INTRODUCTION — Lyme disease is the most common tick-borne disease in the United States, Canada, and Europe. It is a spirochetal infection caused by species in the spirochete family Borreliaceae. The taxonomy of these spirochetes is undergoing revision, and the genus name may be represented as either Borrelia or Borreliella. In either case, the abbreviation for the genus is "B" and stands for both terminologies in the discussion below.
In North America, infection is caused primarily by B. burgdorferi sensu stricto (hereafter called B. burgdorferi) and, less commonly, in a region of the upper Midwest, by B. mayonii. In Europe and Asia, infection is caused primarily by either B. afzelii or B. garinii, less commonly by B. burgdorferi, and rarely by B. spielmanii or B. bavariensis.
Cardiac involvement occurs during the early disseminated phase of the disease (table 1), usually within weeks to a few months after the onset of infection [1,2]. The most common clinical feature of Lyme carditis is atrioventricular (AV) conduction block related to dysfunction of the conduction system, but it may also include decreased cardiac contractility due to myopericarditis. Rarely, patients may have endocarditis or fatal pancarditis [3,4].
The epidemiology, clinical manifestations, diagnosis, treatment, and prognosis of Lyme carditis will be reviewed here. Other manifestations of Lyme disease are discussed separately. (See "Epidemiology of Lyme disease" and "Clinical manifestations of Lyme disease in adults" and "Lyme disease: Clinical manifestations in children" and "Nervous system Lyme disease" and "Musculoskeletal manifestations of Lyme disease" and "Treatment of Lyme disease".)
EPIDEMIOLOGY — The incidence of Lyme carditis has varied in different reports:
●In the United States, Lyme carditis is estimated to occur in approximately one percent of patients with Lyme disease based on surveillance data from 2008 and 2018 . Earlier studies reported carditis in approximately four to ten percent of untreated adults [1,6-8]. This difference is likely due to the widespread recognition and treatment of early Lyme disease. As an example, four percent of patients developed carditis with evidence of AV nodal block in a prospective study of patients with erythema migrans who did not receive antibiotic treatment .
●In Europe, carditis has been reported as a complication of Lyme disease in approximately 0.3 to 4.0 percent of untreated adults . Some authors have suggested that the incidence of carditis may be lower in Europe compared with the United States. However, given the possible overestimate of clinically significant cardiac manifestations in the United States described above , the incidence of Lyme carditis may be similar in both regions.
The rate of carditis in children is not known. In a prospective study that included 14 children with proven Lyme disease in the United States who had electrocardiograms, two patients had first degree atrioventricular block, one had left axis deviation, and one had ventricular ectopy .
There is a strong male predominance of approximately 3:1 in cardiac Lyme disease , compared with only a slight predominance of Lyme disease overall among males (53 percent) in the United States .
Appropriate antibiotic therapy for erythema migrans or other features of early localized Lyme disease prevents subsequent Lyme disease, including cardiac manifestations of the disorder .
PATHOPHYSIOLOGY — Because biopsies of the heart are rarely performed and because Lyme carditis is not typically fatal, limited information is available regarding the pathophysiology of Lyme carditis in humans. Animal studies in both monkeys and mice have shown that inflammation can be seen transmurally. In mice, inflammation typically has a predominance of macrophages and lymphocytes, whereas joints have a heavier infiltration of neutrophils . In human Lyme arthritis, neutrophils are often the predominant cell type in joint fluid but are rare in synovial tissue . Although inflammation can affect multiple areas of the heart, in mice the heaviest areas of infiltration include the connective tissue at the base of the heart, the basal interventricular septum, and perivascular regions including the aortic adventitia [16,17].
In humans with fatal pancarditis, diffuse infiltrates affecting multiple areas of the heart have been seen. In a case report, infiltrates were particularly prominent in perivascular areas and in the interstitial regions, similar to the findings in mice . It is unknown what type of pathology and localization occurs in less severe cases or during earlier stages of infection in humans.
