Double-outlet right ventricle (DORV) with a restrictive ventricular septum is a rare but highly morbid phenomenon that can be complicated by progressive left ventricular hypertrophy, arrhythmias, aneurysm formation, severe pulmonary hypertension, and death in the newborn. Surgical creation or enlargement of a ventricular septal defect (VSD) is palliative but may damage the conduction system or the atrioventricular valves in the newborn. This report presents a transcatheter approach to palliation for a newborn that had DORV with a restrictive ventricular septum.
A full-term infant girl (2.9 kg) referred for hypoxia (80 % with room air) and murmur was found to have DORV, interrupted inferior vena cava, and restrictive VSD (95-mmHg gradient). Transhepatic access was performed, and an internal mammary (IM) catheter was advanced through the atrial septal defect and into the left ventricle. By transesophageal echocardiographic guidance, a Baylis radiofrequency perforation wire was used to cross the ventricular septum, and the defect was enlarged using a 4-mm cutting balloon. A bare metal stent then was deployed to maintain the newly created VSD. The patient did well after the procedure but required pulmonary artery banding 4 days later. She returned 5 months later with cyanosis and the development of obstructing right ventricle muscle bundles, requiring further surgical palliation.
This report describes the first transcatheter creation of VSD in DORV with a restrictive ventricular septum in a newborn infant. Use of the radiofrequency catheter in combination with cutting balloon dilation and stent implantation is an efficient method for creating a VSD in such a patient.
Electronic supplementary material
The online version of this article (doi:10.1007/s00246-012-0337-1) contains supplementary material, which is available to authorized users.
Restrictive VSD; Transcatheter VSD creation; VSD stenting
Double outlet right ventricle (DORV) and transposition of the great arteries (TGA) with ventricular septal defect (VSD) and pulmonary stenosis (PS) are complex heart diseases, the treatment of which remains a surgical challenge. The Rastelli procedure is still the most commonly performed treatment. Aortic root translocation including an arterial switch operation is advantageous anatomically since it has a lower possibility of conduit blockage and the left ventricle outflow tract remains straight. This study reports successful aortic root transpositions in two patients, one with DORV with VSD and PS and one with TGA with VSD and PS. Both patients were discharged without postoperative complications.
Congenital heart disease (CHD); CHD-great vessel anomalies; CHD-arterial switch; Nikaidoh operation; Aortic root translocation
Patient: Male, 2
Final Diagnosis: Obstructive hypertrophic cardiomyopathy
Symptoms: Congestive heart failure
Clinical Procedure: Left ventricular septal myectomy • repair of congenital heart disease
Hypertrophic cardiomyopathy (HCM) is uncommon in Down syndrome (DS). When combined with congenital heart disease (CHD) both morbidity and mortality may be greater compared to CHD alone. Whether HCM in DS patients is related to having trisomy 21 versus a second site mutation is unknown.
We report a case of severe HCM in an infant with DS in combination with double outlet right ventricle (DORV) who required surgery for relive of sub-aortic obstruction and congestive heart failure. We predicted that this infant would have a second site mutation involving either a sarcomeric protein or metabolic disorder as a cause for his HCM. Using current genetic and metabolic testing as well as histologic assessment of excised cardiac tissue we sought to further characterize the nature of the HCM. A successful resection of sub-aortic stenosis and DORV repair was performed. Genetic and metabolic testing was negative for gene defects and/or syndromes commonly associated with familial HCM. Excised cardiac tissue from the ventricular septum exhibited myocyte hypertrophy and sub-endocardial fibrosis but no sarcomeric disarray, myocyte fibrosis or glycogen storage. Metabolic testing for common forms of mitochondrial disease was negative. Post-operative echocardiograms show persistent, non-obstructive septal hypertrophy.
Unlike prior reports, this child required a surgical intervention to relieve his sub-aortic obstruction. Thus, HCM in this population can be more serious that previously suspected. Although testing did not reveal the cause of his HCM, we still suggest screening for known causes of HSC until the etiology of the HCM in DS is well understood.
conal-truncal defect; hypertrophic cardiomyopathy; Down syndrome
We aimed to determine outcomes for the Ross procedure in paediatric and adult patients, with particular emphasis on survival, complication and reintervention rates. A retrospective review of 101 patients who had the Ross procedure in a congenital cardiac surgical centre serving a population of approximately 2.5 million was performed. There were 69 adults and 32 children with a mean age of 24.8 ± 13.9 years. Indications for surgery were aortic stenosis (48), regurgitation (10), mixed disease (35) and complex left outflow tract obstruction (8). The mean follow-up duration was 4.7 ± 3.7 years. The mini-inclusion technique was used to incorporate the autograft, and in all cases, pulmonary homografts were placed in the right ventricular outflow tract. Sub-aortic resection was also performed in six and Ross–Konno operations in eight patients. There were no early deaths and there was one late death secondary to endocarditis. Freedom from reintervention was 92% at 5 years and 77% at 10 years. Children were significantly more likely to require reintervention (16%, 5 of 32 versus 4%, 3 of 69, P = 0.05). The Ross procedure carries low early and mid-term mortality, and reintervention rates appear acceptable. The Ross procedure should be considered a feasible alternative to prosthetic valves in patients who require aortic valve replacement.
