Ventricular-infundibular morphology in visceral heterotaxia with left isomerism. An echocardiographic-angiocardiographic study]

We report 2D-echocardiographic and angiocardiographic assessment of 28 cases of visceral heterotaxia with left atrial isomerism, with particular emphasis on infundibular ventricular morphology. Ventricular D-loop was present in 15 cases (52.6%), and ventricular L-loop in 13 (46.4%); 25/48 patients had concordant ventricular loop and cardiac position (89.3%). In 18 patients (64.3%) there were 2 balanced ventricles; of the other 10 patients, 9 (32.1%) presented right and 1 (3.6%) left ventricular dominance. Ventricular septal defect was present in 12 cases (42.8%). Ventriculo-arterial connections were concordant, with "normally related" great arteries in 9/15 cases with ventricular D-loop (60%). In these cases, ventricular morphology, connections and relations of the great arteries were typical of situs solitus. In the remaining 6 patients there was double-outlet right ventricle, also with normally related great arteries. In 12/13 cases (92.3%) with ventricular L-loop ventriculo-arterial connections were concordant with "mirror image normally related" great arteries. In these cases, ventricular morphology, connections and relations of the great arteries were typical of situs inversus. In one patient there was double-outlet right ventricle, also with mirror image normally related great arteries. Twelve patients (42.8%) had pulmonary stenosis and 5 had a systemic outflow obstruction (17.8%). From these observations we conclude that ventriculo-infundibular morphology, either of situs solitus-type or of situs inversus-type, is a typical anatomical feature of left atrial isomerism. These results may have important implications in the diagnosis and in the surgical management of patients with left atrial isomerism.     

Anatomically corrected malposition of great arteries.

Four anomalous hearts are described in which the great arteries arise in unusual fashion from their morphologically appropriate ventricles. This malformation, previously termed anatomically corrected transposition, is now termed anatomically corrected malposition. This is because, following the precedent of Van Praagh and his associates, we now reserve the term 'transposition' to describe the situation in which both great arteries arise from separate morphologically inappropriate ventricles. All the hearts examined exhibited atrioventricular concordance, I with viscero-atrial situs inversus, and 3 with situs solitus. However, there were considerable variations in ventricular morphology between the cases. Thus, 2 cases exhibited atresia of the right atrioventricular valve, and in the remaining 2 cases right and levt ventricular sinuses were both identified. Two of the cases also had pulmonary atresia, and coronary artery anomalies were present in all 4. The cases emphasize the fact that the term anatomically corrected malposition describes not a discrete anomaly but only a ventriculo-arterial relation, which is one of ventriculo-arterial concordance. Doubt has previously been cast upon the existence of this as an anatomical entity. It is concluded that the relation does indeed exist, and furthermore can coexist with all varieties of atrioventricular relations. It is suggested that the differing atrioventricular relations can be distinguished by usage of the terms 'concordant' or 'discordant' anatomically corrected malposition. Finally, it is emphasized that it is necessary to distinguish this anomaly, which in most cases presents with left-sided anterior aorta, from the left-sided anterior aorta more frequently encountered in classically corrected transposition'.     

Surgical correction in complete levotransposition of the great arteries with an unusual subaortic ventricular septal defect

Six children with an uncommon variant of complete (that is, physiologically uncorrected) transposition of the great arteries are described. In this malformation, levoposition of the aorta is coincident with situs solitus and concordant atrioventricular relations. All patients underwent successful surgical correction. Four had a ventricular septal defect; in three, the defect was subaortic and because of its unusual anatomic features, a right ventriculotomy was required for repair. Interatrial transposition of venous return was carried out in all cases by insertion of a baffle, as in complete dextrotransposition of the great arteries. The surgical verification of the arterial positions in these cases illustrated the fallibility of the so-called loop rule. The significance of the cases in relation to terminology, classification and morphogenesis of this variant is discussed.     

Concordant Atrioventricular Connection to L-Looped Ventricles with the Left Ventricle on Top of the Right Ventricle in Situs Solitus: A Case Report with 3D Modelling and Printing

We report the case of a rare complex cardiac anomaly involving situs solitus, concordant atrioventricular connection with left-hand ventricular topology, and L-looped ventricles. The ventricles had a superior-inferior relationship with an inferiorly located right ventricle, which had a double outlet with far posteriorly located great arteries. The left atrium was elongated, with juxta-positioned atrial appendages on the right side. The 3D-printed model using a computed tomography scan taken on the fourth day of birth demonstrated the anatomy clearly and helped us decide on the surgical management.     

