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Lyme Carditis: What Is It, Symptoms, and Treatments

6 min read

By Chelsea Hammond

  • Lyme carditis happens when the bacteria causing Lyme disease travels to the heart.
  • Common symptoms of Lyme carditis include difficulty breathing, irregular heart rate, fainting, and chest pain.
  • Symptoms of Lyme carditis often happen after a person has shown signs or received a diagnosis of Lyme disease.
  • Treatment involves antibiotics and, in severe cases, the placement of a temporary pacemaker.
  • Although Lyme carditis can be fatal, the disease responds well to modern treatments if caught early.

If you or a loved one have been diagnosed with Lyme carditis, you likely have questions about the disease and how it’s treated. Before learning of this condition, you may or may not have already known you had Lyme disease. These two diseases are intricately linked, so the best option in preventing Lyme carditis is to prevent Lyme disease.

Below you’ll find the answers to all your most pressing questions about both these illnesses and how you can prevent them from happening. Let’s get into it!

What Is Lyme Carditis?

Lyme carditis is an illness that occurs in the heart of someone who has been infected with Lyme disease bacteria. Although Lyme disease most often affects the skin and joints, this bacteria can travel to your heart.

It interferes with the electrical signals sent between your upper and lower heart chamber, and this exchange of electricity is necessary for your heart to continue beating. Physicians call this interference, “heart block.” Complications can range from mild to severe and may even be fatal if not found and treated fast enough.

Shutterstock/Syda Productions

What Is Lyme Disease?

Lyme disease is a tick-borne illness that happens when a tick carrying one of four bacterial strains bites you. During this bite, the tick transfers some bacteria onto your skin or bloodstream, and you become infected.

Lyme disease can cause a range of symptoms that vary in severity. The most common symptoms include skin rashes, mild fever, and joint pain. However, the disease can also cause complications for the heart and other internal organs, as well as the immune system.

How Lyme Disease Leads to Lyme Carditis

When an infected tick bites you, it transfers one of four different bacteria to your skin and bloodstream. This bacteria can then multiply inside your body, causing a range of symptoms and complications.

Most people infected with these bacteria have mild to moderate symptoms revolving mainly around the skin and joints. However, in a small percentage of those infected with Lyme disease, the bacteria travel to the heart. This can happen over time if Lyme disease is left untreated or, in some rare cases, it can happen quickly after infection.

Shutterstock/5 second Studio

How Lyme Carditis Affects the Heart

To beat in a regular rhythm, your heart uses electrical signals. These signals transfer between the upper and lower chambers of the heart, causing an expansion and retraction that allows your heart to pump blood throughout your body. The bacteria causing Lyme disease interrupts these normal signals so they can’t travel from the upper chambers to the lower or vice versa. When this happens, the heartbeat may slow, become irregular or, in severe cases, stop altogether.

Shutterstock/New Africa

Primary Symptoms of Lyme Carditis

Primary symptoms of Lyme carditis are caused directly by the problem itself versus stemming from related issues (as discussed below). The most common primary symptoms include:

  • Lightheadedness
  • Shortness of breath
  • Chest pains that may radiate into the left arm, back, or stomach
  • Irregular heart rate

You may also experience high or low blood pressure, fever, and body aches. However, it’s important to understand that most people present with Lyme disease symptoms before or at the same time as those of Lyme carditis.

Secondary Symptoms of Lyme Carditis

Secondary symptoms of Lyme carditis are generally related to Lyme disease. These symptoms often appear first, but they may co-occur with primary symptoms in some cases. Common secondary symptoms include:

  • Low fever
  • Stiffness, especially in the neck
  • Joint pain
  • Skin rashes
  • Headache
  • Chills
  • Fatigue
  • Swollen lymph nodes

Not every person develops the same symptoms after being infected by the bacteria causing Lyme disease. Your symptoms may include all the above or only a few of them.

How Common Is Lyme Carditis?

Around 1 in every 100 people infected with Lyme disease develops Lyme carditis. Since there are estimated to be around 30,000 cases of Lyme disease each year, this means about 300 will develop Lyme carditis.

This means the condition isn’t common and won’t affect even close to everyone infected with Lyme disease. However, this also means not much research has been done on Lyme carditis, how it works, or why some people develop it while others don’t.

novak.elcic / Shutterstock

How Long Is Recovery?

Recovery varies from one person to another based on numerous factors. Significant factors are a person’s overall health, how severe the Lyme carditis infection is, and how quickly the condition was caught.

How a person responds to treatment is also a consideration, as this can be different for everyone. However, most people without other serious health issues recover in 1- to 6-weeks. It’s crucial to follow your treatment plan precisely for the best chance of a quick recovery.

The First Course of Treatment Is Antibiotics

Antibiotics are the first course of treatment for Lyme carditis infections. Medications can be given orally or intravenously (IV), depending on the severity of the disease.

Most people diagnosed with Lyme carditis in the hospital receive antibiotics through IV first and then sent home with oral medications. Severe cases are always treated with IV antibiotics first. A combination of antibiotics may also be given but ultimately, your doctor will decide which ones are best for you.

A Temporary Pacemaker Is Sometimes Necessary

A pacemaker is a device that generates electrical impulses that are delivered by electrodes to the heart’s muscles. This allows the heart’s chambers to contract and pump blood throughout the body, effectively replacing the heart’s electrical conduction system.

In severe cases of Lyme carditis, a pacemaker is used temporarily to keep the heart pumping while the antibiotics take care of the bacteria. Most people with Lyme carditis won’t need a temporary pacemaker. Among those who do, it’s only required for a relatively short time.

Preventing Lyme Disease Is Crucial

The best way to prevent Lyme carditis is by protecting yourself and your loved ones against Lyme disease. The easiest way to do that is by taking precautions against ticks when spending time outdoors.

Avoiding tall grass and wearing long pants while outdoors is helpful. If you’ll be spending time in the woods, use a tick repellant, and remember to check yourself for ticks when you get home. If possible, avoid areas of high tick infestation whenever possible.

Long-Term Outlook for People Diagnosed With Lyme Carditis

Most people diagnosed with Lyme carditis have no lasting heart disease once the bacteria have been treated and the heart’s functioning has returned to normal. However, Lyme carditis must be caught and treated early if you want the best long-term prognosis.

Although rare, a few people go on to have lasting heart problems that are usually mild. These ongoing problems may be treated with medication, a permanent pacemaker, or alternative remedies. Following your treatment plan precisely from the moment of diagnosis is crucial to preventing lasting heart damage.

Chelsea Hammond


Chelsea Hammond is a content creator and marketer with over a decade of experience. She studied towards a bachelor's in English with a minor in media analysis at Arizona State University and received multiple marketing certifications from HubSpot Academy.

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