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.
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.
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.
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.
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.
The standard for ambulatory arrhythmia detection in children is the Holter monitor. The Zio XT (Zio) patch has been FDA-approved for use in adults. However, its utility in children has not been ...directly compared with the Holter. We studied the ability to detect arrhythmias and patient comfort of the Zio versus the Holter in children. Patients <22 years old were prospectively enrolled to wear the Holter and Zio simultaneously for 48 hours at our institution. Detection of clinically significant arrhythmias was compared using McNemar's test. Wear-time and artifact time was compared using Wilcoxon sign test. Patient satisfaction ratings were analyzed with paired t tests. Two hundred patients (57% male) were included for analysis. The median age was 13.5 years (range 23 days to 21.7 years), and 40% had heart disease. The Zio and Holter had comparable median wear-times, 48.2 hours (interquartile range IQR 45.8 to 50.2) versus 48.0 (48.0 to 48.0), respectively, p = 0.14, but the Zio had less artifact than the Holter, 2.8% (IQR 1.1 to 8.6) versus 5.6% (2.4 to 15.7), respectively, p <0.001. There was no difference in detection of clinically significant arrhythmias for the Zio versus the Holter (p = 0.23), however 75% of patients preferred the Zio over the Holter (p <0.001) due to lack of wires and the ability to shower. In conclusion, the Zio patch is as good as the Holter monitor in detection of clinically significant arrhythmias in children with less artifact. Patients/parents more often preferred the Zio over the Holter.
Block in accessory pathway (AP) conduction with adenosine has been previously described. However, conduction characteristics of these APs has not been well defined to date. All patients with APs </ = ...21 years old who underwent an EP study from 2014 to 2017 were included in our study. Patients with adenosine sensitive APs were identified (group 1). Demographic and AP conduction characteristics were compared between group 1 and the entire cohort of patients. Local atrioventricular (AV) or ventriculoatrial (VA) time, cycle length and need for isoproterenol were compared to a control group matched by age and AP location (group 2). Student’s
t
test, Wilcoxon rank sum,
χ
2
and Fisher’s exact were used for analysis. Fourteen (7%) out of 207 patients had an adenosine sensitive AP. The median age of patients with adenosine sensitive APs was 11.8 (IQR 8.5–13.5) years vs. 14 (IQR 10.6–16.7) for the rest of the cohort (
p
= 0.04). Three of the 134 patients with preexcitation had adenosine sensitive APs (2%) vs. 11 of the 73 patients with concealed APs (15%) (
p
= 0.001). The median local AV/VA time at the site of successful ablation was longer in group 1 vs group 2 78 ms, IQR 62–116 vs. 31 ms, IQR 30–38;
p
< 0.001. Antegrade AP effective refractory period and total procedure time were longer in patients with adenosine sensitive APs (
p
= 0.03 &
p
= 0.04, respectively). Adenosine sensitive APs which occur in children are more often concealed. These APs have a longer conduction time at the site of successful ablation.
Abstract Background Advanced second- or third-degree heart block has been reported with variable incidence after surgery for congenital heart disease in children. We report the incidence of heart ...block requiring a pacemaker and describe the risk factors for this complication in a large multicenter study. Methods We performed a retrospective cohort study, using the Pediatric Health Information System database from 45 hospitals in the United States, for all children aged 18 years, discharged between January 1, 2004, and December 31, 2013, who underwent open surgery for congenital heart disease. Patients who had heart block and placement of a pacemaker during the same hospitalization were identified. Demographic characteristics, procedure and diagnostic codes, length of stay, and mortality were analyzed. Univariable and multivariable analyses were performed. Results There were 101,006 surgeries performed. The median age of patients was 0.5 years (interquartile range, 26 days to 3.2 years), and 1% of patients (n = 990) had heart block and placement of a pacemaker. Surgeries associated with the highest incidences of heart block and placement of a pacemaker included the double switch operation (15.6%), tricuspid valve (7.8%) and mitral valve (7.4%) replacement, atrial switch with ventricular septal defect repair (6.4%), and Rastelli operation (4.8%). On multivariable analysis, after controlling for surgical complexity, other comorbidities, age at surgery, admission year, and clustering by institution, patients with heart block and placement of a pacemaker had higher odds of mortality (odds ratio, 1.67; 95% confidence interval, 1.24-2.26; P < .001). Conclusions The incidence of postoperative heart block requiring permanent pacemaker placement immediately after congenital heart surgery is low (1%). However, these patients have higher mortality even after adjusting for heart surgery complexity.
Purpose
An estimated 377 million diagnostic and interventional radiological exams are performed annually in the United States and approximately 4 to 5 billion globally. All use x‐ray tubes that emit ...x‐rays over a broad energy band, a technology that is more than a century old. Only a small fraction of the radiation is useful for imaging while the remaining fraction either increases the radiation dose received by the patient or degrades the image. Monochromatic x‐rays can provide lower dose images in many of these radiological applications while maintaining or improving image quality. We report the development of the first monochromatic x‐ray source suitable for low‐dose, high‐quality imaging in the clinic and demonstrate its first application and performance with mammography phantoms.