Aortic valve; Mortality; Reoperation
Regardless of the preoperative morphology and the type of operation, left ventricular outflow tract obstruction (LVOTO) after biventricular repair of double outlet right ventricle (DORV) may develop. This report presents our 10-yr experience with surgical management of LVOTO after biventricular repair of DORV. Between 1996 and 2006, 15 patients underwent reoperation for subaortic stenosis after biventricular repair of DORV. The mean age at biventricular repair was 23.3±18.3 months (1.1-64.2). Biventricular repairs included tunnel constructions from the left ventricle to the aorta in 14 cases and an arterial switch operation in one. The mean left ventricle-to-aorta peak pressure gradient was 54.0±37.7 mmHg (15-140) after a mean follow-up of 9.5±6.3 yr. We performed extended septoplasty in nine patients and fibromuscular resection in six. There were no early or late mortality. There was one heart block and one aortic valve injury after an extended septoplasty, and two and one after a fibromuscular resection. No patient required reoperation for recurrent subaortic stenosis. The mean pressure gradient was 11.2±11.4 mmHg (0-34) after a mean follow-up of 5.6±2.7 yr. Extended septoplasty is a safe and effective method for the treatment of subaortic stenosis, especially in cases with a long-tunnel shaped LVOTO.
DORV; Aortic Stenosis, Subvalvular
OBJECTIVE—To analyse the spectrum of congenital heart malformations, the frequency of extracardiac malformations, and the proportion of chromosome aberrations among fetuses sent for necropsy.
MATERIAL—Necropsies were performed on 815 fetuses—448 induced abortions (55%), 220 spontaneous abortions (27%), and 147 stillbirths (18%)—during a seven year period (1991-97) in the department of pathology of the Charité Medical Centre in Berlin. A congenital heart defect was identified in 129 cases (16%). For all 129 fetuses, karyotyping and an ultrasound examination had been performed.
RESULTS—Congenital heart defects were present in 22% of induced abortions (99 cases), 9% of spontaneous abortions (20 cases), and 7% of stillbirths (10 cases). The heart malformations were classified into 13 categories. A fetus with more than one defect was included only in the category of the most serious defect. The malformations in order of frequency were: ventricular septal defect (VSD) (28%), atrioventricular septal defect (AVSD) (16%), hypoplastic left heart (HLH) (16%), double outlet right ventricle (DORV) (12%), coarctation of the aorta (CoA) (6%), transposition of the great arteries (TGA) (4%), aortic valve stenosis (AoVS) (4%), tetralogy of Fallot (TOF) (3%), truncus arteriosus communis (TAC) (3%), pulmonary valve stenosis/pulmonary valve atresia (PaVS/PaVA) (3%), tricuspid atresia (TA) (3%), single ventricle (SV) (1.5%), and atrial septal defect (ASD) (0.5%). The most common congenital heart defects were VSD, AVSD, HLH, and DORV, which made up 72% of all the cases. In 11 cases the heart defect was isolated (no other cardiovascular or extracardiac malformations present), 85 cases (66%) were associated with additional cardiac malformations, 85 cases (66%) were associated with extracardiac malformations, and chromosome anomalies were detected in 43 cases (33%).
CONCLUSIONS—Fetal congenital heart malformations are common. These defects are often associated with other cardiovascular and extracardiac malformations, as well as with chromosome anomalies. Complex heart defects such as AVSD, HLH, and DORV are frequent in fetuses, as they often lead to spontaneous abortion or stillbirth or, after prenatal diagnosis, to deliberate termination of pregnancy.
Keywords: congenital heart defects; extracardiac malformations; chromosomal abnormalities; necropsy examination
Reconstruction of branch pulmonary arteries (PAs) can be challenging in redo congenital heart surgeries. Treatment options like percutaneous stent implantation and surgical patch angioplasty may yield suboptimal results. We present our experience with hybrid intraoperative stenting which may be an effective alternative option.
