Cardiac neural crest ablation results in early endocardial cushion and hemodynamic flow abnormalities.

Cardiac neural crest cell (CNCC) ablation creates congenital heart defects (CHDs) that resemble those observed in many syndromes with craniofacial and cardiac consequences. The loss of CNCCs causes a variety of great vessel defects, including persistent truncus arteriosus and double-outlet right ventricle. However, because of the lack of quantitative volumetric measurements, less severe defects, such as great vessel size changes and valve defects, have not been assessed. Also poorly understood is the role of abnormal cardiac function in the progression of CNCC-related CHDs. CNCC ablation was previously reported to cause abnormal cardiac function in early cardiogenesis, before the CNCCs arrive in the outflow region of the heart. However, the affected functional parameters and how they correlate with the structural abnormalities were not fully characterized. In this study, using a CNCC-ablated quail model, we contribute quantitative phenotyping of CNCC ablation-related CHDs and investigate abnormal early cardiac function, which potentially contributes to late-stage CHDs. Optical coherence tomography was used to assay early- and late-stage embryos and hearts. In CNCC-ablated embryos at four-chambered heart stages, great vessel diameter and left atrioventricular valve leaflet volumes are reduced. Earlier, at cardiac looping stages, CNCC-ablated embryos exhibit abnormally twisted bodies, abnormal blood flow waveforms, increased retrograde flow percentage, and abnormal cardiac cushions. The phenotypes observed in this CNCC-ablation model were also strikingly similar to those found in an established avian fetal alcohol syndrome model, supporting the contribution of CNCC dysfunction to the development of alcohol-induced CHDs.

The Natural History of Atrioventricular Valve Regurgitation Throughout Fetal Life in Patients with Atrioventricular Canal Defects.

Atrioventricular valve regurgitation (AVVR) influences morbidity and mortality in the atrioventricular canal defect (AVC). Fetal cardiac structures are subject to hemodynamic changes, as well as growth and maturation during gestation, which may alter the degree of AVVR and affect prognosis. We sought to investigate the frequency of change in degree of AVVR documented by fetal echocardiography (echo) between different periods of gestational age. Subjects with AVC seen in the Fetal Heart Program between January 2008 and September 2010 were identified. Degree of AVVR was assessed by color Doppler imaging and categorized as Grade 0 (no AVVR), Grade 1 (hemodynamically insignificant AVVR = trivial or mild), and Grade 2 (hemodynamically important AVVR = ≥moderate). Levels of AVVR between periods were compared. Forty-three fetuses were analyzed. Overall, 60% had no change, 14% had a decrease, and 26% had an increase in AVVR grade. Two fetuses progressed from Grade 0 or 1 to Grade 2, while one fetus decreased from Grade 2 to Grade 0. Trisomy 21 and heterotaxy syndrome were not risk factors for AVVR progression. Transitional and incomplete canal defects may be more susceptible to AVVR progression. Sixty percent of fetuses with AVC will not exhibit progression of AVVR between the second and third trimesters of gestation. In those who exhibit change, it is most often within a hemodynamically insignificant range between none and mild regurgitation (Grades 0 and 1). These findings have implications for the counseling, follow-up, and delivery plans of the fetus with AVC defect.

Early Complete Atrioventricular Canal Repair Yields Outcomes Equivalent to Late Repair.

