Lyme Myocarditis: Another Cardiac Manifestation of Lyme Disease
Lyme disease can affect the heart in ways that are sometimes unexpected. In one reported case, a patient presented with conduction abnormalities and reduced cardiac function consistent with Lyme myocarditis.
A 30-year-old man presented to the emergency department with “a pulse of 53/min and annular macular rash located over the anterior and posterior aspect of the left chest wall,” writes Cunha. Laboratory testing confirmed Lyme disease by ELISA and both IgG and IgM Western blot.
His ejection fraction was mildly reduced at 50%. The rash and left bundle branch block (LBBB) resolved quickly after two weeks of doxycycline.
Cardiac Manifestations of Lyme Disease
Lyme carditis has been recognized for decades. “The first reported cases of Lyme carditis was in 1980, when Steere and colleagues described 20 North American cases,” Cunha notes.
Since then, a wide range of cardiac manifestations have been described, including:
- Atrioventricular block, including complete or high-grade block
- Alternating right and left bundle branch block
- Diffuse ST segment and T wave changes on electrocardiogram
- Cardiomegaly
- Left ventricular systolic dysfunction
- Congestive heart failure
For a broader overview, see Lyme disease symptoms guide.
Why Lyme Carditis Can Be Dangerous
“The conduction disturbances associated with Lyme carditis can be variable and rapidly fluctuating,” writes Cunha.
Patients may progress from a prolonged PR interval to complete heart block within minutes, sometimes with alternating tachycardia and bradycardia. These features are among the most suggestive signs of cardiac involvement.
Although most conduction abnormalities are reversible, the timing of recovery is unpredictable.
Clinical Implications
This case highlights the importance of recognizing cardiac involvement in Lyme disease. Conduction abnormalities, myocarditis, and reduced cardiac function may occur even in otherwise healthy individuals.
Prompt evaluation and treatment are critical, as cardiac symptoms can evolve rapidly. For more on how Lyme disease affects different organ systems, see how Lyme disease is transmitted and its systemic effects.
Takeaway
Lyme myocarditis is one of several cardiac manifestations of Lyme disease. Although often reversible with treatment, conduction abnormalities can progress quickly and require timely recognition.
References:
- Cunha BA, Elyasi M, Singh P, Jimada I. Lyme carditis with isolated left bundle branch block and myocarditis successfully treated with oral doxycycline. IDCases. 2018;11:48-50.
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
My cardiac lyme list began in my 30s after about 17 yrs of undiagnosed/ misdiagnosed infection with arrhythmias: PACs, PVCs, paroxysmal afib, supraventricular tachycardia, non-sustained ventricular tachicardia. Then episodes of 1st and 2nd degree heart block. Now after about 40 years of infection, left ventricular diastolic dysfunction.
Can I ask what are your symptoms. I was just diagnosed with Lyme disease a few months ago and keep having weird feelings with heart flutters, chest pains, shoulder blade pains. I am on my 2nd round of dox
I have had 15 episode’s post mitro valve repair of flash pulmonary edema.. can chronic Lyme be the cause if that. I went misdiagnosed for Lyme for 18 years then 7 years ago finally Lyme showed up in a blot test. Of course at that point the heart issues began. But post open heart my echo heart pressures are still not normal.. But the docs say you were already given 3 months if antibiotics so your Lyme is gone. I am Not convinced of that whatsoever.. I’m still very I’ll
I have not seen it. I have seen individuals with two illnesses. It can be difficult to be sure a tick borne illness has resolved it here is another concurrent illness.
Do you see the heart symptoms worse when lying down?
I was misdiagnosed for 18 years, then have treated with several antibiotics and herbals for 4 now. The worse heart symptoms seem to come when I lie down in exhaustion. Rest rarely feels restful.
I have patients in my practice with autonomic issues related to a tick borne infection. Some have been told they suffer from POTS.
I was diagnosed and treated for lyme disease and several co-infections in 2021. My eye sight suffered and I had cataract surgery in Dec.2022 and January 2023. Two months of prednisolone after the cataract surgeries resulted in all kinds of symptoms. I met with a cardiologist in May 2023, had ekg, Holter monitor, and echo/stress tests. I have been diagnosed with LBBB. Should I be treated further for lyme that may have reactivated after being on prednisolone or is this most likely to be residual damage from the original infection?
I advise my patients to return for an evaluation is there is a recurrence of symptoms with or without steroids.
My recent EKG revealed a Complete Left Bundle Branch Block and, having lived in the Hudson Valley for the prior seven years, I am wondering if this could be Lyme Disease. I have low cholesterol, normal blood pressure, and I’m not obese.
I rely on my cardiologists and the hospital for initial care. Lyme disease is only one of many causes of left bundle branch block for a doctor to consider. I have had patients where other symptoms have helped identify Lyme disease.