Lyme Carditis Diagnosis and Treatment

Diagnostic Approach

In patients with acute myocarditis/pericarditis of unknown cause in an appropriate epidemiologic setting, the American College of Rheumatology recommends testing for Lyme disease 1, 2, 3
The American College of Rheumatology suggests looking for specific cardiac symptoms that warrant evaluation, including dyspnea, palpitations, lightheadedness, chest pain, or syncope 1, 2, 3
The American College of Rheumatology also recommends considering exercise intolerance, presyncope, or pericarditic pain as symptoms that warrant evaluation 1, 2, 3
Evidence of pericardial effusion or elevated cardiac biomarkers, such as troponin, should also be considered 1, 2, 3
Edema or shortness of breath are additional symptoms that may indicate Lyme carditis 1, 2, 3

The American College of Rheumatology recommends performing an ECG only in patients with signs or symptoms consistent with Lyme carditis 1, 2, 3
In the absence of concomitant erythema migrans, serologic confirmation is necessary, according to the American College of Rheumatology 4
The American College of Rheumatology suggests that cardiac biomarkers, such as troponin, may be elevated in patients with Lyme carditis 1, 2, 3
The American College of Rheumatology recommends admitting patients with continuous ECG monitoring if they have a PR interval >300 milliseconds 2
The American College of Rheumatology suggests starting IV ceftriaxone initially, then switching to oral antibiotics once clinical improvement occurs, for hospitalized patients 1, 5, 6
For outpatients, the American College of Rheumatology recommends using oral antibiotics, with options including doxycycline, amoxicillin, cefuroxime axetil, and azithromycin 1, 5, 6
The American College of Rheumatology recommends treating for 14-21 days total, not longer durations 1, 5, 6, 4

For symptomatic bradycardia that cannot be managed medically, the American College of Rheumatology recommends using temporary pacing modalities rather than implanting a permanent pacemaker 1, 2, 3

The American College of Rheumatology recommends not routinely testing for Lyme disease in patients with chronic cardiomyopathy of unknown cause 1, 2, 3
The American College of Rheumatology suggests not implanting permanent pacemakers prematurely, as conduction abnormalities typically resolve with antibiotic treatment 1, 2, 3