Positional abnormalities of atrioventricular valves in transposition of the great arteries including double outlet right ventricle, atrioventricular valve straddling and malattachment.

Positional abnormalities (straddling or overriding) of the atrioventricular (A-V) valves were studied using angiographic, sector scan echocardiographic and postmortem anatomic data in 10 patients with transposition of the great arteries including double outlet right ventricle. Group I included six patients with tricuspid valve abnormalities. This group was further classified into: (a) patients with anular straddling and abnormal attachment of portions of the tricuspid leaflets in the left ventricle (malattachment) or on the ventricular septum, or both (four patients with d-transposition of the great arteries and hypoplastic right ventricle); and (2) patients with malattachment of portions of the tricuspid valve leaflet to the crest or left ventricular surface of the septum (septal malattachment) without significant anular straddling (two patients with d-transposition of the great arteries).Group II included four patients with mitral valve abnormalities without significant anular straddling, further classified into: (1) patients with septal malattachment of the portions of the mitral valve to the crest and right ventricular surface of the ventricular septum (two patients with double outlet right ventricle); and (2) patients with ventricular malattachment of portions of the mitral valve leaflets to the papillary muscles in the right ventricle (two patients with ventricular septal defect and discordant criss-cross atrioventricular connections).On the basis of these observations and reported experience, two main types of positional abnormalities of the A-V valves were recognized: (1) anular straddling in which the A-V anulus straddled the ventricular septum above the contralateral ventricle, together with ventricular leaflet malattachments, and (2) leaflet malattachment of either the septal or ventricular type without significant straddling of the valve anulus. Angiocardiography and sector scan echocardiography helped to identify these abnormalities of the A-V valves.     

Double outlet left ventricle with intact ventricular septum: a cross-sectional and Doppler echocardiographic diagnosis.

Double outlet left ventricle with intact ventricular septum, valvar pulmonary stenosis, an atrial septal defect within the oval fossa, dysplastic tricuspid valve and normally related great arteries are described in a four-year old male child presenting with cyanosis since birth. The diagnosis was made by cross-sectional and Doppler echocardiography and confirmed by cineangiocardiography.     

Overriding atrioventricular valves. An angiographic-anatomical correlate

An analysis of 6 patients with overriding atrioventricular valve was performed in order to correlate the anatomic and angiographic features of this malformation. The atrial arrangement was usual (situs solitus) in each patient. The ventricular chambers were normally related in 4 and the mirror image of normal in 2. The atrioventricular connexion was concordant in parallel fashion in 4, discordant in 1 and double inlet left ventricle in 1 heart. In 2 of 4 hearts with concordant atrioventricular connexion, the right atrioventricular valve (tricuspid) overrode the septum and connected partially to the left ventricle. In 2, the left atrioventricular valve (mitral) overrode the septum and partially connected with the right ventricle. One heart with discordant atrioventricular connexion had its right atrioventricular valve (mitral) overriding the septum. The remaining heart with double inlet left ventricle had an overriding left atrioventricular valve. Each overriding atrioventricular valve had its "septal" leaflet (the one committed to the contralateral ventricle) divided into 2 segments by a large cleft. Ventricular septal defects at different locations were present in all cases. The ventriculoarterial connexion was double outlet right ventricle in 5 patients and was discordant in 1. Malalignment of the atrial and ventricular septa was present to some degree in all cases. This was well depicted on ventriculograms in four chamber view in those with an overriding tricuspid valve. It was not detected in those with an overriding mitral valve. The displaced leaflets of the overriding and/or stradding valve had a vertical motion on cineangiograms similar to those observed in atrioventricular septal defects. Abnormal morphology and motion of the septal leaflet of the overriding atrioventricular valve and malalignment of the atrial and ventricular septal structures were the most important angiographic findings in this series.     

