With the rapid expansion of the COVID-19 pandemic, the disease burden and its consequences on the paediatric population has been progressively recognised. Although COVID-19 infection in children presents as asymptomatic to mild illness, instances of hyperinflammation and multi-organ involvement following the viral infection have been described. This condition, known as the multisystem inflammatory syndrome in children (MIS-C), has gained a wide global attention. Despite the global efforts to uncover the disease characteristics and management, a clear pathogenesis and a unified treatment regimen have not been reached yet. This paper tackles the epidemiology of the MIS-C, discusses its suggested pathogenesis, drives through its varying clinical presentations, and evaluates the different treatment regimens employed in managing MIS-C.

The surgical treatment of transposition of the great arteries, ventricular septal defect, and significant left ventricular outflow tract obstruction continues to evolve. The survival of an unrepaired transposition of the great arteries into late adulthood is a rarity. Even when large intracardiac shunts are present, it remains a lethal cyanotic CHD if it is not surgically corrected soon after birth. We present our experience of two cases, both of whom underwent a single-stage arterial switch operation and an aortic valve replacement for this defect.

We describe a newborn with a congenital left atrial appendage aneurysm. The aneurysm size did not change prenatally. However, it rapidly enlarged after birth. MRI was useful for assessing the aneurysm extent and exact size, and for diagnosis. Respiratory distress and feeding difficulties appeared, and surgery was performed. These symptoms disappeared post-operatively. The patient is alive without complications or recurrence.

The carotid artery is a valuable vascular access that can be used in patients who have undergone repetitive interventional and surgical procedures and premature babies. In the past, cut-down was used but nowadays, mostly the procedure is performed under ultrasonographic guidance. Complications such as bleeding, haematoma, and pseudoaneurysm may occur when the carotid artery is used as a vascular access for the procedures such as aortic balloon valvuloplasty, coarctation balloon angioplasty, or after interventional or surgical treatments to the carotid artery. Although pseudoaneurysm is very rare, prompt diagnosis and accurate treatment planning are life-saving. In this article, the diagnosis and treatment of pseudoaneurysm in the left common carotid after transcatheter coarctation balloon angioplasty in a 6-month-old infant will be presented.

Vena caval filters remain as a useful tool in patients with deep vein thrombosis and contraindications to anticoagulation. Although they are rarely used in paediatric patients, they have been shown to be safe and effective when used in the inferior vena cava.

In this case report, we describe the off-label use of a retrievable vena caval filter in the superior vena cava in an adolescent with acute lymphoblastic leukaemia with extensive thrombosis of the right upper neck veins as a means to reduce the risk of pulmonary embolism.

Mitral valve replacement for small pediatric patients is technically difficult because of the small annulus and requires some technical ideas. The chimney technique is useful for supra-annular mitral valve replacement. We describe a paediatric case of early re-replacement owing to pannus formation after mitral valve replacement using the chimney technique.

Pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries is an extremely complex, heterogeneous, and rare anomaly. This group of patients may not be able to survive until adulthood without any interventions or treatment. Although surgical management of patients diagnosed in newborn, infant, or early childhood is clear, treatment of patients diagnosed in adulthood still remains a significant problem. The pre-operative clinical status, imaging methods, and operative findings might be helpful for planning the most appropriate management. Herein, we report a unique case of pulmonary atresia and ventricular septal defect with major aortopulmonary collateral arteries who remained asymptomatic until the age of 18 years.

Danon disease is a rare and fatal disease caused by a mutation in the lysosome-associated membrane protein 2 gene. Impaired intracellular autophagy causes lysosomal vacuoles to accumulate mainly in myocardial and skeletal muscle cells, leading to hypertrophic cardiomyopathy, skeletal myopathy, and varying degrees of intellectual disability. Two distinct childhood presentations of Danon disease are described in this report.

We reported a case of pheochromocytoma with initial presentation of cardiac arrest. The patient underwent implantable cardioverter defibrillator for primary prevention but subsequently experienced repeated implantable cardioverter defibrillator shocks and syncopal episodes. A mass was found in the adrenal gland by CT, which was confirmed by anatomopathological analysis of the surgical specimen.

A patent ductus arteriosus in patients with transposition of the great arteries is usually beneficial to allow shunting between pulmonary and systemic circulations. However, if the duct is too large, it can cause haemodynamic instability, pulmonary oedema and compromised organ perfusion. We present a neonate in whom a 5 mm short and tubular ductus arteriosus was causing significant cardiac failure with necrotising enterocolitis and liver impairment, leaving him too unstable for the arterial switch operation. At day 14 of life (3.1 kg), the baby underwent successful transcatheter closure using an Amplatzer vascular plug (Abbott, Chicago, Il, USA) delivered through a 5Fr catheter from the aortic side. The procedure was uncomplicated and successful as the neonate was extubated 2 days later. He subsequently underwent successful arterial switch surgery.

Coarctation of aorta post-transcatheter occlusion of patent ductus arteriosus is rare. We report a special case of infant with patent ductus arteriosus complicated by bicuspid aortic valve, who presented severe coarctation of aorta and aortic valve dysfunction post-patent ductus arteriosus occlusion during follow-up, eventually receiving surgical operations. A genetic rather than iatrogenic predisposition towards post-procedural complications has been discussed.

Anomalous systemic venous connection to left atrium is rare anomaly. Previously published cases described this anatomy in patients with left isomerism. Depending on the size of the atrial septal defect, patients usually present with varying degrees of cyanosis and right heart hypoplasia. Here, we report a case of anomalous systemic venous connection to left atrium in a newborn with the usual atrial arrangement.

Native valve aortic endocarditis is rarely seen in the paediatric population. Although, the first-line of treatment is medical, surgical intervention may be indicated in patients with unrepairable valvular and subvalvular disease. Recently, the aortic valve neocuspidization (AVNeo) procedure has gained popularity both in adult and children in whom other repair techniques are not feasible. In this case report, we present an urgent aortic valve replacement using the AVNeo technique in a critically ill infant with a small annulus, severe left ventricular outflow tract stenosis, and severe aortic regurgitation.

A 2-month-old boy with a single ventricle underwent cardiac catheterisation. Inferior vena cava angiography at the end of the examination revealed local stenosis, flexion, and connection to the right hepatic vein. Six hours after catheterisation, he went into haemorrhagic shock. CT revealed contrast extravasation into the liver with ascites. A precise diagnosis of vascular anomalies is mandatory, especially in patients with heterotaxy syndrome.

Pulmonary artery stenosis is one of the most common complications after arterial switch operation. Stent implantation is an effective treatment with some risks related to coronary artery compression. We present the case of a patient affected by pulmonary stenosis after arterial switch operation. Coronary compression testing demonstrated compression of the left coronary artery from the balloon inflated in the left pulmonary artery. We should systematically consider the use of coronary balloon testing before stent implantation in patients with a history of switch operation.

Twelve-lead ECG of a child with Wolff–Parkinson–White syndrome and systolic dysfunction was consistent with the anteroseptal accessory pathway. The earliest atrial activation during electrophysiological study was found between the right anteroseptal region near the HIS. Multiple femoral tract right-sided cryotest lesions followed by radiofrequency catheter irrigated through the jugular vein route were unsuccessful. Then, non-coronary aortic cusp mapping and cryoablation were successfully performed with a retroartic approach.

Left atrial appendage aneurysm is an extremely rare cardiac anomaly with serious complications. It is rarely diagnosed in childhood. Herein, we reported two newborns diagnosed with left atrial appendage aneurysm.