Limited Relationship Between Echocardiographic Measures and Electrocardiographic Markers of Left Ventricular Size in Healthy Children.

Pediatric ECG standards have been defined without echocardiographic confirmation of normal anatomy. The Pediatric Heart Network Normal Echocardiogram Z-score Project provides a racially diverse group of healthy children with normal echocardiograms. We hypothesized that ECG and echocardiographic measures of left ventricular (LV) dimensions are sufficiently correlated in healthy children to imply a clinically meaningful relationship. This was a secondary analysis of a previously described cohort including 2170 digital ECGs. The relationship between 6 ECG measures associated with LV size were analyzed with LV Mass (LVMass-z) and left ventricular end-diastolic volume (LVEDV-z) along with 11 additional parameters. Pearson or Spearman correlations were calculated for the 78 ECG-echocardiographic pairs with regression analyses assessing the variance in ECG measures explained by variation in LV dimensions and demographic variables. ECG/echocardiographic measurement correlations were significant and concordant in 41/78 (53%), though many were significant and discordant (13/78). Of the 6 ECG parameters, 5 correlated in the clinically predicted direction for LV Mass-z and LVEDV-z. Even when statistically significant, correlations were weak (0.05-0.24). R2 was higher for demographic variables than for echocardiographic measures or body surface area in all pairs, but remained weak (R2 ≤ 0.17). In a large cohort of healthy children, there was a positive association between echocardiographic measures of LV size and ECG measures of LVH. These correlations were weak and dependent on factors other than echocardiographic or patient derived variables. Thus, our data support deemphasizing the use of solitary, traditional measurement-based ECG markers traditionally thought to be characteristic of LVH as standalone indications for further cardiac evaluation of LVH in children and adolescents.

QRS fragmentation and prolongation as predictors of exercise capacity in patients after Fontan palliation.

INTRODUCTION: Patients with Fontan anatomy are at increased risk for exercise intolerance and early morbidity and mortality. QRS complex fragmentation (fQRS) and prolongation have been studied in multiple heart diseases, but their clinical importance is unknown in the Fontan population. METHODS: A retrospective cross-sectional study was performed. ECGs were evaluated for QRS prolongation (>98 percentile for age) and fQRS (≥3 R-waves/notches in the R/S complex [more than two in RBBB] in ≥2 contiguous leads). The primary outcome measures were CPET performance. RESULTS: Total 90 patients (median age 18 years, 57% male, 59% RV dominant) were included; 13% had fQRS and 31% had prolonged QRS. Demographically, patients with fQRS or prolonged QRS were like those without. Peak VO2 (64% vs. 63%, p .45), VE/VCO2 slope (85% vs. 88%, p = .74), and O2 pulse (149% vs. 129%, p = .83) were similar in the fQRS group versus those without. Upon multi-variable regression, body mass index (ß = -0.38, p < .01) and QRS duration (ß = -0.29, p < .01) were independently associated with % predicted VO2; fQRS was not. Lower cardiac index (2.2 vs. 2.8 L/min/m2 , p = .03) and higher ventricular end-diastolic pressure (13 vs. 10 mmHg, p = .02) was seen with fQRS. CONCLUSIONS: QRS fragmentation is present in patients with Fontan physiology. fQRS showed no association with CPET performance but was related to invasive hemodynamic markers of ventricular performance. QRS duration may be a better predictor of exercise function following Fontan.

Longitudinal Observational Study of Cardiac Outcome Risk Factor Prediction in Children, Adolescents, and Adults with Barth Syndrome.

