Lyme carditis

Incidence of Lyme Carditis and Lyme Carditis as a Cause of Pacemaker Implantation: A Nationwide Registry-Based Case-Control Study

Background

Lyme borreliosis (LB) of the heart is called Lyme carditis (LC), which often manifests with high-grade atrioventricular block (AVB) requiring pacemaker implantation. LC is treated with antibiotics, and most patients recover fully after treatment. The overall incidence of LC, and of LC as a cause of pacemaker implantation, has not previously been systematically studied.

Methods

This was a case-control study based on data from Swedish national registers. The study was divided into two parts; part 1 including all patients diagnosed with AVB between 2001 and 2018, and part 2 including all patients who had received a pacemaker due to AVB between 2010 and 2018. Patients diagnosed with LB 90 days before and 180 days after the AVB diagnosis were identified among the patients and compared to matched control groups generated from the general population.

Results

Of 81 063 patients with AVB, 102 were diagnosed with LB. In the control group, 27 were diagnosed with LB. The yearly incidence of LC was 0.056 per 100 000 adults and year. Of 25 241 patients who had received a pacemaker for AVB, 31 were diagnosed with LB. In the control group, 8 were diagnosed with LB. The yearly incidence of LC as a cause of pacemaker implantation was 0.033 per 100 000 adults and year. The estimated risk for patients with LC to receive a permanent pacemaker was 59%.

Conclusions

LC is a rare cause of AVB. Nevertheless, more than half of patients with LC receive a permanent pacemaker for a condition that is easily cured with antibiotics.

Disseminated Lyme disease and dilated cardiomyopathy: A systematic review

Lyme carditis is a well-established manifestation of early disseminated Lyme infection, yet the relationship between late disseminated Lyme disease and the development of dilated cardiomyopathy (DCM) remains unclear. The present systematic review aims to summarize existing literature on the association between late disseminated Lyme disease and DCM. A systematic review was conducted in PubMed, Embase, CENTRAL, and MEDLINE databases, after which a total of 11 observational studies (n = 771) were ultimately included for final data extraction. Although most studies (7/11) identified evidence associating Borrelia-infection with DCM, further research is required to isolate late disseminated Borrelia infection as a causative agent of DCM.

Long-Term Follow-Up of Second-Degree Heart Block in Children

Little is known about the outcomes of children with second-degree heart block. We aimed to determine whether children with structurally normal hearts and Mobitz 1, 2:1 block or Mobitz 2 are at increased risk for progressing to complete heart block (CHB) or requiring a pacemaker (PM) at long-term follow-up. We searched our institutional electrophysiology database for children with potentially concerning second-degree block on ambulatory rhythm monitoring between 2009 and 2021, defined as frequent episodes of Mobitz 1 or 2:1 block, episodes of Mobitz 1 or 2:1 block with additional evidence of conduction disease (i.e. first-degree heart block, bundle branch block), or episodes of Mobitz 2. Ambulatory rhythm monitor, ECG, and demographic data were reviewed. The primary composite outcome was CHB on follow-up rhythm monitor or PM placement. 20 patients were in the final analysis. Six (30%) patients either developed CHB but do not have a PM (4 = 20%) or have a PM (2 = 10%). Median follow-up was 5.8 years (IQR 4.4-7.0). Patients with CHB or PM were more likely to have second-degree block at maximum sinus rate (67% vs. 0%, p = 0.003), a below normal average heart rate (67% vs. 14%, p = 0.04), and 2:1 block on initial ECG (50% vs. 0%, p = 0.02). In this study of children with potentially concerning second-degree block, 30% of patients progressed to CHB or required a PM. Second-degree block at maximum sinus rate, a low average heart, and 2:1 block on initial ECG were associated with increased risk of disease progression.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

SYNCOPE: A RARE PRESENTATION OF LYME DISEASE

BACKGROUND

Lyme disease is one of the most common vector-borne illnesses in the United States. It is caused by Borrelia burgdorferi infection transmitted via the Ixodes tick. Rarely, it can progress to early disseminated Lyme disease with cardiac or neurologic manifestations, or both.

CASE REPORT

A 41-year-old previously healthy man presented to the emergency department (ED) by ambulance after an episode of syncope. Electrocardiogram revealed right bundle branch block with borderline first-degree atrioventricular nodal block. During his admission he was noted to have night sweats and elevated procalcitonin. Infectious workup revealed positive Borrelia enzyme-linked immunosorbent assay. Further testing revealed positive Borrelia immunoglobulin M with negative immunoglobulin G, indicating a recent infection. Why should an emergency physician be aware of this? Lyme disease should be on the differential for patients presenting with vague, flu-like symptoms in the summer months in endemic areas. Treatment of early Lyme disease with doxycycline can prevent progression to secondary Lyme, which can present as a true cardiac or neurologic emergency.

Lyme disease presenting as complete heart block in a young man: Case report and review of pathogenesis

Lyme carditis is a serious complication of Lyme disease, the most common vector-borne infection in both the United States and Northern Europe. It is a rare manifestation of Lyme disease that primarily affects young adults with a marked 3:1 male-to-female predominance. The presentation of Lyme carditis is heterogenous and often non-specific, although the most common clinical manifestation is AV block, which can be acute in onset and can rapidly progress to complete heart block. We discuss the case of a young adult male with complete heart block as a complication of Lyme infection, presenting with two episodes of syncope without prodromal symptoms months after tick bites. There are several pathogen, host and environmental factors that can play an important role in the epidemiology and pathogenesis of this serious condition that is reversible if treated in a timely manner. It is important for clinicians to be familiar with the presentation and treatment of this infection that is now being observed in a wider geographic distribution so as to avoid serious long-term complications and unnecessary permanent pacemaking implantation.

