BACKGROUND - Cardiac involvement is common in acute Lyme disease, and case reports suggest that cardiac abnormalities might also occur years after the primary infection.
OBJECTIVE - To determine the prevalence of cardiac abnormalities in persons with previously treated Lyme disease.
DESIGN - Population-based, retrospective cohort study with controls.
SETTING - Nantucket Island, Massachusetts.
PARTICIPANTS - From among 3703 adult respondents to a total-population (n = 6046) mail survey, 336 (176 case-patients and 160 controls) were randomly selected for clinical evaluation.
MEASUREMENTS - Current cardiac symptoms and major or minor abnormal electrocardiographic features, including heart rate; rhythm; axis; PR, QRS, and QT intervals; QRS structure; atrioventricular blocks; and ST-segment and T-wave changes.
RESULTS - Persons with Lyme disease (case-patients, n = 176) (mean duration from disease onset to study evaluation, 5.2 years) and persons without evidence of previous Lyme disease (controls, n = 160) did not differ significantly in their patterns of current cardiac symptoms and electrocardiographic findings, including heart rate (P > 0.2), PR interval (P = 0.15), QRS interval (P > 0.2), QT interval (P > 0.2), axis (P > 0.2), presence of arrhythmias (P > 0.2), first-degree heart block (P = 0.12), bundle-branch block (P > 0.2), and ST-segment abnormalities (P > 0.2). In multivariate analyses that adjusted for age, sex, and previous heart disease, a history of previously treated Lyme disease was not associated with either major (odds ratio, 0.78; P > 0.2) or minor (odds ratio, 1.09; P > 0.2) electrocardiographic abnormalities.
CONCLUSION - Persons with a history of previously treated Lyme disease do not have a higher prevalence of cardiac abnormalities than persons without a history of Lyme disease.