Atrial structure in the presence of visceral heterotaxy

Long-Term Surgical Outcomes of Patients With Isomeric Right and Left Atrial Appendages

Objectives: To compare the long-term outcomes of biventricular, univentricular, and so-called one-and-one-half ventricular repairs in patients with left and right isomerism. Methods: Surgical correction was undertaken, between 2000 and 2021, in 198 patients with right, and 233 with left isomerism. Results: The median age at operation was 24 days (interquartile range [IQR]: 18-45) and 60 days (IQR: 29-360) for those with right and left isomerism, respectively. Multidetector computed-tomographic angiocardiography demonstrated more than half of those with right isomerism had superior caval venous abnormalities, and one-third had a functionally univentricular heart. Almost four-fifths of those with left isomerism had an interrupted inferior caval vein, and one-third had complete atrioventricular septal defect. Biventricular repair was achieved in two-thirds of those with left isomerism, but under one-quarter with right isomerism (P < .001). Hazard regression for mortality revealed odds for prematurity at 5.5, pulmonary atresia at 2.81, atrioventricular septal defect with a common valvar orifice at 2.28, parachute mitral valve at 3.73, interrupted inferior caval vein at 0.53, and functionally univentricular heart with a totally anomalous pulmonary venous connection at 3.77. At a median follow-up of 124 months, the probability of survival was 87% for those with left, and 77% for those with right isomerism (P = .006). Conclusions: Multimodality imaging characterizes and delineates the relevant anatomical details, facilitating surgical management of individuals with isomeric atrial appendages. Continuing higher mortality despite surgical intervention in those with right isomerism points to the need for the reassessment of strategies for management.

Imaging characteristics and associations of left atrioventricular valve atresia and patent aortic root with isometric atrial appendages on multidetector CT

AIM

The present study sought to study the imaging associations of left atrioventricular valve (mitral) atresia and patent aortic root in patients with isomerism of atrial appendages as detected on multidetector computed tomography (CT) angiography MATERIALS AND METHODS: The CT angiography studies performed at a tertiary medical center from January 2014 to December 2021 were retrospectively evaluated to identify patients with left atrioventricular valve atresia and patent aortic root with isometric atrial chambers. The morphology of the atrial appendage and extent of pectinate muscles was used to identify the type of isomeric atrial chambers. A comprehensive assessment of discordant arrangement of organs and the variations in venoatrial connections was done.

RESULTS

Left atrioventricular valve atresia in the presence of patent aortic root and isomeric atrial appendages was identified in eight patients (four males). The mean age at diagnosis was 7 years. Right isomerism of the atrial appendages was seen in five patients while three patients had left isomerism. Disharmonious patterns of abdominal visceral arrangement were seen in two patients. Atrial and ventricular septal defects were seen in all patients. The most common pattern of ventricular arterial connection was DORV (double outlet right ventricle) (n = 4). While five patients had normally related great arteries, three had aorta anterior to the pulmonary trunk. Right ventricular outflow obstruction was seen in seven patients. Right aortic arch with mirror image branching was seen in four patients. Coronary artery anomalies were seen in four patients.

CONCLUSIONS

The presence of left atrioventricular valve atresia and patent aortic root with isomeric atrial appendages is a rare congenital anomaly frequently associated with anomalous systemic and pulmonary drainage, conotruncal anomalies, and right ventricular outflow obstruction. Hence, comprehensive CT-based evaluation is indispensable in providing detailed anatomy and aids in presurgical planning.

Surgical management of hearts with isomeric atrial appendages

BACKGROUND AND AIM

On the basis of previously published accounts, coupled with our own experience, we have assessed the surgical approaches to patients with isomeric atrial appendages.

METHODS

We reviewed pertinent published studies on surgical treatment of individuals with isomeric atrial appendages, with the pertinent surgical details provided by most of the manuscripts.

RESULTS

Half of patients with right isomerism, and two-thirds of those with left isomerism have bilateral superior caval veins. Azygos extension of the inferior caval vein is reported in three-quarters of those with left isomerism. The coronary sinus is universally absent in right isomerism, along with totally anomalous pulmonary venous connection, and is absent in two-fifths of those with left isomerism. Univentricular atrioventricular connections are expected in up to three-quarters of those with right isomerism. Atrioventricular septal defect is reported in up to four-fifths, more frequently in right isomerism, with such patients typically having discordant ventriculoatrial connections or double outlet right ventricle. Reported mortalities extend to 85% for those with right, and 50% for those with left isomerism. In right isomerism, mortality is up to 54% for systemic-to-pulmonary arterial shunting, up to 75% for univentricular repair, and up to 95% for repair of totally anomalous pulmonary venous connection itself. No more than one-quarter had undergone Fontan completion, with reported mortalities of 21%.