Coronary arterial pattern in superoinferior ventricular heart. Implications on significance of morphogenesis of this anomaly.

The coronary arterial pattern was studied in two patients with superoinferior ventricular heart and haemodynamically complete transposition. In one of them the aorta was dextro-positioned and in the other laevo-positioned. In both the right coronary artery arose from the posterior aortic sinus and the left coronary artery from the left aortic sinus. This pattern is similar to the common coronary arterial pattern in complete transposition of the great arteries. The similarity supports the theory that in the superoinferior ventricular heart the connections between the ventricles and the great arteries (concordant or discordant) area those of the basic condition--complete transposition or corrected transposition. The angiocardiographic findings indicate that relations are not always as expected for a given connection.     

Conducting tissues in congenitally corrected transposition with situs inversus.

Three cases of congenitally corrected transposition in situs inversus individuals were characterised by visceroatrial situs inversus, atrioventricular discordance, and ventiruloarterial discordance: one case was studied clinically, and the other 2 were necropsy specimens. The disposition of the atrioventricular conducting tissues was established in each case, in the living patient by intraoperative mapping, and in the necropsy specimens by histopathological investigation. In all, the connecting atrioventricular bundle arose from a normally situated posterior atrioventricular node, normally related to the landmarks of the atrial septum. Though anterior nodes were identified in the necropsy specimens, as reported in congenitally corrected transposition in situs individuals, they differed from those in the latter situation in that they made no atrioventricular connection. These findings have obvious surgical importance. It is suggested that the posterior connection is related to the good septal alignment in these cases which lacked significant septal defects. Posterior connections are not necessarily present in all situs inversus individuals with corrected transposition, particularly when there are malalignment ventricular septal defects: further studies are required in such cases.     

Conducting tissues in congenitally corrected transposition with situs inversus

Three cases of congenitally corrected transposition in situs inversus individuals were characterised by visceroatrial situs inversus, atrioventricular discordance, and ventiruloarterial discordance: one case was studied clinically, and the other 2 were necropsy specimens. The disposition of the atrioventricular conducting tissues was established in each case, in the living patient by intraoperative mapping, and in the necropsy specimens by histopathological investigation. In all, the connecting atrioventricular bundle arose from a normally situated posterior atrioventricular node, normally related to the landmarks of the atrial septum. Though anterior nodes were identified in the necropsy specimens, as reported in congenitally corrected transposition in situs individuals, they differed from those in the latter situation in that they made no atrioventricular connection. These findings have obvious surgical importance. It is suggested that the posterior connection is related to the good septal alignment in these cases which lacked significant septal defects. Posterior connections are not necessarily present in all situs inversus individuals with corrected transposition, particularly when there are malalignment ventricular septal defects: further studies are required in such cases.     

Supero-inferior ventricles and hearts with crossed circulation. Apropos of 2 cases. Review of the literature

Two cases of supero-inferior heart are reported. Segmental analysis of the first case showed: situs solitus, atrioventricular (left sided loop) and ventriculoarterial discordance, resulting in a corrected transposition with the aorta in L malposition. The second malformation arose on a situs inversus, atrioventricular concordance (left sided loop) and double outlet right ventricle. The right ventricle was on the right and above the left ventricle giving an appearance of paradoxal discordance. The atrioventricular connections determined a plane of cleavage between right and left circulations in the supero-inferior ventricles and an appearance of crossed circulations in the second case. Hypoplasia of the inflow tract, of the right ventricular sinus is almost constant in this type of spatial orientation of the ventricles. The embryological hypoplasias are suggestive of an abnormality in the rotation of the cardiac tube in a frontal plane for the superimposed ventricles and abnormal rotation secondary to ventricular septation in the hearts with crossed circulations. The different classifications proposed in the literature are discussed with respect to these cases.     

Congenitally corrected transposition in a patient with situs inversus, atrioventricular discordance and mesocardia (I,D,D)

The clinical, hemodynamic and angiographic features of a patient with situs inversus, atrioventricular discordance, corrected transposition of the great arteries (I,D,D) and mesocardia are presented. A review of the literature concerning corrected transposition of the great arteries in situs inversus is included. The incidence of associated cardiovascular and electrocardiographic anomalies is compared with that found in corrected transposition of the great arteries in situs solitus; special surgical aspects of the above cases are also discussed.     