DNA lipid nanoparticle vaccine targeting outer surface protein C affords protection against homologous Borrelia burgdorferi needle challenge in mice

Introduction

The incidence of Lyme disease (LD) in Canada and the United States has risen over the last decade, nearing 480,000 cases each year. Borrelia burgdorferi sensu lato, the causative agent of LD, is transmitted to humans through the bite of an infected tick, resulting in flu-like symptoms and often a characteristic bull’s-eye rash. In more severe cases, disseminated bacterial infection can cause arthritis, carditis and neurological impairments. Currently, no vaccine is available for the prevention of LD in humans.

Methods

In this study, we developed a lipid nanoparticle (LNP)-encapsulated DNA vaccine encoding outer surface protein C type A (OspC-type A) of B. burgdorferi.

Results

Vaccination of C3H/HeN mice with two doses of the candidate vaccine induced significant OspC-type A-specific antibody titres and borreliacidal activity. Analysis of the bacterial burden following needle challenge with B. burgdorferi (OspC-type A) revealed that the candidate vaccine afforded effective protection against homologous infection across a range of susceptible tissues. Notably, vaccinated mice were protected against carditis and lymphadenopathy associated with Lyme borreliosis.

Discussion

Overall, the results of this study provide support for the use of a DNA-LNP platform for the development of LD vaccines.

Cardiac Manifestations of Lyme Disease

Lyme carditis is an uncommon manifestation of Lyme disease. Most cases present with heart block of varying degrees, but the spectrum of disease includes other transient arrhythmias and structural manifestations, such as myopericarditis or cardiomyopathy. Antibiotics hasten the resolution of Lyme carditis, and cardiac pacing can be an adjunctive therapy. Outcomes are generally good, but there are rare fatalities associated with Lyme carditis. The latter underscores the continued need for improved modes of prevention of Lyme disease and the importance of its early recognition and treatment.

Lyme Carditis: From Pathophysiology to Clinical Management

Cardiac involvement is a rare but relevant manifestation of Lyme disease that frequently presents as atrioventricular block (AVB). Immune-mediated injury has been implicated in the pathogenesis of Lyme carditis due to possible cross-reaction between Borrelia burgdorferi antigens and cardiac epitopes. The degree of the AVB can fluctuate rapidly, with two-thirds of patients progressing to complete AVB. Thus, continuous heart rhythm monitoring is essential, and a temporary pacemaker may be necessary. Routinely permanent pacemaker implantation, however, is contraindicated because of the frequent transient nature of the condition. Antibiotic therapy should be initiated as soon as the clinical suspicion of Lyme carditis arises to reduce the duration of the disease and minimize the risk of complications. Diagnosis is challenging and is based on geographical epidemiology, clinical history, signs and symptoms, serological testing, ECG and echocardiographic findings, and exclusion of other pathologies. This paper aims to explain the pathophysiological basis of Lyme carditis, describe its clinical features, and delineate the treatment principles.

Coexisting Thyroiditis and Carditis in a Patient with Lyme disease: Looking for a Unifying Diagnosis

Background/Objective

Lyme disease, the most common vector-borne infection in the United States, causes multisystem inflammation. We describe a patient who presented with symptoms of Lyme disease, carditis, and thyroiditis.

Case Report

A 53-year-old woman developed fatigue and dyspnea on exertion 1 month after returning from a trip to Delaware. Her electrocardiogram (ECG) showed first-degree atrioventricular (AV) block with a P-R interval up to 392 milliseconds, in the setting of elevated free thyroxine and undetectable thyroid-stimulating hormone levels. Lyme serology was positive. She was hospitalized and started on ceftriaxone. During the second day of hospitalization, AV block worsened to second-degree Mobitz type II but converted back to first-degree AV block after a few hours. Her 24-hour I-123 thyroid uptake and scan revealed markedly diminished I-123 uptake of 1.2%. On day 4, the P-R interval improved, and she was discharged on doxycycline for 3 weeks. P-R interval on ECG and repeated thyroid function tests were normal after finishing antibiotic treatment.

Discussion

In our patient, known exposure to the vector, a classic rash on the chest, improvement in the symptoms, and normalization of thyroid function tests after antibiotic therapy support Lyme infection as a cause of carditis and painless, autoimmune thyroiditis.

Conclusion

Our case highlights the importance of considering Lyme disease as a cause of painless, autoimmune thyroiditis, especially in patients with concurrent cardiovascular involvement.

Rash and Heart Block: A Unique Case of Lyme Carditis

Lyme disease is a multisystem disease that can present as a life-threatening condition known as Lyme carditis. While most commonly manifesting as a fluctuating atrioventricular block, Lyme carditis can also emerge as myocarditis and coronary artery events. This case report will detail the clinical scenario of a 23-year-old patient who presented with acute onset fluctuating atrioventricular block and erythema migrans and was found to have Lyme carditis. The patient was treated promptly with antibiotics, thus avoiding long-term Lyme disease sequela, with a complete resolution of his disease, including his high degree atrioventricular block.

