Growing List of Cardiac Problems in Lyme Disease

Lyme carditis is a potentially serious complication of Lyme disease that can disrupt the heart’s electrical conduction system.

Although first-degree AV block is the most common presentation, Lyme disease has been associated with a growing list of cardiac rhythm abnormalities described in the medical literature. [1]

A published case report by Kannangara and colleagues described the first reported case of inducible heart block in Lyme disease. [1]

Case Report: Inducible Heart Block in Lyme Disease

A 37-year-old man initially presented to the emergency department after experiencing syncope.

His electrocardiogram (ECG) demonstrated sinus bradycardia with first-degree AV block and a prolonged PR interval of 480 milliseconds. [1]

An exercise stress test performed by a cardiologist had to be terminated early after the patient developed dyspnea.

During exertion, the ECG demonstrated progression from first-degree AV block to high-degree AV block. [1]

The Majority of AV Blocks in Lyme Carditis Are Reversible

Once the patient returned to rest, the high-degree AV block reverted back to first-degree AV block.

The patient experienced a similar episode while walking in the hospital hallway while wearing a Holter monitor several days later. [1]

Most AV conduction abnormalities associated with Lyme carditis improve with appropriate antibiotic treatment.

The patient was diagnosed with Lyme disease based on:

Exposure history
History of tick bites
Positive IgG Western blot testing
Absence of another identifiable cause
Clinical recovery following treatment

He was treated with intravenous ceftriaxone followed by oral doxycycline.

The patient reportedly returned to work and remained symptom-free two years later. [1]

Cardiac Problems Reported in Lyme Disease

Kannangara and colleagues summarized the growing list of cardiac rhythm abnormalities reported in Lyme disease. [1]

First-degree heart block
Wenckebach phenomenon (Mobitz type I)
Mobitz type II
Complete heart block / high-degree AV block
Bundle branch block
Sinus arrest and sinus pauses
Supraventricular tachycardia
Atrial fibrillation
Junctional tachycardia
Fascicular tachycardia
Ventricular tachycardia
Ventricular flutter
Bradycardia
Narrow QRS escape rhythm
Prolonged QT interval
ST depression and T-wave inversion
ST elevation
Asystole

Some reports have also described Lyme carditis in patients with underlying conduction abnormalities or preexisting cardiac conditions. [1]

Clinical Pearls From the Authors

The authors emphasized several important clinical observations about Lyme carditis. [1]

Heart block may be the initial or only manifestation of Lyme disease
First-degree AV block can rapidly progress to complete heart block
Exercise or stress testing should be avoided until recovery is complete
Lyme carditis should be considered in younger patients from endemic regions with unexplained cardiac symptoms

Learn more about Lyme carditis and Lyme disease symptoms.

Frequently Asked Questions

Can Lyme disease cause heart block?

Yes. Lyme carditis may cause first-degree AV block, high-degree AV block, or complete heart block.

Is Lyme carditis reversible?

Many conduction abnormalities associated with Lyme carditis improve with antibiotic treatment.

Can exercise worsen Lyme carditis?

In some cases, exertion may worsen conduction abnormalities or provoke progression of heart block.

What cardiac problems have been linked to Lyme disease?

Reported complications include AV block, atrial fibrillation, ventricular arrhythmias, bradycardia, and other rhythm disturbances.

Who is at risk for Lyme carditis?

Lyme carditis should be considered in patients from endemic areas who develop unexplained cardiac symptoms, particularly younger individuals without another clear cause.