[Double inlet left ventricle. Morphopathology and surgical anatomy]. / Doble entrada ventricular izquierda. Morfopatología y anatomía quirúrgica.

Because of the possibility of surgical treatment of double inlet left ventricle, its basic morphologic features of surgical and imaging importance are analyzed. Seventeen hearts were studied with the segmental sequential system. The situs was solitus in thirteen; dextroisomerism in three and levoisomerism in one. The atrioventricular valves were separated in nine; there was a common atrioventricular valve in eight; straddling of the atrioventricular valve in seven and stenosis in two. The rudimentary right ventricle was to the right side in twelve hearts and to the left side in five. The discordant ventriculoarterial connection was the most frequent (seven), followed by the concordant one (five) and double outlet right ventricle (five). There was pulmonary stenosis in five. The ventricular septum did not reach the crux cordis. The ventricular septal defect was bigger in straddling atrioventricular valves than in valves completely open into the left ventricle, being restrictive in ventriculoarterial concordance. Surgical treatment varies as the complexity of this cardiopathy does, from cardiac septation to palliation procedures. The morphologic knowledge of this cardiac malformation is basic to interpret correctly the diagnostic imaging.

[Absence of right and left atrioventricular connexion]. / Ausencia de conexión atrioventricular derecha e izquierda.

Fifty seven hearts with absence of atrioventricular (A-V) connection were studied morphologically to specify their types of ventriculoarterial connection and their associated anomalies; the anatomic features of the hearts were correlated with their echocardiographic and cardioangiographic images in order to establish their mutual correspondence. Fifty six hearts had situs solitus; fifty specimens had right absent A-V connection and six had left absent A-V connection. One had situs inversus. All the specimens had: A deep A-V sulcus at the site of the absent A-V connection, a dimple in the muscular floor of the involved atrium connected with the dilated and hypertrophic left ventricle, incomplete right ventricle without inlet portion, ventricular septal defect of variable dimensions (it was obliterated in two), atrial septal defect, the ventricular septum deviated from the crux cordis. The left absent A-V connection had ventricular inversion and discordant ventriculoarterial connection. In the right absent A-V connection the ventriculoarterial connections were concordant in thirty eight hearts, from which thirty four had pulmonary stenosis both infundibular and valvular (five had the tetrad of Fallot), two had pulmonary valve atresia and two had a dilated pulmonary artery; discordant in nine hearts, one with aortic atresia; double outlet, from the right ventricle in two, (one with the tetrad of Fallot) and from the left ventricle in one. The heart in situs inversus had ventricular inversion, right absent A-V connection (left-sided), single (right) ventricle and atresia of the left ventricle. The correlations between cardiac morphology and imaging were precise. Developmentally, this cardiopathy is the result of an ectopic unequally lateralized septation of the common atrioventricular canal, which separates two canals, one stenotic leading to atresia and the other which develops too wide.

[Persistent common trunk. Anatamopathological study of 25 specimen]. / Tronco común persistente. Estudio anatomopatológico de 25 especímenes.

In order to inform the pathologic features and their associated anomalies twenty five hearts with common trunk were studied with the segmental sequential system. An anatomico-embryological correlation was made to understand the pathological complex of this malformation. The results were: type I truncus (96%), infundibular ventricular septal defect (96%), displastic truncal valve (28%), ventriculo infundibular fold (92%), left coronary artery arising from the posterior wall of the truncus (75%), right coronary artery arising from their anterior wall (96%), coronary arteries arising from opposite Valsalva sinuses in the tetracuspid valves; the biventricular conection of the truncus was balanced in 60%, prevailing on the right (16%) or on the left (16%) ventricles. Among the associated anomalies there were right aortic arch, interruption of the aortic arch, anomalous origin of the left subclavian artery, vascular ring, aneurysm of the sinus of Valsalva, and absence of the left branch of the pulmonary artery. Developmentally common trunk is explained as a failure of truncoconal septation in the embryonic heart; a migration arrest of neural crest cells is implicated in the Di George syndrome. Knowledge of the anatomic features of common trunk and their associated anomalies, provides the morphological basis to interpret correctly the clinical diagnostic imagenology.

[Anatomopathologic-embryologic correlation in atrioventricular connection absence]. / Correlación anatomopatológica-embriológica de la ausencia de conexión atrioventricular.

In order to offer a pathogenetic explanation for the absence of atrioventricular connexion, a correlation was made between the pathologic anatomy of this cardiac malformation and the embryonic processes which take part in the septation of the atrioventricular canal and the development of atrioventricular connections. The correspondence was made between the development of the canal's atrioventricular cushions, the septation of the common atrioventricular canal, the right and left atrioventricular canals and the morphogenesis of the mitral valve, all these processes were correlated with the anatomic elements derived from them. This led to infer that the malposition of the atrioventricular cushions divide the common atrioventricular canal unequally, giving rise to a narrow canal becoming atretic and a big canal where the mitral valve is evolved. The extreme lateralization of the atrioventricular septum to the right side would led to the absence of the right atrioventricular connection and the same process but to the left side, would give rise to the left absence of the atrioventricular connection. This ectopic septation process is supported by similar ones which can occur in other segments of the heart such as in tetralogy of Fallot and the transposition of the great arteries. This hypothesis explains sufficiently the pathologic anatomy of this type of congenital heart disease.

