Recognizing Lyme Carditis

Joseph D. Forrester, MD, MSc


January 13, 2014

Editorial Collaboration

Medscape &

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Hello. I am Dr. Joe Forrester, an Epidemic Intelligence Service Officer in the Bacterial Diseases Branch of CDC's Division of Vector-Borne Diseases. I'm pleased to speak with you as part of the CDC Expert Commentary Series on Medscape.

Today I will discuss Lyme carditis and describe 3 recent cases of sudden cardiac death among young adults with this condition. I will also provide guidance on evaluating patients with suspected Lyme carditis.

Lyme disease is a multisystem illness caused by Borrelia burgdorferi, a spirochete transmitted by certain species of Ixodes ticks. More than 30,000 cases are reported annually in the United States, primarily from high-incidence states in the Northeast and the upper Midwest.[1,2] The most common signs of Lyme disease are the erythema migrans rash, which appears in approximately 70% of reported cases, followed by rheumatologic and neurologic manifestations.

Carditis is a rare complication of Lyme disease that occurs when Lyme spirochetes invade the tissues of the heart, producing in some cases a pancarditis that involves the endo-, myo-, epi-, and pericardium simultaneously. The most commonly recognized clinical feature of Lyme carditis is atrioventricular block, which can fluctuate between first-, second-, and third-degree block. Among Lyme disease cases reported to CDC, second- or third-degree heart block occurs in approximately 1% of patients about whom clinical details are available.[2]

Typical symptoms include palpitations, syncope, chest pain, and dyspnea. These symptoms usually occur in conjunction with more common symptoms of Lyme disease, such as muscles aches, fever, fatigue, and erythema migrans, and they usually begin within 2-4 weeks of these other symptoms, although a gap of up to 7 months has been reported.[3,4] Why carditis develops in some patients and not others is not known.

The prognosis is generally excellent with appropriate antimicrobial therapy.[5] Because a temporary pacemaker may be required, hospitalization is recommended for patients with second- or third-degree heart block, and for patients with first-degree block and a PR interval > 30 milliseconds. Signs of cardiac involvement usually resolve within 1-6 weeks after initiation of antibiotics.[6] Detailed management recommendations are available in "The Clinical Assessment, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: Clinical Practice Guidelines," by the Infectious Diseases Society of America.[5]

Although death due to Lyme carditis is rare,[7,8,9,10] CDC recently reported[11] 3 cases of sudden cardiac death, occurring between November 2012 and July 2013, among patients with unrecognized Lyme carditis. These cases were identified in conjunction with a tissue bank and state and local health departments. The deaths involved 1 female and 2 male patients, ages 26 to 38, all from Northeastern states with high rates of reported Lyme disease. One of the 3 patients had malaise and muscle and joint pain in the week before death but did not seek care. Another developed shortness of breath and anxiety but was not diagnosed or treated for Lyme disease. None of the patients had evidence or a known history of erythema migrans rash. All 3 patients had serologic evidence of acute early disseminated Lyme disease, and spirochetes were detected in heart tissue by histopathologic examination, immunohistochemistry, and polymerase chain reaction.

In response to these deaths, CDC and state health department partners are working to better define groups at increased risk for Lyme carditis. Preliminary findings indicate that:

Males are disproportionately affected by Lyme carditis;

Persons aged 15-45 develop Lyme carditis more frequently than would be expected when compared with patients who develop Lyme disease as a whole;

Most cases occur in the summer or early autumn in high-incidence Lyme disease states; and

Only 40% patients with Lyme carditis report having erythema migrans rash, as compared with 70%-80% of patients overall.

Prompt recognition and early, appropriate therapy for Lyme disease is essential. Healthcare providers should:

Ask patients with suspected Lyme disease about cardiac symptoms, including palpitations, chest pain, lightheadedness, fainting, and shortness of breath, and obtain an ECG if indicated;

Ask patients with unexplained heart block about possible exposure to infected ticks; and

Encourage taking personal prevention measures, specifically using tick repellent, conducting daily tick checks, and showering soon after potential tick exposure.

For more information about Lyme disease, visit Lyme Disease. Thank you.

Web Resources

CDC: What You Need to Know About Lyme Carditis

National Heart, Lung, and Blood Institute: What Is Heart Block?

Joseph D. Forrester, MD, MSc, is an Epidemic Intelligence Service Officer with the US Centers for Disease Control and Prevention, Division of Vector-Borne Diseases, in Fort Collins, Colorado. His work involves epidemiologic investigations related to Lyme disease, plague, tickborne relapsing fever, tularemia, and other infectious diseases. Dr. Forrester holds a medical degree from the University of Virginia and a master of science degree in infectious disease from the London School of Hygiene and Tropical Medicine. He is a categorical general surgery resident at Stanford University.