Lyme carditis is increasingly being recognized as a serious health concern related to untreated Lyme disease or Tick-Borne Relapsing Fever (TBRF). Recently, Queen’s University, Ontario, Canada Professor of Medicine Adrian Baranchuk, MD gave a presentation about Lyme carditis at Stanford University. Read on to learn more about this potentially fatal symptom of Lyme disease, including details from some of Dr. Baranchuk’s cases.
Lyme carditis is inflammation of the heart caused by a Lyme infection. It occurs when B. burgdorferi – Lyme-causing bacteria – enter the heart tissues and interfere directly with the electrical signals that regulate the heartbeat. This is sometimes referred to as “conduction derangement.”
As such, a dangerous manifestation of Lyme carditis is what is known as atrioventricular block (AVB), or a blockage that prevents electrical signals from moving from the upper to the lower chambers of the heart. When these electrical signals are blocked, the heart can’t beat regularly, and patients can suffer arrhythmias or cardiac arrest. Atrioventricular block can progress rapidly from first to third degree, and total blockage is possible.
Lyme carditis is especially a risk of untreated Lyme or TBRF, since it sometimes doesn’t show up for weeks to months after an initial tick bite. It is typically a symptom of Stage 2 Lyme disease, also known as “Late Disseminated” Lyme, when neurological, musculoskeletal, and cardiac symptoms are more common. However, it can crop up earlier and progress rapidly, and antibiotic treatment should be adjusted depending on the stage of the disease.
Other Types of Lyme Carditis
Though AV blocks are the focus here, Lyme disease can affect every part of the heart. Beyond the conduction system, that includes the inner and outer membranes, cardiac muscle, cardiac blood vessel, and heart valves.
Symptoms of Lyme Carditis
When Lyme carditis is symptomatic, Dr. Baranchuk and the CDC report that patients may experience:
- Light-headedness
- Syncope (fainting)
- Dyspnea (shortness of breath)
- Heart palpitations
- Chest pain
However, symptoms can vary depending on the patient and may go unnoticed, especially if you don’t remember a rash, any other Lyme-like symptoms, or a tick bite. In fact, in over half of reported cases of Lyme carditis, the patient did NOT experience a characteristic bull’s-eye rash.
When Lyme carditis is asymptomatic or when it is the only symptom of Lyme disease a patient experiences, making a proper diagnosis can be especially difficult.
How common is Lyme carditis?
Dr. Baranchuk reports that Lyme carditis is fairly “rare,” with only 4-10% of patients with untreated Lyme developing some kind of Lyme carditis and only 1% of those patients developing AVB.
However, for those who do develop AVB, it can progress rapidly and become dangerous. Three of five male patients Dr. Baranchuk studied in 2018 developed third degree AVB, and one of them did not recover for 10 days, requiring the implantation of a temporary pacing wire for treatment.
Mirroring data from the CDC, Dr. Baranchuk reports that Lyme carditis is more common in males, who are affected three times as often as females.
Is Lyme carditis fatal?
Though death from Lyme carditis is rare, it is possible. The CDC reported three sudden deaths due to undetected Lyme disease between November 2012 and July 2013 alone.
The patients were one female and two males, all between the ages of 26 and 38, from Northeastern states where Lyme is endemic. Two of the patients had reported some symptoms beforehand, but there was no evidence of the bull’s-eye rash in any of the patients.
Treating Lyme Carditis: Why Proper Diagnosis is Crucial
When a patient presents with a condition like Lyme carditis, doctors will typically install a permanent pacemaker to regulate the heartbeat. However, this treatment comes with associated risks, including the need to replace the battery every ten years.
Crucially, Dr. Baranchuk’s cases – which typically resolved with antibiotics and only temporary pacemakers – show that it is NOT necessary to implant a permanent pacemaker (or expose the patient to associated risks) when the cause of carditis is Lyme disease.
Diagnosing and Treating Lyme Carditis
As with other Lyme and TBRF cases, doctors use a combination of a patient’s history and symptoms, a physical exam, and positive Lyme serology to diagnose Lyme carditis.
Rather than installing permanent pacemakers, Dr. Baranchuk recommends antibiotic treatment with a possible temporary pacing wire. The length and method of administration (i.e. oral or IV) of the antibiotic course depend on the stage of the disease, but the following is recommended:
- 10-21 days for Stage 1 (Early Localized)
- 14-28 days for Stage 2 (Early Disseminated)
- 28 days for Stage 3 (Late Disseminated)
Dr. Baranchuk’s cases showed that Lyme carditis can clear up, with or without temporary pacing, when Lyme is caught early and treated properly with antibiotics.
To recap, Dr. Baranchuk stresses the following information for physicians:
- Doctors should consider a diagnosis of Lyme carditis in younger patients presenting with severe conduction abnormalities.
- Atrioventricular block can progress rapidly in Lyme carditis and be fatal.
- Early treatment with antibiotics may prevent irreversible conduction disease in Lyme carditis.
- Before considering implantation of a permanent pacemaker, clinicians should wait for a response to antibiotic treatment for atrioventricular block requiring temporary pacing.
In addition, Dr. Baranchuk suggests using a COSTAR score as follows:
C – Constitutional symptoms – 2
O – Outdoor activity/endemic area – 1
S – Sex = male – 1
T – Tick bite – 3
A – Age < 50 – 1
R – Rash = erythema migrans – 4
Cardiologists should consider Lyme carditis for any patient with a score of 4 or higher. (Clinical Cardiology 2018;Dec;41(12):1611-1616)
As Dr. Baranchuk’s presentation makes clear, Lyme carditis is treatable with a timely diagnosis. When Lyme carditis is a possibility, his recommendation is to start IV antibiotics. For laboratory confirmation, it’s critical to get tested at a reputable center with the most accurate testing available so that doctors can make proper diagnoses and patients can avoid any unnecessary treatment. Learn about IGeneX’s tests for Lyme disease, TBRF, and more.
