You & Me: Test and Treat study protocol for promoting COVID-19 test and treatment access to underserved populations.

BACKGROUND: Infections and deaths from the COVID-19 pandemic have disproportionately affected underserved populations. A community-engaged approach that supports decision making around safe COVID-19 practices is needed to promote equitable access to testing and treatment. You & Me: Test and Treat (YMTT) will evaluate a systematic and scalable community-engaged protocol that provides rapid access to COVID-19 at-home tests, education, guidance on next steps, and information on local resources to facilitate treatment in underserved populations. METHODS: This direct-to-participant observational study will distribute at-home, self-administered, COVID-19 testing kits to people in designated communities. YMTT features a Public Health 3.0 framework and Toolkit prescribing a tiered approach to community engagement. We will partner with two large community organizations, Merced County United Way (Merced County, CA) and Pitt County Health Department (Pitt County, NC), who will coordinate up to 20 local partners to distribute 40,000 COVID tests and support enrollment, consenting, and data collection over a 15-month period. Participants will complete baseline questions about their demographics, experience with COVID-19 infection, and satisfaction with the distribution event. Community partners will also complete engagement surveys. In addition, participants will receive guidance on COVID-19 mitigation and health-promoting resources, and accessible and affordable therapeutics if they test positive for COVID-19. Data collection will be completed using a web-based platform that enables creation and management of electronic data capture forms. Implementation measures include evaluating 1) the Toolkit as a method to form community-academic partnerships for COVID-19 test access, 2) testing results, and 3) the efficacy of a YMTT protocol coupled with local resourcing to provide information on testing, guidance, treatment, and links to resources. Findings will be used to inform innovative methods to address community needs in public health research that foster cultural relevance, improve research quality, and promote health equity. DISCUSSION: This work will promote access to COVID-19 testing and treatment for underserved populations by leveraging a community-engaged research toolkit. Future dissemination of the toolkit can support effective community-academic partnerships for health interventions in underserved settings. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05455190 . Registered 13 July 2022.

Multicenter research priorities in pediatric CMR: results of a collaborative wiki survey.

Multicenter studies in pediatric cardiovascular magnetic resonance (CMR) improve statistical power and generalizability. However, a structured process for identifying important research topics has not been developed. We aimed to (1) develop a list of high priority knowledge gaps, and (2) pilot the use of a wiki survey to collect a large group of responses. Knowledge gaps were defined as areas that have been either unexplored or under-explored in the research literature. High priority goals were: (1) feasible and answerable from a multicenter research study, and (2) had potential for high impact on the field of pediatric CMR. Seed ideas were contributed by a working group and imported into a pairwise wiki survey format which allows for new ideas to be uploaded and voted upon ( https://allourideas.org ). Knowledge gaps were classified into 2 categories: 'Clinical CMR Practice' (16 ideas) and 'Disease Specific Research' (22 ideas). Over a 2-month period, 3,658 votes were cast by 96 users, and 2 new ideas were introduced. The 3 highest scoring sub-topics were myocardial disorders (9 ideas), translating new technology & techniques into clinical practice (7 ideas), and normal reference values (5 ideas). The highest priority gaps reflected strengths of CMR (e.g., myocardial tissue characterization; implementation of technologic advances into clinical practice), and deficiencies in pediatrics (e.g., data on normal reference values). The wiki survey format was effective and easy to implement, and could be used for future surveys.

Society for Cardiovascular Magnetic Resonance 2021 cases of SCMR and COVID-19 case collection series.

The Society for Cardiovascular Magnetic Resonance (SCMR) is an international society focused on the research, education, and clinical application of cardiovascular magnetic resonance (CMR). "Cases of SCMR" is a case series hosted on the SCMR website ( https://www.scmr.org ) that demonstrates the utility and importance of CMR in the clinical diagnosis and management of cardiovascular disease. The COVID-19 Case Collection highlights the impact of coronavirus disease 2019 (COVID-19) on the heart as demonstrated on CMR. Each case in series consists of the clinical presentation and the role of CMR in diagnosis and guiding clinical management. The cases are all instructive and helpful in the approach to patient management. We present a digital archive of the 2021 Cases of SCMR and the 2020 and 2021 COVID-19 Case Collection series of nine cases as a means of further enhancing the education of those interested in CMR and as a means of more readily identifying these cases using a PubMed or similar literature search engine.

