Complex Congenital Heart Disease Research Articles

Processing Speed Partially Mediates Executive Function Impairments in Adolescents with Congenital Heart Disease: Results from a Prospective Cohort Study

To assess processing speed, fine motor function, attention, and executive function (EF) impairments in adolescents with complex congenital heart disease (CHD) who underwent open-heart surgery during infancy. We administered a comprehensive neuropsychological test battery evaluating 5 EF domains: working memory, inhibition, cognitive flexibility, fluency, and planning and primary neurodevelopmental processes (PNPs): processing speed, fine motor function, and attention. The sample included 100 adolescents with complex CHD from a previous University Children's Hospital Zurich study, with 104 healthy controls for comparison. We generated scores for each EF domain and computed an EF summary score. Group comparisons and associations were analyzed with multiple regression, accounting for parental education. Mediation analysis explored how PNPs mediate the effect between a CHD diagnosis and EF. In adolescents with complex CHD all EF domains and the EF summary score were impaired (β=0.20 to 0.37, all P<0.05). Furthermore, they exhibited slower processing speed (β=0.27, P<0.01) than healthy controls, with no differences in attention (β=-0.07, P=0.34) and fine motor function (β=0.08, P=0.34). Processing speed showed a strong association with the EF summary score (β=0.60, P<0.001) and partially mediated the relationship between CHD diagnosis and the EF summary score (β=0.37, 95% CI [0.24, 0.50], P<0.001). Adolescents with complex CHD show difficulties in EFs and processing speed. Notably, processing speed is strongly associated with EFs and partly accounts for EFs disparities between patients and healthy controls. Early detection and interventions for processing speed difficulties may improve EF outcomes in these patients.

Identification of a novel MYO1D variant associated with laterality defects, congenital heart diseases, and sperm defects in humans.

The establishment of left-right asymmetry is a fundamental process in animal development. Interference with this process leads to a range of disorders collectively known as laterality defects, which manifest as abnormal arrangements of visceral organs. Among patients with laterality defects, congenital heart diseases (CHD) are prevalent. Through multiple model organisms, extant research has established that myosin-Id (MYO1D) deficiency causes laterality defects. This study investigated over a hundred cases and identified a novel biallelic variant of MYO1D (NM_015194: c.1531G>A; p.D511N) in a consanguineous family with complex CHD and laterality defects. Further examination of the proband revealed asthenoteratozoospermia and shortened sperm. Afterward, the effects of the D511N variant and another known MYO1D variant (NM_015194: c.2293C>T; p.P765S) were assessed. The assessment showed that both enhance the interaction with β-actin and SPAG6. Overall, this study revealed the genetic heterogeneity of this rare disease and found that MYO1D variants are correlated with laterality defects and CHD in humans. Furthermore, this research established a connection between sperm defects and MYO1D variants. It offers guidance for exploring infertility and reproductive health concerns. The findings provide a critical basis for advancing personalized medicine and genetic counseling.

Role and Applications of Experimental Animal Models of Fontan Circulation.

Over the last four decades, the Fontan operation has been the treatment of choice for children born with complex congenital heart diseases and a single-ventricle physiology. However, therapeutic options remain limited and despite ongoing improvements in initial surgical repair, patients still experience a multiplicity of cardiovascular complications. The causes for cardiovascular failure are multifactorial and include systemic ventricular dysfunction, pulmonary vascular resistance, atrioventricular valve regurgitation, arrhythmia, development of collaterals, protein-losing enteropathy, hepatic dysfunction, and plastic bronchitis, among others. The mechanisms leading to these late complications remain to be fully elucidated. Experimental animal models have been developed as preclinical steps that enable a better understanding of the underlying pathophysiology. They furthermore play a key role in the evaluation of the efficacy and safety of new medical devices prior to their use in human clinical studies. However, these experimental models have several limitations. In this review, we aim to provide an overview of the evolution and progress of the various types of experimental animal models used in the Fontan procedure published to date in the literature. A special focus is placed on experimental studies performed on animal models of the Fontan procedure with or without mechanical circulatory support as well as a description of their impact in the evolution of the Fontan design. We also highlight the contribution of animal models to our understanding of the pathophysiology and assess forthcoming developments that may improve the contribution of animal models for the testing of new therapeutic solutions.

Genetic Testing for Supravalvar Aortic Stenosis: What to Do When It Is Not Williams Syndrome.