A rare and reversible cause of third-degree atrioventricular block: a case report

Background

Cardiac involvement of Lyme disease (LD) typically results in atrioventricular (AV) conduction disturbance, mainly third-degree AV block.

Case summary

A 54-year-old patient presented to our emergency department due to recurrent syncope. Third-degree AV block with a ventricular escape rhythm (33 b.p.m.) was identified as the underlying rhythm. Transthoracic echocardiography (TTE) was normal. To rule out common reversible causes of complete AV block, a screening test for Lyme borreliosis was carried out. Elevated levels for borrelia IgG/IgM were found and confirmed by western blot analysis. Lyme carditis (LC) was postulated as the most likely cause of the third-degree AV block given the young age of the patient. Initiation of antibiotic therapy with ceftriaxone resulted in a gradual normalization of the AV conduction with stable first-degree AV block on Day 6 of therapy. The patient was changed on oral antibiotics (doxycycline) and discharged without a pacemaker. After 3 months, the AV conduction recovered to normal.

Discussion

Lyme carditis should always be considered, particularly in younger patients with new-onset AV block and without evidence of structural heart disease. Atrioventricular block recovers in the majority of cases after appropriate antibiotic treatment.

Incidence of carditis and predictors of pacemaker implantation in patients hospitalized with Lyme disease

BACKGROUND

Lyme carditis, defined as direct infection of cardiac tissue by Borrelia bacteria, affects up to 10% of patients with Lyme disease. The most frequently reported clinical manifestation of Lyme carditis is cardiac conduction system disease. The goal of this study was to identify the incidence and predictors of permanent pacemaker implantation in patients hospitalized with Lyme disease.

METHODS

A retrospective cohort analysis of the Nationwide Inpatient sample was performed to identify patients hospitalized with Lyme disease in the US between 2003 and 2014. Patients with Lyme carditis were defined as those hospitalized with Lyme disease who also had cardiac conduction disease, acute myocarditis, or acute pericarditis. Patients who already had pacemaker implants at the time of hospitalization (N = 310) were excluded from the Lyme carditis subgroup. The primary study outcome was permanent pacemaker implantation. Secondary outcomes included temporary cardiac pacing, permanent pacemaker implant, and in-hospital mortality.

RESULTS

Of the 96,140 patients hospitalized with Lyme disease during the study period, 10,465 (11%) presented with Lyme carditis. Cardiac conduction system disease was present in 9,729 (93%) of patients with Lyme carditis. Permanent pacemaker implantation was performed in 1,033 patients (1% of all Lyme hospitalizations and 11% of patients with Lyme carditis-associated conduction system disease). Predictors of permanent pacemaker implantation included older age (OR: 1.06 per 1 year; 95% CI:1.05-1.07; P<0.001), complete heart block (OR: 21.5; 95% CI: 12.9-35.7; P<0.001), and sinoatrial node dysfunction (OR: 16.8; 95% CI: 8.7-32.6; P<0.001). In-hospital mortality rate was higher in patients with Lyme carditis (1.5%) than in patients without Lyme carditis (0.5%).

CONCLUSIONS

Approximately 11% of patients hospitalized with Lyme disease present with carditis, primarily in the form of cardiac conduction system disease. In this 12-year study, 1% of all hospitalized patients and 11% of those with Lyme-associated cardiac conduction system disease underwent permanent pacemaker implantation.

Reversible Causes of Atrioventricular Block

Atrioventricular blocks may be caused by a variety of potentially reversible conditions, such as ischemic heart disease, electrolyte imbalances, medications, and infectious diseases. Such causes must be always ruled out to avoid unnecessary pacemaker implantation. Patient management and reversibility rates depend on the underlying cause. Careful patient history taking, monitoring of vital signs, electrocardiogram, and arterial blood gas analysis are crucial elements of the diagnostic workflow during the acute phase. Atrioventricular block recurrence after the reversal of the underlying cause may pose an indication for pacemaker implantation, because reversible conditions may actually unmask a preexistent conduction disorder.

Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Management of Tick-Borne Illness in the United States

The Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the prevention and management of tick-borne illness (TBI). Recommendations are graded based on quality of supporting evidence according to criteria put forth by the American College of Chest Physicians. The guidelines include a brief review of the clinical presentation, epidemiology, prevention, and management of TBI in the United States, with a primary focus on interventions that are appropriate for resource-limited settings. Strong recommendations are provided for the use of DEET, picaridin, and permethrin; tick checks; washing and drying clothing at high temperatures; mechanical tick removal within 36 h of attachment; single-dose doxycycline for high-risk Lyme disease exposures versus "watchful waiting;" evacuation from backcountry settings for symptomatic tick exposures; and TBI education programs. Weak recommendations are provided for the use of light-colored clothing; insect repellents other than DEET, picaridin, and permethrin; and showering after exposure to tick habitat. Weak recommendations are also provided against passive methods of tick removal, including the use of systemic and local treatments. There was insufficient evidence to support the use of long-sleeved clothing and the avoidance of tick habitat such as long grasses and leaf litter. Although there was sound evidence supporting Lyme disease vaccination, a grade was not offered as the vaccine is not currently available for use in the United States.

