Ventricular Infundibulum Research Articles

Exploring the Role of Modified Vascular Anatomical Molding (MVAM) in Prenatal Diagnosis Teaching and Prognosis Prediction of Fetal Complex Congenital Heart Disease (CCHD): A Preliminary Study.

The present study aimed to explore the role of modified vascular anatomical molding (MVAM) in prenatal diagnosis teaching and prognosis prediction of fetal complex congenital heart disease (CCHD). Step 1, MVAM method was used to cast the micro-blood vessels and trachea of 52 CCHD specimens. Subsequently, 52 MVAMs were analyzed and compared with the prenatal ultrasound to summarize their characteristics, misdiagnosis and MVAM's teaching role. Step 2, the surgical and follow-up data of 206 CCHD cases were retrospectively analyzed. Cases that evolved into critical illnesses or died within 1-3 years after surgery (poor prognosis) were classified into the study group (n = 77) and those with good prognosis into the control group (n = 129), which were split into the training set and the test set in the ratio 7:3 based on the time cut-off. In the training set, the prognosis of CCHD was predicted using the MVAM anatomical soft markers (distortion and narrowing of aorta/pulmonary artery, right ventricular infundibulum, etc.) and the decision curve analysis (DCA) performed. The model was validated using the test set, and a nomogram was finally established. It was observed that all 52 CCHD cases were confirmed using MVAM. A total of 91 cardiac malformations were recorded, among which 41 malformations were misdiagnosed, and 29 malformations were missed by the prenatal echocardiography. The MVAM method has a good teaching/feedback effect on prenatal diagnosis. The combined model exhibited a higher predictive performance in the training- and test-set. Its high clinical net benefit was proved by DCA. Additionally, the nomogram established using the combined model received a favorable response in clinical practice. The research results indicated that MVAM improved the prenatal diagnosis teaching and training performance. The combined model established based on MVAM anatomical soft markers can offer a high clinical significance for prognosis prediction of CCHD.

Right Ventricular Outflow Tract Stenting as Palliation of Critical Tetralogy of Fallot: Techniques and Results

Background. Despite current trends toward early primary repair, the surgical systemic-to-pulmonary shunt is still considered the first-choice palliation in patients with critical tetralogy of Fallot (TOF) and duct-dependent pulmonary circulation unsuitable for primary repair. However, stenting of the right ventricular outflow tract (RVOT) is nowadays emerging as an effective alternative to surgical palliation in selected patients. Methods and results. RVOT stenting is usually performed from a venous route, either femoral or, in selected cases, the right internal jugular vein. Less frequently, mostly in pulmonary infundibular/valvar atresia, this procedure can be performed using a hybrid surgical/interventional approach by surgical exposure of the RVOT, puncture of the atretic valve, and stent deployment under direct vision. The size and type of the most appropriate stent may be chosen, based on ultrasound measurements of the RVOT, to cover the right ventricular infundibulum completely and, at the same time, sparing the pulmonary valve, unless significant pulmonary valve annulus hypoplasia and/or supra-valvular stenosis is a significant component of the obstruction. In the large series so far published, early mortality of RVOT stenting is less than 2%, comparing favourably with either Blalock-Thomas-Taussig shunt or early primary repair. In addition, morbidity and clinical sequelae of this approach do not significantly differ from surgical palliation, even if RVOT stenting shows lesser durability and a higher rate of trans-catheter re-interventions over a mid-term follow-up. Finally, similar but more balanced pulmonary artery growth than surgical palliation following RVOT stenting is reported over a mid-term follow-up. Conclusions. RVOT stenting is a technically feasible, well-tolerated, and effective palliation in critical TOF. This approach is cost-effective with respect to surgical palliation either in high-risk neonates or whenever a short-term pulmonary blood flow source is anticipated due to the early surgical repair. It effectively increases pulmonary blood flow, improves arterial saturation, and promotes balanced pulmonary artery growth over a mid-term follow-up.

