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.

Tetralogy of Fallot with obstruction of the ventricular septal defect: spectrum of echocardiographic findings.

Tetralogy of Fallot with a restrictive ventricular septal defect and suprasystemic right ventricular pressure is an uncommon anomaly with a high mortality rate. In previous studies, the identity of the tissue obstructing the ventricular septal defect has usually not been determined preoperatively. This report describes the echocardiographic and anatomic features in 4 patients with a restrictive ventricular septal defect among 269 patients with tetralogy of Fallot undergoing surgical repair. Echocardiography determined the presence and identity of the obstructing tissue in all four patients. In one patient, the defect was small in association with marked septal hypertrophy. In three patients, accessory or excessive tricuspid valve tissue obstructed the defect in a manner similar to spontaneous closure of isolated membranous ventricular septal defects. Autopsy and catheterization findings are also presented of an additional case with a unique mechanism of obstruction by a tricuspid valve with Ebstein's anomaly. In patients with tetralogy of Fallot, recognition of an obstructed ventricular septal defect is important because it appears to have a poor prognosis.

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.

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.

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.

Postoperative pathology of congenital heart disease.

Complete and unselected data concerning the postoperative pathology of congenital heart disease are presented for the first time. This study was based on 2,365 autopsies performed at the Children's Hospital Medical Center, Boston, in the 9 years from 1966 through 1974. Of these, 586 autopsies (25 percent) revealed congenital heart disease--238 performed in medically treated patients (41 percent) and 348 in surgically treated patients (59 percent). Tetralogy of Fallot, including cases with pulmonary outflow tract atresia and other associated malformations, was the congenital heart disease most often encountered in the postoperative autopsy series (88 cases, 25 percent of that series). D-transposition of the great arteries, including cases with other associated anomalies, was second (54 cases, 15.5 percent). Early death (hospital mortality) accounted for 320 (92 percent) of the 348 surgical cases; late death occurred in 28 patients (8 percent). Causes of late postoperative death included arrhythmias, excessively small ventricular septal defect with tricuspid atresia, massive hemoptysis, rupture of the pulmonary artery, cyanotic spell, congestive heart failure and infection. Prophylactic penicillin is recommended for patients with the asplenia syndrome because of their probably enhanced vulnerability to fulmfulminating septicemia by encapsulated bacteria such as the pneumococcus. Completeness and lack of selection in reporting data are essential in the interests of perspective and comparability of findings.

Extracardiac anomalies in the heterotaxy syndromes with focus on anomalies of midline-associated structures.

The extracardiac defects in patients with heterotaxy have not been examined as extensively as cardiac defects. We found a high incidence of midline-associated defects in 160 autopsied cases of heterotaxy (asplenia, polysplenia, or single right-sided spleen). Fifty-two percent of patients with left-sided polysplenia had a midline-associated defect, as did 45% of those with asplenia. Most common were musculoskeletal or genitourinary anomalies, as well as cleft palate. Fused adrenal glands and anal stenosis or atresia occurred exclusively among patients with asplenia. A midline anomaly was twice as likely to be detected on complete autopsy than from clinical findings alone. Linkage studies should take into account that affected subjects may have isolated subclinical midline defects. The high incidence of midline-associated defects supports the theory that the midline plays a critical role in establishing left-right asymmetry in the body. Comparison of these defects with mouse models of laterality defects suggests that mutations that disrupt the transforming growth factor beta pathway may result in heterotaxy.

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.

Patch repair of subsemilunar conal septal defect resulting in severe left ventricular outflow tract obstruction.

A subsemilunar conal septal defect was closed at 8 months of age with a redundant Dacron patch that bowed into the left ventricular outflow tract, resulting in severe subaortic stenosis and massive left ventricular hypertrophy. Mistaken for cardiomyopathy or myocarditis, this rare complication of subsemilunar ventricular septal defect patch closure led to orthotopic cardiac transplantation followed by death.

Unusual vascular anomalies causing persistent pulmonary hypertension in a newborn.

A unique case of pulmonary vascular anomalies causing persistent pulmonary hypertension in a newborn is described. The child died 3 days after birth. Necropsy revealed marked hypoplasia of the right and left pulmonary arteries with a normal main pulmonary artery, patent ductus arteriosus, bilateral systemic arteries to the lungs from the abdominal aorta, and partial anomalous pulmonary venous connection. Quantitative morphometric techniques demonstrated slight abnormalities of alveolar development and severe arterial medial hypertrophy with abnormal extension of muscle into small peripheral arteries. Bronchopulmonary development appeared relatively normal in spite of the vascular abnormalities.

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.

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.

Truncus arteriosus with anomalous pulmonary venous connection.

The anatomic, diagnostic, and management findings of 6 patients with truncus arteriosus and anomalous pulmonary venous connections are described. Additional risk factors indicative of poor prognosis were found in 3 of 4 patients with truncus arteriosus and totally anomalous pulmonary venous connection and in 1 patient with partially anomalous pulmonary venous connection.

Two-dimensional and Doppler echocardiographic and pathologic characteristics of the infantile Marfan syndrome.