We aimed to describe the frequency and yield of genetic testing in supravalvar aortic stenosis (SVAS) following negative evaluation for Williams-Beurensyndrome (WS). This retrospective cohort study included patients with SVAS at our institution who had a negative evaluation for WS from May 1991 to September 2021. SVAS was defined as (1) peak supravalvar velocity of ≥2 meters/second, (2) sinotubular junction or ascending aortic Z score <-2.0, or (3) sinotubular junction Z score <-1.5 with family history of SVAS. Patients with complex congenital heart disease, aortic valve disease as the primary condition, or only postoperative SVAS were excluded. Genetic testing and diagnoses were reported. Of 162 patients who were WS negative meeting inclusion criteria, 61 had genetic testing results available (38%). Chromosomal microarray had been performed in 44 of 61 and was nondiagnostic for non-WS causes of SVAS. Sequencing of 1 or more genes was performed in 47 of 61. Of these, 39 of 47 underwent ELN sequencing, 20 of 39 (51%) of whom had a diagnostic variant. Other diagnoses made by gene sequencing were Noonan syndrome (3 PTPN11, 1 RIT1), Alagille syndrome (3 JAG1), neurofibromatosis (1 NF1), and homozygous familial hypercholesterolemia (1 LDLR1). Overall, sequencing was diagnostic in 29 of 47 (62%). When WS is excluded, gene sequencing for SVAS is high yield, with the highest yield for the ELN gene. Therefore, we recommend gene sequencing using a multigene panel or exome analysis. Hypercholesterolemia can also be considered in individuals bearing the stigmata of this disease.

Chest Radiography Pearls in Select Adult Congenital Heart Disease.

Congenital heart disease in adult patients (ACHD) includes individuals with native anatomic deformities and those who have benefited from corrective, ameliorative, or interventional heart and vascular interventions. Congenital heart disease is the most common birth defect, although with interventions most survive into adulthood. Newborns and children with complex congenital heart diseases that feature cyanosis fail to thrive, and once this is identified, heart failure can promptly undergo diagnostic evaluations and treatment. However, patients with simple congenital heart disease and subtle clinical signs and symptoms may escape diagnosis until adulthood or experience changes in their cardiac hemodynamics and physiology in settings such as pregnancy or newly diagnosed arrhythmias. The chest X-ray (CXR) is the most common X-ray among all radiological procedures. Individual features or a constellation of features on a CXR are often present in patients who have congenital heart disease. The ability to recognize these CXR features is a valuable skill for making the diagnosis of ACHD and for following these patients as they age, and can complement echocardiographic findings. When used well to diagnose ACHD, the CXR will be the sharpest arrow in the quiver.

ALCAPA in Children with Complex Congenital Heart Disease: A Multicenter Study.

We sought to report characteristics and outcomes of children with complex anomalous left coronary artery from the pulmonary artery (ALCAPA) and tocompare the outcomes to children with isolated ALCAPA. We performed a retrospective data analysis of children with ALCAPA who underwent cardiac surgery between 1/2009 and 3/2018 at 21 centers. Characteristics and outcomes of patients with complex ALCAPA are provided using descriptive statistics. Outcomes were compared between complex ALCAPA and isolated ALCAPA using Fisher's exact test. We reviewed 258 patients who underwent surgical repair of ALCAPA at 21 centers. We identified 10 patients (3.9%) with complex ALCAPA. Median age at initial cardiac surgery was 49days (range: 4days, 12.8years). Cardiac lesions associated with ALCAPA were HLHS(n = 3); scimitar syndrome (n = 2); VSD with aortic coarctation (n = 2); VSDwith right pulmonary artery discontinuity (1); DORV with mitral atresia (n = 1); and ToF(n = 1). ALCAPA was diagnosed prior to surgical intervention in 1 patient; during the initial cardiac surgery in 4 patients; in the early postoperative period via cardiac catheterization in 3 patients; and later in childhood after initial surgical repair in 2 patients. Following ALCAPA repair, patients with complex ALCAPA, as compared to patients with isolated ALCAPA, were more likely to be placed on ECMO (50% vs 12%, p = 0.002), receive CPR (30% vs 6%, p = 0.017), or suffer operative mortality (50% vs 3%, p < 0.001). Complex ALCAPA is uncommon. All but one with complex ALCAPA was not diagnosed preoperatively and postoperative morbidity and mortality were significantly greater in these complex patients compared to patients with isolated ALCAPA.