Three-dimensional regional bi-ventricular shape remodeling is associated with exercise capacity in endurance athletes

Endurance athletes develop cardiac remodeling to cope with increased cardiac output during exercise. This remodeling is both anatomical and functional and shows large interindividual variability. In this study, we quantify local geometric ventricular remodeling related to long-standing endurance training and assess its relationship with cardiovascular performance during exercise. We extracted 3D models of the biventricular shape from end-diastolic cine magnetic resonance images acquired from a cohort of 89 triathlon athletes and 77 healthy sedentary subjects. Additionally, the athletes underwent cardio-pulmonary exercise testing, together with an echocardiographic study at baseline and few minutes after maximal exercise. We used statistical shape analysis to identify regional bi-ventricular shape differences between athletes and non-athletes. The ventricular shape was significantly different between athletes and controls (p < 1e-6). The observed regional remodeling in the right heart was mainly a shift of the right ventricle (RV) volume distribution towards the right ventricular infundibulum, increasing the overall right ventricular volume. In the left heart, there was an increment of left ventricular mass and a dilation of the left ventricle. Within athletes, the amount of such remodeling was independently associated to higher peak oxygen pulse (p < 0.001) and weakly with greater post-exercise RV free wall longitudinal strain (p = 0.03). We were able to identify specific bi-ventricular regional remodeling induced by long-lasting endurance training. The amount of remodeling was associated with better cardiopulmonary performance during an exercise test.

A Methodology to Assess Subregional Geometric Complexity for Tetralogy of Fallot Patients

Abstract During surgical repair of tetralogy of fallot (TOF), pulmonary valve preservation (preservative repair) has demonstrated improved long-term outcomes compared to repairs that incise into the valve annulus (nonpreservative repair). Given the influence of geometry on hemodynamics, the success of preservative repair may be linked to the suitability of the preoperative patient geometry. However, the specific patient anatomies that may be predisposed to successful preservative repair are unknown due to significant interpatient variability in right ventricular outflow tract (RVOT) and pulmonary artery geometries, as well as the limitations in current methods of subregional geometric analysis. As a first step toward understanding the link between geometry and hemodynamics in TOF patients at a subregion level, we characterize the TOF geometry from the right ventricular infundibulum (INF) to the left and right pulmonary arteries. Our process consists of segmentation of magnetic resonance (MR) images and analysis of cross-sectional slices of the geometries along the centerlines. For the INF, main, left, and right pulmonary arteries individually, we quantify geometric parameters important in determining hemodynamic characteristics such as flow separation and recirculation, which can influence the degree of regurgitation. Specifically, we calculate the diameter along the subregion length, the average diameter, length, and tortuosity for each segment, as well as the bifurcation, left pulmonary artery (LPA) and right pulmonary artery (RPA) branch angles. This approach enables direct geometric comparisons within and among patients and allows for observation of the range in anatomic presentation. We have applied this approach to a dataset of 11 postoperative TOF patients, repaired with both preservative and nonpreservative surgical techniques.

Study of prenatal diagnosis and classification and prognostic evaluation in fetuses with pulmonary atresia with intact ventricular septum

Objective To explore the prenatal diagnosis classification and prognostic evaluation of fetal pulmonary atresia with intact ventricular septum (PA/IVS). Methods Thirty-nine fetal PA/IVS were classified by the developmental condition of the right ventricle and ventriculo-coronary artery communication (VCAC), and tricuspid Z score was calculated. The associated abnormality, chromosome abnormality were follow-up analyzed. Results Fifteen fetuses were diagnosed with type Ⅰ PA/IVS, 14 fetuses with type Ⅱ PA/IVS, and 10 with type Ⅲ PA/IVS. One case with type Ⅰ was associated with right aortic arch, and other 38 fetuses were not associated with other cardiac abnormalities. Thirty-nine fetuses were normal karyotype.Fetuses with type Ⅰ PA/IVS manifested right ventricular inlet portion, well-developed trabecular and infundibulum portions, and no VCAC. The tricuspid Z score of type Ⅰ PA/IVS was from -0.07 to -2.82, and 9 of the fetuses had biventricular repair and 6 had termination. Type Ⅱ PA/IVS manifested right ventricular trabecular portion absence, small inlet and infundibulum portions, and no VCAC. The tricuspid Z score of type Ⅱ PA/IVS was from -3.35 to -5.21, and 7 of the fetuses had single ventricle palliation, 2 underwent fetal interventional procedures, and 5 had termination. Type Ⅲ PA/IVS manifested absence of right ventricular trabecular and infundibulum portions, small inlet portion, and VCAC. The tricuspid Z score of type Ⅲ PA/IVS was from -4.33 to -6.01, and 4 of the fetuses had single ventricle palliation and 6 had termination. The area under the ROC curve of tricuspid Z score in diagnosing PA/IVS postnatal biventricular repair was 1.000 (P<0.01, 95%CI: 1.00-1.00), the cutoff value was -3.08, the sensitivity was 100%, and the specificity was 100%. Conclusions Echocardiography can perform diagnostic classification of fetal PA/IVS and obtain fetal tricuspid valve Z score of >-3.08 and predict the postnatal outcome in PA/IVS. The findings may have important implication for prenatal diagnosis and prognosis evaluation for PA/IVS. Key words: Echocardiography; Fetus; Pulmonary atresia with intact ventricular septum; Prognosis; Tricuspid valve Z score

