Molecular Pathways and Animal Models of Tricuspid Atresia and Univentricular Heart.

The process of valve formation is a complex process that involves intricate interplay between various pathways at precise times. Although we have not completely elucidated the molecular pathways that lead to normal valve formation, we have identified a few major players in this process. We are now able to implicate TGF-ß, BMP, and NOTCH as suspects in tricuspid atresia (TA), as well as their downstream targets: NKX2-5, TBX5, NFATC1, GATA4, and SOX9. We know that the TGF-ß and the BMP pathways converge on the SMAD4 molecule, and we believe that this molecule plays a very important role to tie both pathways to TA. Similarly, we look at the NOTCH pathway and identify the HEY2 as a potential link between this pathway and TA. Another transcription factor that has been implicated in TA is NFATC1. While several mouse models exist that include part of the TA abnormality as their phenotype, no true mouse model can be said to represent TA. Bridging this gap will surely shed light on this complex molecular pathway and allow for better understanding of the disease process.

Genetic and functional analyses detect one pathological NFATC1 mutation in a Chinese tricuspid atresia family.

BACKGROUND: Cardiac valvulogenesis is a highly conserved process among vertebrates and cause unidirectional flow of blood in the heart. It was precisely regulated by signal pathways such as VEGF, NOTCH, and WNT and transcriptional factors such as TWIST1, TBX20, NFATC1, and SOX9. Tricuspid atresia refers to morphological deficiency of the valve and confined right atrioventricular traffic due to tricuspid maldevelopment, and is one of the most common types of congenital valve defects. METHODS: We recruited a healthy couple with two fetuses aborted due to tricuspid atresia and identified related gene mutations using whole-exome sequencing. We then discussed the pathogenic significance of this mutation by bioinformatic and functional analyses. RESULTS: PROVEAN, PolyPhen, MutationTaster, and HOPE indicated the mutation could change the protein function and cause disease; Western blotting showed the expression of NFATC1 c.964G>A mutation was lower than the wild type. What's more, dual-luciferase reporter assay showed the transcriptional activity of NFATC1 was impact by mutation and the expression of downstream DEGS1 was influenced. CONCLUSION: Taken together, the c.964G>A mutation might be pathological and related to the occurrence of disease. Our research tended to deepen the understanding of etiology of tricuspid atresia and gene function of NFATC1, and provide some references or suggestions for genetic diagnosis of tricuspid atresia.

Regenerative Therapy for Patients with Congenital Heart Disease.

Congenital heart disease (CHD) is the most common birth defect, affecting 1 in 100 babies. Among CHDs, single ventricle (SV) physiologies, such as hypoplastic left heart syndrome and tricuspid atresia, are particularly severe conditions that require multiple palliative surgeries, including the Fontan procedure. Although the management strategies for SV patients have markedly improved, the prevalence of ventricular dysfunction continues to increase over time, especially after the Fontan procedure. At present, the final treatment for SV patients who develop heart failure is heart transplantation; however, transplantation is difficult to achieve because of severe donor shortages. Recently, various regenerative therapies for heart failure have been developed that increase cardiomyocytes and restore cardiac function, with promising results in adults. The clinical application of various forms of regenerative medicine for CHD patients with heart failure is highly anticipated, and the latest research in this field is reviewed here. In addition, regenerative therapy is important for children with CHD because of their natural growth. The ideal pediatric cardiovascular device would have the potential to adapt to a child's growth. Therefore, if a device that increases in size in accordance with the patient's growth could be developed using regenerative medicine, it would be highly beneficial. This review provides an overview of the available regenerative technologies for CHD patients.

[RESULTS OF THE TOTAL CAVA-PULMONARY CONNECTION PROCEDURE WITH CORRECTION OF ATRIO-VENTRICULAR VALVES IN PATIENTS OF DIFFERENT AGE, SUFFERING SINGLE CARDIAC VENTRICULUS].

The investigation objective was to improve the patients' management, suffering a single cardiac ventriculus, in whom a total cavа-pulmonary connection (ТСРС) operation was performed together with correction of the atrio-ventricular valves (AVV) insufficiency, basing on analysis of immediate and middle-term results. From 2005 to 2015 yrs in the clinic the ТСРС operation was performed in 132 patients. Of them 24 patients were choosed , in whom moderate and pronounced insufficiency of systemic AVV was diagnosed. Good early and middle-term results were achieved in 92% patients. In 8 observations, while the AVV correcting, in every patient two and more procedures of plasty were applied. Complex approach, using combination of various procedures of plasty, has guaranteed the optimal result. Application of procedures for the fiber ring stabilization have promoted achievement of best results.

