[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.

Congenitally corrected transposition with atrioventricular septal defect.

We describe 4 cases of congenitally corrected transposition associated with atrioventricular septal defect, diagnosed by echocardiography and angiocardiography. Two had usual atrial arrangement and two had mirror imaged atrial arrangement . All cases were associated with subpulmonary valvar stenosis. All patients presented with cyanosis and were in sinus rhythm. Atrioventricular septal defect with common atrioventricular junction was easily diagnosed on the basis of a common atrioventricular valve permitting interatrial and interventricular communications. All patients had balanced right and left ventricles. The echocardiographic recognition of the ventricles was based on the presence of the moderator band within the morphologically right ventricle, the characteristics of the apical septal trabeculations, and the shape of the ventricles. Angiocardiographic recognition of the ventricles was achieved on the basis of right and left ventriculography. In one case with usual atrial arrangement, we recorded two His bundle potentials, one anteriorly and another posteriorly. Atrial stimulation revealed blocked atrioventricular conduction at the level of the posterior bundle, and normal atrioventricular conduction through the anterior bundle. In both cases with atrial mirror-imagery, only a posterior His bundle potential was found, with normal atrioventricular conduction revealed by atrial stimulation The clinical course with this combination depends on the other lesions present in addition to the common atrioventricular valve. Our electrophysiological studies show that the conduction system in presence of a common atrioventricular valve is as expected for congenitally corrected transposition with two atrioventricular valves.

[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.

[Morphofunctional correlation in congenital anomalies of the coronary arteries. II. The ectopic origin of the coronary arteries]. / Correlación morfofuncional en las anomalías congénitas de las arterias coronarias. II. Origen ectópico de las arterias coronarias.

The authors describe the morphogenesis and functional alterations of the coronary arterial net in the ectopic coronary arteries: a) with origin in the aorta or its branches and b) with origin in the pulmonary artery. The coronary arteries are developed from: 1) endothelial sprouts localized in the great arteries walls at the level of the sigmoidal values, 2) right and left subepicardial vascular network and 3) the intramyocardial sinusoids. Most of the ectopic coronary arteries result from alterations in the connection between these three embryonic elements. The deviation of one of the subepicardial vascular network in a wrong way (in direction of pulmonary artery or the opposite Valsalva sinus) will stimulate the development of endothelial sprouts which will connect such network originating abnormal connections and anomalous origin of the coronary arteries. The origin of both coronary arteries from the pulmonary artery is in compatible with life. Myocardial ischemia is absent in patients with type I (infant) or type II (adult) anomalous origin of one coronary artery from the pulmonary artery, only in the transitional phase between both types (I and II) there is myocardial ischemia previous to the formation of the collateral coronary circulation. The ectopic origin of the coronary artery from the aortic Valsalva sinus have very little hemodynamic repercussion in the patient. Although there are cases with postexercise sudden dead. These anomalies associated to atherosclerotic coronary stenosis have an impact on the evolution and prognosis of ischemic heart disease.

[Morphofunctional correlation in congenital anomalies of the coronary arteries. I. Coronary artery fistulas]. / Correlación morfofuncional en las anomalías congenitas de las arterias coronarias. I. Fístulas arteriales coronarias.

In order to explain the congenital coronary arteries malformations, the authors review the recent concepts on the coronary artery morphogenesis, based in the findings that in the human embryo, these arteries evolve from three sources: 1) endothelial aortic buds, 2) cavitary cellular groups from pericardial origin and with angiogenic character, which migrate to the cardiac zones where the coronary arteries will be distributed, and 3) the intramyocardial sinusoids. The anatomic and histologic cardiac alterations will be reflected in modifications of the coronary artery pattern. The coronary artery fistulae are formed by the persistence of the sponge structure of the myocardial wall, present in the early ontogenic steps of the cardiac development; such fistulae alter the normal functions of the coronary vascular tree and are capable to cause angina pectoris to the patient through diverse mechanisms: absence of capillarization, steal phenomenon aggravated by the altered coronary arteries properties when aneurysm or vascular channels are developed. The authors suggest a classification of the congenital coronary arteries anomalies: I. Anomalous origin in the sinus of Valsalva (anomalous and ectopic origin), II. Malformations of the coronary branches (in number, distribution and wall anomalies) and III. Anomalous connection of the coronary arteries: fistulae and persistence of the intramyocardial sinusoids isolated or communicated to left and right ventricles. The latter are frequently associated with aortic or pulmonary valve atresia. They do not cause myocardial ischemia and are formed secondary to the intracavitary elevated pressure which maintained the persistence, dilatation and communication of the ventricular chambers with such sinusoids and coronary arteries in the case of pulmonary valve atresia and with coronary veins in the case of aortic valve atresia.

[A pathological study of valvular dysplasia and attachment in Ebstein's anomaly]. / Estudio patólogico de la displasia y el adosamiento valvulares en la anomalía de Ebstein.

Forty hearts with Ebstein's disease of the tricuspid valve were studied in order to correlate dysplasia and attachment of tricuspid valve leaflets at the ventricular walls, atrialization of the right ventricle and fibrosis in this chamber. The correlation was positive. The right ventricular atrialization was directly proportional to leaflet attachment; the correlation in severity between leaflet attachment; the correlation in severity between leaflet attachment and dysplasia was positive in 45%. The right ventricular fibrosis was very frequent in the group with patent pulmonary valve (90%), and the contrary was in the group with pulmonary valve atresia (10%). The structural damage in the right ventricular wall was directly proportional to leaflet attachment in hearts with patent pulmonary valve (90%); in all of these hearts the anatomic annulus of the tricuspid valve was enlarged but in hearts with pulmonary valve atresia this feature only occurred in 10%. The specimens with atrioventricular discordant connexion, the anatomic annulus size, the degree of leaflet attachment, the dysplasia of the tricuspid valve as well as the fibrosis of the wall of the right ventricle were less severe compared with those hearts with concordant atrioventricular connexion. Ebstein's disease of the tricuspid valve is characterized by a disorder in the histodifferentiation of the right ventricle and the tricuspid valve which originates in great part from it.