Tetralogy of Fallot: Preoperative assessment with MR and CT imaging.

Tetralogy of Fallot has a broad anatomical spectrum. In mild forms of the condition the obstruction is only located in the right ventricular infundibulum, whereas in severe forms the pulmonary valve is atretic, the pulmonary arteries are absent and the lung is supplied by aorto-pulmonary collateral arteries. Surgical management differs from conventional surgery in the former situation, whereas in the latter it is complex and requires reconstruction of the pulmonary arteries (unifocalization) carried out in more than one stage and with a high morbidity rate. The key factors to establish before corrective surgery are the levels and degree of obstruction of the right ventricular outflow tract, the development of the pulmonary arteries and the presence of collateral arteries. The main role of magnetic resonance imaging along with that of computed tomography angiography are discussed and illustrated.

Anomalous Origin of Left Main Coronary Artery from Right Sinus of Valsalva: A Case Report

We present a case of a 79 years old man in whom diagnostic coronary angiography showed anomalous left main arising from the right sinus of Valsalva and followed an intraseptal course beneath right ventricular infundibulum. He also had obstructive lesion in left circumflex artery. In view of his recent ischemic symptoms he was successfully treated by left circumflex angioplasty.

Giant Lipoma Originating from the Right Ventricular Infundibulum - A Case Report

Known as a rare benign cardiac tumor, epicardial lipoma is often an asymptomatic condition discovered due to increasing use of diagnostic imaging techniques. We report a case of a 54-year old patient referred to our institution with mild dyspnea, chough and an enlarged cardiac siluette on a routine chest X-ray. A large intrapericardial mass suggestive for lipoma encompassing the left and right ventricles was detected by echocardiographic examination and computer tomography scan. Resection of a 650 g mass with right ventricular infundibulum origin was performed via sternotomy, with histopathological confirmation of epicardial lipoma.

Low Incidence of Arrhythmias in the Right Ventricular Infundibulum Sparing Approach to Tetralogy of Fallot Repair

To improve outcomes, including arrhythmia incidence, for patients with tetralogy of Fallot (TOF), the authors' institution adopted an approach that minimizes or avoids transmural incision of the right ventricular outflow tract. When pulmonary blood flow is insufficient during the neonatal period, placement of an aortopulmonary artery shunt is preferred, followed by complete repair later in infancy. This study reviewed the perioperative and mid-term arrhythmia outcomes at the authors' institution using this approach. Patients who underwent TOF repair from 1995 to 2008 were included in the study. Patient demographics and surgical history were collected. The primary end points of the study included documented perioperative arrhythmias and arrhythmias at the 10-year follow-up assessment. Of the 298 patients who underwent TOF repair, 50 (17%) had undergone prior placement of a systemic-to-pulmonary artery shunt. The median age at repair was 9.7months (interquartile range, 6.3-16.2months). Clinically significant perioperative arrhythmias were found in 12 patients (4%) including 6 junctional tachycardias, 4 atrial tachycardias, and 1 temporary complete heart block. No patients were receiving antiarrhythmic medications more than 24months after surgery. Of the 298 patients, 86 (29%) had a follow-up period of 10years or longer (median, 12.2years). No patients experienced new arrhythmias, received antiarrhythmic therapy, experienced post-discharge ventricular tachycardia, had atrioventricular block, or required a pacemaker or defibrillator. The right ventricular infundibulum sparing approach is associated with an extremely low incidence of perioperative and midterm arrhythmias. The perioperative and mid-term outcomes compare favorably with existing data from programs favoring neonatal repair. Long-term follow-up evaluation is essential to determine whether this strategy can effectively alter late pathophysiology and minimize late-term arrhythmias and associated mortality.