Clinical implications of dextrocardia based on four visceroatrial situs studies

BackgroundPrevious studies on congenital heart diseases (CHD) associated with dextrocardia were based on selective patient databases and did not reflect the full spectrum of dextrocardia in the general population. Additionally, these studies had complex classification and presentation. Nor did these studies elaborate on the distribution of the associated CHD's complexity, the various segmental connections, and associated CHD among the four visceroatrial situs. MethodsWe retrospectively reviewed the medical records of 211 children with primary dextrocardia. We used a segmental approach to diagnose CHD. We then analyzed and compared the distribution of the above-mentioned issues among the four visceroatrial situs. ResultsDextrocardia occurred most commonly with situs inversus (52.6%), followed by situs solitus (28.4%), asplenia (17.1%), and polysplenia (1.9%). Although some patients had a structurally normal heart (22.7%) or they were associated with simple CHD (17.5%), most patients had complex CHD (59.7%) consisting of a single ventricle (34.6%) or conotruncal anomaly (25.1%) (double-outlet right ventricle [7.6%], corrected transposition of the great arteries [6.2%], complete transposition of the great arteries [5.7%], tetralogy of Fallot [4.7%], etc.). Situs inversus or polysplenia had a higher prevalence of a structurally normal heart or associated with simple CHD, two patent atrioventricular (AV) valves connections, and biventricular AV connections. Situs solitus or asplenia had a higher prevalence of associated complex CHD, common AV valve connection, univentricular AV connection, pulmonary outflow tract obstruction, and anomalous pulmonary venous drainage. ConclusionOur study finds that situs inversus is the most common visceroatrial situs in dextrocardia. Although some patients had a structurally normal heart or were associated with simple CHD, most patients have associated complex CHD consisting of a single ventricle or conotruncal anomaly. Dextrocardia is associated with a higher incidence of complex CHD in situs solitus and asplenia groups than in situs inversus and polysplenia groups.

Incidence of Atrial Fibrillation After Radiofrequency Catheter Ablation for Atrial Tachycardia in Congenital Heart Disease

Incidence of Atrial Fibrillation After Radiofrequency Catheter Ablation for Atrial Tachycardia in Congenital Heart Disease

A Case Series and Review of Literature Describing the Use of Midodrine for Vasopressor Effects in Infants With Congenital Heart Disease

Midodrine is an oral vasopressor option that allows for discontinuation of intravenous vasopressors for patients with cardiovascular conditions. It does not have a US Food and Drug Administration-labeled indication for use in children, and there is a paucity of literature in patients ≤6 years of age. This case series describes 2 infants with complex congenital heart diseases initiated on midodrine for augmentation of systolic (SBP) or diastolic blood pressure (DBP) to increase coronary perfusion. Case 1 was initiated on midodrine on hospital day 19 at a dose of 0.5 mg (0.17 mg/kg) enterally every 8 hours that was eventually increased to 1 mg (0.33 mg/kg) every 8 hours. Case 2 was initiated on midodrine on hospital day 15 at a dose of 2.5 mg (0.49 mg/kg) enterally every 8 hours, and this was decreased to 1.25 mg (0.25 mg/kg) every 8 hours due to high SBP. Both patients were discharged home on midodrine; other than the initially high SBP for Case 2, no other adverse drug events were noted. While midodrine was effective based on clinical response in these two infants, additional studies are needed due to the lack of safety and efficacy in children &lt;6 years of age.

Epidemiological Survey of Congenital Heart Disease Among Children Aged from 2 to 18 in Suo County, Nagqu, Tibet.

Lin, Tian, Huaping Jia, Yunming Li, Yongxing Xu, Bei Zhao, Dong Zheng, Hongfeng Yan, Meihui Zhao, Yanlei Li, Liping Xia, Fengxia Zhou, Cuiping Liu, Ke Ma, Ma Mi, and Jianwen Gu. Epidemiological survey of congenital heart disease among children aged from 2 to 18 in Suo County, Nagqu, Tibet. High Alt Med Biol. 00:000-000, 2024. Background: Studies have reported the prevalence of congenital heart disease (CHD) in parts of Tibet, but relative epidemiological surveys are rare. We aimed to explore the prevalence of CHD in children and its relationship with family history in Suo County, Nagqu, Tibet, an altitude of 3,980 meters. Methods: We recruited 4,002 children aged 2-18 years. Subjects underwent a family history investigation, cardiac auscultation, and clinical manifestation examination and then received echocardiographic screening. Results: The prevalence of CHD among children in Suo County was 0.97% (39 cases), much higher than the prevalence at sea level. The most common subtype was atrial septal defect, accounting for 53.9% of CHD, followed by patent ductus arteriosus (33.3%) and ventricular septal defect (12.8%). We also found that children whose mothers had previously borne children with CHD had a higher risk of CHD than those without (p = 0.002); other factors related to CHD during pregnancy, such as smoking, drinking, drug use, and viral infection, showed no statistical differences between children with and without CHD. Conclusions: The prevalence of CHD in children in Suo County is much higher than at low altitude, consisting mostly of simple forms with left-to-right shunt, with rare complex CHD. These results support implementing diagnostic and treatment plans to prevent CHD in Suo County.

