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.

Mitral atresia with a large left ventricle and an underdeveloped or absent right ventricular sinus: clinical profile, anatomic data and surgical considerations.

In mitral atresia with a large left ventricle, the tricuspid valve is either straddling and biventricular or entirely left ventricular. To learn how to assess the identity of the tricuspid valve in such cases 15 heart specimens were examined as well as the echocardiograms of 10 living patients. When the right ventricular sinus was underdeveloped (11 cases), a straddling tricuspid valve was present; when it was absent (14 cases), the tricuspid valve was entirely left ventricular. Regardless of biventricular or exclusively left ventricular attachments, the tricuspid valve was tricommissural (at postmortem examination or on echocardiography) in 22 cases (88%). Its chordal attachments showed considerable variations but were usually paraseptal or on the ventricular septal crest or conal septum. When biventricular, the tricuspid valve straddled through an inlet ventricular septal defect. Clinical or anatomic evidence, or both, of tricuspid regurgitation was present in 14 cases (56%). It is concluded that 1) the identity of the atrioventricular valves is reflected in their chordal attachments more accurately than in their leaflet morphology and depends primarily on the type of ventricular loop present; 2) as a rule, the tricuspid valve is right-sided in D-looped and left-sided in L-looped ventricles; 3) valve identity expressed as the number and position of the papillary muscle attachments is generally recognizable echocardiographically and can be used to diagnose the type of ventricular loop that is present; and 4) the presence and degree of tricuspid regurgitation deserve attention when choosing optimal palliative surgery.

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.

Conal anatomy in 119 patients with d-loop transposition of the great arteries and ventricular septal defect: an echocardiographic and pathologic study.

OBJECTIVES: We sought to study the range of conal morphology in transposition of the great arteries with ventricular septal defect and their embryologic and surgical implications. BACKGROUND: Conal anatomy in transposition of the great arteries and ventricular septal defect is variable and might affect surgical repair. METHODS: Conal anatomy was explored using two-dimensional echocardiography in 119 patients with transposition of the great arteries and a large ventricular septal defect who presented between 1984 and 1991. The influence of conal anatomy on surgical technique was determined by review of the operative reports. Specimens of transposition of the great arteries with unusual conal anatomy were selected from the Cardiac Registry for comparison with the echocardiograms. RESULTS: One hundred five patients (88.2%) had subaortic conus only with no subpulmonary conus (Group 1). Subarterial conus was present bilaterally in eight patients (6.7%) (Group 2). Four patients (3.4%) had only subpulmonary conus with no (or minimal) subaortic conus (Group 3). Among these four patients, the aorta was posterior to the pulmonary artery in one patient, side by side relative to the pulmonary artery in two patients and slightly anterior in the fourth patient. Subarterial conus was absent bilaterally in two patients (1.7%) (Group 4); the aorta was slightly posterior in one and side by side with the pulmonary artery in the other. CONCLUSIONS: This variability of conal anatomy in transposition of the great arteries with ventricular septal defect implies four mechanisms by which transposition can occur. The conal anatomy appeared to affect surgical repair in Groups 1 and 2 insofar as it influenced ventricular outflow tract obstruction. In Groups 3 and 4, an arterial switch operation was performed in four of the six patients. The posterior location of the aorta obviated the need for the Lecompte maneuver in two of these four patients. In the remaining two cases in Groups 3 and 4, the condition was repaired by directing the left ventricular outflow across the ventricular septal defect to the aorta using a patch, with or without placement of a conduit from the right ventricle to the pulmonary artery.

Cardiac malformations in trisomy-18: a study of 41 postmortem cases.

The cardiac malformations in 41 karyotyped and autopsy cases of trisomy-18 are presented in detail. The salient findings were a ventricular septal defect in all cases; tricuspid valve anomalies in 33 cases (80%); pulmonary valve anomalies in 30 (70%); aortic valve malformations in 28 (68%); mitral valve anomalies in 27 (66%); polyvalvular disease (that is, malformations of more than one valve) in 38 (93%); a subpulmonary infundibulum (conus) in 40 (98%); a bilateral conus with a short subaortic infundibulum in 1 case with double outlet right ventricle (this being the only documented case of bilateral infundibulum in trisomy-18); double outlet right ventricle in 4 cases (10%), three having a subpulmonary infundibulum only and all 4 having mitral atresia; tetralogy of Fallot in 6 cases (15%), 2 having pulmonary atresia; and a striking absence of transposition of the great arteries and inversion at any level (visceral or cardiac), findings that appear to be characteristic of all trisomies. These data suggest that excessive chromosomal material (as in trisomies) may result in situs solitus at all levels. The malformations of the atrioventricular and semilunar valves were characterized by redundant or thick myxomatous leaflets, long chordae tendineae and hypoplastic or absent papillary muscles. The ventricular septal defect was associated with anterosuperior conal septal malalignment in 25 cases (61%). On the basis of the characteristic valvular lesions, the type of ventricular septal defect and the absence of transposition or inversions, two-dimensional echocardiographic diagnosis of trisomy-18 in the fetus may become possible.

