Several types of right-sided aortic arch exist, the most common ones being right-sided aortic arch with aberrant left subclavian artery and the mirror-image type. The variant with aberrant left subclavian artery is associated with congenital heart disease in only a small minority of affected people. The mirror-image type of right aortic arch is very strongly associated with congenital heart disease, in most cases tetralogy of Fallot. A right-sided aortic arch does not cause symptoms on itself, and the overwhelming majority of people with the right-sided arch have no other symptoms. However when it is accompanied by other vascular abnormalities, it may form a vascular ring, causing symptoms due to compression of the trachea and/or oesophagus.

Atrial septal defects may also occur in association with a variety of other congenital heart defects, or in new-borns that are relatively small or premature. The following conditions are associated with an atrial septal defect:Ebstein’s anomalyFoetal alcohol syndromeHolt-Oram syndromeDown syndromeEllis van Creveld syndromeLutembacher’s syndrome Ostium primum defects occur frequently in individuals with Down syndrome or Ellis van-Creveld syndrome.Holt-Oram syndrome characterized by an autosomal dominant pattern of inheritance and deformities of the upper limbs (most often, absent or hypoplastic radii) has been attributed to a single gene defect in TBX5Fragile X syndrome is characterized by moderate intellectual disability in affected males and mild intellectual disability in affected females. The physical features in affected males are variable and may not be obvious until puberty. These symptoms can include a large head, long face, prominent forehead and chin, protruding ears, loose joints and large testes. Other symptoms can include flat feet, frequent ear infections, low muscle tone, a long narrow face, high arched palate, dental problems, crossed eyes (strabismus) and heart problems including mitral valve prolapse.

Tetralogy of Fallot usually is diagnosed after a baby is born, often after the infant has an episode of turning blue during crying or feeding (a tet spell). A loud heart murmur is usually present.An atrial septal defect is present at birth, but many babies do not have any signs or symptoms.Coarctation of the aorta is usually diagnosed after the baby is born. How early in life the defect is diagnosed usually depends on how mild or severe the symptoms are. New-born screening using pulse oximetry during the first few days of life may or may not detect coarctation of the aorta.In babies with a more serious condition, early signs usually include:pale skinirritabilityheavy sweatingdifficulty breathingBabies born with pulmonary atresia will show symptoms at birth or very soon afterwards. They may be cyanotic. However, it is not uncommon for a heart murmur to be absent right at birth.

Heart murmurs are common in healthy infants, children, and adolescents. Although most are not pathologic, a murmur may be the sole manifestation of serious heart disease. Historical elements that suggest pathology include family history of sudden cardiac death or congenital heart disease, in utero exposure to certain medications or alcohol, maternal diabetes mellitus, history of rheumatic fever or Kawasaki disease, and certain genetic disorders. Physical examination should focus on vital signs| age-appropriate exercise capacity| respiratory or gastrointestinal manifestations of congestive heart failure| and a thorough cardiovascular examination, including features of the murmur, assessment of peripheral perfusion, and auscultation over the heart valves. Red flags that increase the likelihood of a pathologic murmur include a holosystolic or diastolic murmur, grade 3 or higher murmur, harsh quality, an abnormal S2, maximal murmur intensity at the upper left sternal border, a systolic click, or increased intensity when the patient stands. Electrocardiography and chest radiography rarely assist in the diagnosis.

DiGeorge syndrome is one of the most common microdeletion syndromes, resulting from 22q11 deletion. 10% of the cases can be inherited in an autosomal dominant fashion, while 90% are sporadic. The syndrome is characterized by a deficiency of both T and B-cell lines along with hearing loss, 20-fold increased lifetime chances of developing schizophrenia, renal abnormalities, congenital heart defects, and a borderline or low IQ. Distinctive facial features include micrognathia, long face, short philtrum, cleft palate, and small teeth.

