Comparing flow and pulmonary artery growth post-patent ductus arteriosus stenting in patients with ductal-dependent pulmonary flow using 4D magnetic resonance imaging.

Aims: The 4D magnetic resonance imaging (4D-flow MRI) provides a qualitative and quantitative assessment of cardiovascular structures and processes. 4D-flow MRI was used to study pulmonary flow in post-patent ductus arteriosus (PDA) stent insertion in duct-dependent pulmonary flow neonates at baseline (PDA stent insertion) and after 6 months, and also, to evaluate the effect of flow dynamics on the growth of pulmonary arteries (PAs). Methods and results: This prospective observational study included neonates with ductus arteriosus-dependent pulmonary circulation who underwent ductal stenting between June 2021 and November 2022. Cardiac 4D-flow MRI and magnetic resonance angiography were conducted in two phases; after the deployment of the PDA stent during the neonatal period and after 6 months from stent deployment. Eight neonates were recruited, but only five completed both scans. A total of 10 PAs were evaluated during each phase. The median left PA (LPA) and right PA (RPA) diameters and indexed flow for LPA and RPA were evaluated. The growth rate of LPA was observed to be lower than that of RPA (percentage diameter increase: 74 vs. 153%). LPA Z-score was lower than RPA. Indexed flow in both LPA and RPA showed a reduction in the 6-month scan, which was consistent with reduced stent patency. Conclusion: 4D-flow cardiac MRI showed different growth rates and reduced flow between LPA and RPA post-PDA stent. These insights can aid in future management decisions.

Surgical Repair of Common Arterial Trunk With Ventriculoarterial Septal Defect and Dual Orifice Truncal Valve.

We present a case of a rare example of a ventriculo-arterial septal defect found in a patient with a common arterial trunk, with balanced aortic and pulmonary components, but with separate valvar orifices within the common truncal valve. We managed the lesion using a two-patch approach. Performing a palliative procedure to relieve the elevated right ventricular pressure aided in the preservation of the pulmonary component of the common valve. We validated the success of the technique using postoperative computerized tomography and four-dimensional flow magnetic resonance imaging.

Complex Atrial Baffling Procedures in Left Isomerism With Right- and Left-Hand Topology.

We describe complex atrial baffling procedures in the setting of left isomerism with right-hand as opposed to left-handed ventricular topology. An appropriate understanding of the connections of the systemic and pulmonary veins, along with the internal atrial anatomy, as revealed using 3D printing, allowed for successful biventricular repair.

An Unusual Presentation of Double-Outlet Right Atrium.

We describe an unusual example of double-outlet right atrium with separate atrioventricular junctions. The straddling and overriding tricuspid valve had two orifices, and the mitral valve was morphologically normal. An appropriate understanding of the morphology of the atrioventricular junctions, the valves, and the subvalvar apparatus, along with the location of the atrioventricular conduction axis, allowed for successful biventricular repair.

Significance of the Wnt signaling pathway in coronary artery atherosclerosis.

Introduction: The progression of coronary atherosclerosis is an active and regulated process. The Wnt signaling pathway is thought to play an active role in the pathogenesis of several cardiovascular diseases; however, a better understanding of this system in atherosclerosis is yet to be unraveled. Methods: In this study, real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blotting were used to quantify the expression of Wnt3a, Wnt5a, and Wnt5b in the human coronary plaque, and immunohistochemistry was used to identify sites of local expression. To determine the pathologic significance of increased Wnt, human vascular smooth muscle cells (vSMCs) were treated with Wnt3a, Wnt5a, and Wnt5b recombinant proteins and assessed for changes in cell differentiation and function. Results: RT-PCR and Western blotting showed a significant increase in the expression of Wnt3a, Wnt5a, Wnt5b, and their receptors in diseased coronary arteries compared with that in non-diseased coronary arteries. Immunohistochemistry revealed an abundant expression of Wnt3a and Wnt5b in diseased coronary arteries, which contrasted with little or no signals in normal coronary arteries. Immunostaining of Wnt3a and Wnt5b was found largely in inflammatory cells and myointimal cells. The treatment of vSMCs with Wnt3a, Wnt5a, and Wnt5b resulted in increased vSMC differentiation, migration, calcification, oxidative stress, and impaired cholesterol handling. Conclusions: This study demonstrates the upregulation of three important members of canonical and non-canonical Wnt signaling pathways and their receptors in coronary atherosclerosis and shows an important role for these molecules in plaque development through increased cellular remodeling and impaired cholesterol handling.

Surgical repair of interrupted right-sided cervical aortic arch with hypoplasia of the descending thoracic aorta in a child with PHACE syndrome.

Obstruction of a right cervical aortic arch in association with hypoplasia of the descending aorta is a rare congenital cardiac malformation. We report the case of a 6-month-old boy with posterior fossa anomalies, hemangioma, arterial anomalies, cardiac anomalies and eye anomalies (PHACE) syndrome and interruption of a right-sided cervical aortic arch. The descending thoracic aorta in the child had a long hypoplastic segment and the patient also had small ventricular septal defect and pulmonary valve stenosis. The surgical technique of reconstruction of the aortic arch and the descending thoracic aorta through a median sternotomy is described.

