Adult Congenital Heart Disease

Question 1

Define congenital heart disease [1]

Answer 1

an abnormality of foetal heart development

Question 2

Describe the normal anatomy of the heart

Answer 2

Question 3

Describe the normal physiology of the heart [4]

Answer 3

1. Oxygen poor blood passes into the right atrium through the superior and inferior vena cava (SVC & IVC)
2. This passes through the right atrioventricular valve called the tricuspid valve into the right atrium and is pumped through the pulmonary valve into the pulmonary arteries and passes through the lungs.
3. This blood is oxygenated and passes back into the heart through the pulmonary veins into the left atrium.
4. This then passes through the left atrioventricular valve i.e. the mitral valve into the left ventricle and is pumped through the aortic valve into the aorta and the remainder of the systemic system.

Question 4

How does oxygenation occur in utero? [1]

Answer 4

in utero, oxygenation is by the maternal placenta

• pulmonary circulation is minimal and at high resistance

Question 5

Describe the physiology of foetal circulation [3]

Answer 5

1. Oxygenated blood returns to right atrium via inferior vena cava (IVC)
2. It then bypasses the right ventricle & pulmonary artery via the foramen ovale
3. Of the blood that is pumped to the pulmonary artery via the right ventricle, most passes to the aorta via the ductus arteriosus

Question 6

In the foetal circulation, there are 2 shunts which allow mixing of oxygenated and deoxygenated blood. What are these 2 shunts called? [2]

Answer 6

1. foramen ovale
2. ductus venosus

Question 7

Define levocardia [1]

Answer 7

the heart is on the left side of the body (normal)

Question 8

Define situs solitus [1]

Answer 8

the normal arrangement of abdominal organs with levocardia

Question 9

What are the morphological characteristics of the right atrium? [2]

Answer 9

1. a broad appendage
2. sinoatrial node

Question 10

What are the morphological characteristics of the left atrium? [1]

Answer 10

a narrow sausage shaped appendage

Question 11

What are the morphological characteristics of the right ventricle? [3]

Answer 11

1. heavily trabeculated endocardium
2. contains a muscular band called the moderator band
3. the chordae tendineae insert into the interventricular septum

Question 12

What are the morphological characteristics of the left ventricle? [3]

Answer 12

1. smooth endocardium
2. two papillary muscles
3. an ellipsoid cavity

Question 13

Name the acyanotic conditions that result in left to right shunts [3]

Answer 13

1. ventricular septal defect (VSD)
2. atrial septal defects (ASD)
3. persistent ductus arteriosus

Question 14

Name the acyanotic conditions that result in outflow obstruction [3]

Answer 14

1. Pulmonary stenosis
2. Aortic stenosis
3. Coarctation of the aorta

Question 15

Name the cyanotic conditions that can affect the fetal heart

Answer 15

1. Tetralogy of Fallot
2. Transposition of the Great Arteries
3. Atrioventricular septal Defect (complete)

Question 16

Define an atrial septal defect [1]

Answer 16

hole in the wall between the atria

Question 17

What are the 2 types of atrial septal defect? [2]

Answer 17

1. secundum ASD
2. primum ASD
   
   • also known as partial atrioventricular septal defect (AVSD)

Question 18

Define secundum ASD [2]

Answer 18

1. defect is present in the central part of the atrial septum (the partition separating the atriums).
2. this allows oxygenated blood to pass through into the right side of the heart, leading to enlargement of the right ventricle and excessive flow in the lung circulation

Question 19

What are the typical signs of secundum ASD that can be picked up on examination? [2]

Answer 19

1. pulmonary flow murmur
2. fixed, split second heart sound

Question 20

What are the potential complications of secundum ASD? [5]

Answer 20

1. RV failure
2. Tricuspid regurgitation
3. Atrial arrhythmias
4. Pulmonary hypertension
5. Eisenmenger syndrome

Question 21

Define primum ASD [4]

Answer 21

1. defect that is present in the lower part of the “atrial septum” (the partition separating the atriums).
2. this allows oxygenated blood to pass through into the right side of the heart, leading to enlargement of the right ventricle and excessive flow in the lung circulation
3. the primum variant occurs close to the atrioventricular (AV) valve and as such can distort the valve and lead to it becoming regurgitant or leaky
4. In addition to the primum ASD hole can extend down into the ventricle and cause a VSD, this would then be called a partial atrioventricular septal defect

Question 22

What are the treatment options for ASDs? [2]

Answer 22

ASDs can be fixed either surgically with a sternotomy or through the groin vessels with a transcatheter device if small enough

Question 23

Define coarctation of the aorta [1]

Answer 23

narrowing of the aorta

Question 24

Where does coarctation of the aorta tend to form? [1]

Answer 24

Tends to form distal to the left subclavian artery in a ‘juxta-ductal’ position, at the insertion point of the ductus arteriosus

Question 25

What are the potential complications of coarctation of the aorta? [4]

Answer 25

1. upper body hypertension 2. berry aneurysms 3. claudication 4. renal insufficiency