BACKGROUND: Repair of complete atrioventricular canal early in infancy has traditionally carried greater morbidity and mortality than repair performed later. However, an individualized anatomy-based repair may give young infants outcomes that are equivalent to older patients. METHODS: We retrospectively reviewed 139 patients who underwent complete atrioventricular canal repair from January 2005 to December 2012. An individualized approach was used: 2-patch repair was performed in 98 patients for large ventricular septal defects and a modified single-patch ("Australian technique") was used in 41 for "shallow" ventricular septal defects. RESULTS: The average age was 25.5 ± 3.9 weeks, 50% were boys, and 78% had trisomy 21. Mean follow-up was 5.1 ± 0.2 years, with 100% completeness of data. There were 3 in-hospital deaths (2.1%) and 1 late death (0.7%). A permanent pacemaker was required in 2 patients (1.4%). The rate for left atrioventricular valve reoperation was 8% at a mean of 211 ± 238 days after the original repair (range, 6 to 682 days). Compared with patients aged older than 3 months, the 39 patients (28%) who were younger than 3 months had similar perioperative courses and rate of reoperation. Compared with patients with an Australian repair, the 98 patients (71%) with a 2-patch repair were more likely to have trisomy 21 and had slightly increased cardiopulmonary bypass and cross-clamp times but similar outcomes. Multivariate analysis showed postoperative left atrioventricular valve regurgitation greater than 2 and left ventricular outflow tract obstruction were significant risk factors for reoperation on the left atrioventricular valve (both p < 0.05). CONCLUSIONS: Repair of complete atrioventricular canal using an individualized surgical approach yields reoperation and early mortality rates similar for younger infants compared with older infants, obviating the need to delay operation in symptomatic patients.

Unique combination of atrioventricular septal defect with cor triatriatum and complete vascular ring.

Atrioventricular septal defect can present with one or more associated anomalies. Cor triatriatum (subdivided left atrium) and vascular rings are among the less frequent. We describe a two-month-old patient with these three cardiovascular anomalies. This case highlights the importance of exhaustive preoperative evaluation in order to achieve successful surgical correction in one stage.

Severe Left Atrioventricular Valve Regurgitation Due to Discontinuity between the Leaflets of the Aortic and Left Atrioventricular Valves in a Patient with Endocardial Cushion Defect: A Rare Case Report.

Discontinuities between the leaflets of the aortic and left atrioventricular valves are uncommon congenital malformations. The anomaly may be discovered during surgery without preoperative diagnosis. It represents a spectrum of anomalies that result from interruption of the normal development of the endocardial cushions during the fetal life. We describe a rare case of Down syndrome with transient complete atrioventricular block and discontinuity between the leaflets of the aortic and left atrioventricular valves without intervening fibrous band, leading to separation and detachment between them. It caused severe eccentric jet of regurgitation originated from left ventricular outflow tract and base of anterior leaflet of left atrioventricular valve into the left atrium. He underwent cardiopulmonary bypass, and the defect between left atrioventricular valve and aortic annuli was sewn. Permanent epicardial pacing was inserted during cardiac surgery. To the best of our knowledge, such a case has not been previously reported in the literature.

Echocardiographic features defining right dominant unbalanced atrioventricular septal defect: a multi-institutional Congenital Heart Surgeons' Society study.

BACKGROUND: Definition and management of right dominant unbalanced atrioventricular septal defect (AVSD) remains challenging because unbalance entails a spectrum of left heart hypoplasia. Previous work has highlighted atrioventricular valve (AVV) index as a reasonable defining echocardiographic measure. We sought to assess which additional echocardiographic features might provide further characterization. METHODS AND RESULTS: From a multi-institutional cohort of complete AVSD, 52 preoperative echocardiograms of patients with presumed right dominant unbalanced AVSD (based on AVV index) and 60 randomly selected preoperative echocardiograms from patients with presumed balanced AVSD were reviewed. Cluster analysis of echocardiographic variables was used to group patients with similar features. Discriminant function analysis was used to explore which variables differentiated these groups. Three groups were identified from the cluster analysis. Echocardiographic variables that differentiated these groups were right ventricle:left ventricle inflow angle, LV width/LV length, left AVV color diameter at smallest inflow, left AVV color diameter at annulus, right AVV overriding left atrium, and LV width. Based on procedures and outcomes, 1 group likely represented balanced patients, whereas 2 groups with similar outcomes likely represented unbalanced patients. The dominant differentiating echocardiographic variable between the 3 cluster groups was the right ventricle:LV inflow angle (partial R²=0.86), defined as the angle between the base of the right ventricle and LV free wall, using the crest of the ventricular septum as apex of the angle. CONCLUSIONS: The angle of right ventricle/LV inflow and other surrogates of inflow may be important defining echocardiographic measures of right dominant unbalanced AVSD, although confirmation is needed.

