Congenital Heart Defects

Question 1

Name the types of aetiology of CHD

Answer 1

Genetic

Environmental - teratogenicity

Materal infections

Question 2

What are the haemodynamic effects of a left to right shunt

Answer 2

Blood from left heart returned to lungs.

Increased lung blood flow is not damaging but an increased pulmonary artery/venous pressure is.

Question 3

Haemodynamic effects of a right to left shunt

Answer 3

Requires hole and distal obstruction

De-oxygenated blood bypasses the lung and patient is cyanosed

Question 4

What are the two classifications of CHD

Answer 4

Acynotic - where there is no deoxygenated blood in the systemic circulation

Cynotic - where there is deoxygenated blood in the systemic circulation

Question 5

Name some acynoitc CHD

Answer 5

Left to right shunts: ASD, VSD, PDA

Obstructive lesions: aortic stenosis, pulmonary stenosis, coarctation of aorta, mitral stenosis.

Question 6

Name some cynotic CHD

Answer 6

Tetralogy of Fallot

Transposition of the great arteries

Total anomalous pulmonary venous drainage

univenentricular heart

Question 7

Name some common ASDs

Answer 7

Sinus venous defect

Secundum atrial defect

Primum atrial defect

Question 8

What are the haemodynamic effects of ASD

Answer 8

Increased pulmonary blood flow

RV volume overload

Pulmonary hypertension (rare)

Eventual right heart failure

Question 9

What are the haemodynamic effects of VSD

Answer 9

LV volume overload

Pulmonary venous congestion

Eventual pulmonary hypertension

Question 10

What happens in an atrio-ventricular septal defect

Answer 10

There is only one atrio-ventricular valve, so there is mixing of the blood which enters the systemic circulation, and cyanosis is seen

Question 11

What happens in aortic stenosis

Answer 11

Narrowing of aortic valve, resulting in LV hypertrophy

Question 12

What is coarctation and what can it cause

Answer 12

Narrowing of a short section of the aorta, usually where the ligamentum arteriosus is

Increases the afterload on left ventricle and can lead to LV hypertrophy

Blood flow to the lower limbs and body is reduced but head and upper limbs are not affected

BP in upper body is increased as LV pumps blood harder to push blood through the coarctation

Question 13

What are the four pathologies in tetralogy of Fallot

Answer 13

Pulmonary stenosis

Ventricular septal defect

RV hypertrophy

Over-riding aorta

Question 14

What is the patho-physiology of tricuspid atresia

Answer 14

No RV inlet (no tricuspid valve)

R to L atrial shunt of venous return

Blood flow to lungs via VSD or PDA

Question 15

What happens in the hypoplastic left heart condition

Answer 15

LV is underdeveloped and ascending aorta is very small

RV supports systemic circulation

Obligatory R to L shunt

Must be ASD or PDA for even short survival

Question 16

What happens in transposition of the great arteries

Answer 16

There is failure/defect in the rotation of the great vessels leading to RV being connected to aorta and LV being connected to plumonary artery

Not viable unless the two circuit communicate (ASD, VSD, PDA)

Question 17

What is univentricular heart

Answer 17

Where there is one ventricle which pumps into both aorta and pulmonary artery

Question 18

What is pulmonary atresia

Answer 18

No RV outlet (no pulmonary valve)

R to L atrial shunt (ASD) of entire venous return

Blood flow to the lungs is via PDA

Question 19

What is a PFO and what problem is associated with it

Answer 19

Patent foramen ovale

Common problem is a stroke as small blood clots may pass through the PFO