Ventricular fibrogenesis activity assessed by serum levels of procollagen type III N-terminal amino peptide during the staged Fontan procedure.

OBJECTIVE: We tested the hypotheses that volume overload and cyanosis observed in the pre-Fontan single ventricular circulation are associated with increased ventricular fibrogenesis, that the Fontan procedure helps to reduce fibrogenesis, and that persistently increased fibrogenesis in the Fontan ventricle is associated with ventricular diastolic dysfunction. METHODS: Levels of serum amino-terminal procollagen type III, a marker of tissue fibrogenesis, were measured in 172 patients with single ventricle circulation and 149 controls. Patients were divided into 3 groups according to surgical stage: 59 patients after Blalock-Taussig shunt or pulmonary banding, 60 patients after Glenn surgery (Glenn group), and 53 patients after Fontan surgery (Fontan group). RESULTS: Serum amino-terminal procollagen type III levels were significantly higher among the 3 single ventricle groups than among control patients, but decreased with each surgical stage (0.604, 0.176, 0.143, and 0.073 U/mL, for Blalock-Taussig shunt or pulmonary banding, Glenn, Fontan, and controls, respectively). Severity of volume load and cyanosis were independent determinants of increased amino-terminal procollagen type III levels in patients before Fontan surgery, and persistently increased amino-terminal procollagen type III after Fontan surgery was associated with ventricular diastolic stiffening (r = 0.494, P = .009). Data also indicated close associations between amino-terminal procollagen type III levels and activation of the renin-angiotensin-aldosterone system, suggesting potential involvement of this hormonal system in the increased fibrogenesis after Fontan surgery. CONCLUSIONS: These results suggest that serum amino-terminal procollagen type III may provide important diagnostic information on myocardial fibrosis in patients with single ventricle circulation and raise the possibility that ventricular fibrogenesis may be a potential therapeutic target in this population.

Influence of Morphology and Initial Surgical Strategy on Survival of Infants With Tricuspid Atresia.

BACKGROUND: Tricuspid atresia (TA) is a heterogeneous single-ventricle anomaly in which initial presentation and, consequently, timing and mode of palliation vary based on morphology and degree of pulmonary or systemic outflow obstruction. We report current era palliation outcomes and examine whether morphologic and, subsequently, surgical factors influence survival. METHODS: From 2002 to 2012, 105 infants with TA underwent surgical palliation. Competing risks analyses modeled events after first-stage surgery (Glenn versus death) and after Glenn (Fontan versus death) and examined risk factors affecting outcomes. RESULTS: Seventy-eight patients (74%) required neonatal first-stage palliation, including modified Blalock-Taussig shunt (n = 46, 44%), Norwood (n = 18, 17%), and pulmonary artery band (n = 14, 13%), whereas 27 (26%) received primary Glenn as their initial surgery. Hospital mortality was 5 patients (4.8%). Competing risks models showed that by 1 year after first-stage surgery, 15% of patients had died and 83% had undergone Glenn. By 5 years after Glenn, 2% of patients had died and 80% had undergone Fontan. Overall 8-year survival was 84%. On multivariable analysis, risk factors for mortality were genetic/extracardiac anomalies (hazard ratio 7.0, 95% confidence interval: 2.4 to 20.6, p < 0.001) and pulmonary atresia (hazard ratio 4.4, 95% confidence interval: 1.6 to 12.2, p = 0.004). Survival was not affected by initial palliation type (p = 0.36), ventriculoarterial discordance (p = 0.25), systemic outflow obstruction (p = 0.84), or arch obstruction (p = 0.62). CONCLUSIONS: Despite morphologic and physiologic variations necessitating different palliative sequences, multistage palliation outcomes of various TA subtypes are comparable and generally good, with the exception of patients with associated genetic/extracardiac anomalies. The bulk of mortality is interstage, indicating continued opportunity for improvement in monitoring and managing patients during this critical period.

A case of Seckel syndrome with tricuspid atresia.

Seckel syndrome is an autosomal recessive disease presenting with marked growth retardation, microcephalic dwarfism, some facial and skeletal abnormalities. Tricuspid atresia is a rare and life threatening cyanotic congenital heart diseases, with an incidence of 1% to 3%. It is feature of the anatomically normally related great arteries with a large ventricular septum defect and stenosis of right ventricular outflow tract. Tricuspid atresia has never been reported in patients with Seckel syndrome. Here we report a 15-day-old girl baby diagnosed as having Seckel syndrome with tricuspid atresia.

Congenital coronary arteriopathy and myocardial infarctions occur with tricuspid atresia.