Biventricular conversion after single-ventricle palliation in unbalanced atrioventricular canal defects.

BACKGROUND: Management of unbalanced common atrioventricular canal (UCAVC) defect by a single-ventricle (SV) approach frequently results in poor outcomes, especially in trisomy 21 patients. In this report we describe our results with conversion to biventricular circulation in UCAVC patients with SV palliation. METHODS: Retrospective review of patients with UCAVC undergoing biventricular conversion from prior SV palliation between 2003 and 2011 was conducted. Mortality and freedom from reinterventions were analyzed using nonparametric methods. RESULTS: Sixteen children with UCAVC (8 patients [50%] were left dominant) and prior SV palliation underwent conversion to biventricular circulation between 2003 and 2011. Median follow-up was 18 months (range, 3 to 94 months). Surgical indications included worsening cyanosis, severe atrioventricular valve regurgitation, or failing bidirectional Glenn or Fontan physiology. All patients had either unequal distribution of the common atrioventricular valve of greater than 60% or one hypoplastic ventricle. By magnetic resonance imaging or computed tomography, 8 patients with right dominant atrioventricular canal had a median left ventricular end-diastolic volume of 32 mL/m(2) (range, 22 to 35 mL/m(2)). Eight patients with a left dominant atrioventricular canal had a median right ventricular end-diastolic volume of 42 mL/m(2) (range, 26 to 64 mL/m(2)). Eleven patients (69%) had trisomy 21, and 3 patients (19%) had heterotaxy. Stages of palliation included stage I in 2 patients, bidirectional Glenn in 10 patients, hemi-Fontan in 2 patients, and Fontan in 2 patients. There was 1 (6%) operative (right ventricle dominant) and 1 (6%) late death (left ventricle dominant). Eight patients required reinterventions, 3 (19%) surgical and 6 (38%) catheter-based. On follow-up, all had improvement in cyanosis and symptoms. CONCLUSIONS: Biventricular conversion from failing SV palliation in UCAVC can be accomplished with an acceptable early and late morbidity and mortality, although need for reintervention was not uncommon.

64-Slice MDCT imaging of endocardial cushion defect associated with other cardiac and extracardiac abnormalities.

Electrocardiographic-gated 64-slice multidetector computed tomography (MDCT) was performed on a 30-year-old man who presented with a complete endocardial cushion defect (ECD) and severe pulmonary hypertension diagnosed when he was 3 years old. Multiplanar reconstruction image showed the common atrium without an atrial septum, a large ventricular septum defect, and a small right ventricle due to a complete atrioventricular canal defect. Three-dimensional CT volume-rending imaging showed a patent ductus arteriosus, dilation of the ascending aorta, and an anomalous-origin right coronary artery. This patient also had heterotaxy syndrome with polysplenia and azygos continuation. MDCT proved to be a good noninvasive imaging method for the evaluation of ECD associated with cardiac as well as extracardiac abnormalities.

Quantification of AS and AR.

Trans-esophageal echocardiography (TEE) is routinely used in valvular surgery in most institutions. The popularity of TEE stems from the fact that it can supplement or confirm information gained from other methods of evaluation or make completely independent diagnoses. Quantitative and qualitative assessment permits informed decisions regarding surgical intervention, type of intervention, correction of inadequate surgical repair and re-operation for complications. This review summarizes the various methods for quantification of aortic regurgitation and stenosis on TEE. The application of Doppler echo (pulsed wave, continuous wave and color) with two-dimensional echo allows the complete evaluation of AV lesions.

Understanding atrioventricular septal defect: anatomoechocardiographic correlation.