Physical Therapist Recognition and Referral of Individuals With Suspected Lyme Disease

The most commonly reported vector-borne and tick-borne disease in the United States is Lyme disease. Individuals with Lyme disease may present with a wide array of symptoms with resultant musculoskeletal, neurological, and cardiac manifestations that may cause them to seek physical therapist services. The symptoms may develop insidiously and with a variable presentation among individuals. Many persons with Lyme disease do not recall a tick bite or present with an erythema migrans rash, which is considered pathognomonic for the disease. Even if they do, they may fail to associate either with their symptoms, making the diagnosis elusive. It is important to diagnose individuals early in the disease process when antibiotic treatment is most likely to be successful. Physical therapists are in a unique position to recognize the possibility that individuals may have Lyme disease and refer them to another practitioner when appropriate. The purpose of this article is to (1) present an overview of the etiology, incidence, and clinical manifestations of Lyme disease, (2) review evaluation findings that should raise the index of suspicion for Lyme disease, (3) discuss the use of an empirically validated tool for differentiating those with Lyme disease from healthy individuals, (4) discuss the current state of diagnostic testing, and (5) review options for diagnosis and treatment available to individuals for whom referral is recommended.

Lyme Carditis in Hospitalized Children and Adults, a Case Series

Background

Lyme carditis is an uncommon manifestation of Lyme disease. This report compares Lyme carditis presentation, management, and outcomes in pediatric and adult populations.

Methods

Charts of pediatric and adult patients with heart block (PR interval >300 ms) and positive Lyme serologies hospitalized in Portland, Maine, between January 2010 and December 2018 were analyzed. Data on medical history, presentation, treatment, and outcomes are described.

Results

Ten children and 20 adults were admitted for Lyme carditis between June and October. Ninety percent were male, and 87% had no prior cardiac history. Seventeen had outpatient evaluation before admission. Of these, a minority (41%) had Lyme disease suspected in the outpatient setting, and fewer (12%) were initiated on Lyme disease treatment. The most common alternate diagnoses were viral illness and erythema multiforme. More children than adults had disseminated erythema migrans and fever. First-degree heart block was more prevalent in children, and Mobitz type 2 heart block was more prevalent in adults. Ten patients presented with syncope. Proportionately more adults needed temporary pacing. Children had shorter antibiotic durations compared with adults. Of the 30 cases, 27 had improved heart block, while 3 adults required a pacemaker at discharge. Nine children and 14 adults were discharged with a PR 200–300 ms. There was a single death in this series.

Conclusions

Cases tended to be younger males. Most patients had some heart block on discharge. Of patients evaluated as outpatients, Lyme disease was suspected in 41%. Improved early recognition and treatment of Lyme disease may decrease Lyme carditis.

Lyme Carditis: A Reversible Cause of Acquired Third-Degree AV Block

Patient: Male, 36-year-old

Final Diagnosis: Lyme carditis

Symptoms: Fatigue • myalgia

Medication: —

Clinical Procedure: Transcutaneous pacemaker

Specialty: Cardiology

Jaw Pain and Profound Bradycardia – An Atypical Presentation of Lyme Carditis

In 2018, 23,558 confirmed cases and 10,108 probable cases of Lyme disease were reported in the United States, with 96% of all cases coming from 14 states. Lyme carditis is well described, occurring in less than 1% of Lyme disease. High-grade heart block is uncommon in early disseminated Lyme disease. In Lyme carditis due to sinus node dysfunction and/or high grade atrioventricular block, the pulse rates are significantly lower which can lead to syncope. This can happen in the setting of an unstable ventricular escape rhythm with pulse rates ranging around 30 beats per minute or lower. In patients with low cardiovascular reserve, high-degree AV block can cause sudden death. Here we describe a rare case of profound bradycardia in disseminated Lyme disease. The patient’s only two symptoms are bradycardia and jaw pain. He lacks erythema migrans, neurological symptoms or syncope - despite having high-degree AV block. Initially prescribed doxycycline 100mg BID, his PR interval begins to normalize, but once a Lyme titre was positive for IgM (p41, p39, p23) and IgG (p66, p45, p41, p39, p23, p18), the patient was switched to 2g ceftriaxone IV Q 24h, per Infectious Disease Society of America (IDSA) guidelines. After several days he feels better and was discharged home to complete antibiotics and wear a cardiac event monitor. Lyme disease has three distinct stages that include early localized infection, early disseminated disease, and late infection. At the time of Lyme carditis diagnosis, common symptoms include erythema migrans, malaise, polyarthritis, Bell’s palsy and other neurological symptoms - all of which were lacking in our patient. The prognosis for Lyme carditis is generally good, despite disagreement over the incidence of persistent B. burgdorferi infection. This patient’s unique presentation of Lyme carditis is further evidence of variability in cardiac symptoms depending on one’s immunological and physiological ability to combat acute spirochete infection.

Diagnosing Lyme Carditis Presenting With Complete Heart Block

Diagnosing self-limited conduction abnormality of Lyme carditis in absence of pathognomonic skin rash or history of tick bite is challenging but necessary to avoid placement of pacemaker particularly in young patients. High degree of clinical suspicion, rapidly progressing conduction block and prompt response to antibiotics may help in diagnosis.

