Lyme
carditis is typically characterized by varying degrees of intermittent
atrioventricular block occurring within weeks of
infection with Borrelia burgdorferi.
Myocarditis and/or
pericarditis may occur.
Cardiomyopathy has been associated with B. burgdorferi in Europe, but not in the United States. Patients with unexplained
atrioventricular block or myopericarditis should be questioned for recent travel to tick-endemic areas, and for a history of
erythema migrans
rash, "viral-like" illness,
aseptic meningitis,
cranial nerve palsy,
radiculitis, or
oligoarthritis. However, the absence of a recognized
tick bite or
rash does not rule out
Lyme disease. The diagnosis of Lyme
carditis should be supported by the presence of concurrent
erythema migrans, or by positive results of 2-step laboratory testing for
antibodies to B. burgdorferi. False positive results may occur, emphasizing the importance of clinical judgment in attributing specific manifestations to B. burgdorferi
infection.
Carditis generally resolves spontaneously, but antimicrobial
therapy can shorten symptom duration and prevent potential cardiac and non-cardiac sequelae. Cardiac manifestations generally resolve spontaneously, but antimicrobial
therapy can shorten symptom duration and prevent potential cardiac and non-cardiac sequelae. The prognosis for Lyme
carditis is excellent.