What is Lyme Carditis?
Lyme disease, the most common illness spread by ticks in the U.S, affects multiple parts of the body and is caused by an infection with Borrelia burgdorferi. A complication of this disease is heart inflammation, or carditis, which reportedly happens in 1% to 10% of all Lyme disease cases. This condition usually occurs within weeks to months after the initial infection and shows up in the second phase of the disease, often referred to as the early spread stage.
The most noticeable sign of carditis is disturbances in the electrical system of the heart, specifically involving the atrioventricular (AV) node. This node is crucial for maintaining the heart’s regular rhythm. When Lyme disease affects this node, it can cause various degrees of heart block, a condition where the heart beats slower than normal. In some severe cases, this may require the installation of a temporary pacemaker, a device that helps to regulate the heart’s rhythm.
There are also other ways that Lyme disease can impact the heart, including myocarditis (inflammation of the heart muscle), endocarditis (inflammation of the heart’s inner lining), damage to the heart valves, inflammation of the heart’s outer lining (pericarditis), and a combination of heart muscle and outer lining inflammation (myopericarditis). However, these conditions are less common than the typical disruptions to the heart’s electrical system.
What Causes Lyme Carditis?
Lyme disease is caused by a bacterial infection from Borrelia burgdorferi, also known as B.burgdorferi. This type of bacteria was discovered by a scientist named Dr. Willy Burgdorfer in 1982. Animals such as mice, chipmunks, and other small mammals can carry this bacteria.
Interestingly, deer do not carry the bacteria itself, but they are crucial in helping the bacteria survive and spread. This is because they can host a type of tick known as the Ixodes tick. These ticks can pick up B.burgdorferi by biting an infected animal. When an infected tick then bites a human, it can transmit the bacteria and cause Lyme disease.
Risk Factors and Frequency for Lyme Carditis
Lyme disease is a significant health issue, with about 30,000 cases reported in the United States each year, and possibly more unreported cases. The hotspots for Lyme disease include the Northeast, mid-Atlantic, and upper Midwest states which accounted for 95% of identified cases in 2015. It particularly affects males aged 5-9 and 45-59. Most diagnosis of Lyme disease are made between March and October, with June and July being the peak months. About 1.5% to 10% of Lyme disease patients may experience cardiovascular symptoms. It’s also more common in young adult males, with a male: female ratio of about 3 to 1.
- Lyme disease records about 30,000 cases every year in the U.S, but there may be more unreported cases.
- Most cases, around 95%, were identified in the Northeast, mid-Atlantic, and upper Midwest states in 2015.
- The disease particularly affects males around the ages of 5-9 and 45-59.
- Diagnosis mainly occurs between March and October, with a majority, 60% of cases in June and July.
- About 1.5% to 10% of patients experience cardiovascular symptoms related to Lyme disease.
- Lyme disease is more common in young adult males, with a male: female ratio of about 3 to 1.
Signs and Symptoms of Lyme Carditis
Lyme carditis is a medical condition associated with Lyme disease. This condition usually has several stages. It typically begins with a recognized skin rash known as erythema migrans in the early localized infection phase. As the bacteria causing Lyme disease continue to spread throughout the body, general symptoms such as fatigue, fever, chills, headache, muscle soreness, joint pain and dizziness may occur. This period is when cardiac issues related to Lyme disease can start to develop. Lyme carditis mostly happens between June and December, with symptoms appearing anywhere from four days to seven months, and on average, around 21 days after the initial rash. It’s important to note that many patients don’t recall a tick bite, and only 40% present with the rash.
The most common symptoms related to cardiac issues include disruptions in the heart’s rhythm (heart block), feeling faint, loss of consciousness, breathlessness, heart palpitations, and chest discomfort.
The main sign of Lyme carditis is an issue with the heart’s electrical signals, known as an ‘atrioventricular (AV) block’. This AV block can change rapidly, moving from first degree to complete blockage, and then back again quite quickly.
Other less common manifestations reported in the literature include inflammation of the heart’s lining and valves (endocarditis), inflammation of the heart’s outer layer (pericarditis), inflammation of the heart muscle (myocarditis), and delays in the heart’s electrical conduction. When the disease presents similarly to an acute coronary syndrome, it can cause symptoms and changes in the EKG, with 60% of patients showing alterations in the T wave or ST-segment. Valvular involvement with endocarditis is not common, but if it does occur, patients usually show signs of acute heart failure and a serious condition known as cardiogenic shock.
Testing for Lyme Carditis
Lyme carditis, a complication of Lyme Disease, most often causes an issue called Atrioventricular block (AV block), which affects the rhythm of your heartbeat. People suffering from this condition often have slower heart rates, known as bradycardia. If you belong to a group that tends to suffer from Lyme disease and show this symptom, doctors will usually recommend a heart rhythm test, known as an electrocardiogram (ECG). Lyme carditis can cause varying levels of AV block; it can range from mild first-degree block to a complete heart block, also known as third-degree AV block. The level of block can change rapidly in these patients; it may vary over minutes, hours, or days.
When diagnosing AV block, doctors look for abnormal patterns in your ECG results. A first-degree AV block shows a longer than normal delay between certain components of the heart rhythm (known as the P wave and QRS complex), while a second-degree block shows an increase in this delay, leading to missed heartbeats. In a third-degree block, the heart’s two main sections are not communicating at all, leading to significant heart rhythm abnormalities. If AV block is the only symptom of Lyme carditis, no further tests are usually needed.