Early Disseminated Lyme Carditis Inducing High-Degree Atrioventricular Block

Lyme disease is the most common tick-borne illness in the United States due to Borrelia burgdorferi infection. This case demonstrates a 20-year-old male patient presenting with complaints of annular skin rash, malaise, fever, and lightheadedness after significant outdoor exposure. Physical exam revealed multiple large targetoid lesions on the back and extremities. The rash had raised borders and centralized clearing consistent with erythema migrans chronicum. Electrocardiogram (ECG) revealed a high-degree atrioventricular (AV) block. The patient was started on intravenous ceftriaxone due to clinical suspicion for Lyme carditis. ELISA and Western blot tests were reactive for Lyme IgM and IgG, confirming the diagnosis. The AV block resolved by hospital day four and the patient was discharged with outpatient follow-up. Early identification of disease allowed for effective treatment with no adverse outcomes or sequelae.

Lyme Endocarditis as an Emerging Infectious Disease: A Review of the Literature

Lyme endocarditis is extremely rare manifestation of Lyme disease. The clinical manifestations of Lyme endocarditis are non-specific and can be very challenging diagnosis to make when it is the only manifestation of the disease. Until now, only a few cases where reported. Physicians should keep in mind the possibility of borrelial etiology of endocarditis in endemic areas. Appropriate valve tissue sample should be sent for histopathology, culture, and PCR especially in case of endocarditis of unknown origin PCR on heart valve samples is recommended. With more frequent PCR, Borrelia spp. may be increasingly found as a cause of infective endocarditis. Prompt diagnosis and treatment of Lyme carditis may prevent surgical treatment and pacemaker implantations. Due to climate change and global warming Lyme disease is a growing problem. Rising number of Lyme disease cases we can expect and rising number of Lyme endocarditis.

Lyme Carditis: A Rare Presentation of Sinus Bradycardia Without Any Conduction Defects

Lyme carditis is a rare cardiac manifestation of Lyme disease that occurs when bacterial spirochetes infect the pericardium or myocardium triggering an inflammatory response. The most common electrocardiogram (EKG) findings in these patients include atrioventricular (AV) conduction abnormalities (first, second, and third degree heart block). A 56-year-old male with a history of hypothyroidism, from the Northeastern region of the United States, presented to the emergency department with lightheadedness and chest pain. His EKG revealed sinus bradycardia with a heart rate of 49 beats per minute, without ST segment elevation, T wave inversions, or signs of heart block. An enzyme-linked immunosorbent assay (ELISA) Lyme titer was elevated, and confirmatory Western blot was positive for IgG and negative for IgM. He was treated with intravenous (IV) ceftriaxone; however, he continued to have persistent bradycardia with his heart rate dropping to 20 to 30 beats per minute throughout the night. Additionally, he had several sinus pauses while sleeping, with the longest lasting for 6.1 seconds. A pacemaker and an additional three-week course of IV ceftriaxone was determined to be the best treatment for his resistant bradycardia secondary to Lyme carditis. No symptoms were present at his one month follow-up appointment, as an outpatient, after completing ceftriaxone therapy. The patient follows up with cardiology regularly to have his pacemaker checked. Here we present a unique case of Lyme carditis, without the classical findings of Lyme disease or common EKG findings of AV conduction abnormalities. A high clinical suspicion of Lyme carditis is required when someone from a Lyme endemic region presents with unexplained cardiac symptoms and electrocardiogram abnormalities. This case report aims to add to the knowledge gap between suspicion of Lyme carditis and sinus bradycardia as the only presenting symptom.

The Causes of Canine Myocarditis and Myocardial Fibrosis Are Elusive by Targeted Molecular Testing: Retrospective Analysis and Literature Review

Myocarditis can cause death or permanent heart damage. As epidemiologic and etiopathologic data for canine myocarditis are lacking, we performed a retrospective study using nucleic acid extracted from archived (2007 to 2015) tissues from myocarditis cases and control dogs without myocardial lesions. Heart tissue from pediatric/juvenile and adult dogs was tested with a comprehensive panel of conventional and real-time polymerase chain reaction (PCR) assays targeting recognized agents of canine myocarditis based on a literature review and informed by the comparative epidemiology of human myocarditis. The PCR screen, which included canine parvovirus 2 (CPV-2), canine distemper virus, canine herpesvirus, Borrelia spp, West Nile virus, adenovirus, parainfluenza virus, pneumovirus, respiratory coronavirus, influenza virus, Bartonella spp, Rickettsia spp, Mycoplasma spp, and Neospora caninum, did not detect agents in 35 of 66 cases (53%; 95% confidence interval [CI], 41%-65%) and was frequently negative in adults (21/26); by comparison, agents were not detected in 27 of 57 controls (47%; 95% CI, 35%-60%). Canine distemper virus, herpesvirus, adenovirus, coronavirus, parainfluenza virus, Mycoplasma haemocanis, and N. caninum were occasionally detected in both cases and controls; thus, PCR detection was not considered to indicate causation. We previously reported that CPV-2 continues to be associated with myocarditis in young dogs despite widespread vaccination; in adults, CPV-2 was detected in 2 of 26 cases and 4 of 22 controls. As several agents were similarly detected in cases and controls, it is unclear if these are cardiopathogenic, incidental, or latent. West Nile virus was detected at the analytic limit in 1 adult case. We did not detect Borrelia spp, Bartonella spp, Rickettsia spp, or influenza A virus in the myocarditis cases. These data demonstrate the limitations of current targeted diagnostic tests and the need for additional research to identify unknown agents and develop testing strategies for canine myocarditis.