Tricuspid atresia or severe stenosis with partial common atrioventricular canal: anatomic data, clinical profile and surgical considerations.

The anatomic findings in 11 cases of tricuspid atresia and in two cases of severe tricuspid stenosis, both combined with partial common atrioventricular (AV) canal, are presented in detail. Twelve cases were documented by postmortem examination and the diagnosis was confirmed by echocardiography and surgical observation in the one living patient. Clinical data available in nine cases and cardiac catheterization data obtained in eight are included in this report. In three cases (23%)--two with tricuspid atresia and one with extreme tricuspid stenosis--the tricuspid valve and right ventricle exhibited characteristics seen in Ebstein's anomaly. In all 13 cases, the great arteries were normally related. The ventricular septal defect(s) in 10 (83%) of the 12 postmortem cases rapidly became smaller and this resulted in marked diminution of the pulmonary blood flow and severe hypoxia. Only three of the eight patients with available cardiac catheterization and angiocardiographic data showed the scooped-out appearance of the left ventricular septal surface characteristic of AV canal defects. By contrast, two-dimensional echocardiography, available in the three most recent cases, accurately demonstrated all the defects present and represents the diagnostic method of choice. Early surgical intervention to establish a systemic to pulmonary artery anastomosis is essential for survival. More definitive surgical treatment can be achieved later by an atriopulmonary or cavopulmonary anastomosis with or without replacement of the cleft and often regurgitant mitral valve. The one living patient exemplifies this approach. This is the largest series of this unusual type of tricuspid atresia reported to date.

Double-orifice mitral valve: a study of 27 postmortem cases with developmental, diagnostic and surgical considerations.

What is double-orifice mitral valve anatomically and embryologically? In 27 postmortem cases, an anomaly of the tensor apparatus was always found. These malformations may be summarized as: (1) chordal ring; (2) accessory papillary muscle or muscles; (3) subdividing muscular ridge; (4) fused papillary muscles (parachute mitral valve); (5) crossing chordae tendineae; and (6) central fibrous subdivision. More than 1 of these anomalies often coexisted per case. Double-orifice mitral valve almost always consisted of abnormal holes in essentially normal leaflets, rather than of abnormal fibrous bridges or adhesions between normal leaflets. Since these fibrous "bridges" between the smaller accessory orifice and the larger main orifice are composed of mitral leaflet tissue and chordae, not fibrous adhesions, these bridges should not be transected surgically, to avoid iatrogenic mitral regurgitation. The accessory (smaller) orifice was at the anterolateral commissure in 11 cases (41%), at the posteromedial commissure in 12 (44%) and there was a central fibrous subdivision with approximately equal-sized orifices in 4 (15%). The atrioventricular (AV) canal was normally divided in 12 cases (44%) and a common AV canal was present in 15 (56%). When the accessory orifice was at the anterolateral commissure, the AV canal usually was normally divided (8 of 11, 73%). But when the accessory orifice was at the posteromedial commissure, a common AV canal almost always was present (11 of 12, 92%). Functionally, the mitral valve was normal in 13 (48%), regurgitated in 7 (26%) and stenotic in 7 (26%). The key to the diagnostic and surgical understanding of the double-orifice mitral valve is the underlying tensor apparatus.

Interrupted inferior vena cava in asplenia syndrome and a review of the hereditary patterns of visceral situs abnormalities.

We present the clinical and postmortem findings of the first photographically documented case of asplenia and interrupted inferior vena cava and the anatomic findings of 5 previously reported cases. A brief review of the various hereditary patterns of visceral situs abnormalities suggests that, at least in some cases, the asplenia and polysplenia syndromes are etiologically and pathogenetically interrelated.

Absent right superior vena cava in visceroatrial situs solitus.

