From the Guidelines
Troponin can be elevated in Lyme carditis, as indicated by clinical manifestations of myopericarditis, which include elevated biomarkers such as troponin. Patients with Lyme carditis often show increased cardiac troponin levels as the infection causes inflammation of the heart tissue 1. Lyme disease, caused by the spirochete Borrelia burgdorferi, can affect the heart in approximately 4-10% of untreated cases, leading to various cardiac manifestations including myocarditis and conduction abnormalities. The inflammation damages cardiac myocytes, resulting in the release of troponin into the bloodstream.
Key Points to Consider
- The degree of troponin elevation may vary depending on the severity of cardiac involvement, with some patients showing mild elevations while others demonstrate more significant increases.
- Troponin elevation is not specific to Lyme carditis and can occur in many other cardiac conditions.
- When evaluating a patient with suspected Lyme carditis, clinicians should consider troponin testing alongside other diagnostic measures such as ECG, which typically shows AV block, and Lyme-specific serologic testing 1.
- Treatment involves appropriate antibiotics (typically ceftriaxone 2g IV daily for 14-21 days for severe cases, or doxycycline 100mg twice daily for 14-21 days for less severe cases) and cardiac monitoring, as the troponin levels typically normalize with successful treatment of the underlying infection.
Hospitalization and Monitoring
- Patients with significant PR prolongation (PR >300 milliseconds), other arrhythmias, or clinical manifestations of myopericarditis, including elevated troponin, require hospital admission with continuous ECG monitoring 1.
From the Research
Troponin Elevation in Lyme Carditis
- Troponin elevation in Lyme carditis is observed in some cases, as reported in a study where a patient presented with Lyme disease and had elevated Troponin I levels, mimicking myocardial infarction 2.
- Another study measured high-sensitivity troponin T (hsTnT) in patients with early Lyme disease and found that 14.6% of patients exhibited hsTnT values above the normal cutoff, suggesting possible subclinical cardiac involvement 3.
- However, the provided studies do not consistently report troponin elevation as a characteristic of Lyme carditis, with some studies focusing on the diagnosis and treatment of the condition without mentioning troponin levels 4, 5, 6.
Clinical Presentation and Diagnosis
- Lyme carditis often presents as atrioventricular block (AVB), with the degree of AVB fluctuating rapidly 4.
- Diagnosis is challenging and is based on geographical epidemiology, clinical history, signs and symptoms, serological testing, ECG and echocardiographic findings, and exclusion of other pathologies 4, 5.
- The use of antibiotics, such as doxycycline, is recommended for the treatment of Lyme carditis, and can lead to resolution of the condition, including complete heart block 6.