Evaluation of atrioventricular septal defect by magnetic resonance imaging

Electrocardiographically gated magnetic resonance imaging (MRI) was successfully performed in 9 patients with atrioventricular (AV) septal defect: 6 had complete AV canal and 3 had partial AV canal. The defect was readily visualized in all patients on transverse scans taken at the level of the AV valve. The size and extent of the defect could be easily determined. All patients demonstrated a similar underlying morphologic pattern on MRI scans, consisting of deficiency of the primum atrial septum and inlet ventricular septum and a "common" AV valve ring with absence of the cardiac crux. The 3 patients with isolated atrial septal defect could be distinguished from the 6 with complete AV canal by the dense, fibromuscular bridging tissue, which coursed from the AV valve to the crest of the ventricular septum, obliterating the interventricular communication. Four patients had angiographically proved ventricular hypoplasia, which was also detected by MRI. AV valves and their patterns of chordal attachment were accurately imaged in 7 patients on systolic sections; accessory chordae were identified in 6 patients. MRI is a useful noninvasive imaging modality that can depict the underlying morphologic abnormalities in AV septal defect as well as important anatomic variations.     

Double outlet right ventricle: an unusual variant with overriding of both great arteries, absent outlet septum and mitral-to-aortic-to-pulmonary valve continuity

Double outlet right ventricle constitutes a spectrum of anomalies unified by the fact that both great arteries for their major part arise from the right ventricle. The cases are subcategorized on the basis of the relationship of the great arteries, the precise position of the ventricular septal defect and the muscular morphology of the outflow tracts. The spectrum extends into cases of double outlet left ventricle, while the "in between" cases have been catalogued as double outlet both ventricles. Two hearts are described with overriding of both great arteries, which on morphometric outlet septum and mitral-to-aortic-to-pulmonary valve continuity. To the best of our knowledge, this is the first report of this anatomical arrangement in double outlet right ventricle. Two cases with a similar arrangement have been documented as double outlet left ventricle and double outlet both ventricles. Our two cases further illustrate that the use of the segmental sequential approach to congenital heart disease caters for the most unusual specimens.     

Double outlet left ventricle: Morphology, cineangiocardiographic diagnosis and surgical treatment

In double outlet left ventricle, both the pulmonary artery and the aorta arise from the morphologic left ventricle. This paper presents the anatomic and cineangiocardiographic features of five patients who had this condition proved at surgery or autopsy. The condition of the first patient was incorrectly diagnosed as transposition of the great arteries with pulmonary stenosis and ventricular septal defect; the anatomic features were correctly interpreted at operation in 1966 and appropriate repair was made, but the patient died postoperatively. The condition of the other four patients was correctly diagnosed. The second patient had Ebstein's malformation of the tricuspid valve and hypoplastic right ventricle in addition to double outlet left ventricle; her condition was not considered operable. Two patients, one with visceroatrial situs solitus, concordant d-loop and dextrocardia, were surgically treated with good long-term results. The fifth patient died 2 years postoperatively and is the first patient reported to have double outlet left ventricle with visceroatrial situs inversus, a discordant d-loop and levocardia.

The segmental approach to the classification and diagnosis of connection disorders is discussed and the radiologic criteria by which double outlet left ventricle may be diagnosed considered in detail. The importance of using the radiologic projection (usually left anterior oblique) that profiles the ventricular septum is emphasized because the diagnosis can be established only by delineating the relations of the origins of the great arteries to the ventricular septum. The surgical significance of other anatomic features, including the number, size and position of ventricular septal defects and conal malformations, is also discussed.     

Axial cineangiography in congenital heart disease. Section II. Specific lesions

The value of axial cineangiography in several forms of congenital heart disease serves as an illustrated supplement to Section I. These techniques visualize defects in the entire ventricular and atrial septum. In persistent atrioventricular (A-V) canal, it is possible to visualize all parts of both septa, status of the A-V valves (two valves versus a common A-V valve), and if a common A-V valve, its degree of override. In tetralogy of Fallot, the bifurcation of the pulmonary trunk, entire ventricular septum and coronary arteries are vividly shown. The presence of true and confluent pulmonary arteries versus systemic or bronchial arteries in pseudotruncus is clearcut. In double outlet right ventricle or in transpositions with or without double outlet right ventricle, the mitral valve-semilunar valve relationships, the left ventricular outflow tract, subpulmonary region and a straddling tricuspid valve are well demonstrated. In asymmetric septal hypertrophy, biventricular angiography may be circumvented.     

Double-inlet single left ventricle: echocardiographic anatomy with emphasis on the morphology of the atrioventricular valves and ventricular septal defect.

