Current Understanding of Indications, Technical Aspects and Outcomes of Fetal Cardiac Interventions.

With the improvement in the detection of congenital heart disease in fetal life, fetal cardiac interventions are pushing the envelope in hopes of either altering the natural history of disease or improving survival in certain high-risk lesions. These interventions include fetal aortic valvuloplasty for evolving hypoplastic left heart syndrome, fetal atrial septoplasty with or without atrial septal stenting for hypoplastic left heart syndrome and variants with intact or severely restrictive atrial septum, and fetal pulmonary valvuloplasty for severe pulmonary stenosis or pulmonary atresia with intact ventricular septum. This review discusses their indications, technical aspects, and outcomes based on available literature.

Labyrinthine cor triatriatum sinister in fetal hypoplastic left heart syndrome is associated with poor outcomes.

OBJECTIVES: A subset of hypoplastic-left-heart-syndrome (HLHS) fetuses have a complex cor-triatriatum sinister that we named "labyrinthine-cor (L-cor)". We sought to determine the prevalence of L-cor in HLHS fetuses and hypothesized that it is associated with increased mortality. METHODS: This single-center retrospective cohort study included all HLHS fetuses from January 2010-December 2020. Fetuses with other hypoplastic-left-heart variants, inadequate images, lack of follow-up and fetal atrial-septal interventions were excluded. RAS was defined as the ratio of pulmonary-vein forward-to-reverse velocity-time-integral (VTI) ≤ 5 and severe-RAS defined as VTI-ratio <3. Kaplan-Meier survival-analysis was performed for the primary outcome of transplant-free survival for 62 weeks after gestational-age of 30 weeks (∼1 year). RESULTS: Of the 156 consecutive fetuses with HLHS, 11 (7.7%) had L-cor and 8/11 (72.7%) of these had RAS. When compared to HLHS-RAS without L-cor, fetuses with HLHS-RAS and L-cor were less likely to survive to 28 days (87% vs. 62.5%, p = 0.017) and to 1 year (69.6% vs. 25%, p = 0.029). When comparing by survival analysis, fetuses with severe-RAS with L-cor had lower survival compared severe-RAS without L-cor (p = 0.020). CONCLUSION: L-cor in fetal HLHS is associated with increased mortality. Recognition of this finding is important for prognostication and atrial-septal-intervention planning.

Enteral L-citrulline supplementation in preterm infants is safe and effective in increasing plasma arginine and citrulline levels-a pilot randomized trial.

OBJECTIVE: Deficiencies of citrulline and arginine have been associated with adverse outcomes in preterm-infants and data regarding enteral supplementation in preterm infants is limited. STUDY DESIGN: This randomized -trial [NCT03649932] included 42 preterm infants (gestational age ≤33 weeks) randomized to receive enteral L-citrulline in low (100 mg/kg/day), medium (200 mg/kg/day) and high-dose (300 mg/kg/day) groups for 7 days. Plasma citrulline and arginine levels were obtained pre-and-post supplementation and efficacy was determined by a significant increase in levels after supplementation. A p < 0.05 was considered significant. Safety monitoring included blood-pressure-monitoring as well as complications and death during hospitalization. RESULTS: A total of 40/42 (95%) of the recruits completed the 7-day supplementation with no adverse events. Plasma-citrulline levels increased significantly in all three groups while plasma-arginine levels increased significantly in the high-dose group. CONCLUSION: Enteral L-citrulline supplementation in preterm infants is safe and effective in increasing plasma citrulline and arginine levels. CLINICAL TRIAL REGISTRATION: NCT03649932 https://clinicaltrials.gov/ct2/show/NCT03649932 .

Is Exercise Stress Testing Useful for Risk Stratification in Anomalous Aortic Origin of a Coronary Artery?

