Lyme disease is a multisystem disease caused by infection with Borrelia burgdorferi. Cardiac involvement occurs during the early disseminated phase of the disease, usually within weeks to a few months after the onset of infection [1,2]. The most common clinical feature of Lyme carditis is atrioventricular (AV) conduction block related to dysfunction of the conduction system, but may also include decreased cardiac contractility due to myopericarditis.
The epidemiology, clinical manifestations, diagnosis, treatment, and prognosis of Lyme carditis will be reviewed here. Other manifestations of Lyme disease are discussed separately. (See "Epidemiology of Lyme disease" and "Clinical manifestations of Lyme disease in adults" and "Lyme disease: Clinical manifestations in children" and "Nervous system Lyme disease" and "Musculoskeletal manifestations of Lyme disease" and "Treatment of Lyme disease".)
The incidence of Lyme carditis has varied in different reports:
●In the United States, Lyme carditis is estimated to occur in approximately one percent of patients with Lyme disease based on surveillance data from 2001 and 2010 . Earlier studies reported carditis in approximately four to ten percent of untreated adults [1,4-6]. This difference is likely due to the widespread recognition and treatment of early Lyme disease. As an example, four percent of patients developed carditis with evidence of AV nodal block in a prospective study of patients with erythema migrans who did not receive antibiotic treatment .
●In Europe, carditis has been reported as a complication of Lyme disease in approximately 0.3 to 4.0 percent of untreated adults . Some authors have suggested that the incidence of carditis may be lower in Europe compared with the United States. However, given the possible overestimate of clinically significant cardiac manifestations in the United States described above , the incidence of Lyme carditis may be similar in both regions.