The first data of Lyme carditis, a relatively rare manifestation of Lyme disease, were published in eighties of the last century. Clinical manifestations include syncope, light-headedness, fainting, shortness of breath, palpitations, and/or chest pain.
Atrioventricular (AV) electrical block of varying severity presents the most common conduction disorder in Lyme carditis. Although is usually mild, AV block can fluctuates rapidly and progress from a prolonged P-R interval to a His-Purkinje block within minutes to hours and days.
Rarely, Lyme disease may be the cause of endocarditis, while some studies and reports, based on serological and/or molecular investigations, have suggested possible influence of Borrelia burgdorferi on degenerative cardiac valvular disease.
Myocarditis, pericarditis, pancarditis, dilated cardiomyopathy, and heart failure have also been described as possible manifestations of Lyme carditis. The clinical course of Lyme carditis is generally mild, short term, and in most cases, completely reversible after adequate antibiotic treatment.
Source: By Kostic T1, Momcilovic S2, Perisic ZD1, Apostolovic SR1, Cvetkovic J3, Jovanovic A4, Barac A5, Salinger-Martinovic S1, Tasic-Otasevic S6. Manifestations of Lyme carditis. Int J Cardiol. 2016 Dec 27. pii: S0167-5273(16)34820-3. doi: 10.1016/j.ijcard.2016.12.169. [Epub ahead of print]