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.

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 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.

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.

[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.

Fixed subaortic stenosis in atrioventricular canal defect: a Doppler echocardiographic study.

OBJECTIVES: The objectives of this retrospective study were to describe the Doppler and echocardiographic features of fixed subaortic stenosis in the setting of atrioventricular (AV) canal defect and to document the de novo occurrence of subaortic stenosis and progression of this lesion over time on the basis of sequential echocardiographic studies. BACKGROUND: The coexistence of fixed subaortic and AV canal defect has been sporadically noted, but no single or multicenter experience with this constellation of abnormalities has been previously described. METHODS: All patients with a diagnosis of subaortic stenosis and complete or partial AV canal defect who had one or more Doppler echocardiographic examinations were identified from a computer data bank. Retrospective analysis was performed, including review of patients' charts, operative notes, recorded videotapes and hard copy recordings when available. RESULTS: Twenty-one patients with both subaortic stenosis and AV canal defect were identified over a 13-year period. Fifteen were female and the mean age at diagnosis of subaortic stenosis was 16 years. Fifteen patients had partial AV canal defect with prior repair in 10; 6 patients had complete AV canal defect with prior repair in 4. The mean interval from prior repair to recognition of subaortic stenosis was 6.8 years. In six patients, serial examinations demonstrated the de novo occurrence of subaortic obstruction over a period of 10 to 87 months. In five patients, progression of known subaortic stenosis was documented over a 10- to 59-month period. Surgical resection of subaortic stenosis was performed in 16 patients; the echocardiographic diagnosis was confirmed in 15 of the 16. CONCLUSIONS: In the largest reported echocardiographic series of this lesion complex, it is concluded that subaortic stenosis can occur de novo, is often recognized only after repair of the canal defect and is progressive. Doppler echocardiography is the method of choice for diagnosis and serial follow-up of these patients.

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.

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.

Direct closure of the septum primum in atrioventricular canal defects.

OBJECTIVE: The objective of this study was to assess the safety of directly closing the septum primum during the correction of atrioventricular canal defects. METHODS: We performed a retrospective analysis of our experience with direct closure of the septum primum during the repair of atrioventricular canal defect. The series consisted of 28 consecutive patients presenting with a partial (15 patients) and complete (13 patients) atrioventricular canal defect. The cleft in the atrioventricular valve was closed completely in 25 patients and partially in 3 patients (those with a small left lateral leaflet). In complete atrioventricular canal, the ventricular septum defect was closed with a patch of polytetrafluoroethylene (Gore-Tex, W. L. Gore & Associates, Inc, Flagstaff, Ariz) or xenopericardium. Follow-up was complete and ranged from 3 to 21 months (median 11 months). RESULTS: There were no early or late deaths and no surgical complications. The septum primum defect was closed completely in all patients as assessed by echocardiography. All the patients were in sinus rhythmus, and none had even a temporary complete atrioventricular block. The surgical result and heart rhythm have remained stable over time. CONCLUSIONS: Direct closure of the septum primum is an easy, quick, and safe procedure during repair of atrioventricular defects.

Secondary left atrioventricular valve replacement in atrioventricular septal (AV canal) defect: a method to avoid left ventricular outflow tract obstruction.

Patients with atrioventricular septal defects are morphologically predisposed to subaortic obstruction. Some individuals require secondary left atrioventricular valve replacement for severe incompetence persisting after repair, and they are especially susceptible to left ventricular outflow tract obstruction. A surgical technique is described for replacement of the atrioventricular valve which seems to avoid the complication of left ventricular outflow tract obstruction by the prosthesis.

Surgical repair of aorto-right ventricular tunnel in an infant.

A rare case of aorta to right ventricle tunnel with associated pulmonary stenosis was corrected on cardiopulmonary bypass in a 3-month-old infant. Both the aortic and ventricular openings were closed with a patch. Although the repair was successful and the child was discharged from the hospital, septicemia developed and she died later. Early repair of this defect is recommended.

Direct closure of ostium primum defect in the repair of atrioventricular septal defect.

BACKGROUND: Patch closure is generally performed for atrial septation of an atrioventricular septal defect. We recently developed a new surgical technique for repairing atrioventricular septal defects that avoids the use of any patch material for closing the atrial septal defect. We report our experience with this procedure. METHODS: Seven patients (complete type: 5, partial type: 2) underwent this new operation. The diameters of the atrial septal defects were measured by transesophageal echocardiography. The preoperative electrocardiograms were compared with those taken after the operations. RESULTS: Diameters of the atrial defects ranged from 3 to 10 mm. Electrocardiograms before and after the operations did not change. No significant atrioventricular valve regurgitation and no residual shunts were detected by postoperative echocardiography. CONCLUSIONS: This method simplifies the repair of atrioventricular septal defects. In the short-term results, no arrhythmia and no valve regurgitation was seen.

Repair of complete atrioventricular canal defects: results with the two-patch technique.

