Lyme disease causes heart block within one month of infection

A 26-year-old man was admitted to the hospital with flu-like symptoms, syncope and exhibited third-degree atrioventricular heart block. He had experienced 3 episodes of syncope overnight and reported having a mild cough and congestion for several weeks prior to his admission.

The man had a tick bite one month earlier while visiting his family in Massachusetts, along with an EM rash on his chest. Upon physical exam, clinicians noted an erythema migrans rash on the patient’s feet, as well.

This case represents an occurrence of third-degree atrioventricular block secondary to Lyme disease.

The man had a blood pressure of 109/61 mmHg and a heart rate of 45 beats per minute with an irregular rhythm and an elevated white blood cell count. A chest x-ray and echocardiogram were normal.

“The decision was made to implant a temporary pacemaker,” the authors state.

“Empiric intravenous ceftriaxone and doxycycline were administered due to the suspicion of Lyme disease.”

Test results were positive for Lyme disease by Western blot. And, by the second day of antibiotic treatment, the patient’s heart rhythm had improved to first-degree atrioventricular block.

He continued to show improvement and the temporary pacemaker was removed.

“In this case, a known history of a tick bite helped to diagnose Lyme carditis quickly.”

“Lyme carditis can present with atrioventricular blocks or with new bundle branch blocks,” the authors explain. “With antibiotic therapy, most patients make a full recovery; however, about 30% of patients require temporary pacing.”

Authors conclude:

• “It is important to keep Lyme disease on the list of differential diagnoses for any patient presenting with flu-like symptoms, even in the absence of a tick bite or travel to endemic areas.”
• “Another classic sign of Lyme disease is the erythema migrans rash, though not every case will present with it. Again, the absence of this rash alone should not eliminate the possibility of Lyme disease.”
• “This case report shows just how quickly Lyme disease can disseminate when untreated and is a great example of the grave consequences that can occur.”

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