OBJECTIVE: Correlate the anatomic features of atrioventricular septal defect with echocardiographic images. MATERIALS AND METHODS: Sixty specimen hearts were studied by sequential segmental analysis. Echocardiograms were performed on 34 patients. Specimen hearts with findings equivalent to those of echocardiographic images were selected in order to establish an anatomo-echocardiographic correlation. RESULTS: Thirty-three specimen hearts were in situs solitus, 19 showed dextroisomerism, 6 were in situs inversus and 2 levoisomerism. Fifty-eight had a common atrioventricular valve and 2 had two atrioventricular valves. Rastelli types were determined in 21 hearts. Nine were type A, 2 intermediate between A and B, 1 mixed between A and B, 4 type B and 5 type C. Associated anomalies included pulmonary stenosis, pulmonary atresia atrial septal defect, patent ductus arteriosus and anomalous connection of pulmonary veins. Echocardiograms revealed dextroisomerism in 12 patients, situs solitus in 11, levoisomerism in 7 and situs inversus in 4. Thirty-one patients had common atrioventricular valves and three two atrioventricular valves. Rastelli types were established in all cases with common atrioventricular valves; 17 had type A canal defects, 10 type B, 3 intermediate between A and B, 1 mixed between A and B and 3 type C. Associated anomalies included regurgitation of the atrioventricular valve, pulmonary stenosis, anomalous connection of pulmonary veins, pulmonary hypertension and pulmonary atresia. CONCLUSION: Anatomo-echocardiographic correlation demonstrated a high degree of diagnostic precision with echocardiography.

Echocardiographic evaluation and surgical implications of common atrioventricular canal defects with absent or diminutive ostium primum defect.

Common atrioventricular canal defects without ostium primum defects are rare, and their accurate identification has important surgical implications. Retrospective echocardiographic database review identified subjects with common atrioventricular canal defects with absent or diminutive ostium primum defects. Surgical reports and initial and postoperative echocardiograms were reviewed to identify the imaging planes necessary to characterize this anomaly and the surgical challenges imposed by the diagnosis. Fourteen subjects were identified (93% with trisomy 21) with either absent (n = 6) or diminutive (n = 8) ostium primum defects. Malaligned conal septum was present in 50% of subjects with absent primum defects and 12.5% of subjects with diminutive defects. Immediate or long-term complications of the 11 postoperative patients included atrioventricular block (n = 4) and moderate (n = 5) or severe (n = 3) mitral regurgitation. In conclusion, echocardiographic features for the identification of common atrioventricular canal defects with absent or diminutive ostium primum defects are described. Surgical challenges involve attaining adequate exposure of the mitral component and achieving mitral valve competence.

[Prognosis of atrioventricular canal in euploid foetus without abnormality of atrial situs]. / Pronostic des canaux atrioventriculaires chez les foetus euploïdes sans anomalie du situs atrial.

Atrioventricular septal defects are commonly diagnosed during fetal life. Postnatal prognosis of atrioventricular septal defects associated with trisomy 21 and with heterotaxia sequences are relatively well known. However, predicting postnatal outcome in fetus with atrioventricular septal defects and normal chromosome and normal atrial situs remains a challenge. In a series of 141 fetal atrioventricular septal defects, we analyzed 80 fetuses with normal karyotype. Twenty-seven had an abnormal atrial situs. One fetus was lost for follow-up. Finally, 52 fetuses were included in the study. Termination of pregnancy was performed in 18 cases (34%). Six fetuses died in utero (18% of ongoing pregnancies). Twenty eight infants were born alive, 2 of them were lost for follow-up right after birth and 3 live born infants died postanatally (11%). Postoperative mortality was 3/15 (20%). Complete repair was proceed for 13 infants, palliative repair for 2; and 8 infants didn't have surgery at the end of follow-up because of partial or intermediate atrioventricular septal defect. The only factor significantly associated with poor outcome was the small size of the left ventricle. Isolated atrioventricular septal defects are of poor cardiac prognosis particularly when associated with left heart obstructions.

Common atrioventricular canal in a newborn foal--case report and review of the literature.