Identifying Anomalies of Systemic Venous Drainage: Systemic Venous Anomalies; Atrial Morphology.

So as to produce totally anomalous systemic venous connection, all of the systemic venous tributaries, along with the coronary sinus, should be connected with the morphologically left atrium. Previous descriptions of this rare constellation of anomalous connections of the systemic venous tributaries of the heart have been compromised by the inclusion of individuals having isomeric atrial appendages. In these settings, most frequently, the totally, or almost totally, anomalous systemic venous connections are associated with a sinus venosus defect. It is the anomalous pulmonary venous connections that then create a venovenous bridge, which permits the systemic venous tributaries to drain into the morphologically left atrium, even though they may be predominantly connected to the right atrium. More rarely, it is feasible for the primary atrial septum to develop so as to leave the systemic venous sinus in direct connection with the body of the morphologically left, rather than the morphologically right, atrium. We report a series of patients potentially falling into the category of anomalous systemic venous connections. The findings show a spectrum from partially to totally anomalous connections, with some better interpreted on the basis of anomalous drainage. Included in our cases, nonetheless, is an autopsied example of totally anomalous systemic venous connection produced by an abnormal location of the primary atrial septum. We discuss the potential morphogenesis for this finding. We emphasize the distinction that needs to be made between anomalous systemic venous connections and anomalous systemic venous drainage.

A Newly Detected Left Ventricular Mass Following A Complex Intracardiac Repair.

Appearance of unexpected masses in the chambers of the heart during cardiac surgery can be intriguing. We report the case of a mass in the left ventricle that appeared at the time of separation from cardiopulmonary bypass in a child after a complex intracardiac repair. The child presented for surgery to a tertiary care hospital in Muscat, Oman, in 2022. Prior to the surgical repair the mass was not appreciated by echocardiography. An intraventricular baffle was used to divert left ventricular blood flow towards the outflow tract, after which an intraventricular "mass" was observed. Intraoperative transoesophageal echocardiography identified the mass as a portion of the interventricular septum that was located between the inlet and outlet ventricular septal defects.

Pulmonary Annulus Growth Pattern in Patients with Tetralogy of Fallot Prior to Surgical Repair.

Objectives: The size of the pulmonary valve annulus often determines the feasibility of pulmonary valve preservation at the time of intracardiac repair of Tetralogy of Fallot. Currently, there is limited available data regarding the growth pattern and the determining factors that contribute towards pulmonary valve annulus growth. Methods: This retrospective study included patients who underwent surgical repair of Tetralogy of Fallot with or without prior palliation. These patients had an echocardiogram at the time of initial diagnosis and a second echocardiogram prior to intracardiac repair. The sizes of the pulmonary annulus, the right and left pulmonary arteries with z-scores were recorded. Patients with improvement in the pulmonary annulus z-scores between the 2 echocardiographic examinations were allocated in Group I (n = 46) and Group II (n = 68) were those with no improvement. Results: A total of 114 patients were included in the study. The right and left pulmonary arteries size and z scores improved significantly between the 2 echocardiograms. Although the median size of the pulmonary annulus increased between the 2 echocardiograms (6 and 7.9 mm; P<0.001), there was no significant change in the z-score (-2.2, -2.34; P = 0.185). Multivariate logistic regression analysis showed that gender, blood group, presence of collaterals, and palliation with Blalock-Taussig shunt had no impact on the improvement in pulmonary annulus z-score. Conclusion: In Tetralogy of Fallot, the pulmonary valve annulus z-score may not change significantly prior to the intracardiac repair. Although in certain subgroups there may be an improvement, there was no specific factor that could be identified and had an influence on this improvement.

Blalock-Taussig Shunt versus Ductal Stenting as Palliation for Duct-Dependent Pulmonary Circulation.

Objectives: There is limited data published from outside North America and Europe comparing the outcomes of a modified Blalock-Taussig shunt (MBTS) and ductal stenting as the first palliative procedure for infants with duct-dependent pulmonary circulation. This study reports the National Heart Center's, in Muscat, Oman, experience in comparing the outcomes of these 2 interventions. Methods: This retrospective study included all infants with duct-dependent pulmonary circulation who received either a MBTS or ductal stenting from 2016-2019. The primary outcomes were death or re-interventions. Secondary outcomes included death, subsequent re-interventions, survival to subsequent surgical intervention, survival to hospital discharge, post-procedural mechanical ventilation and duration of intensive care unit stay. Results: A total of 71 patients were included in the study, 33 (46%) of whom received ductal stenting. The prevalence of the primary outcome (death or re-intervention) in the patent ductus arteriosus (PDA) stent group was 54.5% versus 31.6% in the MBTS group but this was not statistically significant (P = 0.06). There was no difference between the 2 groups in terms of time to next surgical intervention (P = 0.233). The PDA stent group had shorter post-procedural, mechanical ventilation and intensive care unit stay durations (P <0.05). Syndromic patients were at higher risk of mortality compared to non-syndromic patients. Conclusion: MBTS and ductal stenting are both acceptable modalities as a palliative intervention for infants with duct-dependant pulmonary circulation. Syndromic patients are at higher risk of mortality. This can be considered an important factor for patient selection.

