Advanced Heart Block in Children with Lyme Disease

Antiarrhythmic Drug Dosing in Children-Review of the Literature

Antiarrhythmic drugs represent a mainstay of pediatric arrhythmia treatment. However, official guidelines and consensus documents on this topic remain scarce. There are rather uniform recommendations for some medications (including adenosine, amiodarone, and esmolol), while there are only very broad dosage recommendations for others (such as sotalol or digoxin). To prevent potential uncertainties and even mistakes with regard to dosing, we summarized the published dosage recommendations for antiarrhythmic drugs in children. Because of the wide variations in availability, regulatory approval, and experience, we encourage centers to develop their own specific protocols for pediatric antiarrhythmic drug therapy.

Electrocardiogram as a Lyme Disease Screening Test

OBJECTIVE

To examine the association between electrocardiographic (ECG) evidence of carditis at the time of Lyme disease evaluation and a diagnosis of Lyme disease.

STUDY DESIGN

We performed an 8-center prospective cohort study of children undergoing emergency department evaluation for Lyme disease limited to those who had an ECG obtained by their treating clinicians. The study cardiologist reviewed all ECGs flagged as abnormal by the study sites to assess for ECG evidence of carditis. We defined Lyme disease as the presence of an erythema migrans lesion or a positive 2-tier Lyme disease serology. We used logistic regression to measure the association between Lyme disease and atrioventricular (AV) block or any ECG evidence of carditis.

RESULTS

Of the 546 children who had an ECG obtained, 214 (39%) had Lyme disease. Overall, 42 children had ECG evidence of carditis, of whom 24 had AV block (20 first-degree). Of the patients with ECG evidence of carditis, only 21 (50%) had any cardiac symptoms. The presence of AV block (OR 4.7, 95% CI 1.8-12.1) and any ECG evidence of carditis (OR 2.3, 95% CI 1.2-4.3) were both associated with diagnosis of Lyme disease.

CONCLUSIONS

ECG evidence of carditis, especially AV block, was associated with a diagnosis of Lyme disease. ECG evidence of carditis can be used as a diagnostic biomarker for Lyme disease to guide initial management while awaiting Lyme disease test results.

MIS-C and Cardiac Conduction Abnormalities

OBJECTIVES

Multisystem inflammatory syndrome in children (MIS-C) has spread through the pediatric population during the coronavirus disease 2019 pandemic. Our objective for the study was to report the prevalence of conduction anomalies in MIS-C and identify predictive factors for the conduction abnormalities.

METHODS

We performed a single-center retrospective cohort study of pediatric patients <21 years of age presenting with MIS-C over a 1-month period. We collected clinical outcomes, laboratory findings, and diagnostic studies, including serial electrocardiograms, in all patients with MIS-C to identify those with first-degree atrioventricular block (AVB) during the acute phase and assess for predictive factors.

RESULTS

Thirty-two patients met inclusion criteria. Median age at admission was 9 years. Six of 32 patients (19%) were found to have first-degree AVB, with a median longest PR interval of 225 milliseconds (interquartile range 200-302), compared with 140 milliseconds (interquartile range 80-178) in patients without first-degree AVB. The onset of AVB occurred at a median of 8 days after the initial symptoms and returned to normal 3 days thereafter. No patients developed advanced AVB, although 1 patient developed a PR interval >300 milliseconds. Another patient developed new-onset right bundle branch block, which resolved during hospitalization. Cardiac enzymes, inflammatory markers, and cardiac function were not associated with AVB development.

CONCLUSIONS

In our population, there is a 19% prevalence of first-degree AVB in patients with MIS-C. All patients with a prolonged PR interval recovered without progression to high-degree AVB. Patients admitted with MIS-C require close electrocardiogram monitoring during the acute phase.

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.

Chest palpitations in a teenager as an unusual presentation of Lyme disease: case report

BACKGROUND

The incidence of Lyme disease (LD) in North America has increased substantially in the past two decades. Concomitant with the increased incidence of infection has been an enhancement in the recognition of LD complications. Here, we report a case of Lyme carditis complicated by heart block in a pediatric patient admitted to our children's hospital. What is unique about this case is that the complaint of chest palpitations is an infrequent presentation of LD, and what it adds to the scientific literature is an improved understanding of LD in the pediatric population.

CASE PRESENTATION

The patient was a 16-year-old male who presented with the main concerns of acute onset of palpitations and chest pain. An important clinical finding was Erythema migrans (EM) on physical exam. The primary diagnoses were LD with associated Lyme carditis, based on the finding of 1st degree atrioventricular heart block (AVB) and positive IgM and IgG antibodies to Borrelia burgdorferi. Interventions included echocardiography, electrocardiography (EKG), and intravenous antibiotics. The hospital course was further remarkable for transition to 2nd degree heart block and transient episodes of complete heart block. A normal sinus rhythm and PR interval were restored after antibiotic therapy and the primary outcome was that of an uneventful recovery.

CONCLUSIONS

Lyme carditis occurs in < 5% of LD cases, but the "take-away" lesson of this case is that carditis can be the presenting manifestation of B. burgdorferi infection in pediatric patients. Any patient with suspected Lyme carditis manifesting cardiac symptoms such as syncope, chest pain, or EKG changes should be admitted for parenteral antibiotic therapy and cardiac monitoring. The most common manifestation of Lyme carditis is AVB. AVB may manifest as first-degree block, or may present as high-grade second or third-degree block. Other manifestations of Lyme carditis may include myopericarditis, left ventricular dysfunction, and cardiomegaly. Resolution of carditis is typically achieved through antibiotic administration, although pacemaker placement should be considered if the PR interval fails to normalize or if higher degrees of heart block, with accompanying symptoms, are encountered. With the rising incidence of LD, providers must maintain a high level of suspicion in order to promptly diagnose and treat Lyme carditis.