Sinusoids and coronary arterial fistulae are well described in fetuses and infants with single ventricles. Coronary arteriopathy is well described as a cause of myocardial infarction in adults and in children with familial hypercholesterolemias. To the best of our knowledge, pathologic alterations in coronary arteries (coronary arteriopathy) have only twice before been described as the cause of infarction in neonates. We present the case of a newborn with perinatal myocardial infarctions and death in the setting of extensive coronary arteriopathy and tricuspid atresia. The child had a pulseless arrest immediately after birth. Autopsy showed multiple areas of infarction ranging in age from acute to >10 days old.

[Functional properties of smooth muscle cells in ascending aortic aneurysm].

Thoracic aortic aneurism (TAA) develops as a result of complex series of events that dynamically alter the structure and composition of the aortic vascular extracellular matrix (ECM). The main elements that alter the composition of aortic wall are smooth muscle cells (SMC). The purpose of the present work was to study alteration of smooth muscle cell functions derived from the patients with TAA and from healthy donors. As it is supposed that TAA associated with bicuspid aortic valve (BAV) and with tricuspid aortic valve (TAV) differ in their pathogenesis, we compared the SMC and tissues samples from BAV-, TAV-patients and healthy donors. We compared TAA patients' derived tissues and SMC to healthy donors' ones in several parameters: SMC growth, migration and apoptotic dynamics; metalloproteinase MMP2 and MMP9 activity (zymography) and elastin, collagen and fibrillin content (Western blot) in both tissue samples and cultured SMC. Proliferation ability of both BAV and TAV SMC was decreased comparing to donors cells; migration ability in scratch tests was increased in TAV-derived SMC comparing to donor cells. BAV-cells migration ability was not changed comparing to donor-SMC. Elastin content was decreased in TAA SMC comparing to donor cells whereas the content of fibrillin and collagen was not altered. At the same time elastin and collagen protein level was significantly higher in tissue samples of TAA patients comparing to donor-derived samples. SMS proliferation and migration ability is differently affected in TAV and BAV-associated TAA that supports the idea of different nature of these two groups of TAA. Also our data show that SMC functional properties are altered in TAA patients and these alterations could play a significant role in the disease pathogenesis.

Two heterozygous mutations in NFATC1 in a patient with Tricuspid Atresia.

Tricuspid Atresia (TA) is a rare form of congenital heart disease (CHD) with usually poor prognosis in humans. It presents as a complete absence of the right atrio-ventricular connection secured normally by the tricuspid valve. Defects in the tricuspid valve are so far not associated with any genetic locus, although mutations in numerous genes were linked to multiple forms of congenital heart disease. In the last decade, Knock-out mice have offered models for cardiologists and geneticists to study the causes of congenital disease. One such model was the Nfatc1(-/-) mice embryos which die at mid-gestation stage due to a complete absence of the valves. NFATC1 belongs to the Rel family of transcription factors members of which were shown to be implicated in gene activation, cell differentiation, and organogenesis. We have previously shown that a tandem repeat in the intronic region of NFATC1 is associated with ventricular septal defects. In this report, we unravel for the first time a potential link between a mutation in NFATC1 and TA. Two heterozygous missense mutations were found in the NFATC1 gene in one indexed-case out of 19 patients with TA. The two amino-acids changes were not found neither in other patients with CHDs, nor in the control healthy population. Moreover, we showed that these mutations alter dramatically the normal function of the protein at the cellular localization, DNA binding and transcriptional levels suggesting they are disease-causing.

Atrioventricular valve repair for patient with heterotaxy syndrome and a functional single ventricle.

Heterotaxy syndrome is a mortality risk factor for patients with complex heart disease. These patients often have common atrioventricular valve (CAVV) morphology and significant atrioventricular valve regurgitation - yet another mortality risk factor in congenital heart disease. Thus, patients with both heterotaxy syndrome and atrioventricular valve regurgitation are at highest risk of mortality. A large number of patients with heterotaxy syndrome have CAVV and a functional single ventricle. These patients are more difficult to operate than patients with biventricular morphology because in the former, the CAVV is often less adapted to systemic afterload than the mitral valve. Herein, we present the results of atrioventricular valve repair surgeries performed at the Okayama University Hospital on patients with heterotaxy syndrome, atrial isomerism, and a functional single ventricle. In addition, we review the current literature in this typically challenging patient population. In-depth understanding of reasonable management strategies and resolution of technical issues will help guide surgeons during this procedure.

Accuracy and reproducibility of strain by speckle tracking in pediatric subjects with normal heart and single ventricular physiology: a two-dimensional speckle-tracking echocardiography and magnetic resonance imaging correlative study.