Echocardiographic and angiographic findings in superior-inferior cardiac ventricles

The anatomy of superior-inferior ventricles was studied in 17 patients, aged 1 day to 22 years, using echocardiography and angiography. In all patients, the right ventricle was located superiorly and the left ventricle inferiorly. The right ventricular sinus was underdeveloped in 14 of the 17 patients. Conversely, the right ventricular outflow tract was normally developed in all 17 patients. The visceroatrial situs was solitus in all patients, and it was associated with a concordant D-loop in 9 patients and with a discordant L-loop in 8. There was a high incidence of associated transposition of the great arteries (9 patients) or double-outlet right ventricle (5). Segmental combination was unpredictable, D-loop being associated with L-position of the great arteries in 4 of 8 patients and L-loop being associated with D-position of the great arteries in 4 of 9. There were only 3 concordant ventriculoarterial connections. Frequently associated anomalies included ventricular septal defect (17 patients), atrioventricular valve malformations (17) subaortic conus (14) and pulmonary outflow tract stenosis or atresia (11). Criss-cross hearts were present in only 7 patients.     

Sequential chamber localization--logical approach to diagnosis in congenital heart disease.

A nomenclature is described for congenital heart disease employing sequential chamber localization. It is an eclectic system based in part upon the previous classifications of Van Praagh and Kirklin. It links together the atrial, ventricular, and arterial segments of the heart and then permits tabulation of associated anomalies. The atrial segment of the heart can exist as situs solitus, situs inversus, or situs ambiguus. Atrioventricular connexions can be concordant or discordant. In certain circumstances the terms concordant and discordant cannot be used. These are in the presence of primitive ventricle and in the presence of situs ambiguus. Alternative terms are described for these contingencies. Ventriculo-arterial connexions can be (a) normal; (b) transposition; (c) double outlet ventricle; or (d) single arterial trunk. These are defined as connexions; relations are relegated to secondary position. Associated anomalies are categorized in terms of venous return, atria, atrioventricular junction, ventricles, and great arteries. Controversial topics are discussed with regard to previous definitions.     

Malposition of the great arteries. Is this term a valid one?

We present four cases of a congenital heart malformation classically known as malposition of the great arteries. This term means there are concordant ventriculo-arterial connections with abnormal spatial relations of the aortic and the pulmonary arteries, in which the former is anterior relative to the latter, and either to the right or to the left, according to the position of the corresponding ventricle. This anomaly can be found in any type of atrial situs, notwithstanding the type or mode of atrioventricular connection, as in the cases we studied. If we consider that this anomaly depends on the associated lesions in order to produce physiological heart alterations, we think that the term of malposition of the great arteries is not valid, since in the anatomic diagnosis of congenital heart disease it is important to consider the connections between atria, ventricles and arteries, the spatial relations between them being of second importance.     

An unusual form of the transposition complex. Uncorrected levo-transposition with horizontal ventricular septum: Report of two cases.

A distinctive angiographic appearance is described in two patients who had uncorrected levo-transposition of the great vessels. Although levo-transposition with inversion of the ventricles usually results in physiologically corrected transposition, in these patients the anatomy was arranged in such a way as to result in an uncorrected transposition. The following elements were responsible for this physiological condition: normal atrial situs, inverted ventricles with "criss-cross" atrioventricular flow, levo-transposed great arteries. In addition, the morphological right ventricle was hypoplastic, left sided and superior to the left ventricle and the ventricular septum was horizontal in position. The two ventricles were connected via a large ventricular septal defect. The importance of accurate, detailed, preoperative angiographic demonstration of the anatomic situation is stressed.     