CLINICAL MANIFESTATIONS — The cardiac features of early disseminated Lyme disease typically occur one to two months (range <1 to 28 weeks) after the onset of infection [2,8]. Cardiac disease can be the only feature of infection or can occur together with other features of early Lyme disease, such as erythema migrans or early neurologic symptoms. (See "Clinical manifestations of Lyme disease in adults" and "Lyme disease: Clinical manifestations in children".)
Patients with cardiac involvement may be asymptomatic or complain of lightheadedness, syncope, shortness of breath, palpitations, and/or chest pain. Sudden cardiac death attributable to Lyme disease has also been reported [19,20].
In a surveillance study of Lyme disease cases in the United States, 875 patients had sufficient data on possible cardiac manifestations . Cardiac manifestations were present in 84 patients (10 percent), 20 percent of whom were hospitalized. The following manifestations were noted:
●Palpitations – 58 patients (6.6 percent)
●Conduction abnormalities – 16 patients (1.8 percent)
●Myocarditis – 8 patients (0.9 percent)
●Left ventricular failure – 4 patients (0.5 percent)
●Pericarditis – 2 patients (0.2 percent)
It is important to note that palpitations can be a nonspecific finding, and therefore may not represent carditis. Cardiomyopathy has not been observed in patients with Lyme carditis in the United States but has been reported rarely in patients in Europe. (See 'Chronic cardiomyopathy' below.)
Atrioventricular conduction abnormalities — Atrioventricular (AV) conduction block of varying severity is the most common objective manifestation of Lyme carditis. The degree of AV block can fluctuate rapidly, with first degree AV block progressing to second degree or complete AV block and sometimes back to first degree AV block over a matter of minutes . In a review of 52 patients with Lyme carditis, 87 percent had AV block; 54 percent had complete or high-grade AV block, which was usually symptomatic . Another review of 105 patients with Lyme carditis in Europe and North America found similar numbers, with complete AV block in 49 percent, second degree AV block in 16 percent, and first degree AV block in 12 percent .
The highest risk for progression to complete AV block, which may develop rapidly, occurs in patients with a PR interval greater than 300 milliseconds . As would be anticipated, patients with higher degrees of AV block are more likely to be symptomatic. In one report, all 10 patients with high-grade AV block were symptomatic with syncope, dizziness, dyspnea, chest pain, or palpitations . In contrast, only two of eight patients with first degree AV block had cardiac symptoms, which consisted only of palpitations.
Electrophysiological studies have usually found conduction delay occurring above the bundle of His, often within the AV node. However, heart block can occur at different levels within the conducting system. Sinoatrial node dysfunction (manifested as SA nodal block), abnormal nodal recovery time, intraatrial block, and fascicular and bundle branch block have all been described [8,11,22-25]. Some patients have variable bundle branch blocks, suggesting multifocal damage in the His-Purkinje system or AV node, whereas others have brief episodes of asystole due to transient failure of an escape rhythm.
AV block caused by Lyme disease has been reported to persist for 3 to 42 days [2,22,25,26]. Complete AV block typically improves to lesser degrees of AV block within one week, and more minor conduction disturbances usually resolve within six weeks [1,8].
The different types of AV block are discussed in detail separately. (See "First-degree atrioventricular block" and "Second-degree atrioventricular block: Mobitz type I (Wenckebach block)" and "Second-degree atrioventricular block: Mobitz type II" and "Third-degree (complete) atrioventricular block" and "ECG tutorial: Atrioventricular block".)
Atrial and ventricular arrhythmias may also be seen when there is involvement of the sinus node and distal conduction system [27-29]; however, these are uncommon.
Myopericarditis — Lyme myopericarditis is often self-limited and mild; it rarely leads to cardiomegaly. A mild pericardial effusion may be present . In most cases, it is asymptomatic and clinically inapparent. The most frequent manifestation of myocardial involvement in Lyme disease is nonspecific ST and T wave changes on the electrocardiogram. However, occasional patients develop symptomatic myocarditis with cardiac muscle dysfunction and/or associated pericarditis [30-32]. Sudden cardiac death has also been reported .
