From the Guidelines
Yes, Lyme disease can cause bradycardia, which is an abnormally slow heart rate, as a result of Lyme carditis affecting the electrical conduction system of the heart. This typically occurs during the early disseminated phase of the infection, about 4-10 weeks after the initial tick bite. The bacteria that causes Lyme disease, Borrelia burgdorferi, can spread to the heart tissue and cause Lyme carditis, which affects the electrical conduction system of the heart, resulting in various degrees of heart block and bradycardia 1. Symptoms may include:
- Lightheadedness
- Fainting
- Shortness of breath
- Chest pain
- Palpitations Treatment typically involves antibiotics such as doxycycline (100mg twice daily for 14-21 days), ceftriaxone (2g IV daily for 14-21 days), or amoxicillin (500mg three times daily for 14-21 days) 1. In severe cases, temporary cardiac pacing may be necessary, as recommended by the Infectious Diseases Society of America (IDSA) for patients with symptomatic bradycardia due to Lyme carditis that cannot be managed medically 1. Lyme carditis is usually reversible with appropriate antibiotic treatment, but prompt medical attention is essential as untreated cases can lead to permanent heart damage or life-threatening complications. Hospital admission with continuous ECG monitoring is recommended for patients with or at risk for severe cardiac complications of Lyme disease, including those with significant PR prolongation (PR >300 milliseconds), other arrhythmias, or clinical manifestations of myopericarditis 1.
From the Research
Lyme Disease and Bradycardia
- Lyme disease can cause bradycardia (abnormally slow heart rate) as a result of Lyme carditis, which is a rare cardiac manifestation of the disease 2, 3, 4.
- Lyme carditis can lead to various cardiac conduction abnormalities, including high-grade atrioventricular block, which can result in profound bradycardia with pulse rates ranging around 30 beats per minute or lower 2.
- Sinus bradycardia without any conduction defects can also occur in patients with Lyme carditis, as reported in a case study where a patient presented with sinus bradycardia and was diagnosed with Lyme carditis 3.
- The treatment of Lyme carditis typically involves antibiotics, such as ceftriaxone, and can lead to the resolution of cardiac symptoms, including bradycardia 5, 6, 4.
Clinical Presentations and Diagnosis
- Lyme carditis can present with various symptoms, including bradycardia, heart block, and perimyocarditis, and can be diagnosed using electrocardiogram (ECG) and serological tests, such as ELISA and Western blot 2, 5, 3.
- A high clinical suspicion of Lyme carditis is required when someone from a Lyme-endemic region presents with unexplained cardiac symptoms and electrocardiogram abnormalities 3.
- The SILC (Suspicious Index in Lyme Carditis) score can assist in recognizing cases of Lyme carditis and prompt initiation of antibiotics usually leads to the resolution of electrocardiographic abnormalities and symptoms 6.
Treatment and Prognosis
- The prognosis for Lyme carditis is generally good, despite disagreement over the incidence of persistent B. burgdorferi infection, and treatment with antibiotics can lead to the resolution of cardiac symptoms, including bradycardia 2, 5, 4.
- In some cases, patients with Lyme carditis may require temporary or permanent pacing, but this is not always necessary, and treatment with antibiotics can often lead to the resolution of cardiac symptoms without the need for pacing 3, 6, 4.