The echocardiographic anatomy of double-inlet single left ventricle was studied in 57 patients, aged 1 day to 27 years (mean 6 years); the variables examined included morphology, size and function of the atrioventricular (AV) valves and ventricular septal defect and their relation to pulmonary stenosis, aortic stenosis and aortic arch obstruction. The visceroatrial situs was solitus and the heart was in the left side of the chest in all 57 patients. A d-loop ventricle was present in 21 patients and an l-loop ventricle in 36. The great arteries were normally related (Holmes heart) in 8 patients and transposed in 49. In all hearts, the right AV valve was anterior to the left AV valve. In 53 patients, the tricuspid valve (right valve in d-loop and left valve in l-loop) was closer to and had attachments on the septum. The tricuspid valve straddled the outflow chamber in eight patients. No significant difference was noted in the mean AV valve diameter when comparing mitral and tricuspid valves within the same group or between the groups with a d- or l-loop ventricle. The right AV valve diameter had a significant direct correlation with the aortic valve diameter and the size of the ventricular septal defect regardless of ventricular loop. Both AV valves were functionally normal in 34 patients. Among patients with AV valve dysfunction, the tricuspid valve tended to be stenotic in patients with an l-loop ventricle and regurgitant in patients with a d-loop ventricle. Mitral valve dysfunction was uncommon. The ventricular septal defect (46 patients) was separated from the semilunar valves in 24 patients (muscular defect) and adjacent to the anterior semilunar valve as a result of hypoplasia or malalignment, or both, of the infundibular septum (subaortic defect) in 19 patients. Multiple defects were present in three patients. The defect was unrestrictive in 26 patients, restrictive in 23 and could not be evaluated in 8. Pulmonary artery banding had been performed in 8 of the 26 patients with an unrestrictive defect and in 10 of the 23 patients with a restrictive defect. Only 4 of 19 subaortic defects compared with 16 of 24 muscular defects were restrictive. The size of the defect was significantly correlated with the measured pressure gradient. Among patients with transposition, only 2 of 13 with pulmonary stenosis had a restrictive ventricular septal defect compared with 15 of 30 without pulmonary stenosis. In patients with transposition, the defect size was significantly smaller when coarctation was present.     

Overriding tricuspid valve: Echocardiographic and angiocardiographic features

Eight cases are presented in which the diagnosis of overriding of the tricuspid valve was made during life and the electrocardiographic, echocardiographic and angiographic features of this defect are presented. Four of the patients had dextrotransposition of the great arteries, three had normally related great arteries and one had corrected transposition. In each case there was hypoplasia of the right ventricle and a ventricular septal defect of the atrioventricular (A-V) canal type. The electrocardiogram in the cases with d-transposition was characterized by diminished right ventricular forces, left ventricular hypertrophy and a superior leftward frontal plane axis. The echocardiogram in seven cases demonstrated a septal leaflet of the tricuspid valve opening posterior to the septum into the left ventricle. In four cases the anterior leaflet of the tricuspid valve was shown crossing the plane of the interventricular septum as it opened in diastole. The diagnosis in five cases was made angiographically by a left ventricular injection in the left anterior oblique projection. In this view the septum was viewed tangentially and in diastole the negative silhouette of the tricuspid valve was seen straddling the interventricular septum. The presence of an overriding tricuspid valve can greatly complicate repair of intracardiac defects. The diagnosis of this A-V valve anomaly can be accurately made with the use of echocardiography and selective left ventricular angiography.     

Tricuspid atresia. An anatomical study of 17 cases.