Myocardial biopsy and autopsy specimens have shown a band-like lymphoid and plasmacytic interstitial infiltrate, variable amounts of myocyte necrosis, fibrosis, and edema, and occasional endarteritis obliterans [22,33-36]. In some cases, spirochetal forms have been found in or near the cellular infiltrate [33,34], or were grown from biopsy material [35,37]. There are no documented patients with aortitis caused by B. burgdorferi.
Gallium and anti-myosin indium scans have been abnormal in individual cases, but no systematic or prospective studies of the usefulness of these nonspecific tests have been performed [38-40].
Chronic cardiomyopathy — In Europe, case reports and small case series have suggested that B. burgdorferi may be a cause of chronic cardiomyopathy in patients with no history of symptomatic Lyme disease . In contrast, chronic cardiomyopathy has not been reported in patients with Lyme carditis in the United States . The following reports from Europe describe the range of findings:
●A case report described a patient with chronic congestive cardiomyopathy who was strongly seropositive for anti-Borrelia burgdorferi antibodies . Myocardial biopsy revealed spirochetal forms and B. burgdorferi was grown from these specimens.
●In two patients with idiopathic dilated cardiomyopathy, B. burgdorferi was grown from their myocardial biopsies . Cardiac function returned to normal in both patients following treatment with IV penicillin G in addition to standard medications used for heart failure.
●In a series of 42 patients with dilated cardiomyopathy, nine were seropositive for anti-B. burgdorferi antibodies and were treated with ceftriaxone: six recovered fully, two had a partial response, and one showed no improvement .
Endocarditis — Rare cases of endocarditis due to Lyme disease have been reported:
●A 61-year-old man in France was reported with damage of the mitral valve . B. afzelii DNA was detected in mitral valve tissue by PCR. After surgery, he was treated with amoxicillin for six weeks and had a positive clinical outcome.
●In the United States, a 68-year-old man was reported with atrial fibrillation and mitral regurgitation . He had a positive PCR test for B. burgdorferi DNA in mitral valve tissue, but PCR testing of blood in the previous months was repeatedly negative. He had had previous episodes of Lyme carditis treated medically over the previous nine years.
EVALUATION AND DIAGNOSIS — The diagnosis of Lyme carditis is established by the presence of consistent epidemiologic and clinical features (eg, atrioventricular [AV] conduction block, acute myocarditis/pericarditis) in conjunction with positive results of Lyme serologic testing. (See "Diagnosis of Lyme disease", section on 'Risk of exposure' and 'Clinical manifestations' above.)
It is important to establish the diagnosis of Lyme disease not only so that antibiotics can be administered but also to avoid placement of a permanent pacemaker in those with severe conduction disturbances; the AV block associated with Lyme carditis is usually short-lived and can be managed with a temporary pacemaker .
When to obtain an EKG — We obtain an electrocardiogram (EKG) in patients with Lyme disease if they have symptoms consistent with Lyme carditis (eg, dyspnea, edema, palpitations, lightheadedness, chest pain, and syncope). For patients without clinical findings, an EKG is usually not needed since asymptomatic patients are unlikely to have significant carditis. (See 'Treatment' below.)
Evaluation for associated features — A careful history should address risk factors or possible evidence of B. burgdorferi infection. These include prior exposure (residence in or travel through an endemic area), previous tick bites, prior or current erythema migrans lesion(s), and coexistence of neurologic dysfunction compatible with neurologic Lyme disease. The first reported series describing 20 patients with Lyme carditis found the following associated features :
●Erythema migrans in 15 (75 percent)
●Joint involvement in 13 (65 percent)
●Meningoencephalitis (some with concurrent facial nerve palsy or radiculoneuritis) in seven (35 percent)
Diagnosis of Lyme carditis is more difficult in patients whose only observed manifestation of Lyme disease is carditis and in those who had only a preceding non-specific febrile illness. In cases of isolated carditis, diagnosis relies on serologic testing in patients with a moderate to high pretest probability of Lyme disease.