Myocardial Parametric Mapping by Cardiac Magnetic Resonance Imaging in Pediatric Cardiology and Congenital Heart Disease.

Parametric mapping, that is, a pixel-wise map of magnetic relaxation parameters, expands the diagnostic potential of cardiac magnetic resonance by enabling quantification of myocardial tissue-specific magnetic relaxation on an absolute scale. Parametric mapping includes T1 mapping (native and postcontrast), T2 and T2* mapping, and extracellular volume measurements. The myocardial composition is altered in various disease states affecting its inherent magnetic properties and thus the myocardial relaxation times that can be directly quantified using parametric mapping. Parametric mapping helps in the diagnosis of nonfocal disease states and allows for longitudinal disease monitoring, evaluating therapeutic response (as in Thalassemia patients with iron overload undergoing chelation), and risk-stratification of certain diseases. In this review article, we describe various mapping techniques and their clinical utility in congenital heart disease. We will also review the available literature on normative values in children, the strengths, and weaknesses of these techniques. This review provides a starting point for pediatric cardiologists to understand and implement parametric mapping in their practice.

Quality Improvement Methodology Facilitates Adherence to Echocardiogram Protocol Measurements.

INTRODUCTION: Local institutional echocardiogram protocols reflect standard measurements as per national guidelines, but adherence to measurements was inconsistent. This inconsistency led to variability in reporting and impacted the use of serial measurements for clinical decision-making. Therefore, we aimed to improve complete adherence to universal and protocol-specific measures for echocardiograms performed for first-time or cardiomyopathy studies from 60% to 90% from July 2019 to February 2020. METHODS: We included all sonographer-performed echocardiograms for first-time or cardiomyopathy protocol studies. We reviewed universal measures and protocol-specific measures for all included studies. We created a scoring system reflecting measurement completion. We used a control chart to measure compliance and established a baseline over 2 months. PDSA cycles over 5 months included interventions such as sonographer education, technical improvements to the measurement toolbar, and group and individual performance feedback. RESULTS: We reviewed over 4000 studies-the reporting of complete universal measures improved significantly from a median score of 60% to 93%. Protocol-specific measures for first-time studies also showed significant improvement from 62% to 90% adherence. Cardiomyopathy-specific measures demonstrated 87% adherence at baseline, which improved to 95% but then returned to baseline. Sonographer education and toolbar adjustment prompted special cause variation with further improvement following performance feedback. The universal and first-time protocol measures reached 90% adherence with sustained improvement for over 9 months. CONCLUSIONS: We employed quality improvement methodology to improve complete adherence to echocardiographic protocol measurements, thereby facilitating echocardiographic quality and reporting consistency. We plan to spread these interventions to improve adherence to other protocols.

Symptomatic Acute Myocarditis in 7 Adolescents After Pfizer-BioNTech COVID-19 Vaccination.

Trials of coronavirus disease 2019 (COVID-19) vaccination included limited numbers of children, so they may not have detected rare but important adverse events in this population. We report 7 cases of acute myocarditis or myopericarditis in healthy male adolescents who presented with chest pain all within 4 days after the second dose of Pfizer-BioNTech COVID-19 vaccination. Five patients had fever around the time of presentation. Acute COVID-19 was ruled out in all 7 cases on the basis of negative severe acute respiratory syndrome coronavirus 2 real-time reverse transcription polymerase chain reaction test results of specimens obtained by using nasopharyngeal swabs. None of the patients met criteria for multisystem inflammatory syndrome in children. Six of the 7 patients had negative severe acute respiratory syndrome coronavirus 2 nucleocapsid antibody assay results, suggesting no previous infection. All patients had an elevated troponin. Cardiac MRI revealed late gadolinium enhancement characteristic of myocarditis. All 7 patients resolved their symptoms rapidly. Three patients were treated with nonsteroidal antiinflammatory drugs only, and 4 received intravenous immunoglobulin and corticosteroids. In this report, we provide a summary of each adolescent's clinical course and evaluation. No causal relationship between vaccine administration and myocarditis has been established. Continued monitoring and reporting to the US Food and Drug Administration Vaccine Adverse Event Reporting System is strongly recommended.

Massive ductal aneurysm in an asymptomatic child with Loeys-Dietz syndrome.

