Congenital Heart Disease (CHD)

• Congenital Heart Disease (CHD) involves abnormalities of the heart's structure or function present at birth
• Most CHDs arise from abnormal embryogenesis
• The average incidence is 8 in 1000 live births
• Clinical presentation hinges on hemodynamic changes
• Two-dimensional and Doppler echocardiography is the best way to evaluate most defects

Best Diagnostic Test

• Echocardiogram

Fetal Circulation

• Fetal circulation has three cardiovascular communications
• Ductus arteriosus
• Foramen ovale
• Ductus venosus

CHD Classification

• CHD is classified as non-cyanotic or cyanotic

Non-Cyanotic CHD: Left to Right Shunt Lesions

• Atrial Septal Defect (ASD)
• Patent Foramen Ovale (PFO)
• Ventricular Septal Defect (VSD)
• Patent Ductus Arteriosus (PDA)

Non-Cyanotic CHD: Stenotic Heart Lesions

• Coarctation of the Aorta
• Pulmonary Stenosis
• Aortic Stenosis

Cyanotic CHD: Right to Left Shunt Lesions

• Truncus Arteriosus (TA)
• Transposition of the Great Vessels (TGV)
• Tricuspid Atresia
• Tetralogy of Fallot (TOF)
• Total Anomalous Pulmonary Venous Connection (TAPVC)
• Ebstein's Malformation
• Hypoplastic left heart

Risk factors

• The risk of CHD in offspring of an individual is 10-15%
• Genetic abnormalities like Down syndrome (VSD and Atrioventricular septal defect most common) and Turner syndrome (coarctation of the aorta) can be the cause CHD
• Environmental factors like alcohol, maternal infections (rubella), medications during pregnancy, and smoking can cause CHD
• It can be a combination of the above factors

Acyanotic Congenital Heart Disease

• Involves Left-to-Right Shunt Lesions

Atrial Septal Defect (ASD)

• ASD is an opening in the atrial septum permitting free communication of blood between the atria
• It creates a Left-to-Right shunt
• Secundum ASD is the most common form

Atrial Septal Defect (ASD): Clinical Signs and Symptoms

• Rarely presents with signs of Congestive Heart Failure (CHF) or cardiovascular symptoms
• Most are asymptomatic but may have easy fatigability or mild growth failure
• Cyanosis does not occur unless pulmonary hypertension (HTN) is present
• Hyperactive precordium, Right Ventricular (RV) heave, fixed widely split S2
• II-III/VI systolic ejection murmur @ LSB (2nd LICS) caused by increased blood flow across the pulmonic valve

Atrial Septal Defect (ASD): Treatment

• Surgical or catherization closure is generally recommended
• Closure is performed electively between ages 2 & 5 years to avoid late complications
• Closure is done earlier in children with CHF or significant pulmonary hypertension

Atrial Septal Defect (ASD): Complications

• Once pulmonary hypertension with shunt reversal occurs (Eisenmenger's syndrome) closure is considered too late.

Patent Foramen Ovale (PFO)

• PFO allows communication between the left and right atria
• PFO is not considered an ASD due to no septal tissue loss

Ventricular Septal Defect (VSD)

• VSD is an opening(s) in the ventricular septum permitting free communication of blood between the ventricles
• It is the most common defect in infancy/childhood
• This causes a Left – Right shunt

VSD: Clinical Signs and Symptoms

• Holosystolic murmur is usually best heard over the "tricuspid area” AKA “Erb's point" or the lower left sternal border.
• Large VSD symptoms: easy fatigability, CHF in infancy, hyperactive heart, frequent respiratory infections

VSD: Treatment

• Small VSDs often close on their own
• Surgery may not be required if the heart shows no evidence of strain
• Surgical repair is often required in multiple VSDs in the first three to six months of life
• Large VSDs: heart failure is managed medically with breathlessness, poor feeding/slow weight gain, and early repair

VSD: Complications

• Once pulmonary hypertension with shunt reversal occurs (Eisenmenger's syndrome) closure is considered too late

Patent Ductus Arteriosus (PDA)

• Continuous murmur (heard in systole and diastole), "machinery," "washing machine-like" murmur
• A large PDA results in failure to thrive, poor feeding and respiratory distress
• Older children present with shortness of breath or easy fatigability