We retrospectively analyzed data of all patients with PA stenosis who underwent intraoperative PA branch stenting in our institution between January 2011 and December 2012.
Ten patients [6 females, median age 10 (1.4 to 37) years], underwent hybrid stenting of the PA. Primary cardiac diagnoses were pulmonary atresia with ventricular septal defect (VSD) in three patients, pulmonary atresia with intact ventricular septum in two, Tetralogy of Fallot (TOF) in one, Double outlet right ventricle (DORV) with pulmonary stenosis (PS) in one, complex single ventricle in two and VSD with bilateral branch PA stenosis in one patient. Concomitant surgeries were revision/reconstruction of RV-PA conduit in 4, Fontan completion in 4, repair of TOF with conduit placement in 1 and VSD closure in 1 patient. The left PA was stented in 7, the right in 2 and both in 1, with a total of 11 stents. There were no complications related to stent implantation. Two early postoperative deaths were unrelated to stent implantation. At mean follow-up period of 14.8 (12–26) months, stent position and patency were satisfactory in all survivors. None of them needed repeat dilatation or surgical reintervention.
Hybrid stenting of branch PA is a safe and effective option for PA reconstruction in redo cardiac surgeries. With meticulous planning, it can be safely performed without fluoroscopy.
Pulmonary artery; Hybrid; Redo surgery; Stent
To evaluate the feasibility and diagnostic accuracy of retrospective electrocardiographically (ECG)-gated dual-source computed tomography (DSCT) for the assessment of double outlet right ventricle (DORV) and associated multiple malformations in pediatric patients.
Materials and Methods
Forty-seven patients <10 years of age with DORV underwent retrospective ECG-gated DSCT. The location of the ventricular septal defect (VSD), alignment of the two great arteries, and associated malformations were assessed. The feasibility of retrospective ECG-gated DSCT in pediatric patients was assessed, the image quality of DSCT and the agreement of the diagnosis of associated malformations between DSCT and transthoracic echocardiography (TTE) were evaluated, the diagnostic accuracies of DSCT and TTE were referred to surgical results, and the effective doses were calculated.
Apart from DORV, 109 associated malformations were confirmed postoperatively. There was excellent agreement (κ = 0.90) for the diagnosis of associated malformations between DSCT and TTE. However, DSCT was superior to TTE in demonstrating paracardiac anomalies (sensitivity, coronary artery anomalies: 100% vs. 80.00%, anomalies of great vessels: 100% vs. 88.57%, separate thoracic and abdominal anomalies: 100% vs. 76.92%, respectively). Combined with TTE, DSCT can achieve excellent diagnostic performance in intracardiac anomalies (sensitivity, 91.30% vs. 100%). The mean image quality score was 3.70 ± 0.46 (κ = 0.76). The estimated mean effective dose was < 1 mSv (0.88 ± 0.34 mSv).
Retrospective ECG-gated DSCT is a better diagnostic tool than TTE for pediatric patients with complex congenital heart disease such as DORV. Combined with TTE, it may reduce or even obviate the use of invasive cardiac catheterization, and thus expose the patients to a much lower radiation dose.
The surgical management of transposition complex with aortic arch obstruction remains technically demanding due to anatomic complexity. Even in the recent surgical era, there are centers that address this anomaly with a staged strategy. This report presents our experiences with a one-stage repair of transposition complexes with aortic arch obstructions more than the last 10 years. Since 2003, 19 patients with a transposition of the great arteries (TGA, 2 patients) or a double outlet of the right ventricle (DORV, 17 patients) and aortic arch obstruction have undergone one-stage repair of their anomalies. The mean age was 6.7 ± 2.3 days, and the mean body weight was 3.4 ± 0.3 kg. The 2 patients with TGA exhibited coarctation of the aorta. The 17 patients with DORV all exhibited the Taussig–Bing type. The great artery relationships were anteroposterior in 4 patients (21.1 %). The coronary artery anatomies were usual (1LCx; 2R) in 8 patients (42.1 %). There were 2 early deaths (10.5 %). Seven patients (36.8 %) required percutaneous interventions. One patient required re-operation for pulmonary valvar stenosis and left pulmonary artery patch angioplasty. The overall survival was 84.2 %. The freedom from mortality was 83.5 % at 5 years, and the freedom from intervention was 54.4 % at 5 years. The one-stage repair of transposition complexes with aortic arch obstructions resulted in an acceptable survival rate and a relatively high incidence of postoperative catheter interventions. Postoperative catheter interventions are highly effective. Transposition complexes combined with aortic arch obstructions can be managed by one-stage repair with good early and midterm results.