An asymptomatic 3-year-old with Loeys-Dietz Syndrome (LDS) followed for a small patent ductus arteriosus and dilated aorta was found to have a massive ductal aneurysm on routine surveillance cardiac magnetic resonance. The aneurysm was successfully resected. Serial advanced imaging tools are useful in surveillance, diagnosis, and management in patients with LDS.

Pediatric Myocardial T1 and T2 Value Associations with Age and Heart Rate at 1.5 T.

The objective of the study was to determine normal global left ventricular reference values for T1 and T2 in children. This is a retrospective study that included healthy subjects, age 5-19 years, who underwent CMR for the indication of pectus excavatum from 2018 to 2019. Linear regression models were used to determine associations of native T1 and T2 values to heart rate, age, and other CMR parameters. 102 patients with a mean age of 14.0 ± 2.4 years were included (range 5.4-18.8). 87 (85%) were males and 15 (15%) were females. The mean global T1 was 1018 ± 25 ms and the mean T2 was 53 ± 3 ms. T1 was negatively correlated with age (r = - 0.39, p < 0.001) and positively correlated with heart rate (r = 0.32, p < 0.001) by univariate analysis. Multivariable analysis showed that age and heart rate were independently associated with T1. T2 demonstrated a weak negative correlation with age (r = - 0.20, p = 0.047) and no correlation with heart rate. There was no difference in T1 (p = 0.23) or T2 (p = 0.52) between genders. This study reports normal pediatric T1 and T2 values at a 1.5 Tesla scanner. T1 was dependent on age and heart rate, while T2 was less dependent on age with no correlation with heart rate.

Weight impacts 1-year congenital heart surgery outcomes independent of race/ethnicity and payer.

Body mass index, race/ethnicity, and payer status are associated with operative mortality in congenital heart disease (CHD). Interactions between these predictors and impacts on longer term outcomes are less well understood. We studied the effect of body mass index, race/ethnicity, and payer on 1-year outcomes following elective CHD surgery and tested the degree to which race/ethnicity and payer explained the effects of body mass index. Patients aged 2-25 years who underwent elective CHD surgery at our centre from 2010 to 2017 were included. We assessed 1-year unplanned cardiac re-admissions, re-interventions, and mortality. Step-wise, multivariable logistic regression was performed.Of the 929 patients, 10.4% were underweight, 14.9% overweight, and 8.5% obese. Non-white race/ethnicity comprised 40.4% and public insurance 29.8%. Only 0.5% died prior to hospital discharge with one additional death in the first post-operative year. Amongst patients with continuous follow-up, unplanned re-admission and re-intervention rates were 14.7% and 12.3%, respectively. In multivariable analyses adjusting for surgical complexity and surgeon, obese, overweight, and underweight patients had higher odds of re-admission than normal-weight patients (OR 1.40, p = 0.026; OR 1.77, p < 0.001; OR 1.44, p = 0.008). Underweight patients had more than twice the odds of re-intervention compared with normal weight (OR 2.12, p < 0.001). These associations persisted after adjusting for race/ethnicity, payer, and surgeon.Pre-operative obese, overweight, and underweight body mass index were associated with unplanned re-admission and/or re-intervention 1-year following elective CHD surgery, even after accounting for race/ethnicity and payer status. Body mass index may be an important modifiable risk factor prior to CHD surgery.

Left Ventricular Magnetic Resonance Imaging Strain Predicts the Onset of Duchenne Muscular Dystrophy-Associated Cardiomyopathy.

BACKGROUND: Early detection of left ventricular (LV) dysfunction before the onset of overt Duchenne muscular dystrophy-associated cardiomyopathy (DMDAC) may direct clinical management to slow onset of dysfunction. We aimed to assess whether LV strain will predict those who develop DMDAC. METHODS: We performed a single center retrospective case control study of patients with Duchenne muscular dystrophy who underwent serial cardiac magnetic resonance between 2006 and 2019. Patients with Duchenne muscular dystrophy with an LV ejection fraction ≥55% on ≥1 cardiac magnetic resonance were identified and grouped into age-matched +DMDAC and -DMDAC. Within 3 years, +DMDAC had a subsequent cardiac magnetic resonance with a decline in LV ejection fraction ≥10% and absolute LV ejection fraction ≤50%. -DMDAC maintained an LV ejection fraction ≥55% on serial cardiac magnetic resonances. Two-dimensional and 3-dimensional global radial strain, global circumferential strain (GCS), and global longitudinal strain were measured using tissue tracking software and their ability to predict DMDAC onset was assessed. Multivariable analysis adjusted for late gadolinium enhancement. RESULTS: Thirty +DMDAC and 30 age-matched -DMDAC patients were included with a total of 164 studies analyzed. Before DMDAC onset, 2-dimensional global radial strain and GCS were significantly worse in +DMDAC compared with -DMDAC (25.1±6.0 versus 29.0±6.3, P=0.011; -15.4%±2.4 versus -17.3%±2.6, P=0.003). Three-dimensional GCS and global radial strain had similar findings. Among strain measures, 3-dimensional GCS had the highest area under the curve to predict DMDAC in our cohort. These findings persisted after adjusting for the presence of late gadolinium enhancement. CONCLUSIONS: Reduced global radial strain and GCS may predict those at risk for developing DMDAC before onset of LV dysfunction and its clinical utility warrants further exploration.