BACKGROUND: Myocardial strain is a sensitive measure of ventricular systolic function. Two-dimensional speckle-tracking echocardiography (2DSE) is an angle-independent method for strain measurement but has not been validated in pediatric subjects. The aim of this study was to evaluate the accuracy and reproducibility of 2DSE-measured strain against reference tagged magnetic resonance imaging-measured strain in pediatric subjects with normal hearts and those with single ventricles (SVs) of left ventricular morphology after the Fontan procedure. METHODS: Peak systolic circumferential strain and longitudinal strain (LS) in segments (n = 16) of left ventricles in age-matched and body surface area-matched 20 healthy and 12 pediatric subjects with tricuspid atresia after the Fontan procedure were measured by 2DSE and tagged magnetic resonance imaging. Average (global) and regional segmental strains measured by the two methods were compared using Spearman's and Bland-Altman analyses. RESULTS: Global strains measured by 2DSE and tagged magnetic resonance imaging demonstrated close agreements, which were better for LS than circumferential strain and in normal left ventricles than in SVs (95% limits of agreement, +0.0% to +3.12%, -2.48% to +1.08%, -4.6% to +1.8%, and -3.6% to +1.8%, respectively). There was variability in agreement between regional strains, with wider limits in apical than in basal regions in normal left ventricles and heterogeneity in SVs. Strain values were significantly (P < .05) higher in normal left ventricles than in SVs except for basal LS, which were similar in both cohorts. The regional strains in normal left ventricles demonstrated an apicobasal magnitude gradient, whereas SVs showed heterogeneity. Reproducibility was the most robust for images obtained with frame rates between 60 and 90 frames/sec, global LS in both cohorts, and basal strains in normal left ventricles. CONCLUSIONS: Strains measured by 2DSE agree with strain measured by magnetic resonance imaging globally but vary regionally, particularly in SVs. Global strain may be a more robust tool for cardiac functional evaluation than regional strain in SV physiology. The reliability of 2DSE-measured strain is affected by the frame rate, the nature of strain, and ventricular geometry.

Tricuspid atresia with absent pulmonary valve and intact ventricular septum: intrauterine course and outcome of an unusual congenital heart defect.

The extremely rare syndrome including absent pulmonary valve associated with membranous tricuspid atresia or severe tricuspid stenosis, intact ventricular septum and patent ductus arteriosus has been reported sporadically in the postnatal literature. This cardiac defect is characterized by right ventricular dysplasia with asymmetrical ventricular septal hypertrophy, ventricular septum bulging into the left ventricle, small right ventricular cavity, membranous tricuspid atresia or severe stenosis with abnormal papillary muscles and leaflets and absence of the pulmonary valve leaflets. The only prenatal case reported so far was diagnosed at 33 weeks of gestation and terminated shortly thereafter; the natural history of prenatally diagnosed cases is therefore unknown. We report on the intrauterine course of a case diagnosed at 17 weeks of gestation that had a favorable postnatal outcome after palliation.

Prenatal diagnosis of tricuspid atresia with hypoplastic right ventricle associated with truncus arteriosus communis type II.

PURPOSE: To confirm the central role of antenatal echocardiography and necropsy in the prenatal diagnosis of rare congenital heart defects. METHODS: A 33-year-old woman undergoing second trimester scan using 2D transabdominal and Doppler sonography. RESULTS: The echocardiographic examination showed, at the level of the four-chamber view, a predominant left ventricle with a rudimental right ventricle and a single artery emerging with failed visualization of the pulmonary trunk: a diagnosis of truncus arteriosus communis associated with tricuspid atresia and hypoplastic right heart was made. No other ultrasound-associated anomalies were seen. Fetal karyotype and 22q11.2 microdeletion for Di George syndrome were sought using cordocentesis performed at 21 weeks and both the results were normal. After extensive counselling, the couple opted for termination of pregnancy at 22 weeks gestation. Necroscopy confirmed the prenatal ultrasound diagnosis. Necroscopy of the heart was performed in a manner that resembled the fetal echocardiographic examination and revealed two atria, two atrio-ventricular valves with recognizable mitral and tricuspid morphology, a prevalent ventricle of left-type and a rudimental ventricle of right type and a ventricular septal defect. The common truncus was seen coming out above the ventricular septum, whilst the pulmonary arteries arise separated from the truncus communis. No other structural thoraco-abdominal anomalies were found. CONCLUSIONS: A combined diagnostic strategy based on second trimester fetal echocardiography, genetic analysis and necroscopy has made identification of a rare congenital heart disease possible.