This is a report on the anatomical characteristics of 17 cases of tricuspid atresia. Three of these cases had a discrepancy between the type of bulboventricular loop (dextro) and the position of the great arteries (the aorta being to the left of the pulmonary artery). In these a characteristic type of ventricular septal defect, located just beneath the tissue of the semilunar valves was found. In 3 cases with cardiac dextroversion and juxtaposition of the atrial appendages the great arteries were on the same frontal plane and there was a separation between the semilunar and the anterior mitral leaflet. One case was associated with a double outlet left ventricle, a D-malposition of the great arteries, and a bilateral subaortic and subpulmonary conus. Among the 6 cases with transposition of the great arteries, the ventricular septal defect was large in 2 (34.4%) only. In the analysis of the 13 cases with intact ventricular septa (2 cases) or restrictive (small and medium-sized) ventricular septal defects (11 cases) obstructive anomalies of the vessel arising from the right ventricle were found in 12 (92.3%). These anomalies involved the aorta in 4 cases. (34.4%) and the pulmonary artery in 8 (66.6%). In the study of the 4 cases with a large ventricular septal defect, obstructive anomalies in the vessel arising from the right ventricle were present in 2 cases (50%), and were located in the aorta in 1 case (25%) and in the pulmonary artery in the other case (25%). The 2 cases with intact ventricular septum were associated with a hypertrophy of this septum and an absent pulmonary valve. In 1 of these cases, a third ventricular chamber was disclosed within the ventricular septum. This chamber communicated with the right ventricle through a very small opening. In 82.3% of the cases, the projection of the dimple, the rest of the tricuspid orifice, was located either on the ventricular septum or over the left ventricle. In the 3 cases with juxtaposition of the atrial appendages there was a positive transillumination of the floor of the right atrium, which corresponded, to the rest of the tricuspid valve in one case and to the atrioventricular portion of the membranous septum in the other 2.     

Isolated ventricular inversion with double inlet left ventricle.

2 patients with viscero-atrial situs solitus, isolated ventricular inversion (IVI) and double inlet right-sided morphologic left ventricle are presented. Isolated ventricular inversion is a rare cardiac anomaly characterized by ventricular inversion, subpulmonary conus, and ventriculo-arterial concordance. Their angiocardiographic and pathologic features are presented, and the morphologic findings of the 9 patients in the literature with isolated ventricular inversion are reviewed. Of the 11 known patients with isolated ventricular inversion, levocardia was present in 10 and dextrocardia in 1; viscero-atrial situs solitus in 9 and inversus in 2; L-ventricular loop in 9 and D-loop in 2. The atrial septum was intact in 4. An intact ventricular septum was noted in only 2 patients while in 3, more than one ventricular septal defects were present, and 2 patients exhibited morphologic single ventricle. A solitary ventricular septal defect was noted in the remainder. Significant tricuspid valve abnormalities, including atresia, stenosis or hypoplasia with supravalvular fibrous ring were found in 7 patients. In 2 of these, both with significant obstruction at the tricuspid valve, both atrioventricular valves emptied into the morphologic left ventricle--thus isolated ventricular inversion with double inlet left ventricle. Pulmonary outflow tract obstruction was evident in only 3 patients. Total anomalous pulmonary venous return occurred twice and right juxtaposition of the atrial appendages once. Thus, while the patient with isolated ventricular iversion may present with clinical and hemodynamic features characteristic of classical transposition physiology the high frequency of significant associated anomalies would complicate this. Finally, the anomaly must be differentiated from the levo-transposition, isolated atrial inversion, and the anatomically corrected malpositions.     

Two dimensional echocardiographic characteristics of double outlet right ventricle.

The reliability was evaluated of two dimensional echocardiography in distinguishing double outlet right ventricle from other anomalies of the great arteries. Accordingly, a combined retrospective and prospective study was conducted in 13 children with double outlet right ventricle, 12 with tetralogy of Fallot, 13 with complete d-transposition of the great arteries, 5 with congenitally corrected I-transposition and 2 with truncus arteriosus. Echographic findings using a standard long axis view in all subjects with double outlet right ventricle included (1) inability to identify a great artery arising from the left ventricle, and (2) lack of continuity between the anterior mitral leaflet and any semilunar valve. In the short axis view constant findings were (1) simultaneous imaging of both great arteries in an anterior location with the ventricular septum identified posteriorly on sweeping into the left ventricle, and (2) lack of a clockwise wraparound of the aorta by the right ventricular outflow tract. Imaging revealed that the great arteries were side by side in seven patients d-malposed in three and l-malposed in two. A modified left precordial tomographic view demonstrated both great arteries arising from the right ventricle in four of nine patients not treated surgically. In four patients with surgically repaired double outlet right ventricle, the left ventricular outflow tract had a tunnel-like configuration in the long axis view. These findings were diagnostic of double outlet right ventricle in all patients and accurately differentiated the malformation from other anomalies of the great arteries.     