[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.

[The pathological remnants of the right sinus venosus valve. A presentation of 6 hearts of the cor tritriatum dexter type]. / Derivados patológicos de la valva derecha del seno venoso. Presentación de seis corazones de tipo cor triatriatum dextrum.

Six hearts specimens of cor triatriatum dextrum, eight with the Chiari's network, and 3 with a membranous remnant of the crista terminalis are studied. These anomalies are interpreted as varying degrees of persistence of the right valve of the sinus venous which reflect different stages of their morphogenesis. The most frequent congenital heart defects associated with these sinus remnants are the absence of a right atrioventricular connexion and pulmonary atresia with intact ventricular septum. There may be some haemodynamic factors in the right atrium such as partial of complete obstruction between the atrium and the right ventricle which explain the fact that the valve is not reabsorbed. In our specimens the persistent right valve divided the right atrium into two compartments; one is located in the medial sinusal portion where both cavae veins and coronary sinus are connected; the other is lateral compartment which represents the primitive right atrium. It must be noted that the persistent right valve favors blood flow to the left atrium through the patent foramen ovale or through an atrial septal defect deviating the course of the blood away from the right ventricle. This could cause the hypoplasia of the right ventricle. When the valve bulges it obstructs the blood flowing into the right ventricle. The diagnosis of these malformations can be made by echocardiographic, angiocardiographic procedures and nuclear magnetic resonance.

[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.

[Pulmonary atresia with an intact interventricular septum and Ebstein's anomaly of the tricuspid valve]. / Atresia pulmonar con septum interventricular intacto y anomalía de Ebstein de la válvula tricuspide.

Patients with pulmonary atresia and intact ventricular septum have a poor prognosis with or without conventional surgical treatment. The best results of surgical treatment are obtained in those cases with a mild underdeveloped right ventricle and minor sinusoidal communication in the absence of important dysfunction of the tricuspid valve. We present five cases of pulmonary atresia with intact ventricular septum associated with dysfunction of the tricuspid valve. On the basis of radiographic, electrocardiographic and hemodynamic findings, this group of patients could not be distinguished from others without dysplasia of the tricuspid valve. Echocardiographic and angiocardiographic studies are mandatory in the differential diagnosis. A combination of systemic-pulmonary artery anastomosis associated with pulmonary valvotomy, when possible, and reconstruction of the right ventricular outflow tract are indicated for surgical solution of these malformations. However, tricuspid valve replacement is indicated in some cases.

[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.

[Echocardiographic diagnosis of the right tri-atrial heart]. / Diagnóstico ecocardiográfico del corazón triatrial derecho.

In this report we describe the two-dimensional echocardiographic features of a case of cor triatriatum dexter. In this situation the right atrium is divided by a membrane in two chambers. Considering the anatomic characteristics of this case we added a new type in the classical classification proposed by Doucette et al.

[Echocardiographic diagnosis of pulmonary atresia with intact interventricular septum and associated Ebstein anomaly]. / Diagnóstico ecocardiográfico de la atresia pulmonar con septum interventricular intacto y malformación de Ebstein asociada.

Pulmonary atresia with intact ventricular septum is an uncommon congenital cardiac anomaly which very often present varying degrees of downward displacement and dysplasia of the tricuspid valve. We describe a case of pulmonary atresia and intact ventricular septum associated with Ebstein's malformation of the tricuspid valve first diagnosed with echocardiography and confirmed by angiocardiography and anatomic studies.

[Double outlet right ventricle with discordant atrioventricular connection. Clinical study]. / Doble cámara de salida del ventrículo derecho con conexión atrioventricular discordante. Estudio clínico.

The clinical and anatomic findings were reviewed in 17 patients with double-outlet right ventricle and atrioventricular discordance. Ten cases had atrial situs solitus, seven with right-sided heart three with left-sided heart. Seven cases had atrial situs inversus, five with left-sided heart and two with right-sided heart. All cases presented ventricular septal defect, 13 subvalvar pulmonary stenosis, two tricuspid regurgitation and two complete atrioventricular block. The spatial relationship between the arterial valves are variable. Most cases in atrial situs solitus had a left-sided and anterior aorta and all patients in atrial situs inversus had a right-sided and anterior aorta. In this study we compared the anomalies found in our cases with double outlet right ventricle with those in 58 patients with corrected transposition. Absolute, relative and attributable risks were calculated for the presence of subvalvular pulmonary stenosis, ventricular septal defect, tricuspid regurgitation and atrioventricular block for each the two groups. We concluded that patients with double-outlet right ventricle are more prone to present ventricular septal defect and subvalvar pulmonary stenosis, while those with corrected transposition have a greater likelihood of presenting with tricuspid regurgitation and atrioventricular block. There is no typical clinical picture for the malformations. Symptoms depend upon the associated anomalies. The final diagnosis is best achieved by the echocardiographic and angiocardiographic studies, but electrocardiogram and chest radiograph may suggest the presence of a discordant atrioventricular connection.