Abstract
Lyme carditis (LC) is an early-disseminated manifestation of Lyme disease, most commonly presenting as a high-degree atrioventricular block (AVB). The degree of AVB can fluctuate rapidly within minutes, and progression to third-degree AVB is potentially fatal if not recognized and managed promptly. However, the AVB in LC is often transient and usually resolves with appropriate antibiotic therapy. LC should be on the differential diagnosis in young patients presenting with new high-degree AVB and factors that increase the index of suspicion for Lyme disease. The Suspicious Index in Lyme Carditis (SILC) score helps clinicians risk-stratify for LC. A systematic approach to the diagnosis and treatment of LC minimizes the unnecessary implantation of permanent pacemakers.