Absence of the right superior vena cava (SVC) in visceroatrial situs solitus is rare (0.07% to 0.13% of congenital cardiovascular malformations), and little is known about the type and frequency of additional heart defects and arrhythmias. We reviewed previous publications and present 9 new cases. Based on 121 known cases, we found that this anomaly is typically characterized by: (1) persistence of the left SVC draining into the right atrium by way of the coronary sinus, and (2) left-sided azygos vein draining into the left SVC. Less constant features were: (3) additional cardiovascular malformations (46%), and (4) rhythm abnormalities (36%) that usually appeared related to the complications of old age. Since absence of the right SVC is clinically silent, its status should be assessed echocardiographically prior to invasive medical or surgical procedures. This is important to avoid various management difficulties during the following procedures: (1) implantation of a transvenous pacemaker, (2) placement of a pulmonary artery catheter for intraoperative or intensive care unit monitoring without fluoroscopy, (3) systemic venous cannulation for extracorporeal membrane oxygenation, (4) systemic venous cannulation for cardiopulmonary bypass, (5) partial or total cavopulmonary anastomoses; and (6) orthotopic heart transplantation and endomyocardial biopsies.

Echocardiographic and anatomic findings in atrioventricular discordance with ventriculoarterial concordance.

Atrioventricular (AV) discordance with ventriculoarterial (VA) concordance is a rare form of congenital heart disease that consists of 5 different anatomic types. The salient therapeutic consideration uniting these 5 different anatomic entities is that anatomic correction can be achieved by an atrial switch procedure with closure of any associated septal defect. Three patients who had AV discordance with VA concordance are presented, with emphasis upon 2-dimensional echocardiographic diagnosis and surgical management. One of these patients had ventricular inversion with inverted normally related great arteries in situs solitus (i.e., [S,L,I]), thus representing a form of congenital heart disease that until now has not been documented anatomically. Although these are complex defects, multiple-plane imaging with 2-dimensional echocardiography was found to be extremely reliable in ascertaining the anatomy when a comprehensive, segmental analysis is applied. This approach includes determination of visceroatrial situs, ventricular loop and great arterial position and alignment. A surgical approach to closure of the ventricular septal defect through the left-sided infundibulum in isolated ventricular inversion afforded excellent exposure of the defect and avoided AV conduction block.

Aristotle's "triventricular" heart and the relevant early history of the cardiovascular system.

Aristotle said that the human heart has three ventricles--right, left, and middle--a concept that has often been viewed as an astonishing error. But was it? Aristotle did not miscount ventricles. In the third century BC, all cardiac chambers were called "ventricles," meaning "cavities." The "ears" (auricles) were distinguished from the "cavities" (ventricles) by Herophilus of Alexandria (c 300 BC) and by Rufus and Ephesus (a contemporary of Jesus Christ). Aristotle regarded the right atrium as a venous dilatation, not as a part of the heart. Aristotle's "right ventricle" was our right ventricle. His "left ventricle" was our left atrium. His "middle ventricle" was our left ventricle. Because he did not count the right atrium, Aristotle considered the human heart to be three-chambered or "triventricular," consisting of the right ventricle, the left atrium, and the left ventricle. This report summarizes the relevant early history of the cardiovascular system.

Transposition of the great arteries with straddling tricuspid valve. Report of two rare cases with acquired subaortic stenosis after main pulmonary artery banding.

The clinical, hemodynamic, angiocardiographic, and postmortem findings of a previously unreported type of subaortic stenosis are presented in two patients who also had straddling tricuspid valve and transposition of the great arteries. The subaortic stenosis became apparent after banding of the main pulmonary artery and was due to hypertrophy of a probably abnormally positioned moderator band resulting in a double-chambered right ventricle. Fibrous tissue accumulation at the stenotic os infundibuli also contributed to the subaortic obstruction. Both patients had situs solitus of the atria. Patient 1 had ventricular inversion (L-loop ventricles) and atresia of the right-sided mitral valve. Patient 2 had normally positioned ventricles (D-loop) and two atrioventricular valves. The presence of a large left ventricle and a small right ventricle in the angiocardiogram led to the erroneous diagnosis of a single left ventricle with an infundibular outlet chamber in both patients. Consequently, the subaortic obstruction was thought preoperatively to be at the site of a restrictive bulboventricular foramen. Patient 1 died 36 hours after placement of a valved conduit from the left ventricle to the descending aorta. Patient 2 was operated on successfully and the surgical procedures performed are described.

Partial or total direct pulmonary venous drainage to right atrium due to malposition of septum primum. Anatomic and echocardiographic findings and surgical treatment: a study based on 36 cases.

The clinical and anatomic findings in 36 patients (21 postmortem cases and 15 living patients) with partially anomalous (16 [44%]) or totally anomalous (20 [56%]) pulmonary venous drainage directly to the right atrium constitute the material basis of this report. Displacement of septum primum--leftward in atrial situs solitus or rightward in atrial situs inversus--was present in all and appeared responsible for the anomalous pulmonary venous drainage. The pulmonary veins were connected with what normally constitutes the posterior wall of the left atrium, which became incorporated into the right atrium because of atrial septal displacement. This abnormality occurred predominantly in patients with visceral heterotaxy, usually with polysplenia, or rarely with asplenia or a normally formed spleen. Poor development or absence of septum secundum appeared responsible for the malposition of septum primum. Echocardiographic recognition of the displacement of septum primum facilitated surgical management.