Atrioventricular septal defect: quantitative anatomy of the left ventricle.

A morphometric study was performed in 18 human hearts with atrioventricular septal defect not associated with other anomalies; 16 hearts had common atrioventricular orifices, and 2 presented separate right and left atrioventricular orifices. A total of eight parameters were analyzed, characterizing ventricular wall thickness, length and circumference of the inflow and outflow tracts, and circumference of the left orifice and aortic orifice. The data were compared with previously published patterns of normality. In addition, the volume of the aortic outflow tract was calculated. The inflow tract was shorter than the outflow tract, and the length of the diaphragmatic wall was equal to the sum of the lengths of the inflow tract and ventricular wall thickness at the level of the apex.

[A morphological study of 23 hearts with Ebstein's anomaly]. / Estudio morfológico de 23 corazones con anomalía de Ebstein.

The literature published of the Ebstein anomaly of the tricuspid valve have been given little attention to the study of the trabecular portion of the right ventricle. This motivate us to study the morphology of twenty-three hearts by the segmentary sequential method determining with special interest the extension and grade of valvular attachment, dysplasia, characteristics of the trabecular portion of the right ventricle and associated anomalies. The three valves had some grade of attachment but this was less frequently in the anterior valve. However in our material this occurred in 43% which is consider high comparing with the rest of the literature; the trabecular portion had several bands at this zone and it was covered by the valve attachment. The downward displacement of the functional ring was directly proportional to the valve attachment. The structural anomalies of the right ventricle related to the valve malformation lead us to consider that the primary damage that causes this cardiopathy occurred at the right ventricle during the embryonic development altering the morphogenesis of the tricuspid valve.

[A morphometric study of the right ventricular infundibulum in complete transposition of the great arteries]. / Estudio morfométrico del infundíbulo del ventrículo derecho en la transposición completa de las grandes arterias.

To demonstrate that the right ventricular infundibulum changes its spatial orientation in hearts with complete transposition of the great arteries, sixty five hearts with this malformation, with anterior and right sided aorta were studied morphometrically. The inlet apex and infundibular arises in the right ventricule were interrelated. The angles formed by the intersection of both arises were measured, and the results were compared with those obtained from a similar study in thirty five normal hearts. The angles obtained in the hearts with transposition of the great arteries were of 156.5 degrees, and those measured in the normal hearts were of 126.6 degrees. This difference was interpreted as an indicator of a vertical shift of the right ventricular infundibulum toward the right, to the same side in which the aorta is located and with which it is connected. In this way this outlet looses its leftward direction observed in normal hearts. It is concluded that although complete transpositions of the great arteries developmentally has its origin primarily in the truncus of the embryonic heart, the infundibulum is also involved modifying its position.

[Bilateral infundibula in congenital cardiopathies]. / Infundíbulos bilaterales en cardiopatías congénitas.

The goal of this paper has been to count and describe congenital heart disease associated with double conus. We studied 196 pathologic specimens from to the Pathologic Collection of the Department of Embryology of the National Institute of Cardiology "Ignacio Chávez" of México. We found 3% of double conus in classic tricuspid atresia with concordant ventriculoarterial connection, 53% with double outlet right ventricle, 16% with discordant ventriculoarterial connection, 91% with double outlet single ventricle, 8% with one outlet right ventricle with pulmonary atresia, 20% with one outlet left ventricle and 25% with one outlet single ventricle. The morphological data of the associated anomalies were gathered in an informatized sheet designed according the segmental and sequential approach to diagnose congenital heart disease. From our results we conclude that double conus cannot be considered pathognomonic of any congenital cardiopathy, although they appear associated more frequently with truncoconal anomalies and single ventricle. It is frequent the association between double conus and stenosis of one of them, specially the subpulmonary one. We found great association between left juxtaposition of the atrial appendages and double conus.

[Absence of the tricuspid valve. A case report]. / Ausencia de la válvula tricúspide. Informe de un caso.

An anatomical embryological and histological study of a malformed heart is presented in which the right concordant atrioventricular connexion is unguarded by the tricuspid valve, due to absence of the three leaflets, chordae tendinae and papillary muscles; only the fibrous ring is present in the atrioventricular junction. This very rare malformation is associated with atresia of the valve connected with the right ventricle generally being the pulmonary valve; the ventricular septum is intact. This congenital lesion always present fibrosis in the free wall of the right ventricle. We believe a primary pathogenetic step occurs in the wall of the right ventricle which prevents the morphogenesis of the tricuspid valve from this ventricle. This malformation must be distinguish from Ebstein's disease and Uhl's disease, although they are pathogenetically related.

Atrioventricular septal defect: quantitative anatomy of the right ventricle.