Transposition of the great vessels; Double outlet right ventricle; Aortic coarctation; Interruption of aortic arch
Maternal phenylketonuria (MPKU) is a syndrome including cardiovascular malformations (CVMs), microcephaly, intellectual impairment, and small for gestational age, caused by in-utero exposure to elevated serum phenylalanine (Phe) due to PKU in the mother. It is becoming a public health concern as more women with PKU reach child bearing age. Although a mouse model of PKU, BTBR Pahenu2, has been available for 20 years, it has not been well utilized for studying MPKU. We used this model to delineate critical parameters in Phe cardiovascular teratogenicity and study the effect of genetic background. Dosing and timing experiments were performed with the BTBR Pahenu2 mouse. A dose response curve was noted, with CVM rates at maternal serum Phe levels <360 μM (control), 360 – 600 μM (low), 600 – 900 μM (mid), and >900μM (high) of 11.86%, 16.67%, 30.86%, and 46.67% respectively. A variety of CVMs were noted on the BTBR background, including double outlet right ventricle (DORV), aortic arch artery (AAA)abnormalities, and ventricular septal defects (VSDs). Timed exposure experiments identified a teratogenic window from embryonic day 8.5-13.5, with higher rates of conotruncal and valve defects occurring in early exposure time and persistent truncus arteriosus (PTA) and aortic arch branching abnormalities occurring with late exposure. Compared to the BTBR strain, N10+ Pahenu2 congenics on the C3H/HeJ background had higher rates of CVMs in general and propensity to left ventricular outflow tract (LVOT) malformations, while the C57B/L6 background had similar CVM rates but predominately AAA abnormalities. We have delineated key parameters of Phe cardiovascular teratogenicity, demonstrated the utility of this MPKU model on different mouse strains, and shown how genetic background profoundly affects the phenotype.
We report the cases of 2 pediatric patients who had Shone complex. Each child had severe left ventricular outflow tract obstruction and marginal mitral obstruction, and both underwent the Ross-Konno operation. The mitral valve was left alone. Both patients survived the operations, and serial follow-up echocardiography up to 4 years later showed a decreased or decreasing trend in the peak mitral diastolic velocity. The Ross-Konno procedure can be an acceptable approach for a subgroup of patients who have Shone complex.
Aortic valve stenosis/congenital/surgery; cardiac surgical procedures/methods; child, preschool; heart defects, congenital/mortality/pathology/surgery; mitral valve/abnormalities/pathology/surgery; reoperation; risk assessment; treatment outcome; ventricular outflow obstruction/complications/congenital/surgery
The optimal surgical approach for complex aortic coarctation or an interrupted aortic arch with associated intracardiac defects is not universally agreed upon. We reviewed our experience with 18 consecutive patients (10 with coarctation, 8 with interrupted aortic arch) undergoing a 1-stage repair through median sternotomy between September of 1995 and February of 1997. Age at operation ranged from 3 days to 3 months (mean 23 days) and weight ranged from 1,700 g to 5,100 g (mean 3,350 g). Under hypothermic circulatory arrest, the aortic arch was reconstructed using native tissue-tissue anastomoses, and coexisting intracardiac anomalies were repaired by standard techniques. All patients survived the procedure and were ultimately discharged from the hospital. There were 2 late deaths in the interrupted aortic arch group, 1 during reoperation for subaortic stenosis and the other from noncardiac causes 5 months after discharge. Another interrupted aortic arch patient required a Ross-Konno procedure 8 months later. There has been no recoarctation among the 16 survivors. Thus a 1-stage repair for complex aortic arch obstruction in neonates can be accomplished with low operative risk, although long-term outcome is strongly influenced by the presence of subaortic obstruction.
Thirty-two patients with double outlet right ventricle (DORV) were studied between 1960 and 1976. Associated congenital defects frequently compounded the difficulty of clinical diagnosis. Cardiac catheterisation was performed in 27 patients, and the ventriculograms were studied with particular regard to the relative positions of the great vessels to each other and to the ventricular septal defect. These relationships determine which corrective operation is possible. Correction has been performed in 12 patients with a perioperative mortality of 25%. Although mitral-aortic discontinuity was demonstrated in all cases, consideration of the anatomical spectrum included in the term DORV suggests that discontinuity is not an essential feature. In common with other clinical data and in contrast with necropsy studies, none of our patients was found to show the normal relationship of the great vessels to each other, in which the aorta lies posterior and to the right of the pulmonary artery. The reason for this difference between the clinical and necropsy findings is not apparent. A similar disparity was shown with regard to pulmonary stenosis, which was demonstrated at catheterisation in 68% of the 27 patients (mean gradient 68 +/- 3 mmHg), in contrast with incidences of 18% and 25% in recent necropsy series. Patients in the necropsy studies were frequently neonates or infants, in whom death may have been the result of intractable cardiac failure secondary to excessive pulmonary blood flow. In older patients without pulmonary stenosis and with pulmonary hypertension, frequent observation is imperative so that surgical treatment can be instituted before the development of irreversible pulmonary vascular disease.
