Congenital Acyanotic heart diseases - Pediatrics

Question 1

What are the types of atrial septal defect (B)

Answer 1

1. Secundum ASD: Center of atrial septum involving foramen ovale
2. Primum ASD: Lower part of septum. Associated with cleft in the mitral valve leaflet (Partial AV canal) common in down syndrome.
3. Sinus venosus defect: Upper part of septum near Vena cava orifice.
4. Coronary sinus defect.

Question 2

Clinical features of ASD (A++)

Answer 2

• Symptoms:
  o Asymptomatic (commonly)
  o May include pulmonary congestion symptoms as infections/wheeze, exercise intolerance, shortness of breath, fatigue, etc.
  o May have palpitations due to atrial arrhythmias (atrial flutter and/or atrial fibrillation in the fourth decade onwards) related to atrial stretch.
• Physical signs:
  o A fixed and widely split-second heart sound (often difficult to hear) due to the right ventricular stroke volume being equal in both inspiration and expiration
  o An ejection systolic murmur best heard at the upper left sternal edge due to increased flow across the pulmonary valve because of the left-to-right shunt.
  o With a partial AVSD, an apical pansystolic murmur from atrioventricular valve regurgitation.

Question 3

Investigations in ASD (B)

Answer 3

• Chest X-ray: cardiomegaly, pulmonary arteries dilatation and increased pulmonary vascular markings.
• ECG:
  o Secundum ASD: partial right bundle branch block (RBBB) is common, right axis deviation due to right ventricular enlargement.
  o Partial AVSD: a ‘superior’ QRS axis (mainly negative in AVF). This occurs because there is a defect of the middle part of the heart where the atrioventricular node is.
• Echocardiography confirms the diagnosis.

Question 4

Complications of ASD and natural history (B)

Answer 4

• PFO( Patent Foramen ovale) close spontaneously in the first few months of life (30% of adults have PFO)
• Secondum defects closes in younger children (40% in the first 4 year)
  1. Infective endocarditis (but rare in ASDs why?)
  2. Recurrent chest infections.
  3. Recurrent heart failure may occur with large defects.
  4. Eisenmenger physiology (5-10%): the increased pulmonary blood flow over time will cause pulmonary hypertension with reversal of the blood flow through shunt (RT to LF shunting) leading to cyanosis.

Question 5

Management of ASD? (B)

Answer 5

1. PFO: no treatment recommended unless there is high risk for paradoxical embolism.
2. Children with significant ASD (cause right ventricle dilatation) will require closure.
3. Trans-catheter (percutaneous) device closure: For secundum ASDs with insertion of an occlusion device
4. Surgical closure: is required in primum, partial AVSD and sinus venosus types and very large secundum ASD.
   - Surgery; better started at age of about 3–5 years in order to prevent right heart failure and arrhythmias in later life.
   - Surgery is contraindicated in patients with Eisenmenger physiology.

Question 6

Types and pathophysiology of VSD (B)

Answer 6

• Ventricular septal defects (VSDs) are accounting for 30% of all cases of CHD.
• VSD is an opening between the right and left ventricles and is categorized by the location of the defect or according to the size of the defect:
  o Membranous or peri membranous (70%): in the membranous portion of the septum.
  o Muscular (5-20%) (completely surrounded by muscle).

Question 7

Hemodynamic and pathophysiology of VSD (B)

Answer 7

• Most VSDs results in shunting of blood from the LV to the RV, with increasing pulmonary blood flow. The amount of shunting depends on the size of the VSD and the relative resistance of the pulmonary and systemic vasculature.
• Large VSD → significant shunting of blood from the LV to the RV → increasing pulmonary blood flow → Pulmonary congestive symptoms and volume overload on RV, LA and LV→ their enlargement.

Question 8

Clinical presentations of VSD (a++)

Answer 8

• Small muscular defects (≤ 3mm) are usually asymptomatic and present with loud pansystolic murmur at lower left sternal edge (90% closed by the age of 1 year)
• Large defects
  1. Symptoms
  o Heart failure with breathlessness and failure to thrive after 1 month old
  o Dyspnea& Recurrent chest infections (Pul. congestion).

2. Physical signs:
   o Tachypnoea, tachycardia and enlarged tender liver (Triad of heart failure).
   o Active precordium
   o Soft pansystolic murmur or no murmur (implying large defect)
   o Apical mid-diastolic murmur (from increased flow across the mitral valve after the blood has circulated through the lungs).
   o Loud pulmonary second sound (P2): from raised pulmonary arterial pressure.

Question 9

Investigations used in VSD (B)

Answer 9

• Chest X- ray
  o Cardiomegaly
  o Enlarged pulmonary arteries
  o Increased pulmonary vascular markings
  o Pulmonary oedema (in large defects).
• ECG: Biventricular hypertrophy by 2 months of age and evidence of pulmonary hypertension.
• Echocardiography: confirm the diagnosis.