Tricuspid atresia is the third most common form of cyanotic congenital heart disease, with a prevalence of 0.3-3.7% in patients with congenital heart disease. The deformity consists of a complete lack of formation of the tricuspid valve with the absence of a direct connection between the right atrium and right ventricle.The following 3 considerations guide the treatment of infants with tricuspid atresia:- The amount of pulmonary blood flow must be regulated to decrease hypoxemia or symptoms of congestive heart failure.- Myocardial function, the integrity of the pulmonary vascular bed, and pulmonary vascular integrity must be preserved to optimize conditions for a later Fontan operation.- The risk of bacterial endocarditis and thromboembolism must be minimized.Infants with decreased pulmonary blood flow: encompasses most of the infants with tricuspid atresia.Marked cyanosis and hypoxemia characterize the clinical course. Acidaemia may occur if the hypoxemia is profound, and death can ensue.Promptly treat infants with severe hypoxemia with prostaglandin E infusions to maintain patency of the ductus arteriosus and improve pulmonary blood flow.Infants with increased pulmonary blood flow: These infants have an associated unrestrictive ventricular septal defect and transposed great vessels.They present with severe congestive heart failure and benefit from digitalis and diuretic therapy until an operative intervention can be undertaken to restrict the pulmonary blood flow.

Transposition of the great arteries (TGA) is a common congenital heart lesion that presents with severe cyanosis that is likely to appear in the first day of life.

Ebstein’s anomaly is characterised by apical displacement and adherence of the septal and posterior leaflets of the tricuspid valve to the underlying myocardium, thereby displacing the functional tricuspid orifice apically and dividing the right ventricle into two portions. The main haemodynamic abnormality leading to symptoms is tricuspid valve incompetence. The clinical spectrum is broad| patients may be asymptomatic or experience right-sided heart failure, cyanosis, arrhythmias and sudden cardiac death (SCD). Many Ebstein’s anomaly patients have an interatrial communication (secundum atrial septal defect (ASD II) or patent foramen ovale). Other structural anomalies may also be present, including a bicuspid aortic valve (BAV), ventricular septal defect (VSD), and pulmonary stenosis. The morphology of the tricuspid valve in Ebstein anomaly, and consequently the clinical presentation, is highly variable. The tricuspid valve leaflets demonstrate variable degrees of failed delamination (separation of the valve tissue from the myocardium) with fibrous attachments to the right ventricular endocardium.The displacement of annular attachments of septal and posterior (inferior) leaflets into the right ventricle toward the apex and right ventricular outflow tract is the hallmark finding of Ebstein anomaly.

The most possible diagnosis is SVT. The boy is suffering from hemodynamic instability, as indicated by his cold extremities. DC cardioversion is the treatment of choice.

Except Tetralogy of Fallot, the others are acyanotic heart diseases. The cyanotic spells and loss of consciousness are due to spasm of the infundibular septum, which acutely worsens the right ventricular outflow tract obstruction. The given murmur is due to a ventricular septal defect.