CONCLUSION

Early surgical results are satisfactory in patients with left isomerism, but disappointing for those with right. Recent advances in cardiac and liver transplantation may offer improved survival.

Discordant Post-natal Patterns in Fetuses With Heterotaxy Syndrome: A Retrospective Single-Centre Series on Outcome After Fetal Diagnosis

OBJECTIVE

Cardiac and extra-cardiac anomalies in 46 pre-natally diagnosed cases of heterotaxy were compared to post-natal anatomical patterns in order to reveal discordant findings. Second, the outcome of these fetuses was evaluated.

METHODS

Fetuses with heterotaxy, diagnosed in a tertiary referral centre, were analysed retrospectively. Based on the foetal abdominal situs view, right atrial isomerism (RAI) and left atrial isomerism (LAI) were defined as foetal sub-types. Post-natally, discordant anatomical patterns for broncho-pulmonary branching, atrial appendage morphology, and splenic status were further clarified with CT scans. In summary, the spectrum of pre-natally and post-natally detected cardiac and extra-cardiac anomalies is systematically reviewed. Necessary surgical interventions and mid-long-term outcomes were compared between the two sub-types in surviving infants.

RESULTS

A total of 46 fetuses with heterotaxy were included; LAI was diagnosed in 29 (63%) fetuses and RAI was diagnosed in 17 (37%) fetuses. Extra-cardiac anomalies were noted in 35% of fetuses. Seven out of the 29 fetuses (24%) with LAI had atrio-ventricular block (AVB) and four of these cases presented with hydrops. Twenty nine out of the 46 participating fetuses (63%) were live births, with 62% in the LAI group and 65% in the RAI group. Five fetuses were lost to follow-up. At the age of 1 year, the overall survival of live births [estimate (95% CI)] was 67% (48; 92%) in patients with LAI and 55% (32; 94%) in patients with RAI. At the age of 5 years, the estimates were 67% (48; 92%) in the LAI group and 46% (24-87%) in the RAI group. The median survival (first quartile; third quartile) was 11.1 (0.1; 14) years for patients with LAI and 1.3 (0.09; NA) years for patients with RAI. Of 17 children who had undergone cardiac surgery, five (29%) children achieved a bi-ventricular repair and 12 (70%) children achieved a uni-ventricular palliation. Three were primarily palliated, but converted to bi-ventricular thereafter. Foetal subtype definition of heterotaxy based on the abdominal situs and post-natal thoracic imaging studies showed a discordant pattern of broncho-pulmonary branching and atrial appendage anatomy in 40% of our live-born children.

CONCLUSION

Heterotaxy is a rare and complex condition with significant morbidity and mortality related to severe cardiac and extra-cardiac associations. Accurate pre-natal diagnosis can help identify the fetuses at risk and allow for timely intervention in a multi-disciplinary setting. Further studies are warranted to shed light on the exact sub-type definition in fetuses with heterotaxy and the presence of discordant post-natal patterns.

Lateral Heterotaxy Syndrome in a Newborn Caucasian Male

Heterotaxy syndrome is a varied spectrum of rearrangements of thoracic and abdominal organs that present many unique complications. Among all congenital deformities, heterotaxy syndrome is rare although this is likely an underestimate without routine imaging due to the benign nature of some defects. Numerous genes have been identified that play a role in its pathogenesis, and it has been hypothesized that heterotaxy syndrome is a consequence of both genetic and environmental impacts on the body axis. This case report also demonstrates the fundamental role of cardiac catheterization and imaging in further specifying the subtype of heterotaxy. Furthermore, it highlights the inconsistency of laterality with functional asplenia, visceral situs ambiguus, double-outlet right ventricle, and a left-sided inferior vena cava apart from other anomalies in a newborn male. 

Characterisation of computed tomography angiography findings in paediatric patients with heterotaxy

BACKGROUND

Heterotaxy refers to the abnormal arrangement of organs across the left-right axis and is typically associated with complex cardiovascular malformations.

OBJECTIVE

To characterise the range of cardiac and extracardiac CT angiography findings in children with heterotaxy using the latest nomenclature consensus and to compare the different types of isomerism.

MATERIALS AND METHODS

We retrospectively analysed the data of 64 consecutive paediatric patients referred to our tertiary paediatric cardiovascular centre who underwent CT angiography for the evaluation of known or suspected heterotaxy within a 52-month period.

RESULTS

Right atrial isomerism was identified in 44 (69%) children, while left atrial isomerism was identified in 18 (28%) children. Atrial appendage anatomy and situs could not be determined in 2 children (3%). Associated heart defects included complete atrioventricular canal (CAVC) in 51 (80%) children, total anomalous pulmonary venous return in 43 (67%) and pulmonary atresia in 23 (36%). The bronchial branching pattern corresponded to atrial appendage morphology in all children except in the two in whom atrial appendage morphology could not be defined. In children with right atrial isomerism, the most common associated abnormalities were CAVC (n=41, 93%) and asplenia (n=34, 77%), while in those with left atrial isomerism, the most common associated abnormalities were polysplenia (n=17, 94%) and an interrupted inferior vena cava with azygos continuation (n=15, 83%).

