We report an interesting case of a young drug addict admitted to the emergency department with a high degree A-V block. The diagnosis of Lyme carditis was made and there was a progressive regression of the A-V block under antibiotic therapy. However, by focusing on the cardiac manifestations and misled by the patient's drug abuse, concomitant neurological manifestations were picked up late in the hospitalization. Missing the diagnosis of Lyme-meningoencephalitis could have compromised the patient's long-term prognosis. Therefore we stress the importance to think outside the heart as cardiologists!