Congenital heart disease

Question 1

what are the basics to know about physiology of heart.

Answer 1

• RV pumps deoxygenated blood to lungs.
• pulmonary circulation has low resistance.
• LV pumps oxygenated blood at systemic pressure to aorta.
• each ventricle is morphologically adapted to function.

Question 2

what are the 4 cardiac shunts?

Answer 2

• atrial shunt
• ventricle shunt
• atrio-ventricular shunt
• aorto-pulmonary shunt

Question 3

what is ‘atrial septal defect’ and what are its effects?

Answer 3

• opening in septum wall between 2 atria after birth.
• as pressure higher in RV blood flow right to left so ACYANOTIC.
• increased pulmonary flow so RV overload high so eventually right heart failure.

Question 4

what is ‘ventricle septal defect’ and what are its effects?

Answer 4

• abnormal opening in membranous part of intraventricular septum.
• LV pressure higher, so blood flow left to right causing mixing, but mixing in RV so ACYANOTIC.
• pulmonary hypertension.
• LV overload

Question 5

what is ‘coarctation of aorta’ and what are its effects?

Answer 5

• narrowing of aortic lumen at ligamentum arteriosum.
• increases afterload on LV to overcome narrowing so LV hypertrophy.
• blood supply to head and upper limbs branch off proximally to this so not affected.
• however to rest of body reduced

Question 6

what is ‘patent ductus arteriosus’?

Answer 6

• failure to close the ductus arteriosus post birth.
• blood flow from aorta to pulmonary down pressure gradient.
• ACYANOTIC but overtime problematic.

Question 7

what is ‘tetralogy of fallot’ ?

Answer 7

• 4 lesions occurring together as a result of defect where intraventricular septum too far in anterior and cephalad direction (towards head).
• VSD.
• Overriding aorta (connected to both ventricles)
• pulmonary stenosis.
• RV hypertrophy.

Question 8

what are the effects of ‘tetralogy of fallot’?

Answer 8

• RV persistent hypertrophy as to overcome pulmonary artery stenosis.
• right heart increased pressure and VSD and overriding aorta allows right to left shunting and mixing of blood.
• CYANOTIC as deoxygenated blood in systemic circulation.

Question 9

what is ‘tricuspid atresia’? and effects?

Answer 9

• lack of development of tricuspid valve, leaving no inlet to RV.
• Right to left shunt needed for venous return.
• blood flow to lungs via VSD or PDA.

Question 10

what is ‘transposition of the great arteries’? and what are its effects?

Answer 10

• results in in two unconnected parallel circulations instead of two in series, RV is connected to aorta and LV to the pulmonary trunk. CYANOTIC.
• not viable without atrial, ventricular or ductal shunts.

Question 11

what is ‘hypoplastic left heart’?

Answer 11

• in some cases LV and ascending aorta (small) fail to develop properly.
• RV supports systemic circulation by obligatory right to left shunt.
• even for short term survival ASD or PDA defect required.

Question 12

what is ‘pulmonary atresia’?

Answer 12

• pulmonary valve doesn’t develop properly leaving no outlet to RV.
• right to left atrial shunt of entire venous proportion.
• blood flow to lungs via PDA.
• reduced blood flow to lungs.