The Sinus Venosus Veno-Venous Bridge: Not a septal defect.

This review provides an update on the morphology of the sinus venosus defect. It was earlier believed that a 'common wall' separated the right pulmonary veins from the superior caval vein. In the sinus venosus defects, this wall was absent. Current evidence shows that the superior rim of the oval fossa, rather than forming a second septum or representing a common wall, is an infolding between the walls of the caval veins and the right pulmonary veins. The sinus venosus defect is caused by the anomalous connection of one or more pulmonary veins to a systemic vein. However, the pulmonary vein(s) retain their left atrial connections, leading to a veno-venous bridge that allows interatrial shunting outside the oval fossa. True atrial septal defects are located within the oval fossa or in the anteo-inferior buttress, while sinus venosus defects, ostium defects and coronary sinus defects are morphologically distinct from them.

Sudden Cardiac Death in Patients Under 49 Years Including Adolescents: A single-centre study from Oman.

Objectives: This study aimed to identify the incidence of sudden cardiac death (SCD0 in adult patients under the age of 49 years, including adolescents with an out-of-hospital cardiac arrest that presented to the emergency department of a tertiary care hospital. Methods: This retrospective cross-sectional study was conducted at the Royal Hospital, Muscat, Oman, between January 2015 and December 2019. All patients with out-of-hospital cardiac arrest were enrolled. The incidence of SCD was evaluated. Information about the patient's demographic data, the site of cardiac arrest, the mode of arrival, the duration of pre-arrest symptoms and if cardiopulmonary resuscitation was performed was gathered. Survival data at 3-year follow-up was obtained. Results: A total of 117 out of 769 (15%) patients met the criteria for SCD. Male gender was predominant, with a median age of 33 years. In about 79.5% of the patients, cardiac arrest was witnessed. Only 43 patients (36.8%) received cardiopulmonary resuscitation at the arrest site; 21 patients (17.9%) had a shockable rhythm and 96 patients (82.1%) had a non-shockable rhythm. Spontaneous circulation was returned in 15 patients (12.8%). Nine patients (7.7%) were discharged from the hospital and 8 (6.8%) survived at least 36 months. Conclusion: The study findings indicate the prevalence of SCD among patients who experienced a cardiac arrest outside the hospital. Unfortunately, only a small number of patients were able to survive in the long term. By implementing preemptive screening for individuals and their families, it may be possible to prevent SCD and improve outcomes for those affected.

Evaluation of pulmonary blood flow in bilateral bidirectional Glenn shunts: value of 4-D flow cardiac magnetic resonance in the evaluation of pulmonary artery confluence stenosis.

Bilateral bidirectional Glenn shunts are associated with the risk of developing pulmonary artery bifurcation stenosis, resulting in variable pulmonary blood flow to either lung. This could negatively impact the subsequent stages of the single ventricle palliation pathway. This report highlights the value of 4D flow sequence from the cardiac magnetic resonance imaging in demonstrating the pulmonary blood flow characteristics following a bilateral bidirectional Glenn procedure. Mapping the blood flow pattern and its quantification to each lung provide objective insights into the possible predisposing factors for the development of pulmonary bifurcation stenosis.

Echo Rounds: Partial Anomalous Systemic and Pulmonary Venous Return.

Anomalous drainage of a right-sided superior vena cava to the left atrium is a rare variant of systemic venous return anomalies. During the course of investigation for a heart murmur, an asymptomatic child was found to have a superior sinus venosus atrial septal defect with partial anomalous systemic and pulmonary venous drainage. Despite the right superior vena cava overriding the upper end of the atrial septum and draining into the left atrium, the child did not exhibit hypoxemia. Saline contrast transesophageal echocardiography suggested an explanation for the absence of hypoxemia.

Cor Triatriatum Sinistrum: A rare disease with a common presentation.

Cor triatriatum sinistrum (CTS) is a rare congenital cardiac anomaly characterised by an abnormal septum within the left atrium impairing blood flow to the left ventricle. We report the case of a two-month-old male infant who presented with symptoms of heart failure since the age of two weeks. He was admitted to a local hospital and was managed with antibiotics because of the impression of pneumonia. Due to persistent unresolved tachypnoea and tachycardia, he was referred to Sultan Qaboos University Hospital, Muscat, Oman, in 2019 for cardiac evaluation which confirmed a diagnosis of isolated CTS with severe stenosis and pulmonary hypertension. He underwent an urgent surgical excision of the membrane with uneventful recovery.