The most probable diagnosis for this child would be rheumatic fever due to a previous history of rheumatic fever, evidence of streptococcal disease from a throat swab, a raised ASO titre and a positive streptococcal antigen test or a leukocytosis.Acute Rheumatic Fever:ARF occurs because of an abnormal immune response to a streptococcal antigenic component. It has a latent period of 1–3 weeks and is more common in the lower socio-economic classes. It peaks at around 5–15 years of age and affects the blood vessels, joints, nervous system and subcutaneous tissues. It is characterised as an autoimmune disease, and there is a risk of rheumatic fever occurring after infection in 3% of the population. The recurrence is greater in younger children and increases with each attack. Duckett-Jones criteria:The diagnostic criteria for acute rheumatic fever.Major: – Pancarditis- Chorea (Sydenham’s) – Polyarthritis (flitting)- Erythema marginatum- Subcutaneous nodulesMinor criteria include the presence of arthralgia, fever, prolonged PR interval, raised ESR, raised CRP.Note that:To make the diagnosis of rheumatic fever: Two major and/or one major with two minor criteria are required. Evidence of a recent streptococcal infection with a raised ASO titre or an antiribonuclease B level is sufficient. Exceptions to this rule are mentioned below:- Chorea alone is diagnostic.- Insidious or late-onset carditis with no other explanation.- Rheumatic recurrence: The presence of one major and one minor criterion with a prior streptococcal disease that is recurring.Consequences of pericarditis include heart block, pericardial effusion, tachycardia, cardiomegaly, pericardial friction rub, congestive cardiac failure, valvular disease and a Carey–Coombes apical mid-diastolic rumbling murmur.New heart murmurs are often audible, including those of mitral regurgitation and aortic regurgitation. Skin nodules affect the perivascular tissues and are non-specific lesions resulting from fibroid degeneration.Management:Medication includes aspirin for the acute phase, non-steroidal anti-inflammatory drugs for arthritis, prednisolone for severe carditis, and high-dose penicillin for immediate management with antibiotic prophylaxis in the long term. Antibiotics may include penicillin V, erythromycin or benzylpenicillin. Diazepam and haloperidol may be required to control the chorea.

A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.

The murmur of tricuspid valve regurgitation is typically a high-pitched, blowing, holosystolic, plateau, nonradiating murmur best heard at the lower left sternal border. The intensity is variable, but tends to increase during inspiration (Carvallo’s sign), with passive leg raising, after a post-extrasystole pause, and following amyl nitrite inhalation. The intensity of the murmur tends to correlate positively with the severity of regurgitation. Right ventricular enlargement may displace the location of the murmur leftward. Right ventricular failure may abolish respiratory variation. When tricuspid regurgitation is caused by pulmonary hypertension, a pulmonic ejection click may be audible. Severe tricuspid regurgitation is commonly accompanied by a third heart sound emanating from the right ventricle and best heard at the lower left sternal border. Severe tricuspid regurgitation typically produces an accentuated jugular cv wave and may produce hepatic congestion with a pulsatile liver.The auscultatory findings associated with ventricular septal defect are variable, depending on a variety of morphologic and hemodynamic considerations. The systolic murmur associated with a Roger’s-type ventricular septal defect (regurgitant jet flows directly into the right ventricular outflow tract) in patients with low pulmonary vascular resistance is a low to medium pitched, holosystolic murmur with midsystolic accentuation. The intensity of the murmur is typically grade 3 or higher.Patent ductus arteriosus produces a continuous murmur in patients with normal pulmonary vascular resistance.

Although WPW syndrome is a type of supraventricular re-entrant tachycardia, CCBs are contraindicated in its management. This is because CCBs depress AVN conduction| the current then passes through the accessory pathway (bundle of Kent) instead, causing ventricular tachycardia.

Kawasaki disease is an acute febrile illness of early childhood characterized by vasculitis of the medium-sized arteries. Diagnostic criteria include fever of at least 5 days duration along with 4 or 5 of the principal clinical features – extremity changes, polymorphous rash, oropharyngeal changes, conjunctival injection and unilateral nonpurulent cervical lymphadenopathy.

