Lyme carditis in children: presentation, predictive factors, and clinical course.

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.