BACKGROUND: Between 1983 and 1994, 115 infants and children underwent repair of a complete atrioventricular canal defect with the two-patch technique and routine mitral valve "cleft" closure. METHODS: A retrospective review of these 115 patients was performed. Age at the time of repair ranged from 1 month to 108 months (mean age, 14.2 +/- 16.5 months; median age, 8 months). Preoperative cardiac catheterization in 113 patients revealed a mean pulmonary to systemic flow ratio of 3.37 +/- 1.8, a mean pulmonary artery systolic pressure of 71.1 +/- 15.7 mm Hg, and a mean pulmonary vascular resistance of 4.9 +/- 3.3 units. Associated anomalies included Down's syndrome (99 patients), patent ductus arteriosus (47), and coarctation of the aorta (4). Rastelli classification was A (76 patients), B (10), C (24), and unknown (5). Twenty-four patients had intraoperative epicardial or transesophageal echocardiography. RESULTS: Although there was a trend toward increasing mean preoperative pulmonary vascular resistance with age from 2.1 +/- 0.9 units (0 to 3 months) to 4.0 +/- 2.6 units (4 to 6 months) to 5.7 +/- 3.0 units (7 to 12 months), the mean pulmonary vascular resistance of each age group was not significantly different from that of the main group. The operative survival rate was 94% (seven early deaths) and the overall survival rate, 91% (three late deaths). Intraoperative echocardiography altered the surgical therapy for 1 patient. No patient has required reoperation for a residual ventricular septal defect. Four patients (3.5%) had heart block requiring permanent pacemakers. Eight patients (7%) required reoperation for mitral insufficiency; 6 of whom had successful repair of a residual cleft. CONCLUSIONS: For infants with complete atrioventricular canal defect, repair using the two-patch technique with routine mitral valve cleft closure at 4 to 6 months of age results in a low operative mortality, a low incidence of permanent heart block, and a low reoperation rate for mitral insufficiency.

Partial atrioventricular canal with congestive heart failure in the first year of life: surgical options.

BACKGROUND: An important subgroup of patients with partial atrioventricular canal require an operation in the first year of life because of refractory congestive heart failure. METHODS: From June 1982 to April 1995, of 128 patients with partial atrioventricular canal, 35 patients (27%) underwent surgical treatment at less than 1 year of life. Associated cardiac anomalies were present in 22 patients. Only 7 patients (20%) had Down's syndrome. Five patients with left ventricular hypoplasia underwent aortic coarctectomy (3 patients) or Norwood operation (2 patients). The other 30 patients underwent anatomic repair in 24 cases and aortic coarctectomy in 6. The surgical results of patients submitted for anatomic repair were retrospectively correlated with the echocardiographic mitral valve diameter. RESULTS: There were 7 deaths (29%) after anatomic repair, 2 (22%) after aortic coarctectomy, and 2 (100%) after Norwood operation. Infants with a mitral valve diameter less than 2.5 x 10-2 m/m2 died at repair. In a mean follow-up of 73.5 months there were five secondary mitral valve plasties and three repairs after aortic coarctectomy. CONCLUSIONS: Among patients with partial atrioventricular canal, there is an important subgroup with clinical signs of heart failure in the first year of life. Left-sided obstructive lesions and complex mitral valve anomalies seem to play a fundamental role in the clinical evolution and prognosis of these patients. The echocardiographic mitral valve diameter may be useful for determining the correct surgical indication.

Transesophageal echocardiography (TEE) in congenital heart disease with focus on the adult.

Remarkable innovations in medical and surgical approaches over the past several decades now allow for correction of major cardiac defects in children, even in early infancy. These advances have provided for survival of many pediatric patients with congenital heart disease into adulthood. Although transthoracic echocardiography remains the primary imaging technique for the characterization of simple and complex congenital cardiovascular malformations in the pediatric and adult age groups, high-resolution transesophageal imaging has markedly expanded the anatomic and hemodynamic assessment in these patients. The benefits of this imaging approach apply particularly to those with challenging or limited transthoracic examinations or poorly characterized congenital cardiovascular malformations. The utility of TEE in defining the anatomy of the usual spectrum of congenital cardiac malformations is well established. The transesophageal approach has been shown to provide additional diagnostic information over conventional transthoracic imaging for specific structural cardiac anomalies and in the perioperative setting, the opportunity for confirmation of preoperative diagnoses, and modification of the surgical plan if new or different pathology is identified. This imaging modality also may reliably provide for immediate detection of suboptimal surgical repairs and significant postoperative residua, potentially improving the efficacy of the surgical intervention. This accounts for the vital role of this technology in perioperative management and integration into the standard of care in many congenital heart centers. The usefulness of TEE also has been documented during diagnostic and therapeutic cardiac catheterizations of patients with structural cardiac anomalies, allowing for safer and more effective application of these technologies. The experience supports the use of TEE as a useful approach in the surveillance of the adult with operated and unoperated congenital heart disease.

Plain chest radiography of congenital heart disease in adults.

The plain chest radiograph can be an invaluable aid in the diagnosis of congenital heart disease in adults. Evaluation of the chest radiograph is made simpler and more accurate by the use of a systematic approach based on physiology. In many instances, a definitive diagnosis can be made; in others, only a differential diagnosis can be arrived at. The majority of adults with congenital heart disease will have some telltale abnormality on the chest radiograph that will occasionally furnish the first clue to the presence of a congenital anomaly.

Unbalanced atrioventricular septal defects.

Complete atrial ventricular septal defects (AV canal) generally have right and left valve components equally divided. However, in unbalanced AV canal either right or left ventricle dominance may occur. The spectrum may vary between those readily able to undergo biventricular repair at no increased risk to those requiring a single ventricle approach in cases with severe hypoplasia of the ipsilateral ventricle. The most challenging diagnostic cases fall within the gray area between the two ends of the spectrum, in which one ventricle is not clearly hypoplastic. Diagnostic modalities that are used to evaluate these ventricles include echocardiography and angiographic ventriculography using volume formulae. Magnetic resonance imaging (MRI) has also recently been found to be a useful technique with which further experience is being developed. Once the determination of a single ventricle physiology has been made, early intervention (ie, pulmonary artery banding) to protect both the pulmonary vasculature and the ventricular function is performed. Follow-up with catheterization and bidirectional Glenn should be completed usually by around 4 to 6 months of age. This palliation and subsequent Fontan completion has had good results based largely on two factors: ventricular dominance, left being better than right, and the absence of pulmonary vascular hypertension.