Barth Syndrome (BTHS) is an X-linked mitochondrial cardioskeletal myopathy caused by defects in TAFAZZIN, a gene responsible for cardiolipin remodeling. Altered mitochondrial levels of cardiolipin lead to cardiomyopathy (CM), muscle weakness, exercise intolerance, and mortality. Cardiac risk factors predicting outcome are unknown. Therefore, we conducted a longitudinal observational study to determine risk factors for outcome in BTHS. Subjects with minimum two evaluations (or one followed by death or transplant) were included. Cardiac size, function, and QTc data were measured by echocardiography and electrocardiography at 7 time points from 2002 to 2018. Analysis included baseline, continuous, and categorical variables. Categorical risk factors included prolonged QTc, abnormal right ventricle fractional area change (RV FAC), left ventricle (LV) or RV non-compaction, and restrictive CM phenotype. The association between variables and cardiac death or transplant (CD/TX) was assessed. Median enrollment age was 7 years (range 0.5-22; n = 44). Transplant-free survival (TFS) was 74.4% at 15 years from first evaluation. The cohort demonstrated longitudinal declines in LV size and stroke volume z-scores (end-diastolic volume, p = 0.0002; stroke volume p < 0.0001), worsening RV FAC (p = 0.0405), and global longitudinal strain (GLS) (p = 0.0001) with stable ejection (EF) and shortening (FS) fraction. CD/TX subjects (n = 9) displayed worsening LV dilation (p = 0.0066), EF (p ≤ 0.0001), FS (p = 0.0028), and RV FAC (p = .0032) versus stability in TFS. Having ≥ 2 categorical risk factors predicted CD/TX (p = 0.0073). Over 15 years, 25% of BTHS subjects progressed to CD/TX. Those with progressive LV enlargement, dysfunction, and multiple cardiac risk factors warrant increased surveillance and intense therapy.

Sex-specific lean body mass predictive equations are accurate in the obese paediatric population.

BACKGROUND: The clinical assessment of lean body mass (LBM) is challenging in obese children. A sex-specific predictive equation for LBM derived from anthropometric data was recently validated in children. AIM: The purpose of this study was to independently validate these predictive equations in the obese paediatric population. SUBJECTS AND METHODS: Obese subjects aged 4-21 were analysed retrospectively. Predicted LBM (LBMp) was calculated using equations previously developed in children. Measured LBM (LBMm) was derived from dual-energy x-ray absorptiometry. Agreement was expressed as [(LBMm-LBMp)/LBMm] with 95% limits of agreement. RESULTS: Of 310 enrolled patients, 195 (63%) were females. The mean age was 11.8 ± 3.4 years and mean BMI Z-score was 2.3 ± 0.4. The average difference between LBMm and LBMp was -0.6% (-17.0%, 15.8%). Pearson's correlation revealed a strong linear relationship between LBMm and LBMp (r = 0.97, p < 0.01). CONCLUSION: This study validates the use of these clinically-derived sex-specific LBM predictive equations in the obese paediatric population. Future studies should use these equations to improve the ability to accurately classify LBM in obese children.

Estimating equations for cardiopulmonary exercise testing variables in Fontan patients: derivation and validation using a multicenter cross-sectional database.

Cardiopulmonary exercise testing (CPET) is a common method of evaluating patients with a Fontan circulation. Equations to calculate predicted CPET values are based on children with normal circulation. This study aims to create predictive equations for CPET variables solely based on patients with Fontan circulation. Patients who performed CPET in the multicenter Pediatric Heart Network Fontan Cross-Sectional Study were screened. Peak variable equations were calculated using patients who performed a maximal test (RER > 1.1) and anaerobic threshold (AT) variable equations on patients where AT was adequately calculated. Eighty percent of each cohort was randomly selected to derive the predictive equation and the remaining served as a validation cohort. Linear regression analysis was performed for each CPET variable within the derivation cohort. The resulting equations were applied to calculate predicted values in the validation cohort. Observed versus predicted variables were compared in the validation cohort using linear regression. 411 patients underwent CPET, 166 performed maximal exercise tests and 317 had adequately calculated AT. Predictive equations for peak CPET variables had good performance; peak VO2, R (2) = 0.61; maximum work, R (2) = 0.61; maximum O2 pulse, R (2) = 0.59. The equations for CPET variables at AT explained less of the variability; VO2 at AT, R (2) = 0.15; work at AT, R (2) = 0.39; O2 pulse at AT, R (2) = 0.34; VE/VCO2 at AT, R (2) = 0.18; VE/VO2 at AT, R (2) = 0.14. Only the models for VE/VCO2 and VE/VO2 at AT had significantly worse performance in validation cohort. Of the 8 equations for commonly measured CPET variables, six were able to be validated. The equations for peak variables were more robust in explaining variation in values than AT equations.

Preparticipation Cardiac Evaluation from the Pediatric Perspective.