Question 10

Management of VSD (A++)

Answer 10

• Prophylaxis against infective endocarditis.
• Small VSDs: follow up, spontaneous closure in 30-40%.
• Haemodynamically significant VSDs:
  o Drug therapy for heart failure is with diuretics, often combined with ACE inhibitors. Additional calorie input is required.
  o Surgical closure: for infants before 1 year of age or if failure to thrive (before 6 months)
  o Trans-catheter (percutaneous) device closure: for muscular VSDs.
  o Surgery is contraindicated in patients with Eisenmenger syndrome.

Question 11

Hemodynamic of PDA

Answer 11

• The flow of blood across a PDA is from the aorta to the pulmonary artery (i.e. left to right), following the fall in pulmonary vascular resistance after birth.
• In the preterm infant, the presence of a persistent ductus arteriosus is not from congenital heart disease but due to prematurity.
• A small PDA rarely causes effects.
• A large PDA→ significant shunting of blood from the aorta to pulmonary artery →
  I: increasing pulmonary blood flow → 1) pulmonary congestive symptoms.
  2) Volume overload on LA and LV→ Their enlargement.
  3) Elevated pulmonary vascular resistance, ultimately leading to Eisenmenger syndrome.
  II: Shunting of blood from aorta to pulmonary artery during diastole → Decreased diastolic pressure → big pulse volume and hyperdynamic circulation

Question 12

Clinical presentation of PDA (A++)

Answer 12

• Small PDAs are usually asymptomatic. They may be first suspected as a systolic or continuous murmur.
• Moderate to large PDAs are associated with:
  o Increased risk of respiratory tract infections (pulmonary congestion symptoms).
  o Congestive heart failure symptoms
  o Examinations: grade I-IV/VI continuous murmur, often described as “machinery -like” and usually heard at the upper left sternal border.
  o May be associated with wide pulse pressure and bounding pulses (all peripheral signs of hyperdynamic circulation as AR).
• In premature infants: PDAs can cause a hemodynamically significant left to right shunting severe enough (murmur less common) → to lead to systemic hypoperfusion → increased risk of pulmonary edema, NEC, renal injury, myocardial ischemia

Question 13

Investigations of PDA (A++)

Answer 13

• Chest X- ray: Cardiomegaly (LV & LA), PA enlargement, and plethora, or pulmonary edema
• ECG: →LVH with large left to right shunt (tall R in left leads). RVH with pulmonary hypertension
• Echocardiogram: confirm diagnosis

Question 14

Natural history and complications of PDA (A++)

Answer 14

• After few weeks of life spontaneous closure is rare especially in full-term infants & children
  1. Infective endocarditis
  2. Heart failure.
  3. Recurrent chest infections PDA devices and Coils
  4. An untreated large PDA → pulmonary hypertension → Eisenmenger syndrome → differential cyanosis (normal saturations in the upper extremities and lower saturation in the lower extremities with clubbing in the toes).

Question 15

Management of PDA (A++)

Answer 15

Significant PDAs in premature:
* Fluid restriction and diuretics
* Indomethacin or NSAIDs to close the PDA
* If medical treatment fail → surgical ligation

Persistent PDAs in full-term infants & children:
* Small PDA on Echo. with no murmur → follow up.
* Small PDA with audible murmur → catheterization closure by device.
* Moderate to large PDAs → catheterization closure by device better than surgery.

Question 16

Basic information about pulmonary stenosis (B)

Answer 16

• PS is characterized by obstruction to pulmonary blood fl
• According to the site of stenosis, PS is classified into:
  o Valvular PS: stenosis at the level of the valve (80-90
  o Sub valvular PS (infundibular): below the level of the
  o Supravalvular PS: above the level of the valve
  o In the branch of pulmonary artery
• The spectrum of the disease varies from mild PS to critical PS.
  A small number of neonates with critical PS have a duct-dependent pulmonary circulation and present in the first few days of life with cyanosis because of the Rt to Lt shunt.

Question 17

Clinical presentation of pulmonary stenosis ? (B)

Answer 17

• Mild PS:
  o Usually asymptomatic
  o Systolic ejection murmur heard at upper left sternal border.
• Moderate to severe PS:
  o May be asymptomatic in early life
  o Exertional dyspnea and fatigue
  o Cyanosis develops if there is a PFO or ASD with RT to LT shunting → 2ry to higher pressure in the RT side of the heart.
  o Physical signs:
  -An ejection systolic murmur with an ejection click best heard at the upper left sternal edge; thrill may be present.
  -When severe, there is a prominent right ventricular impulse (heave).
• Critical PS:
  o If the duct is opened → cyanosis but can maintain cardiac output.
  o If the duct is closed → severe cyanosis and hypoxia → up to shock.
  o No murmur for PS but we may hear of holo-diastolic tricuspid regurgitation.