Spectrum of tricuspid atresia--a study of 23 cases.

The present report describes the clinical and angio-cardiographic features of 23 cases of tricuspid atresia. Nineteen patients had type I anatomy, 2 patients had type II anatomy and 2 patients had type III anatomy. In addition to the standard features, there were some uncommon associations observed. These included double outlet right ventricle, double outlet left ventricle, single coronary artery, complete heart block, right axis deviation, ostium primum atrial septal defect and coarctation of the aorta.     

Criss-cross heart with straddling right atrioventricular valve

Angiocardiographic appearance of a criss-cross heart with straddling tricuspid valve has been presented. Atrial situs was normal and the right atrium was connected to the morphological right ventricle situated superiorly and to the left of the left ventricle. The left atrium was connected to the morphological left ventricle situated inferiorly and to the right of the right ventricle. The interventricular septum was horizontal in position. Both great arteries arose from the right ventricle with the anterior aorta. The case was concluded as a criss-cross heart with concordant atrioventricular (A-V) connection and double outlet right ventricle (DORV). Straddling of the right A-V valve was recognized in another institution by two-dimensional (2-D) echocardiography and confirmed by right atrial angiography in our institution. The value of combined investigation with selective four-chamber angiography, especially including right atrial angiography and 2-D echocardiography in the diagnosis of such complex cardiac anomalies has been stressed.     

Double outlet right ventricle: Hemodynamic and anatomic correlations

There are 16 possible variations of double outlet right ventricle with regard to interrelations of the great arteries and to location of the ventricular septal defect. In a series of 62 cases, approximately two thirds of patients had the great arteries in a side by side relation, and most (28 of 41) had the ventricular septal defect in a subaortic position. In double outlet right ventricle with malposition of the great arteries, the ventricular septal defect was either subpulmonary or subaortic. Four of the 13 patients with subpulmonary ventricular septal defect had a supracristal defect with side by side relation of the great arteries (Taussig-Bing anomaly), and 9 patients had malposition of the great arteries with an infracristal ventricular septal defect. In all patients with subpulmonary ventricular septal defect, pulmonary arterial oxygen saturation was greater than systemic arterial saturation regardless of the relation of the great arteries.Forty patients had subaortic ventricular septal defect. In 24 of these patients, including 7 with malposition of the great arteries, systemic arterial oxygen saturation was greater than pulmonary arterial saturation. However, in 9 patients (25 percent) the reverse was true, as seen in complete transposition of the great arteries and in Taussig-Bing anomaly. Thus, pulmonary arterial oxygen saturation greater than systemic arterial saturation is not reliable evidence of a Taussig-Bing anomaly. Of the 25 patients with such saturation, only 4 had the Taussig-Bing anomaly.     

Identification and analysis of left atrial isomerism

The veno-atrial connections, atrial morphology, atrioventricular (AV) junction, ventricular mass, ventriculoarterial (VA) connection and great arteries in 22 autopsied hearts, diagnosed as having bilateral left-sidedness because of the morphology of the atrial appendages, were studied. The findings were correlated with the arrangement of the thoracic-abdominal organs. A solitary spleen was found in 3 and double spleens in 2 hearts (the remaining 17 hearts had multiple spleens) but left bronchial isomerism existed in all hearts in which bronchial arrangement could be determined. The heart was in the left chest in 14 cases, in the right chest in 5 and midline in 3. The apex pointed to the left in 18 hearts while in 4 hearts it pointed to the right. Fifteen hearts had a biventricular and ambiguous AV connection, 3 hearts had an absent left AV connection and 4 had double-inlet connection via a common valve (to the left ventricle in 3 and the right ventricle in 1). The VA connection was concordant in 14 hearts, discordant in 1, double outlet from the right ventricle in 4, double outlet from a solitary indeterminate ventricle in 1 and single outlet from the right ventricle through a pulmonary trunk with aortic atresia in 2 hearts. Superior caval veins were present bilaterally in 13 hearts. There was interruption of the infrahepatic inferior caval vein with azygos or hemiazygos continuation in 19 hearts while in 3 hearts the inferior caval vein continued upwards to drain into the right-sided morphologically left atrium.(ABSTRACT TRUNCATED AT 250 WORDS)     