Serologic testing — An enzyme-linked immunosorbent assay (ELISA) and confirmatory Western blot analysis should reveal seropositivity for Lyme disease in patients with Lyme carditis . Two-tiered testing using two different ELISAs has also been approved for use in the diagnosis of Lyme disease and shows similar sensitivity and specificity as two-tiered testing employing a Western blot, but the blot provides additional information. (See "Diagnosis of Lyme disease", section on 'Serologic testing algorithms'.)
As with the use of serologic testing for other manifestations of Lyme disease, serologic test results alter the likelihood that a patient has Lyme disease, but do not establish the diagnosis alone. Test results need to be interpreted in light of the pre-test probability that the patient has Lyme disease. (See "Diagnosis of Lyme disease", section on 'Clinical suspicion for Lyme disease'.)
The following factors should be kept in mind when obtaining these tests in patients with suspected Lyme carditis:
●If IgM positivity is found, it is likely that the infection is recent and that B. burgdorferi is the etiologic agent . However, IgM reactivity, both by ELISA and Western blot, is subject to higher rates of false positivity than IgG tests. In addition, the IgM response may persist for years in patients with prior Lyme disease.
●Because Lyme carditis is a manifestation of the disseminated stage and typically occurs one to two months after the initial infection, the vast majority of patients have positive serologic responses (IgM and/or IgG) when two-tier testing is performed . Thus, patients with a negative serologic test are very unlikely to have Lyme carditis. (See "Diagnosis of Lyme disease", section on 'Early disseminated and late Lyme disease'.)
●In endemic areas, baseline seroprevalence rates can substantially affect the interpretation of diagnostic tests. For example, in endemic areas of the United States, studies performed prior to 2001 found that up to 5 percent of the population was seropositive by ELISA [45,47]. More recent data are not available. As a result, a positive ELISA result does not confirm the diagnosis of Lyme carditis; all positive or equivocal ELISA results should be corroborated by a Western blot.
●Serum antibody levels may persist long after cure of Lyme disease. Thus, even IgM seropositivity may be related to a prior episode of Lyme disease, rather than recent infection, and the current cardiac disease may not be causally related to B. burgdorferi infection. Likewise, persistence of serologic reactivity after an episode of cardiomyopathy does not represent ongoing infection, nor does it suggest a need for prolonged therapy.
TREATMENT — Patients with Lyme carditis are treated with antimicrobial therapy to shorten the duration of cardiac manifestations and prevent later complications of Lyme disease. If there is a high suspicion for Lyme carditis (eg, patient with multiple erythema migrans and conduction delay), empiric treatment should be initiated pending the initial evaluation. Lyme carditis can be fatal if left untreated . (See 'Prognosis' below.)
Because of the potential for life-threatening complications, patients who are symptomatic (eg, syncope, dyspnea, or chest pain), have second- or third-degree atrioventricular block, have a markedly prolonged PR interval (≥300 milliseconds), or have other arrhythmias should be hospitalized, monitored with cardiac telemetry, and treated initially with intravenous (IV) antibiotics (table 2) . In addition, some patients may require a temporary pacemaker. The indications for pacing are the same as in other causes of heart block ; however, a permanent pacemaker is usually not warranted since atrioventricular (AV) block caused by Lyme disease is typically short-lived. (See "Temporary cardiac pacing", section on 'Indications' and 'Atrioventricular conduction abnormalities' above.)
For patients with mild disease (eg, asymptomatic patients with first-degree AV block and PR interval <300 milliseconds), therapy with one of the preferred oral agents (doxycycline, amoxicillin, cefuroxime) is reasonable (table 2).
The treatment of Lyme carditis is discussed in detail elsewhere. (See "Treatment of Lyme disease", section on 'Carditis'.)
PROGNOSIS — The prognosis of Lyme carditis is good among treated patients. In most reports, atrioventricular (AV) block caused by Lyme disease persisted for 3 to 42 days [2,22,25,26]. Complete AV block typically resolves within one week, and more minor conduction disturbances within six weeks [1,8]. There have been a few reports of permanent AV block or persistence of first degree AV block after more severe heart block has resolved [9,24,50].