Question 18

Investigations in Pulmonary stenosis (B)

Answer 18

• Chest x-ray: pulmonary oligemia and post stenotic pulmonary artery dilatation.
• ECG: shows evidence of right ventricular hypertrophy (upright T wave in V1).
• Echocardiogram: confirm the diagnosis.

Question 19

ttt of Pulmonary stenosis (PS) (B)

Answer 19

• Mild PS: may improve over time without intervention.
• Moderate to severe PS: may progress over time and require dilatation by catheter balloon dilatation or surgery.
• Critical PS:
  o Prostaglandin E should be given to keep PDA.
  o Catheter balloon valvuloplasty or surgery is attempted

Question 20

Types of congenital Aortic stenosis (B)

Answer 20

• Supravalvular: Uncommon, associated with William’s Syndrome.
• Valvular: Most common type.
• Aortic valve is bicuspid (common) or (unicuspid) rare.
• Bicuspid aortic valve is the most common congenital cardiac anomaly 0.5 –2%
• Subvalvular: Subaortic membrane, fibrous ring, or associated with hypertrophic cardiomyopathy (HOCM)

Question 21

Clinical features of Congenital Aortic stenosis (B)

Answer 21

• Most cases with mild to moderate AS present with an asymptomatic murmur.
• Severe AS: present with exercise intolerance, chest pain on exertion or syncope.
• In the neonatal period, those with critical aortic stenosis and a duct-dependent systemic circulation may present with severe heart failure leading to shock.
• Physical signs:
  o Small volume, slow rising pulses
  o Carotid thrill (always) + thrill on aortic area.
  o Ejection systolic murmur maximal at the upper right sternal edge radiating to the neck with delayed aortic component of second sound.
  o Apical ejection click.

Question 22

Investigations of Congenital Aortic stenosis (B)

Answer 22

• Chest X-ray: normal or prominent LV with post-stenotic dilatation of the ascending aorta.
• ECG: There may be left ventricular hypertrophy (Deep S wave in V2 and tall R wave in V6)
• Echocardiogram: confirm the diagnosis

Question 23

Complications of Congenital AS (B)

Answer 23

• Recurrent chest infections
• Infective endocarditis
• Left sided heart failure

Question 24

Treatment of AS (B)

Answer 24

• Mild AS → no treatment, but require meticulous follow up for more stenosis.
• Balloon catheter dilatation of aortic valve in older children is generally safe.
• Aortic valve replacement is required in most neonates and children with significant AS.

Question 25

Types of Aortic coarctation (B)

Answer 25

o Adult type (Post ductal) is usually located just distal to the site of ductus arteriosus, It can be discrete narrowing or long segment narrowing, the most common type.
o Infantile type (preductal) which can be critical coarctation (complete interruption of the aortic arch) or interrupted aortic arch.
o Juxtaductal: At the site of the ductus arteriosus. This kind usually appears when the ductus arteriosus closes.

Question 26

Neonate clinical presentation of Aortic coarctation

Answer 26

• Acute circulatory collapse may occur on the second day of age when the duct closes.
• Physical signs
  o A sick baby, with severe heart failure, metabolic acidosis and shock.
  o Absent femoral pulses
  o Differential cyanosis: as areas past the narrowing will be supplied by PDA flow (RT to LF shunting with cyanosis of the lower half of the body

Question 27

Adult-type clinical presentation of Aortic coarctation (A++)

Answer 27

• This lesion is not duct dependent. It gradually becomes more severe over years.
• Clinical features:
  o Asymptomatic, but may present with fatigue or pain with exercise.
  o Four- extremity blood pressures will show a differential between the upper and lower extremities (usually right arm hypertension)
  o Ejection systolic murmur at upper sternal edge
  o Collaterals heard with continuous murmur at the back
  o Radio-femoral delay. This is due to blood bypassing the obstruction via collateral vessels in the chest wall and hence the pulse in the legs is delayed.

Question 28

Diagnosis of Aortic coarctation (A++)

Answer 28

• Critical presentation;
  o Chest x-ray: cardiomegaly from heart failure and shock.
  o Echocardiography confirms diagnosis.
• Adult-type coarctation: clinical finding plus
  o Chest X-ray:
  ✓ ‘Rib notching’ due to the development of large collateral intercostal arteries running under the ribs posteriorly to bypass the obstruction.
  ✓ ‘3’ sign, due to dilated descending aorta post coarctation, with visible notch in the descending aorta at site of the coarctation.
  o ECG: normal or left ventricular hypertrophy.
  o MRI: also confirm diagnosis and identify collateral supply
  o Echocardiography: confirms diagnosis.

Question 29

ttt of aortic coarctation (B)

Answer 29

-Critical coarctation: (Ductal dependant lesion)
o initiate immediate PGE to maintain ductal patency
o Management of heart failure plus inotropic support
o Urgent surgical repair

-Asymptomatic children: surgical repair or balloon angioplasty.