Damus-Kaye-Stansel anastomosis in a patient with tricuspid atresia, transposition of the great arteries, VSD and total cavo-pulmonary connection (TCPC).

A Damus-Kaye-Stansel (DKS) anastomosis, i.e. an end-to-side anastomosis between the pulmonary artery and the aorta, has been applied in a wide spectrum of congenital heart disease including the Fontan circulation. We hereby present a 19-year-old woman with tricuspid atresia, transposition of great arteries, hypoplastic right ventricle, and a ventricular septal defect who was operated with total cavo-pulmonary connection (TCPC) and a DKS anastomosis. The Cardiovascular Magnetic Resonance (CMR) study showed that the systemic ventricular outflow tract is not obstructed with a good overall result of the previous interventions. CMR therefore, is an ideal mean for studying detailed anatomy and physiology without any need for radiation or contrast media.

Survival and prognostic factors in patients with an absent atrioventricular connection.

INTRODUCTION AND OBJECTIVES: To identify anatomical and functional characteristics associated with survival in adult patients with an absent atrioventricular connection and to highlight the diagnostic importance of echocardiography. METHODS: The clinical histories and echocardiographic and hemodynamic test results of 24 patients were recorded. RESULTS: Some 87.5% of patients were in New York Heart Association (NYHA) functional class I/II. In 92%, the ECG demonstrated sinus rhythm and left ventricular dilatation. Chest X-ray showed grade-II cardiomegaly in 83%. Situs solitus and an absent right atrioventricular connection were found on echocardiography in 92%. The ventriculoarterial connection was most frequently concordant (in 71%). All patients had an atrial septal defect, 21 had a ventricular septal defect and 21 had decreased pulmonary flow. The ejection fraction of the main ventricle in the whole patient group was 55% +/- 10%; 52% +/- 12% in those who did not undergo surgery and 58% +/- 8% in those who did (P=NS). Factors associated with poor survival were an ostium secundum atrial septal defect, hemoglobin <16 g/dL and a main ventricle ejection fraction <50%. Of the 54% of patients who underwent surgery, 85% are alive and the majority are in NYHA functional class I/II. Among those who did not, 82% are alive and 73% are in NYHA functional class I/II. CONCLUSIONS: The presence of a wide atrial septal defect, a normal hemoglobin level and a normal main ventricle ejection fraction were associated with the survival of these patients into adulthood. Echocardiography can provide clinicians and surgeons with information that is valuable for selecting treatment and monitoring follow-up.

Colecistectomía en paciente portadora de valvulopatía grave: a propósito de un caso. / Cholecystectomy in a patient with severe valvular disease: presentation of a case

Paciente femenina de 30 años de edad, raza blanca con antecedentes patológicos personales de Atresia Tricuspídea tipo 1c, que acude al Servicio de Cirugía del Hospital Universitario Camilo Cienfuegos de Sancti Spíritus, refiriendo cuadros periódicos de cólicos biliares de difícil control que la convierte en tributaria de tratamiento quirúrgico. Fue ingresada en sala de Cardiología y presentada al Servicio de Anestesiología para el estudio de las patologías de base y su intervención quirúrgica. En este artículo se abordan con detalles todos los procederes de diagnóstico y tratamiento realizados desde el ingreso, así como el manejo anestésico perioperatorio de la paciente la cual fue dada de alta satisfactoriamente a los cinco días del acto quirúrgico(AU)

A white female patient of 30 years of age, of white race with a previous personal history of tricuspíd atresia type 1c comes to the Surgery Service of the Camilo Cienfuegos University Hospital of Sancti Spíritus, reporting periodic episodes of vesicle colic pains of difficult control that warrant a surgical treatment. She was admitted at the Cardiology Ward and presented to the Service of Anesthesiology for the study of underlying diseases and her surgical intervention. In this article, a thorough approach is made of all the procedures of diagnosis and treatment carried out from admission, as well as the perioperative anesthetic management of this patient who was satisfactorily discharged five days after the surgical act(AU)

Conduit from hypoplastic right ventricle to pulmonary artery in tricuspid atresia.

Tricuspid atresia with transposition of the great arteries produces single ventricle physiology. Ultimate goals of neonatal palliative operations are to provide optimum anatomic and physiologic conditions for a Fontan procedure. A modification of the Norwood procedure is reported, with an aorto-pulmonary anastomosis, utilizing the hypoplastic right ventricle as the pulmonary outflow conduit, avoiding a left ventriculotomy and preserving its function with excellent recovery. We believe this technique has not been previously published in the English literature.