Paediatric cardiovascular

Question 1

Atrial septal defect : definition

Answer 1

Opening between the right and left atrium of the heart

Question 1

Atrial septal defect : Normal foetal physiology of circulation

Answer 1

1. Embryonic development : Foramen ovale is a one way valve between the right atrium and left atrium
2. Oxygenated blood —>Placenta —> Umbilical vein **—> **Right atrium ->via foramen oval -> Left atrium -> left ventricle —>body
   -Lungs get bypassed
3. Birth : Septum seconded and septum primum fuse and close off foramen oval

Question 2

Atrial septal defect : Pathophysiology of development

Answer 2

Atrial septal defect - the foramen ovale does not close after birth
* Blood shunted : Left atrium -> Right atrium
* Oxygenated blood enters pulmonary circulation } TWICE

-Most cases caused by ostium secundum (second opening) not closing fully

-Down’s syndrome : Osmium Primum not closing fully

Question 3

Atrial septal defect : Risk factors

Answer 3

1. Down’s syndrome
2. Fetal alcohol syndrome

Question 4

ASD : Murmur

Answer 4

1. ‘splitting S2 sound’ + systolic murmur }

• Increased blood volume entering the right side of the heart
• Delays pulmonary valve close

Question 5

ASD : Complication

Answer 5

Embolism : if reaches the heart by travel via the ASD and enter systemic circulation

Question 6

VSD : definition

Answer 6

• Ventricular septum gap between Right and Left ventricle
• Most common congenital defect in babies

Question 7

VSD : Risk factors

Answer 7

1. Fetal alcohol syndrome
2. Down’s syndrome

Question 8

VSD : Pathophysiology

Answer 8

1. Oxygenated blood shunted from high to low pressure
2. Left ventricle -> Right ventricle
3. Oxygenated blood travels through pulmonary circulation } TWICE via ventricle septal defect

Question 9

VSD : Murmur

Answer 9

Murmur : Holosystolic murmur lower left sternal border

Cause : Left to right shunting of blood - leads to volume overload and increased blood flow leads to
Turbulence and vibration through the systolic phase

Question 10

VSD : Complication

Answer 10

1. Pulmonary hypertension
2. Eisenmenger’s syndrome : Increase in RV pressure 2nd to pulmonary hypertension, shifts pressure gradient, thus shifting direction of blood shunting
   * Right —> Left } by passing oxygenation via lungs
   * Hypoxic blood circulated
   * Cyanosis

Question 11

Patent Ductus arteriosus : Risk factors

Answer 11

Congential rubella syndrome - Maternal infection of rubella in the first trimester

Question 12

Patent Ductus arteriosus : Definition

Answer 12

1. Ductus arteriosus : connects Pulmonary artery to the Aorta on the aortic arch during fetal development
2. Remains open after birth

Question 12

Patent Ductus arteriosus : Normal foetal physiology of circulation

Answer 12

1. Ductus arteriosis function in utero; shunts oxygenated blood that doesn’t pass through the foramen ovale

2. Placenta -> ulmbilical vein -> right atria -> Right ventricle -> Pulmonary artery
-> Ductus arteriosus -> Aorta -> circulation
* Hence - bypassing the lungs

3. Ductus arteriosis closes after birth due to drop in prostaglandins

4. Becomes ligament - ligament arteriorsum

Question 13

Patent Ductus arteriosus : Pathophysiology

Answer 13

1. After birth; Remains open
2. Shunts Aortic (oxygenated) blood back into the Pulmonary artery
3. Enters pulmonary circulation } TWICE

Question 14

Patent Ductus arteriosus : Complications

Answer 14

1. Pulmonary hypertension } increased volume of blood in RV and pulmonary circulation
   Can lead to
2. Eisenmenger’s syndrome :
   * RV pressure > LV pressure 2nd to Pulmonary HTN
   * Reverses shunt : RV —-> LV - Bypassing lungs
   * Hypoxic blood enters systemic circulation

3 . Cyanosis in lower extremities :
* Sx confined to lower extremities as PDA connects to the aortic arch below the arteries which supply the upper extremities e.g. head, arms etc

Question 15

Patent Ductus arteriosus : Management

Answer 15

1. Indomethasin / ibuprofen (NSAID)
   * Inhibits prostaglandin release -> Closes PDA
2. Prostaglandin E1: keeps PDA patent if mixing of blood is amenable in the context of another coexistent cyanotic congenital heart disease.

