Search Results (6)

Heterotaxy syndrome is characterized by a tendency for bilaterally symmetric arrangement (isomerism) of inner organs. It is frequently associated with complex congenital heart defects (CHDs). In “heterotaxic” hearts, the tendency for isomerism is confined to the atria. The ventricular segment always shows asymmetric arrangements (D-hand or L-hand topology). This study aimed to determine the statistical distribution of ventricular topology among patients with CHDs associated with heterotaxy and to identify possible associations between ventricular topology and cardiovascular disorders and survival. It is a retrospective cross-sectional study on 192 patients treated at a single center between 2000 and 2023. Our cohort had 115 patients of left atrial isomerism (LAI) and 77 of right atrial isomerism (RAI). The whole cohort (n = 192) showed a bias towards ventricular D-hand topology (67%), which was statistically significant in LAI (74%). In contrast, RAI showed an almost equal distribution (57% D-hand, 43% L-hand). No significant associations were found between ventricular topology and major CHDs or mortality. Significant associations were observed between ventricular topology and cardiac apex position, direction of p-wave axis, and aortic arch sidedness. We conclude that, in the setting of heterotaxy, especially RAI, ventricular topology and aortic arch sidedness both behave as binary anatomical variables showing a tendency for randomized occurrence. This tendency for statistically symmetric distribution is interpreted as reflecting the syndrome-specific tendency for bilateral symmetry. Full article

Background/Objectives: It is increasingly realized that the advances in diagnosis and treatment for those born with congenitally malformed hearts have now resulted in avoidance of morbidity being equally as important as avoiding postoperative mortality. Detailed personalized diagnoses will now be key to achieve such improvements. Methods: We have reviewed our own experience in diagnosing major phenotypic variations on selected congenital cardiac malformations, showing that the ability to personalize the findings is at hand, although not always to date universally employed. Results: We have chosen four categories to illustrate how the definitions now provided by the International Nomenclature Society, and incorporated in the 11th iteration of the International Classification of Disease, make it possible to provide personalized diagnoses. The lesions chosen for review are the arrangement of the atrial appendages, the lesions permitting interatrial shunting, the options in the setting of deficient ventricular septation, and the abnormal morphology of the aortic root. We show that not all centers, as yet, are taking advances of these opportunities at hand to tailor the chosen treatments. Conclusions: Detailed phenotypic definitions have now been provided for all the major congenital cardiac malformations. Use of these definitions should now provide personalized medicine for all those born with malformed hearts. As yet, the definitions are not used to their full effect. Full article

Splenic torsion is an unusual condition that results in congenital abnormality, especially in the visceral abnormal arrangement. We report the case of an 8.5-year-old boy with features in the right upper quadrant. Radiological investigations revealed heterotaxy syndrome with polysplenia and a hypodense tumor in the right upper quadrant adjacent to several spleens. We initially treated it as an intra-abdominal tumor. Laparoscopy was performed to check the tumor condition and revealed a congestive tumor located in the abdomen of the right upper quadrant below the central liver, which was suspected to be a torsion spleen without attaching ligaments. Laparoscopic splenectomy was successfully carried out without complications. The pathological report shows splenic tissue with hemorrhagic infarction. Physicians should be vigilant of the differential diagnosis of the acute abdomen in adolescents. Full article

The alignment of visceral and brain asymmetry observed in some vertebrate species raises the question of whether this association also exists in humans. While the visceral and brain systems may have developed asymmetry for different reasons, basic visceral left–right differentiation mechanisms could have been duplicated to establish brain asymmetry. We describe the main phenotypical anomalies and the general mechanism of left–right differentiation of vertebrate visceral and brain laterality. Next, we systematically review the available human studies that explored the prevalence of atypical behavioral and brain asymmetry in visceral situs anomalies, which almost exclusively involved participants with the mirrored visceral organization (situs inversus). The data show no direct link between human visceral and brain functional laterality as most participants with situs inversus show the typical population bias for handedness and brain functional asymmetry, although an increased prevalence of functional crowding may be present. At the same time, several independent studies present evidence for a possible relation between situs inversus and the gross morphological asymmetry of the brain torque with potential differences between subtypes of situs inversus with ciliary and non-ciliary etiologies. Full article

The outer shape of most vertebrates is normally characterized by bilateral symmetry. The inner organs, on the other hand, are normally arranged in bilaterally asymmetric patterns. Congenital deviations from the normal organ asymmetry can occur in the form of mirror imagery of the normal arrangement (situs inversus), or in the form of arrangements that have the tendency for the development of bilateral symmetry, either in a pattern of bilateral left-sidedness (left isomerism) or bilateral right-sidedness (right isomerism). The latter two forms of visceral situs anomalies are called “heterotaxy syndromes”. During the past 30 years, remarkable progress has been made in uncovering the genetic etiology of heterotaxy syndromes. However, the pathogenetic mechanisms causing the spectrum of cardiovascular defects found in these syndromes remain poorly understood. In the present report, a spontaneous case of left cardiac isomerism found in an HH-stage 23 chick embryo is described. The observations made in this case confirmed the existence of molecular isomerism in the ventricular chambers previously noted in mouse models. They, furthermore, suggest that hearts with left cardiac isomerism may have the tendency for the development of non-compaction cardiomyopathy caused by defective development of the proepicardium. Full article

Pediatric cardiologists treating patients with severe congenital cardiac defects define “visceral heterotaxy” on the basis of isomerism of the atrial appendages. The isomeric features represent an obvious manifestation of disruption of left-right asymmetry during embryonic development. Thus, there are two subsets of individuals within the overall syndrome, with features of either right or left isomerism. Within the heart, it is only the atrial appendages that are truly isomeric. The remainder of the cardiac components shows variable morphology, as does the arrangement of the remaining body organs. Order is provided in this potentially chaotic arrangement simply by describing the specific features of each of the systems. These features as defined by clinicians, however, seem less well recognized by those investigating the developmental origins of the disruption of symmetry. Developmental biologists place much greater emphasis on ventricular looping. Although the direction of the loop can certainly be interpreted as representing an example of asymmetry, it is not comparable to the isomeric features that underscore the clinical syndromes. This is because, thus far, there is no evidence of ventricular isomerism, with the ventricles distinguished one from the other on the basis of their disparate anatomical features. In similar fashion, some consider transposition to represent abnormal lateralization, but again, clinical diagnosis depends on recognition of the lateralized features. In this review, therefore, we discuss the key questions that currently underscore the mismatch in the approaches to “lateralization” as taken by clinicians and developmental biologists. Full article