OBJECTIVES. We sought to identify predictive factors for Lyme carditis in children and to characterize the clinical course of these patients.
METHODS. We reviewed all cases of early disseminated Lyme disease presenting to our institution from January 1994 through July 2008, and summarized the presentation and course of those patients with carditis. A case-control study was used to identify predictive factors for carditis. Controls were patients with early disseminated Lyme disease without carditis.
RESULTS. Of 207 children with early disseminated Lyme disease, 33 (16%) had carditis, 14 (42%) of whom had advanced heart block, including 9 (27%) with complete heart block. The median time to recovery of sinus rhythm in these 14 patients was 3 days (range: 1–7 days), and none required a permanent pacemaker. Four (12%) of 33 patients with carditis had depressed ventricular systolic function, 3 (9%) of whom required mechanical ventilation, temporary pacing, and inotropic support. Complete resolution of rhythm disturbances and myocardial dysfunction occurred in 24 (89%) of 27 patients for whom follow-up data were available. Most patients with carditis also had other systemic Lyme involvement. By using multivariate logistic regression analysis, we found that children >10 years of age, those with arthralgias, and those with cardiopulmonary symptoms were more likely to have carditis.
CONCLUSIONS. The spectrum of presentation for children with Lyme carditis is broad, ranging from asymptomatic, first-degree heart block to fulminant myocarditis. Variable degrees of heart block are the most common manifestation and occasionally require temporary pacing. Transient myocardial dysfunction, although less common, can be life-threatening. Advanced heart block resolves within 1 week in most cases. In children with early disseminated Lyme disease, older age, arthralgias, and cardiopulmonary symptoms independently predict the presence of carditis.