Each year millions of children and adolescents undergo sports preparticipation evaluations (PPEs) before participating in organized sports. A primary aim of the PPE is to screen for risk factors associated with sudden cardiac death. This article is designed to summarize the current thoughts on the PPE with a specific slant toward the pediatric and early adolescent evaluation and how these evaluations may differ from those in adults.

Epicardial pacing outcomes in infants with heart block: Lead and device complications from a multicenter experience.

BACKGROUND: Infants with complete heart block (CHB) require epicardial pacemaker (PM) insertion. Prior studies described epicardial pacing outcomes in infants and children, although they were limited by small or heterogeneous populations. OBJECTIVE: This study aimed to explore patient- and procedure-level associations with device complications in infants with CHB who received a permanent PM. METHODS: This was a multicenter, retrospective cohort study including infants receiving an epicardial PM between 2000 and 2021 for CHB. The primary outcome was time to device-related adverse event: lead failure requiring revision; pocket infection; exit block requiring increased pacing output; or lead-related coronary artery compression. Time-to-event analysis was performed by the Kaplan-Meier method with a multivariable Cox proportional hazards model. RESULTS: There were 174 infants who received an epicardial PM (282 bipolar, 39 unipolar leads) for CHB. Median age and weight at PM were 93.5 days and 4.5 kg, respectively. Pacing indication was postoperative CHB in 63% and congenital CHB in 37%. The median follow-up was 2.1 years. The primary outcome occurred in 26 infants at a median time to event of 0.6 year. Age ≤90 days at PM implantation was the most significant risk factor for a device-related adverse event (hazard ratio, 7.02; P < .001), primarily driven by pocket infections. Lead failure occurred in 3% of leads with a 5- and 10-year freedom from failure of 93% and 83%, respectively. CONCLUSION: Device complications affect 15% of infants receiving a permanent PM for heart block. Age ≤90 days at PM implantation is especially associated with infectious complications. Epicardial lead durability appears similar to previously reported pediatric experiences.

Preparticipation Cardiac Evaluation from the Pediatric Perspective.

Each year millions of children and adolescents undergo sports preparticipation evaluations (PPEs) before participating in organized sports. A primary aim of the PPE is to screen for risk factors associated with sudden cardiac death. This article is designed to summarize the current thoughts on the PPE with a specific slant toward the pediatric and early adolescent evaluation and how these evaluations may differ from those in adults.

Persistent Elevation of Troponin I in a Pediatric Patient Resulting From Macrotroponin Complex.

ABSTRACT: Although chest pain is a common chief complaint among pediatric patients, cardiac pathology historically has accounted for a small percentage of cases. However, the emergence of COVID-19 and particularly its potential for leading to multisystem inflammatory syndrome has changed the threshold for the evaluation of cardiac etiologies of chest pain. This evaluation often includes measurement of the serum cardiac troponin I level. We present a case of a 16-year-old male athlete who presented to an outside emergency department with chest pain and was found to have elevated serum troponin I levels. Despite sports restriction, his troponin level remained elevated for months in the absence of other clinical findings and he was subsequently referred to our outpatient pediatric cardiology clinic. Further laboratory evaluation revealed that, in addition to troponin I, the assay measured an immune complex of uncertain significance formed by anti-troponin I antibodies bound to troponin I, known as macrotroponin. Delayed clearance of this complex from the bloodstream can result in overestimation of troponin I levels that can affect clinical management and create anxiety for our patients and their families. Macrotroponin complex deserves increased recognition among the research and clinical communities, especially in the pediatric realm.

The use of a traditional nonlooping event monitor versus a loan-based program with a smartphone ECG device in the pediatric cardiology clinic.