Atrioventricular Valve Regurgitation in Single Ventricle Heart Disease: A Common Problem Associated With Progressive Deterioration and Mortality.

The Fontan procedure has provided patients with single ventricle physiology extended survival into adulthood and in many cases has improved their quality of life. Atrioventricular valve regurgitation (AVVR) is common in single ventricle patients and is associated with increased risk of mortality. AVVR is more common in patients with a systemic tricuspid or common atrioventricular valve but is generally progressive irrespective of underlying valve morphology. AVVR can be attributable to diverse structural and functional abnormalities at multiple levels of the valvar apparatus, as well as ventricular dysfunction and dilation. Multiple imaging modalities including recent advances in 3-dimensional echocardiography and cross-sectional imaging have been used to further understand AVVR. Surgery to address AVVR must be tailored to the underlying mechanism and the timing of surgical repair should be chosen carefully. In this review, we discuss the etiologies, treatment options, surgical timing, and outcomes of valve repair or replacement for AVVR in patients with single ventricle congenital heart disease, with a focus on those with a Fontan circulation as AVVR is associated with increased risk for Fontan failure and mortality. In-depth understanding of the current literature will help guide clinicians in their approach and management of AVVR in this population.

Staged Surgical Management of Anatomically Corrected Malposition of Great Arteries.

A nine-month-old girl diagnosed with anatomically corrected malposition (atrioventricular discordance, ventriculoarterial concordance, and malposed great arteries) complicated by multiple ventricular septal defects (VSD) and multifactorial left ventricular outflow tract obstruction (LVOTO) presented for management after pulmonary artery banding. She underwent interim palliation in the form of bilateral cavopulmonary connections, a modified Damus-Kaye-Stansel-type anastomosis, and subsequent staged one-and-a-half ventricle repair (1.5 repair) at the age of three years in the form of VSD closure, hemi-Mustard, and LVOTO resection.

Abdominal Skeletal Muscle Index as a Potential Novel Biomarker in Adult Fontan Patients.

BACKGROUND: Fontan palliation results in a chronic multisystem disorder with diminished exercise capacity and increased risk of muscle wasting. The aims of this study were to assess the feasibility of skeletal muscle mass measurements in Fontan patients undergoing magnetic resonance imaging liver surveillance to compare muscle mass with a historic control and to assess its correlation with cardiorespiratory fitness. METHODS: Skeletal muscle area (SMA) and skeletal muscle index (SMI) were measured at T12 and L3. A young, healthy historic cohort was used as a comparison group. RESULTS: Forty patients with a Fontan circulation (mean age, 25.5 ± 7.9 years; 50% were men) were included. Measurements of SMA and SMI were feasible and highly reproducible. Mean SMA and SMI were significantly lower in women compared with men at both T12 (SMA: 25.1 ± 4.9 cm2 vs 33.5 ± 8.4 cm2, P < 0.001; SMI: 9.7 ± 2.1 cm2/m2 vs 11.3 ± 2.7 cm2/m2, P = 0.045) and L3 (SMA: 121 ± 12 cm2 vs 162 ± 24 cm2, P < 0.001; SMI: 46.9 ± 7.0 cm2/m2 vs 54.5 ± 7.4 cm2/m2, P = 0.002). Mean SMI at L3 was significantly lower in the male Fontan population compared with the healthy historic cohort (54.5 ± 7.4 cm2/m2 vs 60.9 ± 7.8 cm2/m2, P < 0.001), but was similar for women (46.9 ± 7.0 cm2/m2 vs 47.5 ± 6.6 cm2/m2, P = 0.692). SMI at L3, but not at T12, was positively correlated with peak oxygen consumption, oxygen pulse, and workload. Four patients (10%) met criteria for muscle wasting in the sarcopenic range based on L3 measurements. CONCLUSIONS: Abdominal skeletal muscle mass can be reproducibly determined on surveillance liver magnetic resonance imaging scans. Muscle wasting appears to occur commonly in Fontan patients. Further research is needed to better define the value of SMI as a biomarker in the Fontan population.