Mitral Valve Endocarditis: A Rare Manifestation of Lyme Disease

Valvular involvement in Lyme disease is rare. Confirmation of Borrelia species as the causative agent with polymerase chain reaction was done in a few cases in Europe and the United States. We describe a case of mitral regurgitation with a preoperative diagnosis of myxomatous mitral valve degeneration. During surgery, the surgeon suspected infective rather than degenerative etiology; the results of tissue cultures were negative. However, universal bacterial polymerase chain reaction on explanted valve tissue detected Borrelia burgdorferi DNA. If a surgeon suspects infective endocarditis at the time surgery, appropriate specimens should be sent for histopathologic analysis, culture, and polymerase chain reaction assay.

Lyme borreliosis-from tick bite to diagnosis and treatment

Lyme borreliosis is caused by certain genospecies of the Borrelia burgdorferi sensu lato complex, which are transmitted by hard ticks of the genus Ixodes. The most common clinical manifestation is erythema migrans, an expanding skin redness that usually develops at the site of a tick bite and eventually resolves even without antibiotic treatment. The infecting pathogens can spread to other tissues and organs, resulting in manifestations that can involve the nervous system, joints, heart and skin. Fatal outcome is extremely rare and is due to severe heart involvement; fetal involvement is not reliably ascertained. Laboratory support-mainly by serology-is essential for diagnosis, except in the case of typical erythema migrans. Treatment is usually with antibiotics for 2 to 4 weeks; most patients recover uneventfully. There is no convincing evidence for antibiotic treatment longer than 4 weeks and there is no reliable evidence for survival of borreliae in adequately treated patients. European Lyme borreliosis is a frequent disease with increasing incidence. However, numerous scientifically questionable ideas on its clinical presentation, diagnosis and treatment may confuse physicians and lay people. Since diagnosis of Lyme borreliosis should be based on appropriate clinical signs, solid knowledge of clinical manifestations is essential.

A Serological Survey of Borrelia burgdorferi Infection in Sheep in Northeast China Regions Through Outer Surface Protein C-Based Enzyme-Linked Immunosorbent Assay

Borrelia burgdorferi as a causative agent of Lyme disease is transmitted by Ixodes spp. ticks to humans and animals. Sheep is considered a natural reservoir for B. burgdorferi and plays a pivotal role in disease transmission and the expansion of natural foci. An epidemiological investigation of B. burgdorferi in sheep is essential for prevention and control of Lyme disease. In this study, we developed a recombinant outer surface protein C (OspC)-based ELISA for serological study of B. burgdorferi in sheep with a specificity and sensitivity of 84.4% and 86.2%, respectively. A total of 972 collected serum samples from the Northeast China regions in 2015 and 2016 were determined with positive rates of 5.8% and 12.2%, respectively. Thus, specific pathogen-free sheep were infected with B. burgdorferi SZ strain to study on the secretion of specificity antibody against OspC. It revealed that specific antibody was detected on day 5 postinoculation and sustained in a high level for ∼28 days, the peak occurred at ∼13 days. Taken together, the result indicated that the established ELISA is capable for clinical diagnosis and epidemiological study on B. burgdorferi in sheep at the early stage of infection and detecting the specific antibody during the secretion period.

Treating Lyme carditis high-degree AV block using a temporary-permanent pacemaker

A 28-year-old previously healthy male presented with nonprodromal syncope and a 4-day history of chest pain, shortness of breath, and malaise. His ECG showed rapidly progressive high-degree AV block. His Suspicious Index in Lyme Carditis (SILC) score was 8, indicating high risk for Lyme carditis. Lyme serology revealed to be positive (anti-Lyme IgM). During the second day of hospitalization, the patient deteriorated his AV conduction, and a temporary-permanent pacemaker was implanted allowing ambulating in hospital the very same day. Temporary-permanent pacemakers for the management of transient high-degree heart block associated with Lyme carditis were only occasionally used in the past.

Lyme Endocarditis

BACKGROUND

Valvular involvement as a manifestation of Lyme carditis is rare. The first case describing a possible association between Lyme disease and cardiac valvular disease in the United States was published in 1993. Since that time there have been 2 cases of Lyme endocarditis confirmed by Borrelia-positive 16S ribosomal RNA polymerase chain reaction and sequencing from valvular tissue and reported from Europe. Here we describe a case of Lyme endocarditis that, to our knowledge, is the first reported case confirmed by molecular diagnostics in the United States.

METHODS

We present the case of a 68-year-old man with progressive dyspnea who had mitral valve perforation with severe mitral valve insufficiency seen on transesophageal echocardiogram.

RESULTS

Subsequently resected valve tissue had signs of acute inflammation without organisms seen. Although blood and valve tissue cultures were negative, 16S ribosomal RNA polymerase chain reaction and sequencing demonstrated Borrelia burgdorferi.

CONCLUSION

Lyme endocarditis can be a challenging diagnosis to confirm, given the rarity of cases and the need for molecular tools of resected valve tissue. It should be included among diagnostic possibilities in patients with culture-negative endocarditis who have exposure to ticks in endemic and emerging areas of Lyme disease.

