptoms may fluctuate over hours to days, which is why repeat electrocardiograms (ECGs) or continuous cardiac monitoring are sometimes necessary.
Studies suggest conduction abnormalities account for most presentations of Lyme carditis, and rhythm changes can fluctuate rapidly over hours to days. Continuous monitoring may be necessary in higher-risk cases.
What Are Common Cardiac Symptoms of Lyme Disease?
Patients with Lyme-related cardiac involvement may experience:
- Palpitations
- Lightheadedness
- Dizziness
- Chest discomfort
- Fainting or near-fainting
- Shortness of breath
- Exercise intolerance
- Rapid heart rate (tachycardia)
- Slow heart rate (bradycardia)
- Irregular heartbeat (arrhythmia)
- Fatigue
These symptoms can overlap with dysautonomia, anxiety, dehydration, viral illnesses, medication side effects, or primary heart disease, making diagnosis more challenging.
Can Lyme Disease Cause Tachycardia and Palpitations?
Some patients experience rapid heart rate, pounding heartbeat, or positional symptoms that overlap with autonomic dysfunction. Lyme disease has also been associated with autonomic symptoms involving blood pressure regulation and heart rate control.
Not every patient with a rapid heart rate has Lyme carditis. Tachycardia may also occur because of autonomic dysfunction, dehydration, fever, pain, anxiety, or other medical conditions, making careful evaluation important.
Patients with dizziness, racing heart, and standing intolerance may also benefit from learning more about autonomic dysfunction in Lyme disease and POTS symptoms and postural tachycardia syndrome.
Why Not Every Racing Heart Is Lyme Carditis?
Not everyone with Lyme disease who experiences palpitations or a rapid heart rate has Lyme carditis. Some patients develop autonomic dysfunction, including symptoms consistent with postural orthostatic tachycardia syndrome (POTS), which can cause tachycardia, dizziness, exercise intolerance, and lightheadedness when standing.
Unlike Lyme carditis, these symptoms are generally related to abnormal regulation of heart rate and blood pressure rather than inflammation of the heart’s electrical conduction system. Some patients with autonomic dysfunction also report blood pressure fluctuations, which may reflect dysregulation of the autonomic nervous system rather than direct infection of the heart itself.
Why Lyme Carditis Can Be Missed
Diagnosis may be delayed because many patients do not remember a tick bite or rash. Cardiac symptoms may appear weeks after infection and may initially resemble anxiety, dehydration, viral illness, or primary cardiac disease.
Patients with delayed recognition may already have experienced multiple evaluations before Lyme disease enters the differential diagnosis. This pattern overlaps with broader issues involving delayed Lyme disease diagnosis.
Heart symptoms may also overlap with symptoms related to autonomic dysfunction, making clinical evaluation more complicated.
How Is Lyme Carditis Evaluated?
Evaluation often includes:
- History of tick exposure or outdoor activity
- Physical examination
- Electrocardiogram (ECG)
- Continuous cardiac monitoring when indicated
- Serologic testing for Lyme disease
- Echocardiography or additional cardiac imaging in selected cases
Patients with fainting, severe symptoms, or significant conduction abnormalities generally require closer monitoring because progression can occur rapidly.
Frequently Asked Questions
Can Lyme disease cause heart palpitations?
Yes. Palpitations are among the more common cardiac complaints reported by patients with Lyme-related cardiac involvement or autonomic dysfunction.
Can Lyme disease cause tachycardia?
Some patients develop rapid heart rate due to dysautonomia, inflammation, or conduction abnormalities. Careful evaluation is important because not all tachycardia is caused by Lyme carditis.
Can Lyme disease cause an irregular heartbeat?
Yes. Lyme carditis may cause abnormalities in the heart’s electrical conduction system that lead to an irregular heartbeat (arrhythmia), although atrioventricular block remains the most characteristic finding.
How common is Lyme carditis?
Cardiac involvement is less common than neurologic or joint symptoms but remains clinically important because conduction abnormalities can occasionally become severe.
Can Lyme disease cause fainting?
Yes. Syncope or near-syncope may occur in patients with rhythm abnormalities, conduction disturbances, or autonomic dysfunction.
Can heart symptoms improve after treatment?
Many rhythm abnormalities improve with treatment and monitoring, although recovery timelines vary.
Clinical Takeaway
Cardiac symptoms can be among the more concerning manifestations of Lyme disease because they may overlap with both primary heart disease and autonomic dysfunction. Distinguishing Lyme carditis from conditions such as POTS or other forms of dysautonomia is important, as the underlying mechanisms and management may differ.
Patients with dizziness, fainting, palpitations, chest discomfort, or unexplained conduction abnormalities—particularly in Lyme disease endemic regions—may warrant evaluation for Lyme carditis, as many conduction abnormalities improve with appropriate treatment.
Heart symptoms should remain part of the Lyme disease differential diagnosis, especially when the clinical picture does not fit neatly into a single explanation.
Related Articles
You may also find these articles helpful when exploring the cardiovascular and neurologic manifestations of Lyme disease:
Lyme Disease Symptoms Guide
How Lyme Disease Is Misdiagnosed
Persistent Lyme Disease: An Overview
Recovery from Lyme Disease
Lyme Disease Pain: Types, Causes, and Treatment
References
- Scheffold N, Herkommer B, Kandolf R, May AE. Lyme carditis—Diagnosis, treatment and prognosis. Dtsch Arztebl Int. 2015;112(12):202-208.
- Radesich C, Del Mestre E, Medo K, et al. Lyme carditis: From pathophysiology to clinical management. Pathogens. 2022;11(5):582.
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