PDA: Treatment

• In a preterm case (before 37 weeks), closure medically using indomethacin (prostaglandin inhibitor) is an option
• In a term baby, coil closure or a device by cardiac catherization is preferrable if it remains open after 3 months

Eisenmenger's Syndrome

• Over time causes increased Pulmonary Vascular Resistance (PVR), resulting in bi-directional flow
• Blood flow is redirected through VSD, ASD, or PDA from Left-to-Right to Right-to-Left shunt
• Correction of the abnormality is too late and patients must be managed in centres specializing in CHD and pulmonary arterial hypertension

Eisenmenger's Syndrome: Possible Complications

• Hyperviscosity
• Cerebral hemorrhage
• Poor blood flow to the brain
• CHF
• Heart attack
• Stroke
• Sudden death

Eisenmenger's Syndrome: Hallmarks

• Cyanosis + Pulmonary Hypertension + Erythrocytosis

Noncyanotic CHD (cont.)

• Stenotic heart lesions

Noncyanotic CHD: Stenotic Heart Lesions

• Coarctation of the aorta (narrowing)
• Aortic Stenosis
• Pulmonic Stenosis

Coarctation of the Aorta

• Narrowing of the aorta

Coarctation of the Aorta: Clinical Signs and Symptoms

• Older infants and children are usually asymptomatic but may have chest pain, cold extremities, and lower extremity claudication with physical activity
• Young Adults classic presentation is hypertension. Headache, epistaxis, heart failure, or aortic dissection may occur and lower extremity claudication

Coarctation of the Aorta: Clinical Signs and Symptoms

• High Blood Pressure (BP) in the Upper Extremities
• Low or unobtainable BP in the Lower Extremities
• Diminished or delayed femoral pulses (brachial-femoral delay)
• Cardiac exam may be normal or there may be a murmur if another cardiac defect is present (AS, PDA, VSD etc)
• Over 70% of patients have a bicuspid aortic valve and will have AS

Coarctation of the Aorta: CXR

• Notching of the ribs from erosion by the large collateral arteries
• Indentation of aorta wall at the site of coarctation can produce a 3 sign

Coarctation of the Aorta: Diagnostic Studies

• Echocardiogram
• CT or MRI
• Angiogram

Coarctation of the Aorta: Treatment

• Surgical repair
• Stent placement

Cyanotic Heart Disease

• Red Flags in Pediatrics are Sweating and Cyanosis including lips/tongue
• In dark skinned populations assess areas where skin tone is lightest and pallor and cyanosis is easiest to detect i.e Lips, Mucous membranes, Nail beds, Palms/soles

Prostaglandin (PGE1) in Cyanotic Congenital Heart Disease

• Maintains ductal patency
• Prevents postnatal ductal closure, improving pulmonary blood flow and oxygenation
• Stabilizes the cyanotic neonate for corrective surgery

ExtraCorporal Membrane Oxygenation (ECMO) in Cyanotic Congenital Heart Disease

• Used as perioperative bridge to recovery or temporary support if failure of medical management with oxygen, mechanical ventilation, prostaglandin, inotropic support, diuretics

Cyanotic Heart Disease "5 Ts"

• Truncus arteriosus → 1 trunk instead of 2
• Transposition of the great arteries (TGA) - pulmonary artery switches position with aorta
• Tricuspid Atresia - born without the tricuspid valve
• Tetralogy of Fallot (TOF) - has four abnormalities that always occur together
• Total anomalous pulmonary venous return - pulmonary u. should be hooked up to inferior vena cava of superior vena cava

Tetralogy of Fallot

• Pulmonary stenosis
• Large Ventricular Septal Defect (VSD)
• Overriding aorta
• Right ventricular hypertrophy

Tetralogy of Fallot (ToF)

• It is the most common cause of cyanosis in infancy/childhood
• Severity of cyanosis is related to the severity of right ventricular outflow tract obstruction

TOF: Hypercyanotic “tet” spell

• Decreased systemic vascular resistance (hot bath, fever, exercise) increases R-L shunt, increasing cyanosis
• Agitation increases subpulmonic obstruction
• It is life-threatening if untreated