Data on maximal exercise-stress-testing (m-EST) in anomalous-aortic-origin-of-coronary-arteries (AAOCA) is limited and correlation with stress perfusion imaging has not been demonstrated. AAOCA patients ≤20 years were prospectively enrolled from 6/2014-01/2020. A m-EST was defined as heart rate >85%ile on ECG-EST and respiratory-exchange-ratio ≥1.05 on cardiopulmonary-exercise-testing (CPET). Abnormal m-EST included significant ST-changes or high-grade arrhythmia, V̇O2max and/or O2 pulse <85% predicted, or abnormal O2 pulse curve. A (+) dobutamine-stress cardiac-magnetic-resonance-imaging (+DS-CMR) had findings of inducible-ischemia. Outcomes: (1) Differences in m-EST based on AAOCA-type; (2) Assuming DS-CMR as gold-standard for detection of inducible ischemia, determine agreement between m-EST and DS-CMR. A total of 155 AAOCA (right, AAORCA = 126; left, AAOLCA = 29) patients with a median (IQR) age of 13 (11-15) years were included; 63% were males and a m-EST was completed in 138 (89%). AAORCA and AAOLCA had similar demographic and m-EST characteristics, although AAOLCA had more frequently evidence of inducible ischemia on m-EST (P = 0.006) and DS-CMR (P = 0.007). Abnormal O2 pulse was significantly associated with +DS-CMR (OR 5.3, 95% CI 1.6-18,P = 0.005). Sensitivity was increased with addition of CPET to ECG-EST (to 58% from 19%). There was no agreement between m-EST and DS-CMR for detection of inducible ischemia. A m-EST has very low sensitivity for detection of inducible ischemia in AAOCA, and sensitivity is increased with addition of CPET. Stress perfusion abnormalities on DS-CMR were notconcordant with m-EST findings and adjunctive testing should be considered for clinical decision making in AAOCA.

Trends in hospitalization and factors associated with in-hospital death among pediatric admissions with implantable cardioverter defibrillators.

BACKGROUND: As pediatric implantable cardioverter-defibrillator (ICD) utilization increases, hospital admission rates will increase. Data regarding hospitalizations among pediatric patients with ICDs are lacking. In addition, hospital mortality rates are unknown. This study aimed to evaluate (1) trends in hospitalization rates from 2000 to 2016, (2) hospital mortality, and (3) factors associated with hospital mortality among pediatric admissions with ICDs. METHODS: The Kids' Inpatient Database (2000, 2003, 2006, 2009, 2012, 2016) was used to identify all hospitalizations with an existing ICD ≤20 years of age. ICD9/10 codes were used to stratify admissions by underlying diagnostic category as: (1) congenital heart disease (CHD), (2) primary arrhythmia, (3) primary cardiomyopathy, or (4) other. Trends were analyzed using linear regression. Hospital and patient characteristics among hospital deaths were compared to those surviving to discharge using mixed multivariable logistic regression, accounting for hospital clustering. RESULTS: Of 42 570 716 hospitalizations, 4165 were admitted ≤20 years with an ICD. ICD hospitalizations increased four-fold (p = .002) between 2000 and 2016. Hospital death occurred in 54 (1.3%). In multivariable analysis, cardiomyopathy (odds ratio [OR]: 3.5, 95% confidence interval [CI]: 1.1-11.2, p = .04) and CHD (OR: 4.8, 95% CI: 1.5-15.6, p = .01) were significantly associated with mortality. In further exploratory multivariable analysis incorporating a coexisting diagnosis of heart failure, only the presence of heart failure remained associated with mortality (OR: 8.6, 95% CI: 3.7-20.0, p < .0001). CONCLUSIONS: Pediatric ICD hospitalizations are increasing over time and hospital mortality is low (1.3%). Hospital mortality is associated with cardiomyopathy or CHD; however, the underlying driver for in-hospital death may be heart failure.

Benign Structures Mimicking Right Atrial Masses on Prenatal Ultrasound.