Methods
X‐ray fluorescence was used to generate monochromatic x‐rays with selectable energies from 18 to 60 keV. This patented technology was incorporated into a laboratory prototype of a monochromatic x‐ray mammography system. Image quality was evaluated as a function of radiation dose in standard breast phantoms using the signal‐to‐noise ratio (SNR) measured for high and low contrast masses and microcalcifications. Spatial imaging properties were assessed from these images as well as from modulation transfer function (MTF) analysis. Measurements using an iodine contrast agent were also performed. The results were compared to those obtained using a commercially available, conventional x‐ray mammography system.
Results
Our prototype system reduced radiation dose by factors of five to ten times for the same SNRs as obtained from the conventional system. This performance was demonstrated in phantoms simulating a wide range of lesion sizes and microcalcifications in a variety of breast thicknesses. The high SNRs for very thick breast phantoms provide evidence that screening with less breast compression is possible while maintaining image quality. Contrast‐enhanced digital mammography (CEDM) with monochromatic x‐rays was shown to provide a simpler and more effective technique at substantially lower radiation dose. The MTF value at 20% was 9 lp/mm.
Conclusions
The monochromatic x‐ray system is more sensitive for imaging a wide range of breast sizes and compositions than conventional broadband mammography. High image quality and lower dose are its hallmarks. It also makes CEDM much more effective than current methods developed for use with conventional broadband mammography systems.
The AliveCor KardiaMobile (ACKM) is a remote electrocardiogram (ECG) monitoring device. Little research has been conducted on its accuracy with pediatric patients. This prospective study aims to ...compare the ACKM six-lead device with a standard fifteen-lead ECG in measuring the QTc, QRS, and axis in pediatric patients. Pediatric patients ages 5 to 21 years were enrolled prospectively to have their ECG recorded using an ACKM six-lead device following a recording with the standard 15-lead ECG. A pediatric electrophysiologist measured the QTc, QRS interval, and QRS axis for both ECGs. Bland–Altman analysis was performed to assess agreement among measurements. The study included 141 patients. The mean age was 12.3 ± 4.4 years. Average heart rate was 79 ± 16 bpm. The mean difference in the QTc measurements for a paired standard ECG and ACKM was − 0.6 ms 95% confidence interval − 48 to 47 ms. Of the ACKM QTc measurements, 117 (83%) were within 30 ms of the standard ECG. The mean difference in paired QRS measurements was − 1.3 ms 95% confidence interval − 23 to 21 ms. Of the ACKM QRS measurements, 134 (95%) were within 20 ms of the standard ECG. The measured axis was the same for 84% of ACKM and standard ECGs. Over 80% of the ACKM six-lead ECGs produced QTc, QRS, and axis deviation measurements within a clinically useful range of the standard ECG. However, it is not accurate enough to be used consistently in place of a standard ECG for QTc and QRS measurement for pediatric patients.
Background
The clinical course of children with advanced heart block secondary to Lyme disease has not been well characterized.
Objective
To review the presentation, management, and time to ...resolution of heart block due to Lyme disease in previously healthy children.
Methods
An IRB approved single-center retrospective study was conducted of all patients < 21 years old with confirmed Lyme disease and advanced second or third degree heart block between 2007 and 2017.
Results
Twelve patients (100% male) with a mean age of 15.9 years (range 13.2–18.1) were identified. Six patients (50%) had mild to moderate atrioventricular valve regurgitation and all had normal biventricular function. Five patients had advanced second degree heart block and 7 had complete heart block with an escape rate of 20–57 bpm. Isoproterenol was used in 4 patients for 3–4 days and one patient required transvenous pacing for 2 days. Patients were treated with 21 days (
n
= 6, 50%) or 28 days (
n
= 6, 50%) of antibiotics. Three patients received steroids for 3–4 days. Advanced heart block resolved in all patients within 2–5 days, and all had a normal PR interval within 3 days to 16 months from hospital discharge.
Conclusion
Symptomatic children who present with new high-grade heart block from an endemic area should be tested for Lyme disease. Antibiotic therapy provides quick and complete resolution of advanced heart block within 5 days, while steroids did not appear to shorten the time course in this case series. Importantly, no patients required a permanent pacemaker.
Supraventricular tachycardia is the most common tachyarrhythmia encountered in infants. In older children and adults, definitive treatment of the supraventricular tachycardia substrate with catheter ...ablation is a common approach to management. However, in infants, the risks of catheter ablation are significantly higher, and the patients often outgrow the potential to experience episodes. Therefore, antiarrhythmic medications are often utilized to minimize the likelihood of experiencing episodes. This article reviews the common arrhythmia mechanisms encountered in infants and the medications used to treat these patients.
Clinically significant bradycardia is an uncommon problem in children, but one that can cause significant morbidity and sometimes necessitates implantation of a pacemaker. The most common causes of ...bradycardia are complete heart block (CHB), which can be congenital or acquired, and sinus node dysfunction, which is rare in children with structurally normal hearts. Pacemaker is indicated as therapy for the majority of children with CHB, and while early mortality is lower in postnatally diagnosed CHB than in fetal CHB, it is still up to 16%. In young children, less invasive transvenous pacemaker systems can be technically challenging to place and carry a high risk of complications, often necessitating surgical epicardial pacemaker placement, which usually entails a median sternotomy. We report three cases of pediatric patients referred for pacemaker implantation for different types of bradycardia, treated at our institution with oral albuterol with therapeutic results that avoided the need for surgical pacemaker implantation at that time.
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