Cardiovascular Manifestations of Lyme Disease

Lyme disease is a tick-borne zoonosis caused by Borrelia burgdorferi that can involve multiple organ systems, including the cardiovascular (CV) system, noted in ~1-10% of untreated patients. This can produce atrioventricular (AV) or bundle branch block, atrial fibrillation, and myopericarditis in the acute phase, and dilated cardiomyopathy in the chronic phase. Myocardial involvement may lead to ventricular tachyarrhythmias and sudden death. AV block is reported in ~90% of cases, and in 30-60% of cases, it may necessitate cardiac pacing, at least temporarily, as most cases of high-degree AV blocks resolve with antibiotic therapy within 1 week. Occasionally, aortic dissection may occur. Although Lyme carditis, in the form of myocarditis, pericarditis, and less often endocarditis, is generally self-limited with early appropriate therapy, there is also the potential for lasting CV sequelae, such as persistent AV block (noted in 90% of cases), dilated cardiomyopathy and heart failure, and the rare occurrence of coronary artery involvement and aneurysmal changes. Patients with Lyme disease should receive oral tetracycline or penicillin, which can decrease the incidence of late-stage disease; however, some patients may fail early treatment. In cases of aseptic meningitis and radiculoneuritis, IV penicillin will be needed. As Lyme disease has now replaced syphilis as the "Great Imitator," physicians should be at vigilance for the disease, especially in endemic areas, and be familiarized with the particular skin rash of erythema chronicum migrans, an expanding skin lesion with the characteristic "bull's-eye" appearance patch with a center of clear skin and a distinct peripheral outer erythematous ring.