Although rare, cases of fatal Lyme disease secondary to carditis have been reported [3,18-20,34]. Some cases have documented pathological evidence of cardiac inflammation and the presence of B. burgdorferi in cardiac tissue [18,19,34]. As an example, one series reported fatal cases of Lyme carditis in three individuals ages 26 to 38 years . All three had non-specific symptoms (eg, malaise, muscle and joint pain) for one to two weeks prior to cardiac arrest, but did not receive antibiotic therapy. Examination of cardiac tissue showed extensive myocarditis and evidence of B. burgdorferi in the tissue by polymerase chain reaction and immunohistology. In addition, all patients had positive serologic findings for early disseminated infection. One of the three patients had a pre-existing heart condition (ie, Wolff-Parkinson-White syndrome), but it is not clear if this increased the risk of death.
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Tick-borne infections (Lyme disease, ehrlichiosis, anaplasmosis, babesiosis, and Rocky Mountain spotted fever)".)
INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.
Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)
●Basics topics (see "Patient education: Lyme disease (The Basics)")
●Beyond the Basics topics (see "Patient education: Lyme disease symptoms and diagnosis (Beyond the Basics)" and "Patient education: Lyme disease treatment (Beyond the Basics)" and "Patient education: Lyme disease prevention (Beyond the Basics)")
SUMMARY AND RECOMMENDATIONS
●Overview – Lyme disease is a multisystem disease caused by six species in the spirochete family Borreliaceae. Cardiac involvement usually occurs during the early disseminated phase of the disease (table 1). (See 'Introduction' above.)
●Clinical manifestations of carditis – The cardiac features of Lyme disease typically occur one to two months (range <1 to 28 weeks) after the onset of infection. Cardiac disease can be the only feature of infection or can occur together with other features of early Lyme disease, such as erythema migrans or early neurologic symptoms. (See 'Clinical manifestations' above.)
•Patients with cardiac involvement may be asymptomatic or complain of lightheadedness, syncope, shortness of breath, palpitations, and/or chest pain. Sudden cardiac death attributable to Lyme disease has also been reported. (See 'Clinical manifestations' above.)
•Varying degrees of atrioventricular (AV) block are the most common manifestation of Lyme carditis. The degree of AV block can fluctuate rapidly, with first-degree AV block progressing to second-degree or complete AV block and sometimes back to first-degree AV block over a matter of minutes. The highest risk for progression to complete AV block occurs in patients with a PR interval greater than 300 milliseconds. (See 'Atrioventricular conduction abnormalities' above.)
•Less common manifestations include Lyme myopericarditis, which is often self-limited and mild. Lyme disease in Europe has been associated with chronic cardiomyopathy. (See 'Myopericarditis' above and 'Chronic cardiomyopathy' above.)
●Diagnosis – The diagnosis of Lyme carditis is established by the presence of clinical features in conjunction with positive results of Lyme serologic testing. An enzyme-linked immunosorbent assay (ELISA) and Western blot analysis should reveal seropositivity for Lyme disease. (See 'Evaluation and Diagnosis' above.)
●Management – Patients with Lyme carditis who are symptomatic (eg, syncope, dyspnea, or chest pain), have second- or third-degree AV block, have a markedly prolonged PR interval (≥300 milliseconds), or have other arrhythmias should be hospitalized, monitored with cardiac telemetry, and treated initially with intravenous (IV) antibiotics. Such patients may also require temporary pacing. For other patients, therapy with one of the preferred oral agents (doxycycline, amoxicillin, cefuroxime) is reasonable. The treatment of Lyme carditis is summarized in the table (table 2) and discussed in detail elsewhere. (See "Treatment of Lyme disease", section on 'Carditis'.)
●Prognosis – The prognosis of Lyme carditis is good in treated patients. In most reports, AV block caused by Lyme disease has persisted for 3 to 42 days. Complete AV block typically resolves within one week, and more minor conduction disturbances within six weeks. (See 'Prognosis' above.)
آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