Madison Area Lyme Support Group

“[Lyme carditis] is caused by direct invasion of myocardial tissue by spirochetes and an immunological host response causing lymphocyte inflammation,” writes Marcos.¹

Furthermore, “B. burgdorferi has a predisposition to cause inflammation of the atrioventricular (AV) node resulting in variable conduction abnormalities.”

The 18 patients with possible Lyme carditis were predominantly Caucasian males with a mean age of 44.5 years (range was 24-79).

All of the patients met the CDC surveillance case definition for Lyme disease. One patient had an erythema migrans (EM) rash with negative blood tests.

The remaining 17 individuals had 2-3 IgM specific bands for Lyme disease. Of these, 5 presented with an EM rash and 11 had 5 or more IgG bands, explains Marcos.

“The most common symptoms at presentation were chest tightness, dizziness, and dyspnea on exertion and symptoms had been present for 4-30 days,” writes Marcos.

The 18 patients exhibited a wide range of abnormal EKG findings:

4 – AV block (2nd and 1st degree AV block)
6 – Right bundle branch conduction abnormalities
2 – New onset of atrial fibrillation
3 – T wave inversion
1 – Sinus bradycardia with ST elevation
2 – Prolonged QT interval

The authors were not able to address the outcome as the study was retrospective.

Marcos and colleagues were able to find a growing number of Lyme carditis cases in the literature. The most common presentation involved atrioventricular conduction abnormalities. Others included: right bundle branch block (RBBB), left bundle branch block (LBBB), widening of the QRS complex, AV dissociation, atrial fibrillation, ventricular dysfunction, fulminant myocarditis, and cardiac arrest.

“The spectrum of ECG abnormalities in [Lyme disease] may be broader than that previously suspected,” the authors conclude. “Clinicians should be aware of these ECG abnormalities that may be a sign of [Lyme carditis] in hyperendemic areas.”

In their article “Increasing Burden of Lyme Carditis in United States Children’s Hospitals,” Beach et al.¹ reveal the rise in Lyme carditis cases throughout the U.S. The largest increases, they write, were found in the Midwest, including the Ohio valley.

According to the authors, the children with Lyme carditis were older than children with Lyme disease, who did not have Lyme carditis. On average, they were 13 years old and more likely to be male.

“Encounters for Lyme carditis are dramatically costlier than those for Lyme disease without carditis,” the authors explain. In fact, the median cost of treating a child with Lyme carditis was $9,104 with a range of $3,741 to $19,003. The median cost of treating a child with Lyme disease without Lyme carditis was $922 with a range of $238 to $4,987.

None of the 189 children identified in the database died. However, the database did not include out-of-hospital outcomes.

In the study, there was a broad range of cardiac codes identified among the 189 children. The authors could not be sure of the accuracy of the cardiac codes or whether there were pre-existing cardiac cases.

The list of cardiac cases is much broader than heart block, as identified in the Centers for Disease Control and Prevention’s (CDC) surveillance case definition.

Cardiac codes for 189 children with Lyme carditis

Out of the 189 children, cardiac codes identified in the database included:

First degree AV block – 28%
Acute myocarditis – 27%
Complete AV block – 17%
Second degree AV block – 15%
Heart disease NOS – 9%
Non-specific ECG abnormality – 4%
Cardiomyopathy – 4%
Premature beats – 3%
Right bundle branch block – 3%
Acute pericarditis – 2%
Atrial fibrillation/flutter – 2%
Suspected cardiovascular disease – 2%
Paroxysmal ventricular tachycardia – 2%
Cardiac arrest – 2%
Congestive heart failure NOS – 2%
Conduction disorder NOS – 1%
Left bundle branch block – 1%
Anomalous AV excitation – 1%
Paroxysmal supraventricular tachycardia – 1%
Paroxysmal tachycardia – 1%
Pericardial disease NOS – 1%
Other cardiac dysrhythmias – 38%

Additional costs

The authors were not able to address other costs due to Lyme carditis. “In addition to this financial burden, it is important to consider the additional costs of missed school and work, long-term morbidity, and emotional distress when considering the importance of preventing, diagnosing, and treating Lyme carditis,” writes Beach.

“The increasing number of serious cardiac events and costs associated with Lyme disease emphasize the need for prevention and early detection of disease and control of its spread,” the authors conclude.