Inverted Left Atrial Appendage Bonded to Atrial Septum

Inverted left atrial appendage (LAA) is a rare surgical complication. Our patient, a boy aged 2 years, was diagnosed with a partial atrioventricular defect with mild regurgitation of the left atrioventricular valve and a large primum atrial septal defect. Direct postoperative transesophageal echocardiography revealed a new left atrial mass attached to the atrial septum, without left ventricle inflow obstruction. Out of concern about the nature of this mass, we chose surgical direct examination. Intraoperatively, we diagnosed it as an inverted LAA accidentally attached to the atrial septum suture line. Awareness of this condition can avoid unnecessary diagnostic and therapeutic procedures.     

Straddling mitral valve with hypoplastic right ventricle, crisscross atrioventricular relations, double outlet right ventricle and dextrocardia: morphologic, diagnostic and surgical considerations

The clinical, surgical and morphologic findings in five cases of a rare form of straddling mitral valve are presented. Three patients were diagnosed by two-dimensional echocardiography, cardiac catheterization and angiocardiography and two had diagnostic confirmation at autopsy. All five cases shared a distinctive and consistent combination of anomalies: 1) dextrocardia; 2) visceroatrial situs solitus, concordant ventricular D-loop and double outlet right ventricle with the aorta positioned to the left of and anterior to the pulmonary artery; 3) hypoplasia of right ventricular inflow (sinus) with tricuspid valve stenosis or hypoplasia; 4) large right ventricular infundibulum (outflow); 5) malalignment conoventricular septal defect; 6) straddling mitral valve with chordal attachments to the left ventricle and right ventricular infundibulum; 7) severe subpulmonary stenosis with well developed pulmonary arteries; and 8) superoinferior ventricles with crisscross atrioventricular (AV) relations. The degree of malalignment between the atrial and ventricular septa was studied quantitatively by measuring the AV septal angle projected on the frontal plane. The AV septal angle in the two postmortem cases was 150 degrees, reflecting marked malalignment of the ventricles relative to the atria. This AV malalignment appears to play an important role in the morphogenesis of straddling mitral valve. As judged by a companion study of seven postmortem cases, the more common form of straddling mitral valve with a hypertrophied and enlarged right ventricular sinus had less severe ventricular malposition than did the five rare study cases with hypoplastic right ventricular sinus. A competent mitral valve, low pulmonary vascular resistance and low left ventricular end-diastolic pressure were found at cardiac catheterization in the three living patients who underwent a modified Fontan procedure and are doing well 2.2 to 5.8 years postoperatively.     

Morphological aspects of Ebstein's anomaly in adults

The essence of the Ebstein's malformation is that the tricuspid valve leaflets do not attach normally to the valve annulus, and the effective orifice is displaced downward into the right ventricular cavity at the junction of the inlet and trabecular components of the right ventricle. Only the septal and posterior leaflets are displaced and divide the right ventricle into two portions. The inlet portion is usually integrated functionally with the right atrium ("atrialized portion"), while the other, including the trabecular and outlet portions, constitutes the functional right ventricle. The proximal atrialized right ventricle often has a wall thinner than the distal functional right ventricle, due to partial congenital absence of myocardium. An atrial septal defect is present in more than one-third of hearts, and the majority of the remainder has a patent foramen ovale resulting in a right-to-left shunt. The downward displacement of the septal tricuspid valve leaflet is associated with discontinuity of the central fibrous body and septal atrioventricular ring, thus creating a potential substrate for accessory atrioventricular connections and ventricular pre-excitation making the patient at risk of sudden death. Angiography has demonstrated that a significant number of patients with Ebstein's anomaly also have morphofunctional abnormalities of the left ventricle, which may be explained by increased fibrosis in the left ventricular wall and ventricular septum as demonstrated by histological studies. Regarding embryology, the leaflets and tensile apparatus of the tricuspid valve are believed to be formed mostly by a process of delamination of the inner layers of the inlet zone of the right ventricle. The downward displacement of the leaflets in Ebstein's anomaly suggests that delamination from the inlet portion failed to occur.