Lyme Carditis: A Case Report and Review of Management

Purpose: A case report of a patient who presented with an acute onset, fluctuating atrioventricular (AV) block and was diagnosed with Lyme carditis is presented. Summary: A 55-year-old man with progressively worsening generalized malaise, flu-like symptoms, dyspnea on exertion, and near syncope was admitted with bradycardia (heart rate was between 20 and 30 beats per minute upon admission). He endorsed having several tick bites after which he developed erythema migrans on his arm and abdomen. An electrocardiogram (ECG) revealed a second-degree AV block, fluctuating between Mobitz type I and Mobitz type II heart block, with a P-R interval of 300 ms. A presumptive diagnosis of Lyme carditis was made based on a confirmed history of tick exposure, presence of erythema migrans, and AV block. The patient was started on ceftriaxone. On day 3 of hospitalization, patient's heart rate was between 50 and 60 beats per minute. A diagnosis of Lyme disease was confirmed based on serologic testing. A repeat ECG revealed a first-degree AV block with a P-R interval of 300 ms. On day 5 of hospitalization, a peripherally inserted central catheter line was placed and the patient was discharged to his home on a 28-day course of ceftriaxone. Patient's heart rate was 65 beats per minute on discharge day. Conclusion: Considering Lyme carditis as a differential diagnosis in patients with an AV block of an unknown etiology can result in a timely diagnosis and treatment of Lyme carditis.

Lyme carditis: Early occurrence and prolonged recovery

Lyme carditis is an uncommon manifestation of early disseminated Lyme disease. This case illustrates a 66-year-old male with complaints of fatigue, myalgias, and fever after a tick bite 3days earlier. A large erythema migrans was found on the chest wall. Initial electrocardiogram showed sinus rhythm with second degree 2:1 atrioventricular (AV) block, which progressed to intermittent complete AV block rapidly. He was treated with intravenous ceftriaxone. Over the course of 2-weeks of antibiotic therapy, the intermittent high-grade AV block improved slowly and progressively. This case highlights the importance of timely diagnosis and appropriate management to achieve a favorable prognosis.

Management of Lyme Disease in European Children: a Review for Practical Purpose

PURPOSE OF REVIEW

Lyme disease is a tick-borne zoonosis transmitted through a bite of a tick carrying a spirochete belonging to Borrelia species. In the last 20 years, the reported incidence of Lyme disease is increased by three times in Europe. Clinically, the illness develops through a primary stage with a typical skin rash (erythema marginatum), then a secondary stage with possible neurologic or cardiac involvement. The last stage (chronic Lyme disease) is mainly represented by arthritis or late neurological complications but nowadays is rarely seen due to precocious antibiotic use.

RECENT FINDINGS

The diagnosis of Lyme disease is essentially based on history in agreement with tick exposure (living/recent traveling in endemic area or tick bite) and clinical findings compatible with the disease. At present, no laboratory diagnostic tool available can neither establish nor exclude the diagnosis of Lyme disease. The management of Lyme disease should comprise a prophylactic administration of antibiotic in selected population (patients exposed to a tick bite in endemic regions) in which the typical signs of Lyme disease are not yet appeared; conversely, patients with current signs of Lyme disease should undergo a standard therapeutic course. First-line therapy should be oral tetracycline or oral penicillin/cephalosporin (in pediatric populations, beta-lactamic drugs are preferred). In severe courses, intravenous route should be preferred. The aim of this review is to provide an updated guide to the management of pediatric Lyme patients, from prophylaxis to first- and second-line therapy in European setting.

Successful treatment of fulminant Lyme myocarditis with mechanical circulatory support in a young male adult: a case report

We describe the case of fulminant myocarditis due to Lyme disease and use of mechanical circulatory support (MCS) for the treatment of the Lyme carditis associated with refractory cardiogenic shock. Fulminant Lyme myocarditis in young adult male patient led to a sudden onset of acute, severe biventricular heart failure with progressive cardiogenic shock, and multiorgan failure immediately after admission.

The previously healthy 28-year-old man was admitted to hospital with dyspnea, atrial flutter with 160/min ventricles rate, normotension, cardiomegaly, and incipient cardiogenic pulmonary edema on chest x-ray. Within the next 24 hours, the acute heart failure (AHF) progressed to the refractory cardiogenic shock with severe systemic hypotension, respiratory distress, anuria, liver congestion, and laboratory evidence of extremely high level of the anaerobic metabolism in the arterial blood (pH 7.16; HCO₃ 12.3 mmol/L; BE -14.6; lactates level 17 mmol/L). The transesophageal echo imaging showed severe dilatation and global biventricular akinesis, with left ventricular ejection fraction of 5%. The diagnosis of acute fulminant myocarditis of unknown etiology was reached. Since the patient did not respond rapidly to vasoactive and supportive therapy, MCS was immediately inserted. Broad differential diagnosis of fulminant myocarditis was considered and disseminated Borrelia infection was serologically confirmed and appropriate antimicrobial therapy was started from the fifth day after admission. MCS used over the next 26 days was successfully integrated with pharmacologic support and artificial ventilation in therapy. The patient was discharged from hospital after 65 days with a complete restoration of bilateral heart ejection fraction.

This case shows that the clinical course of the Lyme carditis can present uncommonly with profound cardiovascular collapse and the MSC implementation should be considered in the early stage of drug resistant hemodynamic instability. Rapid transfer to the cardiac center where the MCS is available for all patients with signs and symptoms of AHF due to confirmed or suspected Lyme carditis would be recommended, as this treatment could be the only life-saving method.