Here, we report a rare case of a 23-year-old term parturient with Eisenmenger syndrome due to Taussig–Bing anomaly presenting with gestational hypertension, oligohydramnios, and intrauterine growth retardation posted for elective cesarean section. Preoperatively, echocardiography of the patient was suggestive of double-outlet right ventricle (DORV) with large sub-pulmonic ventricular septal defect (VSD), right ventricular hypertrophy, bidirectional shunt and severe pulmonary artery hypertension. The surgery was successfully performed under a graded segmental epidural anesthesia with 2% lignocaine. Further contrast-enhanced computer tomography scan was done postoperatively and a diagnosis of Taussig–Bing anomaly (DORV with sub-pulmonic VSD) with transposition of the great arteries physiology was made. This is one of the rare cases of anesthetic management for cesarean section in a parturient with uncorrected Taussig–Bing anomaly being reported.
Caesarean section; segmental epidural anesthesia; Taussig-Bing anomaly
Total surgical correction of a Taussig-Bing type double outlet right ventricle (DORV) was successfully performed in a severely cyanotic 3-year-old girl. The malformation was associated with bilateral conus, d-transposition of the great arteries, d-loop, and a subpulmonary ventricular septal defect (VSD) without significant pulmonary stenosis in situs solitus. It was impossible to create a tunnel repair by resecting the markedly hypertrophied muscular conus that separated the aortic valve from the subpulmonary ventricular septal defect. Therefore, the VSD was repaired with a Dacron patch, transforming the double outlet right ventricle into a transposition, after which total correction was achieved by means of a Mustard procedure.
The basic helix-loop-helix DNA binding protein Hand2 has critical functions in cardiac development both in neural crest-derived and mesoderm-derived structures. Targeted deletion of Hand2 in the neural crest has allowed us to genetically dissect Hand2-dependent defects specifically in outflow tract and cardiac cushion independent of Hand2 functions in mesoderm-derived structures. Targeted deletion of Hand2 in the neural crest results in misalignment of the aortic arch arteries and outflow tract, contributing to development of double outlet right ventricle (DORV) and ventricular septal defects (VSD). These neural crest-derived developmental anomalies are associated with altered expression of Hand2-target genes we have identified by gene profiling. A number of Hand2 direct target genes have been identified using ChIP and ChIP-on-chip analyses. We have identified and validated a number of genes related to cell migration, proliferation/cell cycle and intracellular signaling whose expression is affected by Hand2 deletion in the neural crest and which are associated with development of VSD and DORV. Our data suggest that Hand2 is a multifunctional DNA binding protein affecting expression of target genes associated with a number of functional interactions in neural crest-derived cells required for proper patterning of the outflow tract, generation of the appropriate number of neural crest-derived cells for elongation of the conotruncus and cardiac cushion organization. Our genetic model has made it possible to investigate the molecular genetics of neural crest contributions to outflow tract morphogenesis and cell differentiation.
Hand2(dHand); neural crest; bHLH; heart; outflow tract; cardiac cushion; cell type-specific gene regulation; gene microarray
The aim of this study was to review the early and mid-term outcomes of the total cavopulmonary connection (TCPC) procedure and evaluate risk factors for prolonged pleural effusions.
The clinical records of 82 consecutive patients, who underwent a TCPC operation between January 2008 and December 2013, were reviewed for incidence of prolonged pleural effusions, duration of ventilation time and pleural drainage, length of intensive care unit (ICU) stay, and early and mid-term morbidity and mortality.
