Lyme disease is the most common vector-borne illness in North America and can now be found in most of the world. Many people associate the disease with symptoms like a bull’s-eye shaped rash, joint pain, headache, and fever, which are common in its acute stage. But did you know that Lyme disease can also affect the heart muscle?
This, too, can occur in the early stages – often within the first 6 weeks. While cardiac involvement is less common than other symptoms, it can be serious and even fatal if it goes untreated. Aside from musculoskeletal and cardiac involvement, Lyme disease can also affect other systems of the body like the skin and nervous system.
It is estimated that at least 5-8% of Lyme patients will develop heart complications. The most common type is Lyme carditis, which occurs when the bacteria enters the heart tissue and interferes with electrical impulses between the upper and lower chambers of the heart. This can lead to what’s called “heart block.” Symptoms of Lyme carditis may include fainting, heart palpitations, light-headedness, and shortness of breath. But it can also be asymptomatic, making it harder to diagnosis. Lyme carditis is similar to rheumatic fever except that in Lyme carditis, heart valves are generally not affected and complete heart block is more likely to occur.
Diagnosis & Treatment
Although only a small percentage of people who contract Lyme disease get a bull’s-eye rash, called erythema migrans, the presence of a rash does appear to correspond with a greater risk of developing cardiac involvement. Sometimes it is also preceded by meningoencephalitis, facial palsy, and arthritis. Athletes may be at greater risk for severe heart complications, since their well-conditioned heart may result in symptoms not presenting right away. This population is more likely to contract the disease in the first place due to their active lifestyle (more time outside).
Lyme carditis is diagnosed using electrocardiogram and can be confirmed and monitored using a cardiac MRI. The most common and most effective treatment is oral antibiotics for milder cases and IV antibiotics for more severe cases. Ceftriaxone is the drug of choice, but other antibiotics may be used, particularly in young children. In about 30% of patients, temporary pacemaker implantation is necessary. The patient should also be tested for the presence of antibodies to Borellia burgdorferi, although current serologic tests such as the ELISA and the Western Blot are not always accurate, particularly within the first 3 weeks after exposure and in chronic Lyme disease. The Western Blot is thought to be more accurate than the ELISA in Lyme carditis patients.
Other Heart Problems
Most cases of Lyme carditis cause atrioventricular block of varying degrees. More rarely, other manifestations of cardiac involvement may occur, including acute myopericarditis, left ventricular dysfunction, cardiomegaly, endocarditis, pericardial effusion, coronary artery aneurysm, QT interval prolongation, tachyarrhythmias, or congestive heart failure.
Although Lyme disease does not normally cause atrial fibrillation, one case report of this unique manifestation is documented in a 68-year-old active male (a cardiologist, ironically enough!). The study urges physicians to rule out Lyme disease in presentations of atrial fibrillation, particularly if other Lyme symptoms are reported. If Lyme disease is not ruled out, the usual treatments for atrial fibrillation could cause serious complications or even death.
In the last few decades, 5 cases of sudden cardiac arrest due to Lyme disease have been reported by the CDC (3 confirmed and 2 suspected). Although this is extremely rare, it must be noted that Lyme disease is continually on the rise. If more physicians don’t start considering Lyme disease in patients who present with heart-related symptoms, this complication could occur more often. Diagnosing this acute manifestation of the disease is only part of the problem. Many people with milder or more chronic symptoms go undiagnosed for many years and develop other chronic health issues, including heart problems, that get chalked up to other causes. The best way to avoid Lyme disease and associated complications is prevention. As ticks become more active due to the warmer weather, take the proper precautions to protect you and your loved ones.