Congenital Heart Disease

Question 1

What is a shunt?

Answer 1

A shunt is a transfer of blood from one side of the circulation to the other through an abnormal pathway.

Question 2

What is the most common shunt at the atrial level?

Answer 2

Atrial septal defect - ASD

Question 3

What is the most common shunt at the ventricular level?

Answer 3

Ventricular septal defect - VSD

Question 4

What is the most common shunt at the ductal level?

Answer 4

Patent ductus arteriosus - PDA

Question 5

What is the most common type of ASD?

Answer 5

Fossa ovalis or secundum type

Question 6

What is the 2nd most common type of ASD?

Answer 6

Ostium primum type

Question 7

What is the result of an ASD? (what is the orientation of the shunt)

Answer 7

The pressure in the left atrium is slightly higher than that of the right atrium and the compliance of the right ventricle is far greater than that of the left ventricle. Therefore, a shunt at the atrial level will produce volume hypertrophy of the right atrium and right ventricle with increased pulmonary flow and hemodynamic changes in the tricuspid and pulmonic valves.

Question 8

Where do VSDs tend to occur?

Answer 8

Sub-atrially

Question 9

What is the defect in ASD - secundum?

Answer 9

Fossa Ovalis

Question 10

What are the changes in ASD - secundum?

Answer 10

L to R shunt

RA and RV hypertrophied and dilatated

Question 11

What is the defect in ASD - primum?

Answer 11

Defect distal to Fossa Ovalis, close to the MV and TV

Question 12

What are the changes in ASD - primum?

Answer 12

L to R shunt
RA and RV hypertrophied and dilatated
Cleft of MV
LV hypertrophy ONLY if there is mitral stenosis

Question 13

What are the changes in VSD?

Answer 13

L to R shunt
RA hypertrophy
RV hypertrophy and dilation

This can lead to pulmonary HTN which would cause a R to L shunt causing:
LA hypertrophy and dilation
LV hypertrophy and dilation

Question 14

What are the changes in PDA?

Answer 14

L to R shunt that increases pulmonary flow

Leads to LA and LV hypertrophy and dilation without pulmonary HTN and RA and RV hypertrophied and dilated as well

Question 15

What are the changes in Isolated Pulmonary Stenosis?

Answer 15

No shunts
RA and RV with hypertrophy
Left side of heart is normal

Question 16

What are the changes in Isolated Aortic Stenosis?

Answer 16

No shunts
LA and LV with hypertrophy
Right side of the heart is normal

Question 17

What are the changes in Adult Coarctation?

Answer 17

Narrowing of the aorta in the region of the ligamentum arteriosum
No shunts
LA and LV hypertrophy
RA and RV are normal

Question 18

What are the changes in Fetal Coarctation?

Answer 18

Long narrowing of the aorta with pulmonary HTN
RA and RV dilated with hypertrophy
LA and LV atrophy due to the non-constrictive narrowing of aorta which increases aortic pressure but not LV pressure
R to L shunt at ductus level
L to R shunt at atrial level

Question 19

What are the 4 features of Tetralogy of Fallot?

Answer 19

• Infundibular Pulmonary Stenosis
• RV Hypertrophy
• VSD
• Overriding Aorta

Question 20

What are the changes in Tetralogy of Fallot?

Answer 20

Large R to L shunt

RA and RV hypertrophy

Question 21

VSD Characteristics

Answer 21

Hence, the most common type of a defect is called subaortic, in part membranous and in part perimembranous type. The complex is characterized by volume hypertrophy of the right ventricle, enlargement of the pulmonic orifice, hemodynamic changes of the tricuspid and pulmonic valves, volume hypertrophy of the left atrium and the left ventricle with enlargement of the mitral valve and hemodynamic changes in the mitral and aortic valves.

Question 22

PDA Characteristics

Answer 22

In this entity, there is volume hypertrophy of the left atrium and left ventricle.

Question 23

What is the likelihood of pulmonary HTN in ASD, VSD and PDA?

Answer 23

Thus, pulmonary hypertension may occur, most commonly in large ventricular septal defect, less commonly in patent ductus arteriosus and least commonly in atrial septal defect.

Question 24

What is muscular type subaortic stenosis?

Answer 24

Hypertrophic cardiomyopathy is an autosomal dominant pattern of inherited genetic disease. Here there is asymmetrical septal hypertrophy of the muscular septum. This may produce subaortic obstruction and sudden death.

Question 25

What is a sign of Tetralogy of Fallot?

Answer 25

U-shaped VSD

Question 26

What is the more common type of Tetralogy of Fallot?

Answer 26

Cyanotic

Question 27

What is Cyanotic T. of Fallot?

Answer 27

Here there is pressure hypertrophy of the right atrium and right ventricle with significant infundibular pulmonary obstruction. The left atrium and left ventricle have a tendency to be smaller than normal. The right ventricle is contracting against systemic and infundibular resistance, decreased pulmonary flow, and predominant right to left shunt at the ventricular level.

Question 28

What is Non-Cyanotic T. of Fallot?

Answer 28

In acyanotic, tetralogy there is pressure and volume hypertrophy of the right ventricle, pressure hypertrophy of the right atrium, volume hypertrophy of the left atrium and left ventricle and enlargement of the mitral and aortic orifices. Here we are dealing with a left to right shunt at the ventricular level with increased pulmonary flow and increased volume to the left side of the heart.