The median age at surgery was 3.0 years. The main single ventricle diagnoses included 18 cases of a double-inlet single ventricle, 17 cases of heterotaxy, 16 cases of tricuspid atresia, 4 cases of mitral atresia, 12 cases of unbalanced complete atrioventricular canal (CAVC), 5 cases of double-outlet right ventricle (DORV) combined with ventricular septal defect (VSD) and pulmonary stenosis (PS), 4 cases of transposition of the great arteries (TGA) combined with VSD and PS, 4 cases of corrected transposition of great arteries (cTGA) combined VSD and PS, and 2 cases of criss-cross heart. Preoperative mean pulmonary artery pressure (mPAP) was 13.66±2.21 mmHg with 23.2% (n=19) higher than 15 mmHg. A total of 61 (74.4%) patients underwent a fenestration. The perioperative mortality was 4.9%. The median duration of pleural effusion was 10 days (range, 3−80 days), and prolonged pleural effusions occurred in 16 (19.5%) patients. Multivariable analysis revealed that mPAP >15 mmHg was independently associated with prolonged pleural effusions (OR, 8.33; 95% CI, 2.33−29.74; P=0.001), and creation of a fenestration was associated with decreased odds of effusion (OR, 0.21; 95% CI, 0.06−0.74; P=0.015). Five-year estimated Kaplan-Meier survival of two-stage TCPC was significantly higher than that of one-stage group(96.7% vs. 79.7%, P=0.023). Patients with heterotaxy or obstructed totally anomalous pulmonary venous connection (TAPVC) had significantly worse mid-term survival.
Staged TCPC improved the early and mid-term survival of patients with a single ventricle. mPAP >15 mmHg was independently associated with prolonged pleural effusions and a fenestration significantly associated with a lower odds of effusion.
Total cavopulmonary connection (TCPC); outcomes; heterotaxy; totally anomalous pulmonary venous connection (TAPVC); fenestration
Aortic translocation, although technically demanding, could be an excellent surgical option for d-transposition of the great vessels and left ventricular outflow tract obstruction. We report a modification of the aortic translocation technique that uses autologous tissue. The aortic root is mobilized from the right ventricle with an extension of infundibular free-wall muscle for use in closure of the ventricular septal defect, which is similar to the technique for harvesting pulmonary autograft in the Ross-Konno procedure. Our modification may offer an even better surgical outcome for aortic translocation.
Abnormalities, multiple/surgery; aorta/surgery; cardiac surgical procedures; heart ventricles/surgery; transposition of great vessels/surgery
OBJECTIVE--The aim was to define the long term prognosis of isolated ventricular septal defect (VSD) with anteriorly malaligned outlet septum. DESIGN--Cohort study. SETTING--University hospital, tertiary medical care centre. PATIENTS--Between July 1986 and June 1993, 63 patients were studied with an isolated VSD and anteriorly malaligned outlet septum (59 perimembranous; 4 muscular outlet). MAIN OUTCOME MEASURES--The diagnosis of septal malalignment, aneurysmal transformation, right ventricular obstruction, subaortic ridge, and aortic valve prolapse was based on echocardiographic criteria, then confirmed by angiography in 33 patients and by surgery in 28. An actuarial curve for each event was obtained by Kaplan-Meier non-parametric analysis and the significance was examined by log-rank test. RESULTS--Aneurysmal transformation decreased the size of the VSD in 52% of the patients, but was also associated with the appearance of subaortic ridge (p < 0.05). Progressive obstruction in the right ventricle was observed in 51%, more often in those without aneurysmal transformation (p < 0.05). Aortic valve prolapse was quite common whether or not aneurysmal transformation occurred (33% and 23%, respectively). This was attributed to the location of the VSD and the anterior malalignment of the outlet septum. Surgery was performed in 28 patients at a median age of 50 months because of significant left to right shunt (n = 5), or the development of obstruction in right ventricle (n = 9), aortic valve prolapse (n = 3), or combinations (n = 11). The presence of subaortic ridge per se was not considered to be a surgical indication. CONCLUSIONS--Anteriorly malaligned VSDs have variable presentation. Careful echocardiographic evaluation is needed to identify various combinations of progressive right ventricular obstruction, aneurysmal transformation, subaortic ridge, or aortic valve prolapse. In extreme cases a patient may have a pathology complex comprising right ventricular outflow obstruction, subaortic ridge, aortic valve prolapse, and anteriorly malaligned VSD.
Congenital heart disease (CHD) is the most common developmental abnormality, and is the leading noninfectious cause of mortality in neonates. Increasing evidence demonstrates that genetic defects play an important role in the pathogenesis of CHD. However, CHD exhibits substantial heterogeneity, and the genetic determinants for CHD remain unknown in the overwhelming majority of cases. In the current study, the coding exons and flanking introns of the HAND2 gene, which encodes a basic helix-loop-helix transcription factor essential for normal cardiovascular development, were sequenced in 192 unrelated patients with CHD, and a novel heterozygous mutation, p.S65I, was identified in a patient with congenital ventricular septal defect (VSD). Genetic analysis of the index patient’s pedigree revealed that the mutation was present in all seven affected family members available, but absent in the 13 unaffected family members examined. Besides, in addition to VSD, five of the proband’s close relatives also had pulmonary stenosis (PS), and the proband’s son also had double outlet right ventricle (DORV). The missense mutation, which altered an evolutionarily conserved amino acid, was absent in 300 unrelated, ethnically matched healthy individuals. Biological analyses using a dual-luciferase reporter assay system showed that the mutant HAND2 was associated with significantly diminished transcriptional activity. Furthermore, the mutation abolished the synergistic activation between HAND2 and GATA4, as well as NKX2.5—two other cardiac core transcriptional factors that have been causally linked to CHD. These findings indicate that HAND2 loss-of-function mutation contributes to human CHD, perhaps via its interaction with GATA4 and NKX2.5.