Double inlet left ventricle

Twenty-five cases of double-inlet left ventricle, 23 in atrial situs solitus and 2 with dextroisomerism are described. Twenty had both atrioventricular valves and in 3 a common atrioventricular valve connected to the left ventricle. In rest, the left atrioventricular valve was straddling over the left-sided right ventricle in about 15%. The position of the rudimentary right ventricle varied from superior, anterior and to the right of left ventricle (6 with transposition and 9 with concordant ventriculo arterial connection), to superior anterior and to the left of left ventricle (10 cases, all with transposition). Five cases had stenosis of the left atrioventricular valve and 2 stenosis of the right one. In 11, the clinical presentation was dominated by cyanosis, reduced pulmonary blood flow and right to left shunt. The rest had cyanosis and congestive heart failure. Five patients with right ventricle on the left had complete atrioventricular block, 9 right AQRS orientation and all of them findings of left ventricle hypertrophy. Three cases showed initial Q wave in VI and one left bundle branch block. Cases with right ventricle on the right, had left QRS orientation, left ventricle hypertrophy and 2 complete atrioventricular block. Cross-sectional echoes showed in 13, two atrioventricular valves committed to the left ventricle; in 3 of them the right ventricle was visualized. In 22 cases angiography determined the type of atrioventricular connection. Double inlet left ventricle is one of the most challenging diagnosis in congenital heart disease. Considering its lack of clinical specificity and according to our results, the electrocardiogram, echocardiogram and angiographic findings are of great help for its identification.     

Selective coronary arteriography in congenitally corrected transposition of the great arteries.

Three cases of congenitally corrected transposition of the great arteries in adults who underwent selective coronary arteriography are presented. The morphologic features of the epicardial coronary anatomy are distinctive and are identifiable angiographically as morphologically right and left coronary arteries that are specifically concordant with the morphologically right and left ventricles. This relation is constant in the presented cases, in previously published coronary arteriograms of congenitally corrected transposition of the great arteries and in a review of the anatomic studies of congenitally corrected transposition of the great arteries that identify the coronary arterial pattern. Thus the angiographic characteristics of the epicardial coronary arterial pattern permit identification of the morphologic features of the underlying ventricle regardless of other spatial relations.     

Double-outlet left ventricle

Two cases of double-outlet left ventricle with ventricular septal defects and pulmonic stenosis are described. Both had atrial situs solitus, one with concordant and another with discordant atrioventricular connections. Considering the clinical behaviour of the malformation, the diagnosis is difficult. Although the echocardiographic findings suggest the abnormality, angiocardiography is the best procedure for the accurate diagnosis.     

Congenitally corrected transposition of the great arteries: Morphologic study of 32 cases

The detailed anatomy of the heart is described in 32 autopsy cases of congenitally corrected transposition of the great arteries. This condition is defined as the combination of atrioventricular (A-V) discordance and transposition of the great arteries. Examples of primitive (single) ventricle with “inverted” (that is, left-sided in situs solitus) outlet chamber are excluded. Six hearts with A-V discordance and pulmonary atresia are described in an appendix. In 29 cases of corrected transposition the heart was in situs solitus; in 3 it was in situs inversus totalis. Only 5 of these 32 hearts had no potential for intracardiac shunting. Anomalies of the tricuspid valve (91 percent of cases), ventricular septal defect (78 percent) and pulmonary outflow tract obstruction (44 percent) occurred with sufficient frequency to be considered part of the basic malformation and are described in detail. The precise anatomy and disposition of the A-V valve tension apparatus, the coronary arteries and the conducting tissues are described with special reference to possible surgical approaches for repair of the anomalies. In two hearts with situs solitus the aortic valve was right-sided with respect to the pulmonary valve. This finding is important for both diagnosis and nomenclature.     

Complete transposition of the great arteries: visualization of left and right outflow tract obstruction by oblique subcostal two-dimensional echocardiography

Subcostal oblique 2-dimensional echocardiography was performed in 64 infants younger than 2 years with complete transposition of the great arteries (TGA) (situs solitus, concordant atrioventricular and discordant ventriculoarterial connections). All patients examined before cardiac catheterization had a correct diagnosis by 2-dimensional echocardiography using the subcostal oblique views. Twelve patients had associated left ventricular (LV) outflow tract obstruction and 7 had right ventricular (RV) outflow obstruction. The standard parasternal views failed to diagnose obstruction in 1 patients with LV outflow obstruction and 5 with RV outflow obstruction; the subcostal left oblique cut and long axis of the left ventricle visualized all left-sided obstructions, and right-sided obstructions were correctly displayed in 5 of 7 cases using a combination of left oblique and right oblique cuts. Two-dimensional echocardiographic subcostal oblique views allow an excellent definition of the morphologic characteristics of RV and LV outflow tracts in patients with TGA and improve the diagnosis of the outflow obstruction in these malformations.