Lyme disease patient presented as complete heart block: Case study

Dr. Milena Semproni, Infectious Diseases fellow at the University of Manitoba and Winnipeg Regional Health Authority, Winnipeg, Manitoba, with coauthors has reported a case of Fatal Lyme carditis presenting as fluctuating high-grade atrioventricular block.The case has been published in the Canadian Medical Association Journal ( CMAJ) .

In the instant case the patient originally presented to his family doctor with flu-like symptoms, including fever, sore throat, nasal congestion and migratory joint pain. Several weeks earlier, he had been in contact with ticks but didn't recall removing one. His physician suspected a viral infection, and the patient's symptoms resolved.

After few weeks later, he developed heart palpitations, shortness of breath and chest discomfort for which he was sent to the emergency department. Lyme disease was suspected as electrocardiography (ECG) showed complete heart block.

He was admitted to hospital and started on treatment for Lyme carditis, but his condition worsened quickly. Clinicians were unable to reverse the course of illness and he died. Serology results confirmed Lyme disease, and an autopsy showed signs of Lyme carditis.

"The diagnosis of Lyme carditis is based on clinical suspicion and serology consistent with acute Lyme disease," writes Dr. Milena Semproni, Infectious Diseases fellow at the University of Manitoba and Winnipeg Regional Health Authority, Winnipeg, Manitoba, with coauthors. "Unfortunately, diagnosis can be delayed while serology is being processed, and clinical suspicion should guide empiric treatment. Given that the early diagnosis is clinical, cases may be overlooked by clinicians, especially as Lyme disease moves into new geographic areas."

In suspected cases of Lyme carditis, patients should have an urgent ECG performed and be started on antibiotics without waiting for serologic confirmation.

The authors note that serious heart rhythm abnormalities and sudden cardiac death can occur in a small group of patients, although it is uncommon. In the 10 other North American cases of sudden cardiac death attributed to Lyme carditis described in the literature, 8 patients were male, and the cases occurred between June and November, when ticks are active.

"Given that most conduction abnormalities caused by Lyme carditis resolve with appropriate antibiotic therapy, recognition of atypical dermatologic presentations in the context of Lyme carditis prevents unnecessary permanent pacemaker implantation in these young and otherwise healthy individuals," writes Dr. Adrian Baranchuk, Department of Medicine, Queen's University, Kingston, with coauthors.

Carry home points include-

Clinicians should be aware of the risk of Lyme carditis in patients presenting with atrioventricular (AV) block, especially those with a history of outdoor exposure in Lyme endemic areas, even if they do not endorse tick exposure or history of erythema migrans.

Urgent electrocardiography shoud be obtained and antibiotics started early if there is suspicion of Lyme carditis, without waiting for serologic confirmation.

In patients with suspected Lyme carditis, monitoring with telemetry for at least 24–48 hours should be considered and availability of transcutaneous pacing ensured in case of deterioration.

Clinicians should recognize the potential for rapid progression of AV nodal block and symptomatic bradycardia, as well as sudden cardiac death in patients with Lyme carditis

For further reference log on to:

https://www.cmaj.ca/content/192/21/E574