Advances in imaging have resulted in more frequent reporting of primitive right atrial structures which can sometimes mimic cardiac tumors in prenatal ultrasound. Prominent crista terminalis and Chiari network are examples of these structures. We describe two cases of pregnant women referred to the fetal cardiology clinic for fetal echocardiography for right atrial masses seen on prenatal ultrasound suspicious of tuberous sclerosis. The first case subsequently diagnosed as crista terminalis and the second case as a prominent Chiari network. Postnatal ECHO confirmed the benign nature of these structures. It is important to differentiate tumors from prominent benign structures in the right atrium in fetal ECHO. The location and the similar echogenicity to the adjacent atrial tissue are clues for differentiation of these structures from atrial tumors.

Congenital Aortic Insufficiency From an Abnormal Left Aortic Cusp Results in Acute Coronary Syndrome.

Acute coronary syndrome (ACS) is a rare presentation in children with isolated congenital aortic insufficiency (AI). We report the case of a six-week-old previously well male who presented with an out-of-hospital cardiac arrest and was diagnosed with severe AI from a left aortic cusp anomaly resulting in ACS. The infant successfully underwent an emergent Ross operation.

Milrinone Use in Persistent Pulmonary Hypertension of the Newborn.

Failure of the normal transition from in utero to ex utero physiology leads to "persistent" pulmonary hypertension of the newborn (PPHN). PPHN is frequently associated with low systemic blood pressure and low cardiac output because of increased right ventricular afterload and myocardial dysfunction. The general management of newborns with PPHN is geared toward maintenance of normothermia, normal serum electrolytes, normal intravascular volume, correction of acidosis, adequate sedation/analgesia, adequate ventilation and oxygenation with optimal lung recruitment, and avoidance of hyperoxia. Inotropic and vasoactive agents are commonly initiated early to increase cardiac output, maintain adequate systemic blood pressure, and enhance oxygen delivery to the tissue. Unfortunately, there is not much evidence on the choice, timing of initiation, dosing, monitoring, and titrating of vasoactive agents in this patient population. In this review, we will discuss the pathophysiology of PPHN and review the use of inotropic, lusitropic, and vasoactive agents in the management of PPHN, with particular attention to milrinone.

Left Ventricular Noncompaction in a Child with Turner Syndrome.

Congenital heart disease (CHD) may cause a significant comorbidity in patients with Turner syndrome. The commonly reported CHD in these patients includes bicuspid aortic valve and coarctation of the aorta. Left ventricular noncompaction (LVNC) is a rare form of cardiomyopathy that has been reported in literature only three times in adult patients with Turner syndrome. We report the first case of a 6-year-old asymptomatic female with Turner syndrome who was referred for cardiac evaluation after her Turner syndrome diagnosis. Echocardiogram was suspicious for LVNC, which was confirmed on cardiac magnetic resonance imaging.

Antenatal Magnesium Sulfate Exposure and Hemodynamically Significant Patent Ductus Arteriosus in Premature Infants.

Objective The use of antenatal magnesium sulfate (MgSO 4 ) has been associated with neuroprotective effects. One of its' proposed mechanisms of action includes antagonism of calcium channels. Calcium influx is important for closure of ductus arteriosus. We hypothesized that antenatal MgSO 4 exposure may be associated with an increased risk of hemodynamically significant patent ductus arteriosus (HsPDA) in premature infants (PI). Study Design A prospective cohort study conducted in two parts. PI (< 32 weeks and < 1,500 g) were recruited ( n = 105). All infants had Echocardiograph (ECHO; within 3 days) and blood samples drawn at the same time for B-type natriuretic peptide (BNP; part 1) and NTproBNP (N-terminal pro BNP; part 2) measurements. HsPDA was defined as a PDA diameter > 1.5 mm and BNP levels > 40 pg/mL or NTproBNP > 10,200 pg/mL. Infants were divided into two groups based on antenatal MgSO 4 exposure. Data were analyzed using SPSS 23. Difference in baseline characteristics and antenatal steroid use in the two groups was analyzed. A matched group analysis was performed to adjust for the difference in the numbers between the two groups. A p -value < 0.05 was considered significant. Results There was no significant difference seen in baseline characteristics or use of antenatal steroids in exposed versus unexposed ( n = 95 vs. n = 10). There was a significant negative correlation between antenatal MgSO 4 exposure and HsPDA in PI ( p ≤ 0.05). However, this association was not significant after matched group analysis. Conclusion Antenatal MgSO 4 exposure is not associated with an increased risk of HsPDA. It may be associated with a decreased likelihood of HsPDA.