Since the clinical, 2-dimensional and Doppler echocardiographic and pathologic findings in infantile Marfan syndrome have not been documented in detail, a study of 9 such infants was performed. The previously reported 64 cases were reviewed and the salient findings in 22 additional cases were discussed. The age at diagnosis in our 9 cases ranged from birth to 12 months (mean 2.7 months). Mitral valve prolapse was demonstrated in all, with mitral regurgitation in 8. Tricuspid valve prolapse was present in 8, with tricuspid regurgitation in 6. Marked aortic root dilatation was present in all, and was progressive. The aortic root assumed a "clover leaf" appearance in the parasternal short-axis view. Aortic regurgitation was documented initially in 1 patient, and developed during follow-up in 4 of 7 infants. Dilation of the pulmonary arterial root and pulmonary regurgitation were found in 3 of 7 infants. Severe heart failure associated with mitral or tricuspid regurgitation was present in 7 of the 9 patients. Four infants died during the first year of life. The salient pathologic features were myxomatous thickening and redundancy of the mitral and tricuspid leaflets, marked elongation of chordae tendineae and prominent dilatation of the aortic and pulmonary roots. Histologically, the collagen and elastic fibers were severely disrupted, disarrayed and fragmented with increased interstitial ground substance. These data document that infantile Marfan syndrome is characterized by clinical and morphologic features that are distinctly different from the classic syndrome seen in adolescents and adults. The aforementioned findings should facilitate early clinical and echocardiographic diagnosis of infantile Marfan syndrome.

Pulmonary valve-moderator band distance and association with development of double-chambered right ventricle.

Double-chambered right ventricle (DCRV), a form of right ventricular outflow obstruction that sometimes accompanies a ventricular septal defect (VSD), is associated with superior and rightward displacement of the septal insertion of the moderator band. It was hypothesized that this superior displacement is present and identifiable by echocardiography in patients with a VSD even before right ventricular outflow tract obstruction develops. Eight patients who had a previous echocardiographic study showing a VSD alone were echocardiographically diagnosed as having DCRV. Their initial echocardiographic studies were reviewed, and superior displacement of the moderator band was quantified by measuring the distance between the pulmonary valve and moderator band, normalized to tricuspid anulus diameter. These measurements were compared with those from the initial studies of the following 3 other groups: (1) an age-matched group of 10 patients with no structural heart disease; (2) an age-matched group of 10 patients with a VSD who did not develop DCRV; and (3) a group (not age-matched) of 10 patients with VSD and DCRV in whom subpulmonary obstruction was present on the initial study. The 8 patients who eventually developed subpulmonary obstruction had significant superior displacement of the moderator band at the time of their initial echocardiogram compared with that of the 2 age-matched control groups (p less than 0.01). In contrast, there was no significant difference in moderator band displacement between these patients and the 10 with DCRV who already had right ventricular outflow obstruction at their initial study (p = not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Compression of intrapulmonary bronchi by abnormally branching pulmonary arteries associated with absent pulmonary valves.

In 3 patients with absent pulmonary valve syndrome and absent ductus arteriosus, the lungs were injected and analyzed postmortem using morphometric techniques. Two patients had tetralogy of Fallot and 1 had D-transposition of the great arteries, the latter being the first autopsy-proved case of absent pulmonary valve with transposition. In addition to the expected dilatation of the central pulmonary arteries and compression of the mainstem bronchi, postmortem pulmonary arteriography revealed a bizarre pattern of hilar branching. Instead of single segmental arteries, tufts of arteries arose which entwined and compressed the intrapulmonary bronchi. In all 3 patients the histologic structure of the pulmonary arteries was abnormal. The elastic lamina of the media of the right and left pulmonary arteries were increased in number outside the lung, but were decreased within the lung. At both sites, the elastic laminae were thickened and fragmented. In the 2 ventilator-dependent patients, there was slight medial hypertrophy and extension of muscle into normally nonmuscular arteries. In 1 of the 2 cases in which the number of bronchial generations was counted, they were decreased, and in the 1 case in which bronchial count was unknown, alveolar multiplication was severely impaired. Therefore, our data may explain why, in some patients with absent pulmonary valve syndrome, relief of compression of the mainstem bronchi alone does not appreciably alleviate or reverse severe respiratory disease.

Double outlet right ventricle (S,D,L) with subaortic ventricular septal defect and pulmonary stenosis. Report of six cases.

The clinical, hemodynamic, angiocardiographic and pathologic findings are presented in an infrequent but surgically correctable type of double outlet right ventricle. This study is based on six cases, one with autopsy confirmation. In all, the viscera and atria were in situs solitus (S). A ventricular d-loop was present (D). There was I-malposition of the great arteries, the aorta being to the left of, and anterior to, the pulmonary artery (L). Hence, this anomaly may conveniently be represented as double outlet right ventricle (S,D,L,). The ventricular septal defect to the ventricular septum. A bilateral conus was present beneath both the aortic and pulmonary valves, preventing any semilunar-atrioventricular fibrous continuity. The subpulmonary conus was poorly expanded, resulting in pulmonary infundibular and valvular (annular) stenosis. The clinical features were those of cyanosis, clubbing and accentuation of the second heart sound in the pulmonary area (related to aortic valve closure). There was a systolic ejection murmur along the upper left sternal border, related to pulmonary outflow tract stenosis. Selective right and left ventricular angiocardiography was diagnostic. Relatively early surgical correction is suggested to minimize the progression of pulmonary infundibular stenosis and to avoid acquired atresia. In this malformation, pulmonary outflow tract reconstruction is more difficult than in tetralogy of Fallot because of the rather posterior location of the pulmonary outflow tract, and because the right coronary artery crosses the stenotic pulmonary outflow tract in front of the pulmonary valve.

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.