High-Risk Congenital Heart Disease in Pregnancy.

High-risk congenital heart disease (CHD) in pregnancy presents a complex clinical challenge. With improved medical care and increased survival rates, a growing population of adults with complex CHD are surviving to adulthood, including women of reproductive age. This chapter focuses on risk stratification and management of pregnant women with high-risk CHD, emphasizing the importance of considering both anatomical and physiological complexity. Maternal physiological changes, such as blood volume increase, cardiac output changes, and alterations in vascular resistance, can significantly impact high-risk CHD patients. Management of high-risk CHD in pregnancy necessitates a multidisciplinary approach and individualized care.

Experience of percutaneous closure of small to large patent ductus arteriosus with Nit-Occlud® device in a tertiary referral hospital in Colombia.

The decision to close patent ductus arteriosus should always be individualized and taken together with the child's family once the risks and benefits of both choices have been exposed. This study aims to report the experience and outcomes in patients undergoing endovascular closure of small to medium-size PDA with a Nit-Occlud® device in a tertiary referral hospital in Colombia. Longitudinal descriptive study, which included all patients under 18 years of age who underwent percutaneous ductal closure with Nit-Occlud® device between January 1, 2011, and February 1, 2023. Patients with associated complex congenital heart disease requiring surgical management, pregnant patients, and patients with incomplete data regarding studied variables were excluded from the study. Eighty-seven patients were documented, with a mean age, weight, and height at closure of 51 months, 14 kg, and 95.83 cm, respectively. About 70% of the patients (n = 61) were female, 76% were under 6-years-old and only one patient was over 15. The average size of the ductus at the pulmonary end was 2 mm. Four of the total number of patients did not achieve PDA closure during the procedure. Of the remaining 83, complete immediate closure was achieved in 81 patients. A device exchange for a larger device was required during the same procedure in one of the cases. Two patients presented residual shunt of 0.5 mm during follow-up, and one required a new procedure for device closure 10 months later. Only one device presented repeatedly embolization to the aorta, requiring surgical removal. As a technical difficulty, one device presented repeated passage into the aorta, so it was decided to remove it before releasing it to avoid complications, and given the complex anatomy of the ductus, surgical closure was indicated. Among the complications, one patient presented a hematoma of the subcutaneous tissue in the right thigh, which improved with medical management, and no deaths related to the procedure were registered. Using the Nit-Occlud® device to close small to moderate-sized ductus remains a safe and effective strategy with successful closure rates at 1-year follow-up irrespective of age, weight, height, or whether it involves a small or medium-sized duct. Despite our limitations, results concerning adverse effects are comparable to those observed in multicentric studies conducted in other regions.

Bilateral ductal stenting in an infant with pulmonary atresia and ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct.

Pulmonary atresia with ventricular septal defect, non-confluent pulmonary arteries, and bilateral arterial duct is a rare and complex CHD. Physiologic ductal closure may lead to life-threatening hypoxia. We present a case of successful bilateral ductal stenting as a bridge to further lower-risk surgical repair.

Respiratory syncytial virus subtypes in children with bronchiolitis: does it correlate with clinical severity?

BackgroundIn this retrospective study, we aimed to evaluate the factors associated with the severity of respiratory syncytial virus (RSV) bronchiolitis in children aged under 2 years who were admitted to the Children’s Hospital of Hebei between June 2018 and January 2019.MethodsSputum samples positive for RSV via multiplex PCR were subtyped using real-time PCR. Data collected included risk factors for disease severity, demographics, microbiology, and outcomes.ResultsOf the 82 children with RSV bronchiolitis, 79 were treated and discharged with improvement, while 3 died. All three patients had underlying medical conditions, including complex congenital heart disease and severe combined immunodeficiency. Further, disease severity was associated with preexisting underlying disease, fever duration, and bacterial co-infection, but not with the RSV subtype.ConclusionsOur findings suggest that an appropriate therapeutic regimen should include the detection of bacterial co-infections and the identification of underlying diseases for the effective management of severe RSV bronchiolitis.

