Lyme Carditis Symptoms: Heart Block May Be the Only Clue
Lyme carditis may occur without typical Lyme symptoms
Heart block or bradycardia may be the first clue
Early recognition may reduce serious complications
Lyme carditis symptoms can sometimes appear without a rash, fever, or remembered tick bite. In some cases, patients present with unexplained heart rhythm abnormalities, fatigue, shortness of breath, or dizziness long before Lyme disease is considered.
The authors describe a 70-year-old man who presented without typical Lyme disease symptoms but developed progressive orthopnea and dyspnea on exertion. His medical history included hypertension and calcific aortic stenosis.
Heart block may be the first sign of Lyme carditis symptoms
Laboratory findings were notable for an erythrocyte sedimentation rate of 136, white blood cell count of 16.6, hemoglobin of 9.3, creatinine of 2.6, and elevated brain natriuretic peptide levels. Troponins were negative.
His electrocardiogram showed bradycardia with a heart rate in the mid-40s and first-degree AV block.
“We report a case of a 70-year-old male with Lyme disease presenting with a second-degree, Mobitz type 1 AV block.”
Clinicians initially considered anemia, kidney disease, congestive heart failure, worsening aortic stenosis, or pneumonia before considering Lyme disease.
How Lyme carditis is diagnosed
Because the patient lived in an endemic region, clinicians ordered Lyme testing, which returned positive.
Lyme carditis diagnosis may require combining exposure history, electrocardiogram findings, Lyme testing, and clinical judgment. Some patients present without erythema migrans or remembered tick exposure, increasing diagnostic difficulty.
Questions commonly asked include:
- Can Lyme disease cause bradycardia?
- How is Lyme carditis diagnosed?
- Can Lyme carditis occur without a rash?
- Can Lyme disease cause shortness of breath?
Can Lyme carditis occur without a rash or tick bite?
Yes. Some patients with Lyme carditis do not remember a tick bite and may never develop erythema migrans. Missing these clues can delay diagnosis.
The authors emphasized regional risk:
“In highly endemic areas such as the northeast and Midwest United States, early recognition and treatment of Lyme disease is important for prevention of long-term complications.”
Treatment improved heart rhythm abnormalities
The patient was treated with IV ceftriaxone and oral doxycycline. His symptoms resolved and normal sinus rhythm returned without persistent AV block.
This case highlights why Lyme disease should remain on the differential diagnosis for unexplained conduction abnormalities, especially in endemic regions.
FAQ: Lyme Carditis Symptoms
What are common Lyme carditis symptoms?
Symptoms may include dizziness, fainting, palpitations, chest discomfort, shortness of breath, fatigue, bradycardia, and heart block.
Can Lyme carditis occur without a remembered tick bite?
Yes. Some patients with Lyme carditis do not remember a tick bite or develop a classic rash, which may delay diagnosis.
Can Lyme carditis cause shortness of breath?
Yes. Shortness of breath may occur when conduction abnormalities affect cardiac function.
How is Lyme carditis diagnosed?
Diagnosis typically combines clinical history, ECG findings, Lyme testing, symptoms, and regional exposure risk.
Clinical Perspective
Lyme carditis symptoms may appear without classic Lyme disease findings. Heart block, bradycardia, unexplained fatigue, or dyspnea may be the only clues. Recognizing atypical presentations may reduce complications and unnecessary cardiac procedures.
Clinical Takeaway
Patients with unexplained conduction abnormalities, particularly in endemic regions, should be evaluated for Lyme disease—even when rash and tick exposure are absent.
Related Articles
Learn more about cardiac complications and atypical presentations:
- Pacemakers for Lyme carditis
- Successful removal of pacemakers in patients with Lyme carditis
- Podcast: 3 deaths associated with Lyme carditis
- Unusual symptoms of Lyme disease
References
- Najam US, Sheikh A. An Atypical Case of Lyme Disease Presenting With Lyme Carditis. Cureus. 2023;15(3):e35907.
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