Myocardial extensions over the pulmonary artery sinotubular junction. Implications for the anatomic substrate of supravalvular tachycardias

Purpose: Supravalvular tachycardias form a subgroup of idiopathic outflow tract tachycardias that have their origin at the level of the aortic sinuses or the proximal pulmonary artery (PA). The existence of ventricular myocardium in close anatomic vicinity to the ventriculo-arterial junction is a known fact. However, the presence of myocardial extensions over the level of the sino-tubular junction has not been systematically analyzed. Methods: We examined 40 hearts of post-mortem adult humans (22 male; 56±8 y/o). We performed sagittal histological sections stained with Masson's trichrome. Optical microscopy techniques were used to observe the presence of extensions of myocardium at the pulmonary valve sinuses and over the sino-tubular junction. We measured the distance from the myocardial extensions to the basal insertion of the semilunar leaflets. Results: In all 40 hearts, the muscle fibers around the right ventricle outflow tract joined the ventriculo-arterial junction, forming part of the muscular ring that surrounds the PA. In 8 hearts (20%), the musculature of the ventriculo-arterial junction extended in its epicardial aspect over the pulmonary valve sinuses. These myocardial extensions continued above the sino-tubular junction to a distance of 10±2 mm from the basal insertion of the semilunar leaflets (range 7, 5-14 mm). The extensions were formed by viable myocytes surrounded by adipose tissue that reached the right ventricular infundibulum. ![Figure][1] Myocardium over the sinotubular junction Conclusion: The presence of ventricular myocardial extensions above the PA sino-tubular junction has implications for the anatomical substrate and percutaneous treatment of supravalvular tachycardias. [1]: pending:yes

136 3-Dimensional Late Gadolinium Enhancement Scar Imaging For Surgically Corrected Tetrology Of Fallot: Clinical Feasibility Of Scar Segmentation

Surgical correction of Tetrology of Fallot (TOF) necessitates varying degrees of “scar” within the right ventricular (RV) infundibulum and basal inter-ventricular septum. The visual scoring of scar by late gadolinium enhancement (LGE) MRI is associated with RV dysfunction and may be the primary substrate for ventricular arrhythmia. However, its spatial characterization on 2D LGE imaging is challenging due to complex and thin architecture. In this study we describe the first clinical experience of high-resolution 3D LGE imaging for the characterization and quantification of scar in this population.

Acute coronary syndrome in a patient with a single coronary artery arising from the right sinus of Valsalva

Coronary artery anomalies are usually encountered as coincidental findings during coronary angiography or at autopsy. Life threatening symptoms, such as arrhythmias, syncope, myocardial infarction, or sudden death, can occur in up to 20% of patients. However, the majority of anomalies (80%) are benign and asymptomatic. A single coronary artery (SCA) is one of the most rarely seen coronary anomalies with an incidence of 0.05%. We report the case of a 55-year old male patient who presented with symptoms of chest pain associated with an acute myocardial infarction. Coronary angiography revealed an anomalous left main coronary artery (LMCA) originating from the right coronary ostium, and an occluded distal right coronary artery. The occluded distal right coronary artery was successfully treated by thrombosuction and stenting. In order to confirm the origin and course of the SCA, multi-slice computed tomography (MSCT) of the heart was performed after coronary angiography. MSCT showed that the anomalous LMCA originated from the right coronary artery ostium and then passed the interventricular septum, instead of being intra arterial, and under the right ventricular infundibulum. The anomalous LMCA was classified as R-II S subtype according to Lipton's classification.

Left coronary artery from the right coronary sinus: What can CT angiography tell us?

Left coronary artery from the right coronary sinus: What can CT angiography tell us?