congenital heart disease; genetics; transcription factor; HAND2; reporter gene assay
Cardiac left ventricular outflow tract (LVOT) defects represent a common but heterogeneous subset of congenital heart disease for which gene identification has been difficult. We describe a 46,XY,t(1;5)(p36.11;q31.2)dn translocation carrier with pervasive developmental delay who also exhibited LVOT defects, including bicuspid aortic valve (BAV), coarctation of the aorta (CoA) and patent ductus arteriosus (PDA). The 1p breakpoint disrupts the 5′ UTR of AHDC1, which encodes AT-hook DNA-binding motif containing-1 protein, and AHDC1-truncating mutations have recently been described in a syndrome that includes developmental delay, but not congenital heart disease [Xia, F., Bainbridge, M.N., Tan, T.Y., Wangler, M.F., Scheuerle, A.E., Zackai, E.H., Harr, M.H., Sutton, V.R., Nalam, R.L., Zhu, W. et al. (2014) De Novo truncating mutations in AHDC1 in individuals with syndromic expressive language delay, hypotonia, and sleep apnea. Am. J. Hum. Genet., 94, 784–789]. On the other hand, the 5q translocation breakpoint disrupts the 3′ UTR of MATR3, which encodes the nuclear matrix protein Matrin 3, and mouse Matr3 is strongly expressed in neural crest, developing heart and great vessels, whereas Ahdc1 is not. To further establish MATR3 3′ UTR disruption as the cause of the proband's LVOT defects, we prepared a mouse Matr3Gt-ex13 gene trap allele that disrupted the 3′ portion of the gene. Matr3Gt-ex13 homozygotes are early embryo lethal, but Matr3Gt-ex13 heterozygotes exhibit incompletely penetrant BAV, CoA and PDA phenotypes similar to those in the human proband, as well as ventricular septal defect (VSD) and double-outlet right ventricle (DORV). Both the human MATR3 translocation breakpoint and the mouse Matr3Gt-ex13 gene trap insertion disturb the polyadenylation of MATR3 transcripts and alter Matrin 3 protein expression, quantitatively or qualitatively. Thus, subtle perturbations in Matrin 3 expression appear to cause similar LVOT defects in human and mouse.
Congenital heart defects (CHD) represent the most common human birth defects. Even though the genetic cause for these syndromes has been linked to respective candidate genes, the underlying molecular mechanisms are still largely unknown. Disturbance of neural crest cell (NCC) migration into the derivatives of the pharyngeal arches and pouches can account for many of the developmental defects.
To investigate the function of miRNA in NCCs and cardiovascular system.
Methods and Results
we deleted Dicer from neural crest cell (NCC) lineage and showed that Dicer conditional mutants exhibit severe defects in multiple craniofacial and cardiovascular structures, many of them are observed in human NCCS patients. We found that cranial NCCs require Dicer for their survival and deletion of Dicer led to massive cell death and complete loss of NCC-derived craniofacial structures. In contrast, Dicer and miRNAs were not essential for the survival of cardiac NCCs. However, the migration and patterning of these cells were impaired in Dicer knockout mice, resulting in a spectrum of cardiovascular abnormalities, including Type B Interrupted Aortic Arch (IAA-B), Double Outlet Right Ventricle (DORV) and Ventricular Septal Defect (VSD). We show that Dicer loss-of-function was, at least in part, mediated by miR-21 and miR-181a, which in turn, repressed the protein level of Sprouty 2, an inhibitor of Erk1/2 signaling.