Question 26

How can coarctation of the aorta be treated? [3]

Answer 26

* surgical repair via thoracotomy, where the aorta is either: * cut out or * the narrowed area is reconstructed via the subclavian artery * non-surgical options: * balloon angioplasty via a transcatheter through femoral artery

Question 27

What are the features of transposition of the great arteries (TGA)? [3]

Answer 27

1. cyanosis 2. usually no murmur 3. clubbing

Question 28

Describe the pathophysiology of transposition of the great arteries [5]

Answer 28

1. the aorta and pulmonary artery switch places, so that the aorta is now connected to the right ventricle and the pulmonary artery is connected to the left ventricle. 2. this creates 2 separate circulation systems 3. in the systemic circulation deoxygenated blood returns to the RA via the SVC & IVC, passes through the tricuspid valve into the RV and is then pumped through the AORTIC valve into the AORTA and around the body **without** being oxygenated. 4. In the pulmonary circulation, the oxygenated blood passes back into the LA via the pulmonary veins, through the mitral valve into the LV, and is then pumped back into the PULMONARY artery to the lungs via the PULMONARY valve. 5. Without mixing of the oxygenated & deoxygenated blood there is profound cyanosis and therefore transposition of the great arteries is an example of a cyanotic lesion.

Question 29

Why would you give a child with TGA prostaglandins? [2]

Answer 29

1. When a baby takes it's first breath at birth, the changes in pressure in the lungs and in the heart mean that the foramen ovale and ductus arteriosus closes within a few hours. 2. This loss of the 2 shunts is catastrophic for TGA therefore we delay closing by given the baby prostaglandins. This buys us time to perform surgery.

Question 30

How do you treat TGA? [3]

Answer 30

* treated by the **arterial switch procedure** * in this procedure we disconnect the aorta and pulmonary artery, switch them around and sew them back on. * So the aorta is now above the LV and the pulmonary artery is now above the RV

Question 31

What are the 4 components of Tetralogy of Fallot? [4]

Answer 31

1. Ventricular Septal Defect 2. Right Ventricular Outflow Tract (RVOT) obstruction 3. Overriding aorta 4. Right ventricular hypertrophy

Question 32

Define overriding aorta [1]

Answer 32

the aortic valve is enlarged and appears to arise from both the left and right ventricles instead of just the left ventricle

Question 33

How is Tetralogy of Fallot treated? [1]

Answer 33

BT shunt = connecting the carotid or subclavian artery directly on to the pulmonary artery

Question 34

What conditions does Tertalogy of Fallot put you at increased risk of, even after repair? [5]

Answer 34

1. significant pulmonary regurgitation * RV dilatation +/- dysfunction 2. arrhythmia * ventricular tachycardia * SVT with RBBB 3. pulmonary arterial stenosis

Question 35

Define a univentricular heart [1]

Answer 35

a congenital heart condition which results in only one effective pumping ventricle

Question 36

Define single ventricle anomalies [1]

Answer 36

Common feature that only one of the two ventricles is of **adequate functional size**

Question 37

Name the anomalies that are described as single ventricle defects [5]

Answer 37

1. Tricuspid atresia 2. Hypoplastic left heart syndrome 3. Double inlet left ventricle 4. Many of the heterotaxic defects 5. Some variations of double outlet right ventricle

Question 38

What are the corrective operations used for single ventricle anomalies? [4]

Answer 38

1. Blalock-Taussig (BT) Shunts 2. Norwood Procedure 3. Bi-directional Glenn 4. Fontan Circulation Operation

Question 39

What is involved in BT shunts? [1]

Answer 39

a tube graft is placed from an artery (usually the left subclavian or left innominate artery) to the pulmonary artery

Question 40

What is involved in Norwood Procedure? [3]

Answer 40

1. the right ventricle becomes the systemic or main ventricle pumping to the body. 2. A "neo" aorta is made from part of the pulmonary artery and the original, tiny aorta is reconstructed/enlarged to provide blood flow to the body. 3. Finally, to provide blood flow to the lungs, a small tube graft is placed either from an artery to the lung vessels (called a modified Blalock-Taussig shunt) or from the right ventricle to the lung vessels (called a Sano modification)

Question 41

What is involved in Bi-directional Glenn procedure? [1]

Answer 41

superior vena cava is taken off the heart and sewn directly to the pulmonary artery

Question 42

What is involved in Fontan circulation operation? [2]

Answer 42

inferior vena cava is connected directly to the pulmonary arteries. Until now this blood has bypassed the lungs and has been pumped directly to the body resulting in oxygen levels lower than normal.

Question 43

What are the potential adverse complications of Fontan circulation and why? [5]

Answer 43

* Pulmonary circulation dependent on high systemic venous pressure and low pulmonary vascular resistance * Anything that causes an imbalance can cause catastrophic haemodynamic compromise: * Pulmonary embolism (PE) - these patients need to be on constant anticoagulants * Arrhythmia * Dehydration * Bleeding