Lyme disease is a multisystem disorder affecting dermatologic, cardiac, nervous and musculoskeletal systems. Cardiac manifestations occur in about 5% of Lyme infections and stem from the involvement of the cardiac conduction system, resulting in varying degrees of sino-atrioventricular block. Occasionally, Lyme infection may also present with myopericarditis. Unlike isolated conduction node disease, myocardial involvement presents a great diagnostic and therapeutic dilemma for the physician. We report the case of a 68 year-old male cardiologist who presented with new onset exertional dyspnea and palpitations. Electrocardiograms revealed intermittent Wenckebach with markedly prolonged PR interval varying between 290-350ms. During his hospitalization, he also had a transient episode of atrial fibrillation/flutter with AV block. The patient was promptly treated with intravenous Ceftriaxone. He remained hemodynamically stable, and within 48 hours of antibiotic treatment, the patient’s arrhythmias began to resolve, and the PR interval had shortened to 230ms. He was discharged on oral Doxycyline for three weeks.