Role of MDCT coronary angiography in the evaluation of septal vs interarterial course of anomalous left coronary arteries

Conventional coronary angiography (CCA) may be inaccurate to distinguish between interarterial and septal subtypes of anomalous left coronary arteries (CAs). We compared the classification of anomalous left CA arising from the right sinus of Valsalva (RSV) or right CA on the basis of multidetector computed tomography coronary angiography (MDCTCA) with the classification derived from CCA. A retrospective review of 6000 consecutive electrocardiographic-gated MDCTCAs identified 15 cases of anomalous left main or left anterior descending CA arising from the RSV or right CA coursing between the aorta and the main pulmonary artery. On the basis of MDCTCA findings, the proximal course of each vessel was classified into 3 subtypes: 1, interarterial; 2, septal; and 3, mixed. CCA was reviewed in 5 cases (33%) and classified according to traditional criteria. When CCA images were not available, 3-dimensional volume-rendered reconstructions were used to simulate CCA. On the basis of MDCTCA, subtypes were distributed as type 1 (n = 2), type 2 (n = 4), and type 3 (n = 8). One case could not be classified into any of these subtypes and was classified as type 4, right ventricular infundibulum (RVI). Applying CCA criteria, 2 cases would have been classified as interarterial and 14 as septal without appreciation of the mixed or RVI subtypes. Classification of anomalous left CAs into either septal or interarterial may be too simplistic. There is an anatomic spectrum of anomalous left CAs detected by MDCTCA that challenges the traditional classification based on CCA.

Isolated Congenital Pulmonary Regurgitation with Right Ventricular Outflow Tract Aneurysm-A Rare Variant of Uhl's Anomaly

Isolated absent pulmonary valve syndrome is a very rare entity. We report the case of a four-year-old boy who had congenital absent pulmonary valve with a thin and aneurysmal right ventricular infundibulum. The histological picture was suggestive of Uhl's anomaly. This association of partial right ventricular Uhl's anomaly with absent pulmonary valve syndrome has not been described before. We discuss the embryological and clinical significance of this association.

Hybrid palliation of interrupted aortic arch in a high-risk neonate

We report a case of a high-risk neonate with interrupted aortic arch (IAA) and ventricular septal defect who underwent a successful hybrid palliative procedure using a ductal stent and bilateral branch pulmonary artery banding. This case represents not only a successful use of hybrid approach in high-risk neonates with IAA, but also introduces an alternative and safe access for ductal stent insertion through the right ventricular infundibulum.

Surgical strategy for pulmonary atresia with intact ventricular septum: initial management and definitive surgery

Pulmonary atresia with intact ventricular septum is difficult to manage, and the surgical procedures are associated with high mortality and morbidity. The lesion is morphologically heterogeneous, with varying degrees of right ventricular and tricuspid valve hypoplasia. Aberrations of the coronary circulation are common. A single approach is impractical because the wide spectrum of right heart morphology makes a uniform surgical approach impossible. Anatomical criteria, such as the degree of tricuspid valve or right ventricular hypoplasia or whether a right ventricular infundibulum is present, have been used to assign the infants to single-ventricular or biventricular repair tracks. If the patient is considered a candidate for biventricular repair, right ventricular decompression, either alone or combined with a systemic-pulmonary artery shunt, is performed, whereas only a systemic-pulmonary artery shunt is performed in a candidate for single-ventricular repair. Several authors reported that the Z-value of the tricuspid valve diameter could be a guide to the initial procedure; however, poor interobserver reproducibility and wide normal ranges are serious limitations. Definitive operations, including biventricular repair, one-and-a-half ventricular repair, or Fontan-type operation, are performed to eliminate cyanosis. The most important problem when planning a strategy for a definitive repair is the fact that right ventricular growth and its contribution to pulmonary flow is difficult to predict before the operation. The management protocol should be determined by the precisely estimated morphology of the right ventricle and tricuspid valve, and the adequacy of the protocol should be analyzed based on surgical outcomes.