However, if the doctor suspects problems with your heart valves or heart muscle inflammation (myocarditis), additional tests may be necessary. A chest X-ray might be used to detect abnormalities, and an echocardiogram (heart ultrasound) can help in assessing the size and function of the heart chambers and distinguishing between myocarditis and other conditions such as a heart attack. If the distinction remains difficult, doctors may recommend a cardiac MRI, which provides more detailed images of your heart tissue.
Even though identifying the infectious agent is the gold standard for diagnosing infections, it’s not always feasible with B. burgdorferi, the bacterium causing Lyme Disease. Instead, diagnosis also involves a combination of potential symptoms, lab tests, and the doctor’s overall clinical assessment. But sometimes, patients don’t exhibit typical symptoms or have ambiguous symptoms. In these cases, doctors often use a two-step approach that includes an enzyme-linked immunosorbent assay (ELISA) followed by a Western blot assay. These are blood tests that look for the presence of specific antibodies your body produces in response to the infection. If Lyme disease is suspected as a cause of heart infections, and serologic tests are negative or unclear, doctors may also use PCR, a method to detect the DNA of the bacteria.
Treatment Options for Lyme Carditis
Even though some instances of Lyme carditis, a heart-related complication of Lyme disease, can clear up without treatment, antibiotics are generally prescribed. This is done to lessen the potential for heart-related problems, prevent long-term issues, and shorten the length of the illness. Certain antibiotics like cephalosporins and tetracyclines have been shown to be effective in treating the bacteria (B. burgdorferi) causing Lyme disease. If the disease is mild to moderate, oral antibiotics like amoxicillin or doxycycline can be taken for roughly two to three weeks.
Patients with more severe cases of Lyme carditis often need to be admitted to the hospital. Some reasons for this could include symptoms such as fainting, trouble breathing, or chest pain. Additionally, if there are certain types of issues with the heart’s electrical signals (also known as an AV block), hospitalization may be necessary.
Although both oral and injectable antibiotics can be effective, hospitalized patients generally start treatment with injectable antibiotics usually including ceftriaxone or cefotaxime. This continues until their heart signaling improves substantially. After this, they may switch to oral antibiotics to complete a total treatment period of about two to three weeks.
In some cases, patients may need a temporary pacemaker. This is generally for those who are both unstable and have severe issues with their heart’s electrical signals. This pacemaker can be removed once the heart’s signaling has returned to normal.
Permanent pacemakers are typically not recommended for Lyme carditis. This is because the heart signaling issues seen with this disease are short-term, tend to clear up with antibiotic treatment, and are not expected to come back. This is in line with the 2008 guidelines from the American College of Cardiology, American Heart Association, and Heart rhythm society.
Lastly, it’s important to note that Lyme carditis can occur even if standard tests for Lyme disease come back negative. In these cases, patients who suddenly develop a specific type of heart muscle disease (dilated cardiomyopathy) may need antibiotic treatment.
What else can Lyme Carditis be?
There are several conditions that can affect the heart in various ways. They include:
- Rheumatic fever
- Viral myocarditis
- Systemic lupus erythematosus
- Syphilis
- Bacterial endocarditis
What to expect with Lyme Carditis
Lyme carditis, a heart condition triggered by Lyme disease, usually has a favorable outcome. It often disrupts the heart’s normal rhythm but is treatable most of the time. With proper antibiotic treatment, patients experiencing a severe heart rhythm disorder, known as third-degree heart block, typically recover within a median of six days.
While there have been some rare cases where heart rhythm issues persist, this is exceptionally rare. Although there have been instances of death due to severe myocarditis, which is serious inflammation of the heart muscle, these cases are few and far between.
Interestingly, a connection has been observed between Lyme disease and dilated cardiomyopathy, a condition in which the heart’s ability to pump blood is reduced because its main pumping chamber is enlarged and weakened. However, this observation is still being studied.
Possible Complications When Diagnosed with Lyme Carditis
There have been some recorded fatal cases related to Lyme carditis, which is a heart condition caused by Lyme disease. However, the death rate from this disease has always been low. This rate has further decreased as we’ve gotten better at recognizing the disease early on and treating it promptly with antibiotics.
In 2013, a report was published that mentioned three people had died from complications related to Lyme carditis. Following this report, the Centers for Disease Control and Prevention (CDC) conducted a follow-up study which included information on 1,696 cases reported between 1995 and 2013. After closely examining the details, the CDC confirmed that only two out of the three reported deaths were indeed caused by Lyme carditis. This represents a tiny percentage (0.001%) of the total number of cases.
Preventing Lyme Carditis
If you’re planning to visit areas where ticks are common, there are a few things you can do to reduce your exposure:
* Dress in protective clothes.
* Apply tick repellents such as permethrin or N, N-diethyl-meta-toluamide (also known as DEET) to your clothing.
* Perform daily checks for ticks and if you find any, carefully remove them with tweezers.
If a tick has been attached to you for 36 hours or more, you should take an oral dose of 200 mg of an antibiotic called doxycycline as a preventive measure.
If you notice a rash where a tick was attached, multiple skin spots, or start feeling like you have the flu, you should go to a doctor for an evaluation right away. These could be signs of a tick-borne illness.