Question 16

Patent Ductus arteriosus : Clinical signs

Answer 16

• Continuous ‘machinery’ murmur

-Due to continous shunting of blood between Aorta and Pulmonary artery throughout the cardiac cycle, turbulence of blood flow due to pressure gradient

• Wide pulse pressure }

-2nd to increased stroke volume of the LV due to shunting increasing blood flow in the pulmonary artery
-Reduced peripheral resistance : runoff of aortic blood to the pulmonary artery
- Thus difference between systolic vs diastolic BP

• Large volume, bounding, collapsing pulse
  -Wide pulse pressure and increased stroke volume
• heaving apex beat

Question 17

Coarctation of the Aorta : Definition

Answer 17

1. Narrowing of the aorta - after the aortic arch in infants
2. Patent Ductus Arteriosus - just below level of coarctation

Question 18

Coarctation of the Aorta : Pathophysiology

Answer 18

1. ‘Pre-ductal coarctation’
   Narrowing of the aorta : after the aortic arch
   Upper extremity circulation : unaffected as arteries are upstream from narrowing
2. Patent ductus arteriosus
   * Connects to Aorta just after coarctation/narrowing
3. Coarctation reduces Aortic Pressure
   * Narrowing of the aorta : reduces the blood volume and slows it down
4. Pressure in Pulmonary artery > Pressure in Aorta post coarctation
5. Deoxygenated blood from Pulmonary artery-> via ductus arteriosus -> Aorta -> Lower extremities circulation
   ( Bypassing lungs)

Question 19

Coarctation of the Aorta : Clinical features

Answer 19

Cyanosis in lower extremities - present at birth

Question 20

Coarctation of the Aorta : Risk factor

Answer 20

Turner’s syndrome - strong association

Question 21

Tetralogy of Fallot

Answer 21

• Congential heart condition with 4 main abnormalities ; Narrowing of the RV outflow causes RV hypertrophy**
  Also; **VSD with the Aorta over arching it
• Most common form of cyanotic heart condition

Question 22

Tetralogy of Fallot : Pathophysiology

Answer 22

1. Stenosis
   Narrowing of the Right Ventricular outflow tract
   -The pulmonary valve
   -Narrowing of the infundibulum - the area below the pulmonary valve
   -> Harder for deoxygenated blood to enter the pulmonary circulation
2. Hypertrophy of the Right ventricle
   -Myocardium contracts harder to push blood past the stenosis
   -> ‘Boot shaped’ on X-ray
3. Large VSD -
   -Gap between ventricles which allows shunting of blood between them
   -> RV obstruction causes : RV pressure > LV pressure
   * Right (deoxygenated blood ) -> Left (Systemic circulation) shunt
4. Aorta : Override ventricular septal defect**
   -May appear on right side of the heart

*The severity of symptoms depends on the degree of right outflow obstruction *

Question 23

Tetralogy of Fallot : Risk factors

Answer 23

Chromosome 22 deletion and di George syndrome

Question 24

Tetralogy of Fallot : Clinical symptoms

Answer 24

1 . **At Birth** : Cyanosis of lips and finger nails *  A few months : Clubbing of fingers and toes within months 2 . **Episodic ‘Tet’ spells** - * ***Increase in activity*** -> increases CVS workload -> R-L shunt increases -> sudden increase in cyanosis due to prevalence of deoxygenated blood * Often - **sit down to squat** during these spells * Which increases peripheral vascular resistance thus increasing pressure L> R side of the heart

Question 25

Tetralogy of Fallot : Clinical signs

Answer 25

* Ejection systolic murmur due to pulmonary stenosis

Question 26

Tetralogy of Fallot : Investigation

Answer 26

1. Chest x-ray:  shows a ‘boot-shaped’ heart - due to RV hypertrophy 2. ECG shows right ventricular hypertrophy

Question 27

Tetralogy of Fallot : Management

Answer 27

1. Surgical repair

Question 28

Transposition of the great arteries : Pathophysiology

Answer 28

1. Left ventricle is connected to the pulmonary artery which takes it to the lungs 2. Right ventricle is connected Aorta which takes it to the systemic circulation 3. Two separate systems and blood does not mix 4. In Utero - asymptomatic as lungs are not being used and shunts are available to allow mixing of blood 5. At birth - Non survivable Unless there is a septal defect  which allows for two circuits to mix

Question 29

Transposition of the great arteries : Complication

Answer 29

RV hypertrophy and LV atrophy } congestive heart failure

Question 30

Transposition of the great arteries : Risk factors

Answer 30

Diabetic mothers

Question 31

Transposition of the great arteries : Clinical features

Answer 31

1. Cyanosis 2. Tachypnoea

Question 32

Transposition of the great arteries : Clinical signs

Answer 32

1. loud single S2 :

Question 33

Transposition of the great arteries : Investigation

Answer 33

Chest X-ray : ”Egg-on-Side” Appearance * Abnormal cardiac silhouette : Right-sided bulge created by the aorta contributes to the larger, rounded aspect resembling the “egg,” while the left side appears narrower.

Question 34

Transposition of the great arteries : Management

Answer 34

* Maintenance of the ductus arteriosus with prostaglandins * Surgical correction is the definite treatment.