CONTEXTE: L'intervention palliative de Fontan engendre une atteinte multiviscérale chronique, notamment une diminution de la capacité à l'effort et une hausse du risque d'atrophie musculaire. L'étude visait à évaluer la possibilité de mesurer la masse musculaire squelettique des patients ayant subi une intervention de Fontan et faisant l'objet d'une surveillance du foie par imagerie par résonance magnétique, afin de comparer les résultats à ceux d'une cohorte historique témoin et d'en évaluer la corrélation avec la capacité cardiorespiratoire. MÉTHODOLOGIE: La surface musculaire squelettique (SMS) et l'indice musculaire squelettique (IMS) ont été mesurés en T12 et en L3. Une cohorte historique de sujets jeunes et en santé a servi de groupe témoin. RÉSULTATS: Quarante patients ayant subi une intervention de Fontan (âge moyen, 25,5 ± 7,9 ans; 50 % des sujets étaient de sexe masculin) ont été admis dans l'étude. Il a été possible d'obtenir des mesures de la SMS et de l'IMS hautement reproductibles. Les valeurs moyennes de la SMS et de l'IMS étaient significativement plus faibles chez les femmes que chez les hommes, tant en T12 (SMS : 25,1 ± 4,9 cm2 vs 33,5 ± 8,4 cm2, p < 0,001; IMS : 9,7 ± 2,1 cm2/m2 vs 11,3 ± 2,7 cm2/m2, p = 0,045) qu'en L3 (SMS : 121 ± 12 cm2 vs 162 ± 24 cm2, p < 0,001; IMS : 46,9 ± 7,0 cm2/m2 vs 54,5 ± 7,4 cm2/m2, p = 0,002). L'IMS moyen en L3 était significativement plus bas chez les hommes ayant subi une intervention de Fontan que chez ceux de la cohorte historique de témoins en santé (54,5 ± 7,4 cm2/m2 vs 60,9 ± 7,8 cm2/m2, p < 0,001), mais comparable chez les femmes (46,9 ± 7,0 cm2/m2 vs 47,5 ± 6,6 cm2/m2, p = 0,692). L'IMS mesuré en L3 était corrélé positivement avec la consommation maximale d'oxygène, le pouls d'oxygène et la charge d'effort, ce qui n'était pas le cas de l'IMS mesuré en T12. Selon les mesures effectuées en L3, quatre patients (10 %) répondaient aux critères d'atrophie musculaire de la sarcopénie. CONCLUSIONS: La masse musculaire squelettique abdominale peut être déterminée de façon reproductible à partir des clichés d'imagerie par résonance magnétique obtenus aux fins de la surveillance du foie. Il semble que les patients ayant subi une intervention de Fontan présentent fréquemment une atrophie musculaire. Des recherches plus poussées s'imposent afin de mieux définir l'utilité de l'IMS comme biomarqueur au sein de la population des patients ayant subi une intervention de Fontan.

The AAHKS Clinical Research Award: No Evidence for Superior Patient-Reported Outcome Scores After Total Hip Arthroplasty With the Direct Anterior Approach at 1.5 Months Postoperatively, and Through a 5-Year Follow-Up.