Management of "tet” spell goal: Increase systemic vascular resistance (SVR) and decrease pulmonary vascular resistance (PVR)

• Knee to chest position
• O2
• Fluid bolus IV
• Morphine IV decreases agitation and RVOT obstruction, and pulmonary resistance
• NaHCO3 corrects metabolic acidosis and decreases PVR
• Phenylephrine increases SVR
• B-blocker decreases RVOT obstruction

Tetralogy of Fallot: CXR

• Boot shaped heart (from Right, Ventricular Hypertrophy)
• Decreased Pulmonary vascular markings

Tetralogy of Fallot requires

• Surgical correction

Truncus Arteriosus

• Mixes oxygenated blood/deoxygenated blood mixes in periphery

Transposition of the Great Arteries (TGA)

• pulmonary artery switches position with aorta
• Cyanosis happens immediately after birth and requires immediate treatment
• Survival depends on PDA or PFO in the early days of life until definitive treatment is performed

TGA: Definitive Treatment

• "Arterial Switch Operation" must be done in the first week or two of life
• CXR: Egg on a string appearance: Heart looks like an "egg" due to left atrial enlargement and the mediastinum is narrow due to stress.

Tricuspid Atresia

• No tricuspid value is present
• Severe cyanosis & clubbing
• No connection between right atrium and right ventricle as blood goes from and right atrium to left atrium through Patent Foramen Ovale (PFO)
• Right ventricle is small, requiring VSD for blood to reach the lungs.

Tricuspid Atresia: Clinical Signs and Symptoms

• Shortness of breath, severe cyanosis, clubbing, heart failure symptoms
• Treatment requires multiple surgeries
• Infancy: shunt between aorta and pulmonary arteries
• Bidirectional Cavo Pulmonary Connection (BCPC) connects Superior Vena Cava (SVC) to right pulmonary artery to direct some blood to the pulmonary system (improves but doesn't eliminate cyanosis)
• Definitive surgery is delayed until at least 2 years; Fontan operation

Total Anomalous Pulmonary Venous Return

• Pulmonary veins do not connect normally.
• PFO is required for survival until this is repaired
• Symptoms are cyanosis and signs of heart failure

Supracardiac TAPVR

• All four pulmonary veins connect to superior vena cava
• Treatment is surgical correction in the newborn period
• CXR: Snowman or Figure of 8 appearance
• The dilated vertical vein, superior venacava (head), and the enlarged right atrium (body)

Ebstein’s Anomaly

• Abnormalities of the tricuspid valve and right ventricle
• ASD (or other defect like VSD) is also present.
• Higher incidence if mother took lithium during pregnancy
• Symptoms of exertional dyspnea, fatigue, cyanosis, and palpitations

Ebstein's anomaly of the tricuspid valve: Management

• PG-E (support patency of ductus arteriosus & increases pulmonary blood flow)
• Treatment of arrhythmia's
• Tissue valve replacement

Hypoplastic Left Heart Syndrome (HLHS)

• Rare, but One of the most severe.
• Small left Ventricle and Aorta
• Poorly formed LV cannot support circulation
• Right side takes over.
• Right ventricle pumps blood both to the lungs and periphery through the PDA & oxygen rich blood gets to the RV via the PFO

Hypoplastic Left Heart Syndrome: Symptoms

• Infants are very cyanotic and ill in the first few days of life and need supportive therapy. PGE1 is given to keep PDA open
• Urgent surgery & successive surgeries (or cardiac transplant) are needed to survive such as the Norwood Operation or the Fontan Operation

Endocarditis Prophylaxis in CHD: Who gets it?

• Unrepaired cyanotic CHD
• Completely repaired CHD with prosthetic materials for 6 months, allowing endothelium formation
• Incompletely repaired CHD with residual defects at prosthetic patches or devices

Summary of some Radiology findings

• Rib Notching = Coarctation of the aorta
• Boot shaped heart = Tetralogy of Fallot (TOF)
• Egg on the string appearance = Transposition of the Great arteries (TGA)
• Snowman or Figure of 8 appearance = Total Anomalous Pulmonary Venous Return (TAPVR)