Our results uncovered a central role for Dicer and miRNAs in neural crest cells survival, migration and patterning in craniofacial and cardiovascular development which, when mutated, lead to congenital neuro-craniofacial-cardiac defects.
microRNAs; neural crest cells; Dicer; cardiovascular development
SMAD4 acts as the converging point for TGFβ and BMP signaling in heart development. Here, we investigated the role of SMAD4 in heart development using a novel α skeletal muscle actin Cre recombinase (MuCre) transgenic mouse strain. Lineage tracing using MuCre/ROSA26LacZ reporter mice indicated strong Cre-recombinase expression in developing and adult heart and skeletal muscles. In heart development, significant MuCre expression was noted at E11.5 in the atrial, ventricular, outflow tract and atrioventricular canal myocardium, but not in the endocardial cushions. MuCre-driven conditional deletion of Smad4 in mice caused double outlet right ventricle (DORV), ventricular septal defect (VSD), impaired trabeculation and thinning of ventricular myocardium, and mid-gestational embryonic lethality. In conclusion, MuCre mice effectively delete genes in both heart and skeletal muscles, thus enabling the discovery that myocardial Smad4 deletion causes misalignment of the outflow tract and DORV.
heart; myogenesis; transforming growth factor beta; SMAD; Marfan syndrome.
In three infant cases of double outlet right ventricle (DORV), two with normally related great arteries (NGA) and one with side-by-side great arteries, a transatrial repair was carried out. In all three cases, the results were excellent. It is concluded that in the small baby with DORV with NGA and in DORV with side-by-side great arteries with a hypoplastic crista, a transatrial repair should be successful. This is dependent on the VSD being in the perimembranous (and, therefore, subaortic) location and on the absence of infundibular pulmonary stenosis. In all other varieties of DORV the repair should probably be done through the ventricle.
OBJECTIVE--To compare the incidence and prognosis of subaortic stenosis associated with a ventricular septal defect and to define the morphological basis of subaortic stenosis. DESIGN--Presentation and follow up data on 202 patients with subaortic stenosis seen at the Royal Liverpool Children's Hospital between 1 January 1960 and 31 December 1991 were reviewed. Survivors were traced to assess their current clinical state. Necropsy specimens of 291 patients with lesions associated with subaortic stenosis were also examined. RESULTS--In the clinical study; 65 (32.1%) of the 202 patients with subaortic stenosis had a ventricular septal defect (excluding an atrioventricular septal defect). 32 of these patients had a short segment (fibromuscular) subaortic stenosis. 33 had subaortic stenosis produced by deviation of muscular components of the outflow tracts. In 17 patients (51.5%) this was caused by posterior deviation or extension of structures into the left ventricular outflow tract, resulting in obstruction above the ventricular septal defect. In the other 16 patients (48.5%) there was over-riding of the aorta with concordant ventriculoarterial connections, (without compromise to right ventricular outflow) producing subaortic stenosis below the ventricular septal defect. Additional fibrous obstruction occurred in 39% of the patients with deviated structures. The age at presentation was lower (P < 0.01) in patients with deviated structures (median (range) 0.4 (0 to 9.2) months) than in those with short segment obstruction (median (range) 4.2 (0 to 84.9) months). The incidence of aortic arch obstruction was higher (P < 0.002) in patients with deviated structures than in those with short segment obstruction (38%). In the morphological study 35 pathological specimens showed obstructive muscular structures in the left ventricular outflow tract either above or below the ventricular septal defect. 16 had either posterior deviation of the outlet septum or extension of the right ventriculoinfundibular fold, or both of these together into the left ventricle. 19 had anterior deviation of the outlet septum into the right ventricle with overriding of the aorta (without compromise to right ventricular outflow). The earliest age at which additional fibrous obstruction was seen was 9 months. The aortic valve circumference was small in 18% of specimens. FOLLOW UP--The median (range) duration of follow up in survivors from the clinical study was 6.6 (1 to 25.7) years. 16 patients with deviated musculature (49%) and 16 with short segment fibromuscular stenosis (50%) underwent operation for subaortic stenosis. Patients with deviated structures were younger at operation than those with short segment stenosis (P < 0.005). Patients with posterior deviation or extension of structures into the left ventricular outflow tract underwent operation for subaortic stenosis more frequently (P < 0.05) than those with anterior deviation of the outlet septum and aortic override. The ventricular septal defect required surgical closure more frequently (P < 0.005) in patients with deviation (93.9%) than in those with short segment obstruction (21.9%). There was no significant difference in the mortality between patients with deviation (27%) and those with short segment obstruction (12%). CONCLUSIONS--32% of patients in the clinical study with subaortic stenosis had a ventricular septal defect. Only 51% of these had obstructive and deviated muscular structures in the left ventricular outflow tract. These patients had a significantly higher incidence of aortic arch obstruction and required surgery for subaortic stenosis at a younger age than those with short segment obstruction. The ventricular septal defect also required surgical closure more frequently in those patients with deviation. The morphological study defined the two sites of obstruction. The presence or absence and type of deviation should be clearly defined in all patients with a ventricular septal defect,