Prenatal Diagnosis and Successful Palliation of Absent Aortic Valve with Hypoplastic Left Heart Syndrome: A Case Report and Review of Literature.

Introduction Congenital absence of the aortic valve leaflets is a rare association with hypoplastic left heart syndrome (HLHS). Case A 37-year-old pregnant woman was referred for fetal evaluation of possible HLHS at 22 weeks of gestation. The fetal echocardiogram (ECHO) was remarkable for a hypoplastic left atrium, nearly atretic mitral valve, small left ventricle, and a hypoplastic aortic valve with severe aortic insufficiency. A female infant was born at term and postnatal ECHO confirmed the above findings. In addition, there was complete absence of the aortic valve leaflets. The patient underwent Norwood's procedure at day 5 of life with atrial septectomy, over-sewing of the aortic valve annulus, and a 4 mm Sano's shunt between the right ventricle and the main pulmonary artery. She tolerated this surgery well and subsequently underwent a bidirectional Glenn's procedure at 8 months of life. Conclusion Prenatal diagnosis of absent aortic valve should be suspected in the presence of severe aortic insufficiency in the fetal ECHO. Early postnatal intervention is critical as those patients are likely to deteriorate quickly. The over-sewing of the aortic valve may be important to prevent coronary steal and myocardial hypoperfusion which could potentially be detrimental.

Asymptomatic Right Ventricular Hypoplasia in Twin Siblings: A Normal Variant or Cause of Early Mortality?

Right ventricular (RV) hypoplasia may develop secondary to pulmonary or tricuspid valve atresia. These patients are usually symptomatic early in life and need prompt intervention. Isolated RV hypoplasia is a rare congenital heart disease. We report a case of 23-year-old twins who have been monitored for the last 14 years for isolated right ventricular hypoplasia. ECHO and MRI studies showed a small, heavily trabeculated, nonapex-forming RV and mild tricuspid valve insufficiency. The girl has a patent foramen ovale (PFO). Otherwise, the cardiac anatomy and function was normal. They have both been completely asymptomatic from the cardiac standpoint. The family history is remarkable for death of father at the age of 30 years with autopsy suggestive of a hypoplastic RV. The paternal uncle also died at the age of 46 years, and his son has an unidentified congenital heart disease. The family history appears to suggest an autosomal dominant pattern of inheritance with variable expressivity. However, the chromosome microarray analysis of the twins did not identify any variations of clinical significance.

Sildenafil Use in the Treatment of Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension: A Case Series.

Objective This article studies the role of sildenafil in reducing myocardial stress (measured by serial N-terminal pro b-type natriuretic peptide [NTproBNP] levels) secondary to bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH). Study Design This is a case series of three extremely low birth weight infants with severe BPD at 36 weeks' postmenstrual age. All infants had very elevated NTproBNP (> 2,000 ng/dL) levels and echocardiographic evidence of BPD-PH. Sildenafil was started and infants were followed up every 2 weeks clinically along with NTproBNP levels and echocardiograms. Results After 4 weeks of sildenafil treatment, NTproBNP levels decreased significantly in all infants, echocardiograms showed significant improvement in one infant, and respiratory severity score improved significantly in one infant. All infants tolerated sildenafil. Conclusion Sildenafil reduced NTproBNP levels in all infants with BPD-PH but the echocardiographic findings and respiratory scores did not improve consistently. We speculate that this may be due to a delay in diagnosis and initiation of therapy after irreversible pulmonary changes have set in.