Lyme disease, transmitted by ticks, can affect various body systems. While often associated with rashes and joint pain, the infection can also impact the heart. Cardiac involvement, known as Lyme carditis, occurs when the bacteria spread to heart tissue.
Understanding Lyme Carditis
Lyme carditis involves inflammation of the heart tissue, caused by the bacterium Borrelia burgdorferi. This bacterium can disseminate throughout the body, eventually reaching the heart and triggering an inflammatory response.
This inflammation often disrupts the heart’s electrical signaling system, commonly affecting the atrioventricular (AV) node. The AV node coordinates electrical signals between the heart’s upper and lower chambers, ensuring a synchronized heartbeat. When Borrelia burgdorferi interferes with this process, it can lead to heart block.
Heart block varies in severity, from mild delays in electrical signals to a complete blockage. In severe cases, electrical signals from the upper chambers may not reach the lower chambers, causing them to beat independently and much slower.
Recognizing Cardiac Symptoms
Individuals experiencing Lyme carditis often notice several symptoms. These may include lightheadedness or dizziness, sometimes leading to fainting. Such symptoms arise because the heart’s ability to pump blood effectively is compromised due to electrical disruption.
Shortness of breath, even with minimal exertion, is another common symptom. This occurs when the heart cannot adequately circulate oxygenated blood throughout the body. Patients may also experience heart palpitations, feeling as though their heart is fluttering, pounding, or skipping beats.
Chest pain can also be a symptom of Lyme carditis. These cardiac manifestations are directly linked to the heart block caused by the bacterial infection. Recognizing these symptoms, especially in someone who has had known or suspected tick exposure, prompts the need for medical evaluation.
Diagnosis and Treatment Approaches
Diagnosing Lyme carditis typically involves a comprehensive approach, starting with a thorough patient history and physical examination. Medical professionals will inquire about recent tick exposure or any prior Lyme disease symptoms. An electrocardiogram (ECG) is a crucial diagnostic tool used to detect heart block and other electrical abnormalities.
Blood tests are then performed to confirm the presence of Lyme infection. This usually involves a two-tiered testing process: an enzyme-linked immunosorbent assay (ELISA) as an initial screening test, followed by a Western blot to confirm positive or borderline results. These tests detect antibodies produced by the body in response to Borrelia burgdorferi.
Treatment for Lyme carditis primarily involves antibiotic therapy, which is highly effective. Intravenous (IV) antibiotics, such as ceftriaxone, are often administered, especially in cases with more severe heart block. In situations where the heart block is significant and causes symptoms like fainting or severe lightheadedness, a temporary pacemaker may be implanted to maintain a stable heart rhythm until the antibiotics take effect.
Recovery and Long-Term Outlook
With prompt and appropriate antibiotic treatment, the prognosis for Lyme carditis is generally favorable. Most patients experience a full recovery of heart function. The heart block typically resolves within a few days to several weeks after starting antibiotic therapy.
Cases of persistent heart block requiring a permanent pacemaker are rare when the condition is treated early. While some individuals may experience lingering symptoms after treatment for Lyme disease in general, serious long-term cardiac complications from Lyme carditis are uncommon. Early identification and intervention are important for achieving a positive outcome and preventing long-term cardiac issues.