Systemic and pulmonary venous connections in visceral heterotaxy with asplenia. Diagnostic and surgical considerations based on seventy-two autopsied cases.

To facilitate the preoperative diagnosis and surgical management of visceral heterotaxy and asplenia, 72 postmortem cases were reviewed with particular attention focused on the systemic and pulmonary venous connections. The superior vena cava was bilateral in 51 cases (71%), but in 9 cases one of the superior venae cavae was partly or totally atretic. Patent bilateral superior venae cavae were found in 42 cases (58%) and the superior vena cava was unilateral in 21 (29%). Although the inferior vena cava was never interrupted, a prominent azygos vein was found in 6 cases (8%). Some hepatic veins drained separately from the inferior vena cava in 20 cases (28%). An intact coronary sinus was rare (2 cases, 3%). Anomalous pulmonary venous connection to a systemic vein was total in 42 (58%) of 72 and partial in 2 (3%) of 72, with obstruction in 24 (55%) of 44. Abnormal pulmonary artery branches (severe hypoplasia, localized stenosis, or discontinuity) were present in 21 (29%), and these obstructive arterial anomalies were associated with a significantly higher prevalence of anomalous pulmonary venous connection (p < 0.01) and of pulmonary venous obstruction (p < 0.01). Cardiac pulmonary venous connections were found in 28 (39%), with the pulmonary veins and the inferior vena cava entering the same atrium in 10 (36%) of 28.

Surgical closure of apical ventricular septal defects through a right ventricular apical infundibulotomy.

BACKGROUND: We present a new understanding of the anatomic position of apical ventricular septal defects and its surgical relevance. These defects occur between the left ventricular apex and the infundibular apex, rather than between the left and right ventricular apices. Often a sizable apical recess, the infundibular apex lies anteriorly and inferiorly to the moderator band and is the most leftward part of the right ventricle. METHODS: Four patients (2 boys and 2 girls) with a mean age of 109 days (range, 48 to 217 days) underwent patch closure through an apical infundibulotomy, which allowed complete visualization of the muscular apical ventricular septal defect. RESULTS: There were no early or late deaths at operation. No significant residual shunt at ventricular level was detected by postoperative two-dimensional and Doppler echocardiography. Intraoperative comparison of right atrial and pulmonary arterial blood samples showed a difference of less than 5%. At a mean follow-up of 18 months, all the patients are asymptomatic and growing well. CONCLUSIONS: The successful outcome of these 4 patients indicates that surgical closure of apical ventricular septal defects can be achieved safely and completely in early infancy through a limited right ventricular apical infundibulotomy. Long-term follow-up of these and similar patients is needed to provide further evaluation of this approach.

Total anomalous pulmonary venous drainage in newborns with visceral heterotaxy.

Children with visceral heterotaxy often present with total anomalous pulmonary venous drainage (TAPVD) associated with univentricular congenital heart disease. We reviewed our experience with the primary surgical management of this lesion under these circumstances. Over a recent 10-year span, 38 patients within the first 3 days of life were admitted to our institution and underwent primary palliation. Twenty-one of them had TAPVD, 18 to a systemic vein. Twelve (67%) of these 18 were seen with obstruction of the anomalous connection and underwent emergency operation. In 7 patients, repair of TAPVD was combined with a systemic-pulmonary artery shunt because of additional obstruction of the pulmonary blood supply, with two deaths. One patient had primary shunting and then repair of TAPVD. Four patients underwent repair of TAPVD alone. Two of them then showed signs of insufficient pulmonary blood flow, received a shunt in a second procedure, and subsequently died. Early mortality in the group with obstructed TAPVD was thus 4 (33%) of 12 patients. Statistical analysis of all 38 patients (univariate analysis, chi 2 testing) showed that neither the presence of TAPVD (p = 0.7) nor TAPVD repair alone (p = 0.8) or with shunting (p = 0.8) was a definite risk factor for early death. The performance of a shunt during the first operation, however, was associated with lower early mortality (p = 0.03). Total anomalous pulmonary venous drainage is a common finding in newborns with visceral heterotaxy. Its presence and its subsequent early repair (requiring cardiopulmonary bypass) do not increase the mortality risk. The need of a concomitant shunt in obstructed TAPVD can initially be underestimated.