CONCLUSION

CT angiography provides useful cardiovascular and extracardiac data on heterotaxy, which frequently involves a pattern of side-related findings but has great anatomical variability.

Disharmonious Patterns of Heterotaxy and Isomerism: How Often Are the Classic Patterns Breached?

BACKGROUND

It is advocated that heterotaxy should be segregated into right or left isomerism according to atrial appendage morphology. However, atrial situs determination is often based on the pattern of associated findings rather than on atrial morphology itself, which can be difficult to define. The objective was to assess how often concordant patterns of isomerism classified by atrial appendage morphology, bronchopulmonary pattern, and splenic status are breached using cardiac magnetic resonance or computed tomography. The secondary objective was to determine the feasibility of defining atrial appendage morphology using cardiac magnetic resonance or computed tomography.

METHODS AND RESULTS

Retrospective review of 114 pediatric patients (median, 2.4 years; range, 1 day-17.9 years) with heterotaxy who underwent cardiac magnetic resonance or computed tomography was performed to evaluate atrial appendage, bronchopulmonary, and visceral organ arrangements. Atrial appendage and splenic anatomy were not definable in 17 of 114 (15%) and 4 of 114 (3.5%) patients, respectively. In the remaining 93 patients, 39% had classic right isomerism (bilateral right atrial appendages, right bronchopulmonary pattern, and asplenia) and 40% had classic left isomerism (bilateral left atrial appendages, left bronchopulmonary pattern, and polysplenia). Classic pattern of isomerism was breached in 20 of 93 (21.5%) patients: 13 (65%) displayed incongruent abdominal situs, 5 (25%) incongruent bronchial situs, 1 (5%) had discrepant appendage morphology, and 1 (5%) incongruent situs at all levels.

CONCLUSIONS

Atrial appendage morphology is difficult to assess and not always indicative of bronchopulmonary or abdominal situs. Discordance between bronchopulmonary branching, atrial appendage arrangement, and splenic status was identified in >20% patients with heterotaxy. Independent description of each organ system is required when arrangements are disharmonious among different organ systems.

Functionally Univentricular Heart With Right Atrial Isomerism and Mixed Total Anomalous Pulmonary Venous Drainage

Patients with right atrial isomerism and total anomalous pulmonary venous connection (TAPVC) in a functionally univentricular heart are a challenging subset with a high mortality rate. We present the case of a patient with univentricular heart who had right atrial isomerism and associated mixed TAPVC (supracardiac, cardiac, and infracardiac). The anatomy was delineated precisely, and the patient underwent first-stage univentricular palliation consisting of TAPVC repair and bilateral bidirectional superior cavopulmonary anastomosis.

Clinical Features, Management, and Outcome of Children With Fetal and Postnatal Diagnoses of Isomerism Syndromes

Background— Isomerism is associated with a complex spectrum of anomalies. There is paucity of data on prenatally detected cases.

Methods and Results— Between January 1990 and February 2004, 83 of 166 cases (50%) had a prenatal diagnosis of left isomerism (LAI; 52 of 97) or right isomerism (RAI; 31 of 69) at our institution. The spectrum of anomalies, management, and outcomes was compared for fetal and postnatal diagnoses of LAI and RAI. RAI more often than LAI was associated with AV septal defect (90% versus 56%; P <0.0001), pulmonary outflow obstruction (91% versus 37%; P <0.0001), total anomalous pulmonary venous drainage (73% versus 13%; P <0.0001), and abnormal VA connections (68% versus 33%; P <0.0001), whereas inferior vena cava interruption (3% versus 93%; P <0.0001), complete AV block (0% versus 13%; P =0.004), aortic obstruction (6% versus 33%; P <0.0001), and extracardiac defects (5% versus 25%; P =0.006) were less common. The spectrum of lesions was comparable for fetal and postnatal cases, except for AV block (fetal, 25%; postnatal, 0%; P =0.0002) and AV septal defect (fetal, 67%; postnatal, 42%; P =0.023) in LAI. Fetal demise was due mainly to pregnancy termination (LAI, 42%; RAI, 45%). Survival of actively managed children with LAI was significantly better than for those with RAI ( P <0.0001) but did not differ with regard to fetal versus postnatal diagnosis. Most LAI cases required no intervention or underwent successful biventricular cardiac surgery (65%), unlike RAI cases (13%; P <0.0001).

Conclusions— Prenatal diagnosis did not affect overall survival despite facilitated care. The prognosis of RAI was worse compared with LAI because of more complex associated cardiac defects and the inability to perform successful surgical procedures.