Lyme carditis with complete heart block: management with an external pacemaker

Timely diagnosis and prompt initiation of treatment is essential in Lyme carditis to achieve favorable prognosis. Externalized permanent pacemaker with an active fixation lead as supportive pacing modality is a feasible option till complete resolution of conduction block with continued antibiotic therapy.

Manifestations of Lyme carditis

The first data of Lyme carditis, a relatively rare manifestation of Lyme disease, were published in eighties of the last century. Clinical manifestations include syncope, light-headedness, fainting, shortness of breath, palpitations, and/or chest pain. Atrioventricular (AV) electrical block of varying severity presents the most common conduction disorder in Lyme carditis. Although is usually mild, AV block can fluctuates rapidly and progress from a prolonged P-R interval to a His-Purkinje block within minutes to hours and days. Rarely, Lyme disease may be the cause of endocarditis, while some studies and reports, based on serological and/or molecular investigations, have suggested possible influence of Borrelia burgdorferi on degenerative cardiac valvular disease. Myocarditis, pericarditis, pancarditis, dilated cardiomyopathy, and heart failure have also been described as possible manifestations of Lyme carditis. The clinical course of Lyme carditis is generally mild, short term, and in most cases, completely reversible after adequate antibiotic treatment.

Emergent pacemaker placement in a patient with Lyme carditis-induced complete heart block and ventricular asystole

We report a case of a 31-year-old man who presented to the emergency department after four episodes of syncope within a 24 h time span. He was found to have symptomatic complete heart block associated with episodes of ventricular asystole lasting 5-6 s. He underwent emergent permanent pacemaker insertion during which he was found to have no underlying rhythm. He was later found to have positive serologies for Lyme disease despite no known exposure to ticks and neither signs nor symptoms of the disease. The pacemaker was ultimately removed due to resolution of his heart block with antibiotic therapy.

Cardiac Tropism of Borrelia burgdorferi: An Autopsy Study of Sudden Cardiac Death Associated with Lyme Carditis

Fatal Lyme carditis caused by the spirochete Borrelia burgdorferi rarely is identified. Here, we describe the pathologic, immunohistochemical, and molecular findings of five case patients. These sudden cardiac deaths associated with Lyme carditis occurred from late summer to fall, ages ranged from young adult to late 40s, and four patients were men. Autopsy tissue samples were evaluated by light microscopy, Warthin-Starry stain, immunohistochemistry, and PCR for B. burgdorferi, and immunohistochemistry for complement components C4d and C9, CD3, CD79a, and decorin. Post-mortem blood was tested by serology. Interstitial lymphocytic pancarditis in a relatively characteristic road map distribution was present in all cases. Cardiomyocyte necrosis was minimal, T cells outnumbered B cells, plasma cells were prominent, and mild fibrosis was present. Spirochetes in the cardiac interstitium associated with collagen fibers and co-localized with decorin. Rare spirochetes were seen in the leptomeninges of two cases by immunohistochemistry. Spirochetes were not seen in other organs examined, and joint tissue was not available for evaluation. Although rare, sudden cardiac death caused by Lyme disease might be an under-recognized entity and is characterized by pancarditis and marked tropism of spirochetes for cardiac tissues.

Lyme carditis

Lyme disease is a common disease that uncommonly affects the heart. Because of the rarity of this diagnosis and the frequent absence of other concurrent clinical manifestations of early Lyme disease, consideration of Lyme carditis demands a high level of suspicion when patients in endemic areas come to attention with cardiovascular symptoms and evidence of higher-order heart block. A majority of cases manifest as atrioventricular block. A minority of Lyme carditis cases are associated with myopericarditis. Like other manifestations of Lyme disease, carditis can readily be managed with antibiotic therapy and supportive care measures, such that affected patients almost always completely recover.

Clinical Manifestations and Treatment of Lyme Disease

Lyme disease is the most common tick-borne illness in the United States and is also seen in areas of Europe and Asia. The growing deer and Ixodes species tick populations in many areas underscore the importance of clinicians to properly recognize and treat the different stages of Lyme disease. Controversy regarding the cause and management of persistent symptoms following treatment of Lyme disease persists and is highlighted in this review.

Cutaneous infectious diseases: Kids are not just little people

The changes in immune response that occur with age play a significant role in disease presentation and patient management. Evolution of the innate and adaptive immune systems throughout life, influenced partly by hormonal changes associated with puberty, plays a role in the differences between pediatric and adult response to disease. We review a series of manifestations of dermatologic infectious diseases spanning bacterial, viral, and fungal origins that can be seen in both pediatric and adult age groups and highlight similarities and differences in presentation and disease course. Therapeutic options are also discussed for these infectious diseases, with particular attention to variations in management between these population subgroups, given differences in pharmacokinetics and side effect profiles.

Sinus pause in association with Lyme carditis

Lyme disease is the most prevalent tick-borne disease in the United States. It is caused by the spirochete Borrelia burgdorferi. Cardiac involvement is seen in 4% to 10% of patients with Lyme disease. The principal manifestation of Lyme carditis is self-limited conduction system disease, with predominant involvement of the atrioventricular node. On rare occasions, Lyme carditis patients present with other conduction system disorders such as bundle branch block, intraventricular conduction delay, and supraventricular or ventricular tachycardia. We report the unusual case of a 59-year-old man who presented with new-onset symptomatic sinus pauses one month after hiking in upstate New York. To our knowledge, this is the first case report from North America that describes the relationship between symptomatic sinus pause and Lyme carditis.