Lyme Endocarditis Causing Mitral Valve Disease in a 68-Year-Old Man

In March 2017, a 68-year-old man was admitted to the Mayo Clinic in Rochester, Minnesota,
with symptoms suggestive of advanced heart failure.

“He had a chronic cough and progressive dyspnea, which were consistent with New York Heart
Association class IV symptoms of heart failure,”

writes Fatima. “He also had atrial fibrillation with rapid ventricular response.”

The patient’s medical history was notable for alcoholism and prior treatment for Lyme
carditis in both 2009 and 2014.

Delayed Diagnosis of Lyme Endocarditis

Due to worsening symptoms and multivalve disease, surgeons performed mitral valve surgery.
Routine cultures were negative, but clinicians suspected culture-negative infective
endocarditis and initiated intravenous vancomycin and cefepime.

The diagnosis of Lyme disease was delayed. One week after hospital discharge—and 12 days
after surgery—Borrelia burgdorferi DNA was detected in mitral valve tissue using
polymerase chain reaction (PCR) testing.

Subsequent serologic testing confirmed Lyme disease. Both IgG and IgM Western blot assays
were positive.

IgG-positive bands included p93, p66, p58, p45, p41, p39, p30, p28, p23, and p18. IgM bands
included p39 and p23, confirming the diagnosis of acute Lyme endocarditis according to
Centers for Disease Control and Prevention (CDC) criteria.

Treatment and Clinical Course

Antibiotic therapy was changed to a six-week course of intravenous ceftriaxone.

“Endocarditis caused by Borrelia has been reported only twice previously, and in
both cases the species involved (Borrelia afzelii and Borrelia bissettii)
were not present in North America,” the authors note.

This case was particularly challenging because the patient experienced ongoing atrial
fibrillation with rapid ventricular response, as well as complications related to mitral
valve dysfunction, which led to tonic-clonic seizures and transient right-sided weakness.

[bctt tweet=”For the first time, Lyme disease was identified as the cause of mitral valve endocarditis.” username=”DrDanielCameron”]

Fortunately, the patient was doing well at his 10-month follow-up appointment. A repeat PCR
test for Borrelia burgdorferi was negative.

Cardiac Manifestations of Lyme Disease

According to the authors, Lyme disease can cause two major categories of cardiac involvement:
conduction disturbances and structural heart disease.

“Rhythm abnormalities related to Lyme carditis include atrioventricular conduction block,
sinoatrial block, temporary bundle branch block, and paroxysmal atrial fibrillation,” the
authors explain.

They emphasize that Lyme endocarditis is exceedingly rare and that no disease-specific
treatment guidelines currently exist.

“We opted to treat our patient with six weeks of ceftriaxone, in accordance with general
treatment recommendations for bacterial endocarditis,” Fatima writes.

Editor’s note:
This represents the patient’s third cardiac complication due to Lyme disease over an
eight-year period.