Isolated ventricular inversion with situs solitus.

The clinical and anatomical findings in two patients with isolated ventricular inversion and situs solitus are described. The other 4 previously published cases are reviewed. The 6 patients with this malformation, all without pulmonary stenosis, presented a clinical picture of cyanotic congenital heart disease, associated with increased pulmonary blood flow (hypoxaemia and cardiac failure). The importance of different diagnostic tests is discussed and it is concluded that angiocardiography is the only definitive means of establishing the dianosis. Because the physiopathological disturbance is the same as in transposition of the great arteries, both malformations should be similarly considered with respect to diagnosis and treatment. Nevertheless, the high incidence of certain associated malformations in cases of isolated ventricular inversion adds to difficulty in diagnosis, and makes a good result from the Mustard procedure less likely than in transposition of the great arteries.     

Isolated atrial inversion Visceral situs solitus, visceroatrial discordance, discordant ventricular d loop without transposition, dextrocardia: Diagnosis and surgical correction

After cardiac catheterization and angiocardiographic studies an infant with cyanosis from birth was found to have visceral situs solitus, visceroatrial discordance without venoatrial discordance, a discordant ventricular d loop without transposition, and dextrocardia. The circulatory pathway was from the venae cavae to right atrium to left ventricle to aorta, and from the pulmonary veins to left atrium to right ventricle to pulmonary artery. An atrial defect was present allowing some mixing between the pulmonary and systemic circulations, but this appeared inadequate and the defect was enlarged surgically. Subsequently, a corrective operation using an atrial baffle to direct the pulmonary venous return to the left ventricle and the systemic venous return to the right ventricle was successfully undertaken.     

Right aortic arch with situs solitus

Patients : We reviewed all patients evaluated at our center with situs solitus, levocardia, and a right aortic arch that were born between January 2000 and January 2018. Results : From our databases, we identified 204 patients. We excluded patients with a double aortic arch from analysis. Of the 204 patients, 103 (50%) were male. Of the 204 patients, 95 (47%) had an isolated right aortic arch. Of the 95 with an isolated right aortic arch, 4 (4%) had chromosome 22q11.2 deletion syndrome, and 89 (94%) had a vascular ring. Of the 204 patients, 109 (53%) had a surgical intracardiac malformation. Of the 109, with an associated surgical intracardiac malformation, 38 (35%) had chromosome 22q11.2 deletion syndrome, and 28 (26%) had a vascular ring. Overall, of the 204 patients, 200 (98%) had a vascular ring, an associated intracardiac malformation, or both. Prenatal detection was 85% (40/47) for the subset of patients born in Southern Nevada between January 2015 and January 2018. Conclusion : this review, to best of our knowledge, reports one of largest series of right aortic arches in the literature. Data from our cohort demonstrates that a right aortic arch in situs solitus is almost always associated with pathology. Further, our center's right aortic arch prenatal detection rate exceeds previous reports.     

Discordant atrioventricular connexion with concordant ventriculo-arterial connexion (so-called "isolated ventricular inversion") with usual atrial arrangement (situs solitus)

The combination of a discordant atrioventricular connexion with a concordant ventriculo-arterial connexion (so-called "isolated ventricular inversion") is an extremely rare entity described, to the best of our knowledge, on only 15 occasions in patients with usual atrial arrangement. Initial diagnosis at cross-sectional echocardiography has only been reported three times, but the combination has been diagnosed in life on seven occasions, with successful Mustard or Senning operations having been performed in six of these patients. We report a neonate referred with an initial diagnosis of complete transposition, who was correctly diagnosed at cross-sectional echocardiography, and had closure of an associated ventricular septal defect with a Senning procedure in the neonatal period.     

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.     

Mitral valve replacement in a case of dextrocardia with situs solitus

Cardiac surgery in patients with a positional anomaly of the heart is technically challenging, and very few reports exist of such surgery in patients with dextrocardia. A 73-year-old woman in whom dextrocardia with situs solitus had been diagnosed at a young age, presented with palpitation and shortness of breath due to significant mitral valve insufficiency. Cardiopulmonary bypass (CPB) was initiated through aortic, superior vena cava, and inferior vena cava cannulae. The use of a heart positioner simplified and made safe the initiation of CPB. A left-sided left atriotomy provided excellent exposure of the mitral valve, and mitral valve replacement (MVR) was safely performed with a 25 mm St. Jude Medical mechanical prosthesis. The postoperative course was uneventful. In patients with dextrocardia requiring cardiac surgery, it is important to consider the appropriate surgical strategy. Approaching the mitral valve through a left-sided left atrial incision seems to provide excellent exposure for MVR.     

Spectrum of heart malformations in mice with situs solitus, situs inversus, and associated visceral heterotaxy

BACKGROUND. We present a study of the heart malformations found in a collection of mouse fetuses of the iv/iv strain between days 16.5 and 18.5 of gestation. METHODS AND RESULTS. One hundred hearts were serially sectioned and studied by segmental analysis with a light microscope. Forty additional hearts were analyzed with a scanning microscope. Forty percent of the hearts were found to be malformed. The most frequently occurring heart malformations were persistence of the sinus venosus (9%), common atrium (17%), common atrioventricular canal (24%), double-outlet right ventricle (12%), Fallot's tetralogy (8%), and transposition of the great arteries (5%). These malformations do not usually occur in isolation but rather appear in the formation of complex cardiopathies. The most severe and frequent is the combination of persistence of sinus venosus, common atrium, common atrioventricular canal, and double-outlet right ventricle; this is the "bulboventricular heart." The morphology of each lesion, as well as the degree of association, is similar to that found in human hearts with complex cardiopathies. Some of these cardiopathies appear to be directly related to formation of the cardiac loop. The iv/iv mouse appears to constitute an excellent model with which to study the etiology and pathogenesis of complex heart defects in humans. These hearts show a high phenotypic variability in the presentation of heart lesions. From a genetic viewpoint, there is a basic defect--the bulboventricular heart--which can be considered congenital. The other malformations can be considered formes frustes of the defect type. CONCLUSIONS. The iv gene is a developmental gene that affects basic developmental mechanisms. In this regard, heart lesions may not be the primary result of the abnormal gene activity but rather are secondary to defective interactions during cardiac development.