O miocárdio na tetralogia de Fallot: estudo histológico e morfométrico

FUNDAMENTO: Pacientes com tetralogia de Fallot freqüentemente cursam com disfunção ventricular no período pós-operatório. A base histológica dessa alteração funcional tem sido pouco estudada. OBJETIVO: Avaliar, em espécimes anatômicos, o remodelamento miocárdico comparando as regiões subepicárdica e subendocárdica, especialmente por esta última ser facilmente abordável por meio de biópsias endomiocárdicas. MÉTODOS:Análises em cortes transmurais de miocárdio da via de entrada, parede anterior e infundíbulo do ventrículo direito (VD) e da parede livre do esquerdo (VE), foram avaliados quanto ao grau de hipertrofia de cardiomiócitos, de vascularização e fibrose intersticial. RESULTADOS:O diâmetro médio dos cardiomiócitos do subendocárdio é semelhante ao do subepicárdio em todas as regiões, com exceção do infundíbulo do VD, em que os subendocárdicos se mostraram significativamente maiores em relação aos do subepicárdio (p=0,007). A quantidade de colágeno intersticial encontra-se nos limites superiores do normal e foi similar nas camadas subendocárdicas, comparada à subpericárdica de cada região, sendo, todavia, maior na via de entrada e na parede anterior do VD, do que na parede lateral do VE. A densidade numérica de capilares do subendocárdio foi semelhante à do subepicárdio e esteve menor que a média menos dois desvios-padrão do normal em todas as regiões e camadas, com exceção do infundíbulo, em que o subepicárdio mostrava valores normais e o subendocárdio valores menores que a média menos dois desvios-padrão. CONCLUSÃO: As alterações do miocárdio pós-natal na tetralogia de Fallot estão distribuídas homogeneamente nas metades subepicárdica e subendocárdica das paredes ventriculares, com exceção do infundíbulo, que apresenta características peculiares de remodelamento e que, portanto, não é representativo das demais regiões e camadas ventriculares para estudos morfométricos.

Tetralogy of Fallot Repair: The Right Ventricle Infundibulum Sparing (RVIS) Strategy

Despite the excellent operative survival for tetralogy of Fallot (TOF) repair, well-documented long-term complications and reduced life expectancy remain challenges for these patients and their clinicians. In an attempt to change the natural history of repaired TOF, we at Texas Children's Hospital (Houston, TX) have developed a management strategy not focused on age, but rather focused on preserving the right ventricular (RV) infundibulum. The RV infundibulum sparing (RVIS) repair of TOF consists of a transatrial and transpulmonary approach to close the ventricular septal defect and resect RV infundibular muscle coupled with a mini (< 5 mm) transannular patch or no ventricular incision. This strategy is applied with the ambition of decreasing the well-documented, long-term complications of TOF repair with large right ventriculotomies such as RV dilation, arrhythmias, need for pulmonary valve replacement, and RV failure. The RVIS strategy is an attempt based on our current knowledge and experience to optimize the time of repair so that we can not only maximize the early operative results but the long-term effects of this approach as these children mature into adolescents and adults. We have uniformly applied the RVIS strategy since 1995, which includes over 320 isolated TOF patients. We are currently reviewing this cohort in hopes that it will strengthen our beliefs and known results as well as give us more insight into whether the RVIS strategy can change the natural history of repaired TOF.

Double outlet right ventricle in a calf

Double outlet right ventricle is a conotruncal malformation where both great arteries (aorta and pulmonary trunk) arise from the right ventricle. A 2-month-old Holstein calf was slaughtered due to severe respiratory distress. At necropsy, the heart was enlarged, globose, and had ventricular and atrial septal defects. The only outlet for the left ventricle was a large ventricular septal defect located at 6 cm distance from the heart apex and involved atrial septum too. The right ventricle was enlarged and markedly thickened with a left to right free wall ratio of 2.5:2 and prominent papillary muscles. The aorta arose from the right ventricular infundibulum adjacent to pulmonary trunk. Two valvular hematomas were observed on the edge of the right atrioventricular valve. The lungs were rubbery with ecchymotic and petechial hemorrhages and did not collapse after removing from thoracic cavity. Enhanced lobular pattern was evident on both the capsular and cut surfaces of the liver. Histopathological examination of the lungs revealed thickening of alveolar septa, hemorrhages, and infiltration of hemosiderophages within alveoli. Periportal hepatocellular fatty changes, substitution of centrilobular and midzonal hepatocytes by red blood cells, and dilation of midzonal and periportal sinusoids were seen in the liver. To our knowledge, this particular combination of cardiac defects has not been previously described in domestic animals and the pathological lesions observed in the calf may be resulted as a sequel to left–right blood shunting and heart failure.