BACKGROUND: The direct anterior approach to total hip arthroplasty (THA) may result in superior early postoperative patient-reported outcome measures (PROMs). This study compared PROMs between THA patients treated with the direct anterior or posterolateral approach between 1.5 months and 5 years, using literature-derived patient acceptable symptom state (PASS) and minimal clinically important improvement (MCII) thresholds. METHODS: A propensity score match of 93 direct anterior patients to 93 posterolateral patients from a multicenter US collaboration (6 centers, 398 patients) was performed. The Harris Hip Score (HHS), the Short-Form 36, and a Numerical Rating Scale for Pain were collected preoperatively, postoperatively (mean days: 47), and at 1, 3, and 5 years. The proportion of patients reaching the HHS PASS, Pain MCII, and Function MCII in the direct anterior and posterolateral groups was compared using binary logistic regressions, controlling for age, gender, body mass index, and Charnley score. RESULTS: Direct anterior patients were less likely to reach the HHS PASS at the postoperative visit (P = .015; odds ratio = 0.454), but not at later visits (P > .082). Direct anterior patients had no difference from posterolateral patients in their tendency to reach the Pain MCII postoperatively or at 1 year (P > .090). The direct anterior patients were less likely to reach the Function MCII at the postoperative visit (P = .011; odds ratio = 0.422), but not at 1 year (P = .958). CONCLUSION: No evidence was found of superior early postoperative PROM scores in THA patients treated with the direct anterior approach. No PROM differences were found at or beyond 1 year, indicating that patients reach similar final symptom states, regardless of surgical approach.

Persistent great artery dilatation in Beals syndrome: A novel finding.

We report a unique case of dilated aortic root and pulmonary artery in an infant with clinical features consistent with Beals syndrome confirmed to have fibrillin-2 mutation. This case highlights a novel finding of main pulmonary artery dilatation that has not been previously reported with Beals syndrome or fibrillin-2 mutation. In addition, the importance of serial echocardiography and consideration of medical management is discussed.

Effect of legal status of pharmacy syringe sales on syringe purchases by persons who inject drugs in San Francisco and San Diego, CA.

BACKGROUND: Sharing blood-contaminated syringes is the main risk factor for acquiring and transmitting blood-borne infections among persons who inject drugs (PWID). To reduce this risk, in 2005, California enacted legislation allowing local health jurisdictions to legalize non-prescription syringe sales after approving a disease prevention demonstration project (DPDP). With San Francisco approving a DPDP immediately and San Diego never approving one, we compared PWID across cities for their use of pharmacies PWID to obtain syringes. METHODS: PWID age 18-30 years old were recruited into separate studies in San Francisco (n=243) and San Diego (n=338) between 2008 and 2011. We used multivariable logistic regression to compare the proportions of PWID who obtained syringes from pharmacies by city while controlling for sociodemographics, injection practices and other risk behaviors. RESULTS: Overall, most PWID were White (71%), male (63%), and between the ages of 18-25 years (55%). Compared to San Francisco, a smaller proportion of PWID in San Diego had bought syringes from pharmacies in the prior three months (16.9% vs. 49.8%; p<0.001), which remained statistically significant after adjusting for sociodemographic and behavioral factors (adjusted odds ratio=4.45, 95% confidence interval: 2.98, 6.65). CONCLUSIONS: Use of pharmacies to obtain syringes was greater where it was legal to do so. Public health policy can influence HIV and hepatitis C associated risk among PWID; however, implementation of these policies is crucial for the benefits to be realized.

Autonomic regulation in fetuses with congenital heart disease.

BACKGROUND: Exposure to antenatal stressors affects autonomic regulation in fetuses. Whether the presence of congenital heart disease (CHD) alters the developmental trajectory of autonomic regulation is not known. AIMS/STUDY DESIGN: This prospective observational cohort study aimed to further characterize autonomic regulation in fetuses with CHD; specifically hypoplastic left heart syndrome (HLHS), transposition of the great arteries (TGA), and tetralogy of Fallot (TOF). SUBJECTS: From 11/2010 to 11/2012, 92 fetuses were enrolled: 41 controls and 51 with CHD consisting of 19 with HLHS, 12 with TGA, and 20 with TOF. Maternal abdominal fetal electrocardiogram (ECG) recordings were obtained at 3 gestational ages: 19-27 weeks (F1), 28-33 weeks (F2), and 34-38 weeks (F3). OUTCOME MEASURES: Fetal ECG was analyzed for mean heart rate along with 3 measures of autonomic variability of the fetal heart rate: interquartile range, standard deviation, and root mean square of the standard deviation of the heart rate (RMSSD), a measure of parasympathetic activity. RESULTS: During F1 and F2 periods, HLHS fetuses demonstrated significantly lower mean HR than controls (p<0.05). Heart rate variability at F3, as measured by standard deviation, interquartile range, and RMSSD was lower in HLHS than controls (p<0.05). Other CHD subgroups showed a similar, though non-significant trend towards lower variability. CONCLUSIONS: Autonomic regulation in CHD fetuses differs from controls, with HLHS fetuses most markedly affected.