This paper presents the embryological and pathological features as well as the terminology and classification of common atrioventricular canal, a type of endocardial cushion defect. The authors give a complete description of an extremely rare congenital cardiac malformation in an equine neonate. The diagnosis of a complete, balanced common atrioventricular canal of type C in Rastelli's classification scheme was based on two-dimensional, contrast and colour Doppler echocardiography and subsequent postmortem gross pathology. To support our diagnosis and study the pathophysiological effect of the alteration, physical examination, blood gas analysis and other laboratory tests, electrocardiography and thoracic radiography were also performed. Our search of the literature suggests that this type of developmental anomaly might account for a higher percentage of equine congenital cardiac defects than was thought earlier. We suppose that some previously described congenital heart abnormalities were misinterpreted: these anomalies could have actually represented some type of atrioventricular canal defect, resulting from the failure of the endocardial cushions to undergo complete and proper fusion.

Partial atrioventricular septal defect assessed by real-time three-dimensional echocardiography: a case report.

A 48-year-old woman was admitted with a heart murmur and increased difficulty in breathing. Two-dimensional echocardiography revealed a defect in the lower part of the atrial septum [(primum atrial septal defect (ASD)] and a pouch at the interventricular septum. Color Doppler echocardiography detected grade 3/4 mitral regurgitation. Real-time three-dimensional echocardiography (RT-3DE) revealed a cleft in the anterior leaflet of the mitral valve toward the tricuspid valve, and the ASD located near the atrioventricular valves with 14mm in minor axis. Color Doppler three-dimensional echocardiography disclosed left-to-right ASD shunt toward the atrial posterior wall. No shunt through the pouch at the membranous part, left ventricular outflow obstruction, or partial anomalous pulmonary venous connection was observed. RT-3DE is quite useful to describe complicated congenital heart disease.

Biventricular repair of right-dominant complete atrioventricular canal defect.

Complete atrioventricular (AV) canal defects usually have right and left valve components of approximately equal size, although unbalanced forms do occur. Optimal management of unbalanced AV canal defects is controversial, with no proven guidelines for choosing between biventricular repair and univentricular palliation. We describe successful biventricular repair of a right-dominant unbalanced AV canal with severe left AV valve stenosis. This case illustrates that severely unbalanced AV canal defects can be repaired successfully by tailoring the AV valve to distribute it equally between the ventricles, The increase in left ventricular volume after surgery exceeded prediction based on conformational change alone.

Three-dimensional echocardiography improves the understanding of left atrioventricular valve morphology and function in atrioventricular septal defects undergoing patch augmentation.

OBJECTIVES: We sought to address the role of 3-dimensional echocardiography in the evaluation of the left atrioventricular valve in children with an atrioventricular septal defect who underwent patch augmentation of their valve for either regurgitation or left ventricular outflow tract obstruction. METHODS: Five children whose ages ranged between 4.5 and 9.2 years and who underwent patch augmentation of their left atrioventricular valve had a preoperative and postoperative transesophageal echocardiogram with 3-dimensional reconstruction to evaluate the left atrioventricular valve. The indication for operation was left atrioventricular valve regurgitation in 3 patients and left ventricular outflow tract obstruction in 2 patients. Three were rerepairs, and 2 were primary repairs. Both 3-dimensional morphology and color Doppler data were obtained. Two- and 3-dimensional findings were correlated with surgical observations through the use of direct inspection and video images obtained with a head-mounted super-VHS camera. RESULTS: In each case there was precise correlation between the 3-dimensional and surgical findings as to the cause of leaflet failure in those with regurgitation. The site that would require leaflet augmentation could be determined by means of 3-dimensional echocardiography. Three-dimensional echocardiography provided more specific detail as to the morphology and function of the left atrioventricular valve than did its 2-dimensional counterpart. CONCLUSIONS: Three-dimensional echocardiography provides detailed information about the status of the left atrioventricular valve in the atrioventricular septal defect and can aid in the planning of either primary or secondary repair.