In 19 human fetal and newborn hearts with atrioventricular septal defect (AVSD), not associated with other anomalies, the two ventricles were studied morphometrically. A total of 17 different parameters were studied: nine in the right ventricle and eight in the left. In the right ventricle we analyzed ventricular wall thickness, length of right ventricular inflow and outflow tracts, and volume of right ventricular inflow and outflow tracts. The data for these parameters were compared with the patterns of normality published previously, and the volumetric data were compared with patterns of normality published previously by us. The ventricular inflow tract was shorter than the outflow tract, the difference being especially significant in the left ventricle. The length of the diaphragmatic wall of the heart in both the right and left ventricle was equal to the sum of the length of the inflow tract and the thickness of the ventricular wall at the apex.

[Juxtaposition of the atria]. / Yuxtaposición de las orejuelas.

Left juxtaposition of atrial appendages is an anomaly of their origin and position which is associated with a high incidence of complex congenital heart defects. We studied six cases of juxtaposed right atrial appendages. They emerged from the anterior wall adjacent to the atrial septum and were situated to the left of the origin of the great arteries. Associated congenital heart defects were: single outlet, right ventricular hypoplasia, absent right atrioventricular connection, ventricular and atrial septal defects and pulmonary outflow obstruction. Other abnormal morphological features present were anatomically corrected malposition of the great arteries, bilateral infundibulum and right aortic arch. Although the association of these malformations with juxtaposed atrial appendages does not per se constitute a syndrome, its presence is an ominous sign of severe cyanotic congenital heart disease which should alert both clinicians and surgeons. There are various possible embryological explanations for the genesis of this malformation. We believe that juxtaposition is the consequence of the ectopic origin of the atrial appendage rudiment, which in the presence of truncal alterations grows behind and to the left of the great arteries.

[Surgical anatomy of tetralogy of Fallot]. / Anatomía quirúrgica de la tetralogía de Fallot.

We analyzed 131 hearts with tetralogy of Fallot for their prominent surgical anatomical features. Special attention was paid to the different elements of the right ventricular outflow tract obstruction, the supraventricular bands and types of septal defect and their relations with the conducting tissue and coronary supply. The infundibular region proved to be the core of the malformation in tetralogy, the left and anterior septal deviation being the origin of pulmonary stenosis and the rest of the embryopathological elements that characterize this malformation. Our results support the notion that each case has, besides the general features of the malformation, particular aspects which must be analyzed. This conjunction of general and particular features provides the clinician with a morphological basis for the interpretation of the diverse diagnostic procedures and the surgeon with the general scope of tetralogy and the individual features of each case which must be taken into account in the choice of the best possible surgical procedure.

[Spectrum of biventricular aortic connection and double outlet chamber of the right ventricle produced experimentally in the chicken heart by hypothermia (34.5 degrees C)]. / Espectro de conexión biventricular de la aorta y doble cámara de salida de ventrículo derecho producidos experimentalmente en el corazón de pollo por hipothermia (34.5 grados C).

In this experimental work, fertilized chicken eggs were subjected to hypothermia (34.5 degrees) as to inhibit the incorporation of the aortic infundibulum into the left ventricle. This produced a spectrum of biventricular connection of the aorta including double outlet right ventricle (DORV), a cardiopathy seen naturally in man and in chicken. It represents the persistence in the postnatal heart of the spectrum of embryonic aortic dextroposition, a fact which allowed us to establish a precise anatomoembryologic correlation. Pathogenetically, the failure in the connection of the aortic infundibulum with the left ventricle is due to inhibition, in different degrees, of the leftward morphogenetic movement of the infundibular segment, an embryologic process which is discussed in relation to different theories on the origin of DORV. The role played by cell death in normal and pathologic morphogenesis, is emphasized and some methodological aspects on experimental teratogeneses are mentioned.

Espectro de conexion biventricular de la aorta y doble camara de salida de ventriculo derecho producidos experimentalmente en el corazon de pollo por hipotermia (34.5 grados C) / Spectrum of biventricular conexion of the aorta and double outlet of right ventricle experimentally produced in chicken heart by hypothermia (34.5 centigrades)

En este trabajo experimental se utilizaron huevos embrionados de pollo sometidos a la accion de la hipotermia (34.5oC) con el objetivo de inhibir, la incorporacion del infundibulo aortico hacia el ventriculo izquierdo lo que produjo un espectro de conexion biventricular de la aorta incluyendo la doble camara de salida del ventriculo derecho, el cual se presenta de manera natural en el hombre y en el pollo y representa la persistencia en el corazon postnatal del espectro de dextroposicion aortica embrionaria, hecho que nos permitio establecer una correlacion anatomoembriologica precisa. Patogeneticamente la falla en la conexion del infundibulo aortico con el ventriculo izquierdo se debe a la inhibicion en diferentes grados del movimiento del segmento infundibular hacia la izquierda, hecho que se discute en relacion a diferentes teorias sobre supuestos mecanismos patogeneticos. Se enfatiza sobre el papel que juega la mortalidad celular en la morfogenesis normal y patologica y se mencionan algunos aspectos metodologicos sobre teratogenesis experimental