Impact of COVID-19 Infections among Unvaccinated Patients with Congenital Heart Disease: Results of a Nationwide Analysis in the First Phase of the Pandemic.

Background: The outcome data and predictors for mortality among patients with congenital heart disease (CHD) affected by COVID-19 are limited. A more detailed understanding may aid in implementing targeted prevention measures in potential future pandemic events. Methods: Based on nationwide administrative health insurance data, all the recorded in-hospital cases of patients with CHD with COVID-19 in 2020 were analyzed. The demographics, treatment details, as well as 30-day mortality rate were assessed. The associations of the patients' characteristics with death were assessed using multivariable logistic regression analysis. Results: Overall, 403 patients with CHD were treated in- hospital for COVID-19 in 2020. Of these, 338 patients presented with virus detection but no pneumonia whilst, 65 patients suffered from associated pneumonia. The cohort of patients with pneumonia was older (p = 0.04) and presented with more cardiovascular comorbidities such as diabetes mellitus (p = 0.08), although this parameter did not reach a statistically significant difference. The 30-day mortality rate was associated with highly complex CHD (odds ratio (OR) 7.81, p = 0.04) and advanced age (OR 2.99 per 10 years, p = 0.03). No child died of COVID-related pneumonia in our dataset. Conclusions: COVID-19 infection with associated pneumonia chiefly affected the older patients with CHD. Age and the complexity of CHD were identified as additional predictors of mortality. These aspects might be helpful to retrospectively audit the recommendations and guide health politics during future pandemic events.

Thymic Atrophy and Immune Dysregulation in Infants with Complex Congenital Heart Disease

Congenital heart disease (CHD) is the most common birth defect, and up to 50% of infants with CHD require cardiovascular surgery early in life. Current clinical practice often involves thymus resection during cardiac surgery, detrimentally affecting T-cell immunity. However, epidemiological data indicate that CHD patients face an elevated risk for infections and immune-mediated diseases, independent of thymectomy. Hence, we examined whether the cardiac defect impacts thymus function in individuals with CHD. We investigated thymocyte development in 58 infants categorized by CHD complexity. To assess the relationship between CHD complexity and thymic function, we analyzed T-cell development, thymic output, and biomarkers linked to cardiac defects, stress, or inflammation. Patients with highly complex CHD exhibit thymic atrophy, resulting in low frequencies of recent thymic emigrants in peripheral blood, even prior to thymectomy. Elevated plasma cortisol levels were detected in all CHD patients, while high NT-proBNP and IL-6 levels were associated with thymic atrophy. Our findings reveal an association between complex CHD and thymic atrophy, resulting in reduced thymic output. Consequently, thymus preservation during cardiovascular surgery could significantly enhance immune function and the long-term health of CHD patients.

Queens of hearts: Exploring the lived experiences of mothers caring for infants with complex congenital heart disease in Sri Lanka.

This qualitative study explored the lived experiences of eight Sri Lankan mothers of infants with complex congenital heart disease (CCHD) using semi-structured interviews. Four themes were generated as: illness perception, communication with medical staff, challenges faced, and coping mechanisms. These provided insight into the multi-faceted nature of mothers' experiences, importance of medical-caregiver communications and their need for psychosocial services. The findings enhance the limited knowledge of South-Asian primary CCHD caregiver experiences and will help in improving psychosocial support services in Sri Lanka.

Safety of SGLT-2 inhibitors in the management of heart failure in the adult congenital heart disease patient population

