Congenital Heart Defects

Question 1

List some common acyanotic heart defects.

Answer 1

Atrial septal defect (ASD)
Patent foramen ovale (PFO)
Ventricular Septal Defect (VSD)
Patent Ductus Arteriosus (PDA)
Coarctation of the Aorta.

Question 2

List some common cyanotic heart defects.

Answer 2

Tetralogy of Fallot
Tricuspid Atresia
Transposition of the great arteries.
Hypoplastic Left Heart

Question 3

What is Tetralogy of Fallot?

Answer 3

The Tetralogy of Fallot is a group of 4 lesions occurring together as a result of a single developmental defect placing the outflow portion of the interventricular septum too far in the anterior and cephalad directions.

Question 4

What are the 4 abnormalities of Tetralogy of Fallot?

Answer 4

VSD
Overriding aorta
Pulmonary stenosis
Right ventricular hypertrophy

Question 5

What is tricuspid atresia?

Answer 5

Tricuspid atresia is the lack of development of the tricuspid valve.
This leaves no inlet to the right ventricle. There must be a complete right to left shunt of all blood returning to the right atrium (ASD or PFO) and a VSD or PDA to allow blood to flow to the lungs.

Question 6

What fails to develop in Hypoplastic Left Heart?

Answer 6

In some cases the left ventricle and ascending aorta fail to develop properly (Hypoplasia) resulting in a condition called hypoplastic left heart. A PFO or ASD are also present and blood supply to the systemic circulation is via a PDA.
Without surgical intervention this is lethal.

Question 7

Where are you most likely to see a ventricular septal defect?

Answer 7

VSDs are an opening in the Interventricular Septum. This most commonly occurs in the membranous portion of the septum, but can occur at any point.

Question 8

Why do patients with tetralogy of Fallot develop right ventricular hypertrophy?

Answer 8

Pulmonary stenosis increases the resistance of blood to the lungs and so the right ventricle must increase in size to compensate. Also the ventricular septal defect reduces the pressure the ventricle is able to create to pump the blood to the lungs and again it must increase in size to compensate for this loss.

Question 9

What would you hear upon auscultation of a heart with right ventricular hypertrophy and why?

Answer 9

You would hear a displaced apex beat towards the axilla due to increased size of heart muscle.