Background: A smartphone-enabled device has been developed that provides a single-lead electrocardiogram using a portable monitor. The increase in direct-to-consumer medical devices may lead to health disparities affecting members of socially disadvantaged populations. Objective: Here we provide a single center's experience in the use of this device in a pediatric cardiology clinic using a loan-based program. We also compare it to retrospective data from patients who received a traditional nonlooping event monitor. Methods: Forty AliveCor Kardia monitor devices were purchased with grant support from the South Carolina TeleHealth Alliance. The devices were provided between June 2018 and August 2019 to patients presenting to the pediatric cardiology clinic who would have otherwise received a nonlooping event monitor. A retrospective chart review was performed for all patients who were given a MicroER nonlooping event monitor between May and December of 2017. Results: Over a 15-month period, 65 patients were given the smartphone device. A total of 692 tracings were recorded by patients with 9 abnormal recordings. Of the devices expected to be returned, 35 devices have been returned to clinic (54%). Over an 8-month period, 61 patients received the traditional event monitors, accounting for a total of 142 transmissions with 3 abnormal transmissions. Conclusion: Our results reveal adequate use of the device with reliable tracings and show more frequent utilization of the smartphone-enabled device. Utilization of these devices in a loan-based program may improve access to care with improved methods to ensure return of the devices.

Men's attitudes toward receiving the human papillomavirus vaccine.

OBJECTIVES: To determine men's attitudes toward receiving the human papillomavirus (HPV) vaccine. MATERIALS AND METHODS: Five hundred seventy-one men read a 1-page informational sheet about HPV and the HPV vaccine before completing a 29-item questionnaire. Descriptive statistics were calculated on all variables. RESULTS: Of these men, 33% wanted to receive the HPV vaccine, 27% did not, and 40% were undecided. The main reasons for wanting the vaccine included a desire to stay healthy (67.4%); prevention of cancer in my sexual partner(s) (52.9%); prevention of anal, penile, and head and neck cancer (41.0%); fear of cancer (33.4%); and prevention of genital warts (32.8%). Being in a monogamous relationship and not at risk (18.9%), not interested (13.8%), and not enough evidence yet to prove that it will help men (8.2%) were the main reasons for not wanting to be vaccinated. CONCLUSIONS: Although many men want to receive the HPV vaccine, more remain undecided. Pending favorable safety and efficacy results from a clinical trial for men, substantial factual education will likely convince many ambivalent men to receive the HPV vaccine.

Effects of persistent Fontan fenestration patency on cardiopulmonary exercise testing variables.

Cardiopulmonary exercise testing (CPET) aids in clinical assessment of patients with Fontan circulation. Effects of persistent fenestration on CPET variables have not been clearly defined. Associations between fenestration and CPET variables at anaerobic threshold (AT) and peak exercise were explored in the Pediatric Heart Network Fontan Cross-Sectional Study cohort. Fenestration patency was associated with a greater decrease in oxygen saturation from rest to peak exercise (fenestration -4.9 ± 3.8 v. nonfenestration -3 ± 3.5; P < .001). Physiological dead space at peak exercise was higher in fenestrated v. nonfenestrated (25.2 ± 16.1 v. 21.4 ± 15.2; P = .03). There was a weak association between fenestration patency and maximal work and heart rate. Fenestration patency was also weakly correlated with oxygen pulse, work and VE/VCO2 at AT. The effect of persistent fenestration on CPET measurements was minimal in this study, likely due to the cross-sectional design.

Variables associated with human papillomavirus (HPV) vaccine acceptance by men.

OBJECTIVE: To determine correlates of human papillomavirus (HPV) vaccine acceptance for men. METHODS: A convenience sample of men aged 18 to 45 years read a one-page information sheet about HPV and the HPV vaccine, then completed a 29-item questionnaire. chi(2) tests were used to determine whether differences in demographic, sexual, and vaccine-related variables existed between levels of wanting the HPV vaccine. RESULTS: Positive correlates of HPV vaccine acceptance included higher education (P < .0001); hispanic ethnicity (P = .0003); wearing a seat belt most of the time (P = .02); regular tobacco use (P = <.001); not being sexually active (P = .0008); history of more than 10 female sexual partners (P = .0004); not having oral sex (P = .045); extreme worry about vaccine side effects (P < .0001); extreme concern about vaccine safety (P < .0001); the importance of getting vaccines (P < .0001); familiarity with HPV (P < .0001); and extreme importance of receiving the HPV vaccine (P < .0001). CONCLUSIONS: Men with greater general education, high-risk behaviors, and knowledge about HPV are more likely to want the HPV vaccine. Focused educational efforts should facilitate even wider acceptance of the HPV vaccine by men.