BackgroundSodium glucose transporter 2 inhibitors (SGLT-2i) have shown safety and efficacy in patients with heart failure (HF). However, evidence for the use of SGLT-2i in adult congenital heart disease (ACHD) patients with HF is limited. MethodsWe performed a retrospective, single center analysis of 18 patients (>18 years of age) with ACHD and a diagnosis of HF who were initiated on an SGLT-2i. Patient characteristics, including vital signs, laboratory values, concomitant medications, clinical outcomes, and echocardiograms, were obtained as part of standardized clinical care at our ACHD program before and 2–6 months after initiation of SGLT-2i. The primary outcome was to demonstrate safety of SGLT-2i initiation via potential changes in systolic blood pressure, serum sodium, and serum creatinine. ResultsOf the 18 patients, 11 (61%) had moderate complexity congenital heart disease while 7 (39%) had great complexity congenital heart disease. Post initiation, there were no significant differences in systolic blood pressure (121.8 ± 20.8 mmHg to 114.4 ± 14.9 mmHg, p = 0.06), sodium level (138.7 ± 2.9 mMol/L to 138.0 ± 2.2 mMol/L, p = 0.75), and creatinine level (0.85 ± 0.18 mg/dL to 0.89 ± 0.18 mg/dL, p = 0.07). There was a statistically significant decline in weight (78.9 ± 22.9 kg to 76.0 ± 23.0 kg, p = 0.0039) but without a statistically significant change in NT-pro NBP (1358.2 ± 2735.0 pg/mL to 601.6 ± 786.1 pg/mL, p = 0.36). ConclusionsWe demonstrated the use of SGLT-2i in a small cohort of ACHD population, including patients with complex congenital heart disease, appears safe and well tolerated. The safety and potential efficacy of SGLT-2i in patients with ACHD will require further evaluation in prospective multicenter studies.

Single-Chamber and Dual-Chamber Pacemaker Devices in Adults with Moderate and Complex Congenital Heart Disease: A Single Tertiary Referral Center Experience.

The number of device implantation procedures has increased in adult patients with congenital heart disease (ACHD). Despite significant improvements in materials and implantation techniques, these patients are exposed to higher risk of device related complications than general population. Herein, we describe our single tertiary referral center experience on transvenous pacemaker (PM) implantation and follow-up in adult patients with moderate and complex congenital heart disease (CHD) as limited data are available on long-term outcome. We considered all adults with moderate and complex CHD aged more than 16 years who underwent transvenous single-chamber and dual-chamber PM implant for sinus node dysfunction or atrioventricular block between January 2013 to December 2022 at our Unit. Seventy-one ACHD patients were included in the study (mean age 38.6 ± 15.2 years, 64% with moderate CHD, 36% with complex CHD). Among 32 patients implanted with a dual chamber PM (DDD PM), 4 devices were reprogrammed in VDD mode, 3 in VVI and 2 in AAI mode during follow-up because of lead dysfunction or permanent atrial arrhythmia. In addition, 26 patients had a single chamber PM (AAI or VVI PM) and 13 patients had single-lead pacing system with a free-floating atrial electrode pair (VDD PM). Just one of 13 single-lead VDD PM was reprogrammed in VVI mode due to a low atrial sensing. In DDD PM group, 10 re-interventions were needed due to lead dysfunction (8 cases) and lead-related infective endocarditis (2 cases). Only 3 patients in the single-lead PM group developed lead dysfunction with 2 re-interventions needed, but no infective endocarditis was reported. The rate of long-term complications is high in moderate and complex ACHD with transvenous PM devices, and it is mainly lead-related. In our experience, the less leads implanted, the less complications will occur. Considering the heterogeneity of the ACHD population, transvenous single-chamber or dual-chamber PM device implantation should always be tailored on the single patient, balancing risks and benefits in this complex population.

An Observational Study of Dialogue about Uncertainty in Clinician-Family Counseling Conversations Following Prenatal Diagnosis of Complex Congenital Heart Disease

ObjectiveFamilies who receive a prenatal diagnosis of complex congenital heart disease (cCHD) often experience severe psychological distress and identify uncertainty as a key source of that distress. This study examined clinician-family conversations during initial fetal cardiology consultations to identify the topics of uncertainty discussed. MethodsIn this observational, qualitative study, initial fetal cardiology consultations were audio-recorded, transcribed verbatim, and coded by two independent coders. A codebook was inductively and deductively developed and applied. This content analysis focused on uncertainty-related codes and associated themes. ResultsDuring 19 consultations including five clinicians, 13 different cardiac diagnoses were discussed (seven with high mortality risk). Median consultation length was 37 min (IQR: 26–51), with only 11% of words spoken by families. On average, 51% of total words spoken focused on uncertainty in relation to cardiac diagnosis, etiology, comorbidities, prognosis, childbirth, therapeutics, and logistics. Family-initiated discussion on uncertainty largely focused on childbirth and pregnancy and postpartum logistics. ConclusionsHalf of dialogue within initial fetal cardiology encounters discussed uncertainty surrounding prenatally diagnosed cCHD. Parent and clinician perspectives should be gathered on the essential content and optimal delivery of uncertainty-related topics. InnovationThis study is conceptually and methodologically innovative as one of the first to examine audio-recorded dialogue between fetal cardiology clinicians and families.