The most probable diagnosis for the clinical scenario provided is coarctation of the aorta. It contributes to about 4% of all congenital heart disease and is more prominent in males than females.It is associated with trisomy 13 and 18, Turner syndrome, valproate toxicity as well as ventricular septal defects, persistent ductus arteriosus, mitral valve abnormalities and berry aneurysms of the circle of Willis. Other associated cardiac abnormalities include a bicuspid aortic valve (50%), mitral valve disease, aortic regurgitation (20%) and subaortic stenosis. Ninety-eight per cent of coarctations occur at the level of the pulmonary artery after the subclavian artery. It is for this reason that, on observation, the proximal blood pressure varies compared with the distal blood pressure. The blood pressure in the right arm is often higher than that in the left arm. Clinically, these children present with hypertension, prominent carotid pulses, radio-femoral delay, left ventricular hypertrophy and an ejection systolic murmur maximum over the posterior left interscapular area. An apical click over the aortic valve may be heard. Coarctation of the aorta may be simple (post-ductal), or complex (pre-ductal or with a septal defect), and may be associated with aortic stenosis, transposition of the great arteries or a bicuspid aortic valve. The ECG and chest radiograph may be normal. However, as the child enters the first decade, evidence of cardiomegaly, congestive heart failure, post-stenotic dilatation with a dilated subclavian artery and rib notching may be noticed. The ECG may show right ventricular hypertrophy, left ventricular hypertrophy in infancy and right axis deviation. Complications of coarctation of the aorta include left ventricular failure, cerebral haemorrhage, aortic dissection, renal vascular stenosis and infective endocarditis. This condition may result in death due to an aortic aneurysm or rupture in the third or fourth decade of life. It may also cause premature ischaemic heart disease as a result of hypertension. If left untreated, 20% of individuals die before 20 years of age and 80% before 50 years of age. Treatment options include surgical balloon dilatation or the grafting of a subclavian flap, and should surgical correction not normalise the blood pressure, further medical management is required.

A ventricular septal defect (VSD) is a common form of congenital heart defects and is characterised by the presence of a hole in the wall that separates the right from the left ventricle. Medium or large defects can cause many complications. One of these complication is Eisenmenger syndrome, characterised by reversal of the shunt (from left-to-right shunt into a right-to-left) ,cyanosis and pulmonary hypertension.

The best answer is Henoch-Schönlein Purpura (HSP). This patient has a characteristic rash and the labs are consistent with this diagnosis.

Tooth extraction or any surgical procedure may introduce bacteria into the blood stream. The most commonly involved organisms include Staphylococcus aureus and Streptococcus viridans. Once in the blood, these organisms have a very high tendency of attaching to the walls of the heart and causing inflammation known as endocarditis.

Key Observations:

1. Cyanosis and Low Oxygen Saturation:
   • Central cyanosis indicates mixing of oxygenated and deoxygenated blood.
   • The aortic oxygen saturation is low (76%), indicating a significant amount of deoxygenated blood entering systemic circulation.
2. Pressure Analysis:
   • The right ventricle pressure is significantly elevated (110/6 mmHg), suggesting an obstructive lesion like pulmonary stenosis or an increased volume load due to a shunt.
   • The pulmonary artery pressure is low (20/5 mmHg) despite the high right ventricular pressure, suggesting an obstruction to flow from the right ventricle to the pulmonary artery, consistent with pulmonary stenosis.
3. Oxygen Saturation Analysis:
   • There is a notable drop in oxygen saturation from the left ventricle (87%) to the aorta (76%), indicating a mixture of oxygenated and deoxygenated blood in the systemic circulation, suggestive of a right-to-left shunt.

Differential Diagnosis:

1. Pulmonary Stenosis:
   • Supported by elevated right ventricular pressure and low pulmonary artery pressure.
2. Ventricular Septal Defect (VSD):
   • Would typically cause left-to-right shunting, leading to increased pulmonary blood flow and higher oxygen saturation in the right ventricle and pulmonary artery, which is not observed here.
3. Over-riding Aorta:
   • Seen in conditions like Tetralogy of Fallot where the aorta receives blood from both the right and left ventricles, leading to mixed oxygen saturation.
4. Right-to-Left Shunt:
   • The data indicates a right-to-left shunt, with low oxygen saturation in the aorta, suggesting that deoxygenated blood is bypassing the lungs and entering systemic circulation.
5. Aortic Stenosis:
   • Typically presents with high left ventricular pressure and a pressure gradient between the left ventricle and the aorta, which is not observed here.

Conclusion:

Given the data, the most likely abnormalities present in this patient are Pulmonary Stenosis, Right-to-Left Shunt, and Over-riding Aorta. These findings are consistent with a condition like Tetralogy of Fallot, where all these features are present.