Congenital Heart Disease

Question 1

Congenital Heart Disease

Answer 1

An abnormality of formation or function present at or before birth

Question 2

Cause of congenital heart diseases (3)

Answer 2

• some direct genetic
• 2% environmental
• rest multifactorial/uncertain

Question 3

Example of genetic cause CHD (3)

Answer 3

• abnormal # of chromosomes i.e. Down syndrome
• monosomies (Turner’s)
• microdeletions (diGeorge)

Question 4

Example of environmental cause of CHD (1+ 2+ 2)

Answer 4

• alcohol intake during pregnancy
• teratogens:
• viruses = rubella
• drugs = retinoic acid, alcohol
• maternal diseases = diabetes, lupus

Question 5

When is the heart forming

Answer 5

Weeks 4-8

Cardiac structures essentially complete by 7-8 weeks of gestation

Question 6

When does the heart begin beating

Answer 6

About day 28 (actually more like day 22)

Question 7

When are genetic and environmental influences more important to development of CHD, when are pathogenic?

Answer 7

• 4-8 weeks for genet and environmental influences

- pathogenic mechanisms later

Question 8

Pathogenesis of CHD

Answer 8

-development of cardiac malformation results from an injuring agent that acts during a critical time to produce the abnormal development = pathogenic mechanism

Question 9

Simple lesions

Answer 9

Simple defects usually restricted to one abnormality such as ventricular septal defect or patent ductus arteriosus

Question 10

Complex lesions

Answer 10

• several defects comprising the whole

- ex: tetralogy (4) of fallot

Question 11

Tetralogy of fallot (4)

Answer 11

1) VSD
2) Sub-pulmonary stenosis
3) Aortic overide
4) RV hypertrophy

Question 12

Most common congenital defect

Answer 12

-Bicuspid aortic valve (1%)

Question 13

Situs

Answer 13

abnormal position/location of heart as whole in the body

Question 14

Situs of different components of the heart

Answer 14

1) Atrial situs
2) Atrio-ventricular connections
3) Ventriculo-arterial connection

Question 15

Heart failure-definition

Answer 15

A clinical syndrome characterized by symptoms resulting from heart disease

Question 16

LV failure

Answer 16

When LV dysfunction results in fluid retention or exercise intolerance

Question 17

LV dysfunction

Answer 17

Abnormality of relaxation (diastolic) or contraction (systolic)

Question 18

Symptoms of congestive failure (6)

Answer 18

1. Shortness of breath (alveolar edema)
2. Abdominal bloating (ascites)
3. Fluid accumulation in legs/face
4. Diaphoresis/faints
5. Difficulty feeding/growing in young
6. Impaired exercise tolerance

Question 19

Structural defects with congestive heart failure (2)

Answer 19

1) To much pulmonary blood flow
- ventricular septal defects
- patent ductus arteriosus
- atrioventricular septal defect
2) Reduced forward flow
- obstructive left heart lesions

Question 20

Non-structural causes of CHF (3)

Answer 20

• myocardial failure
• circulatory volume overload (anemia)
• severe respiratory disease (pre-term with broncho-pulmonary dysplasia)

Question 21

Signs of heart disease in infants

Answer 21

1. Cyanosis = blue ting to skin

2. O2 sat 5 gm/L of desaturated jemoglobin

Question 22

Causes of cyanotic lesions

Answer 22

1. Transposition of the great arteries
2. Tetralogy of Fallot
3. Tricuspid valve abnormalities
4. Total anomalous pulmonary venous drainage
5. Pulmonary valve atersia

Question 23

Questions for history -diagnosis CHD (10)

Answer 23

1. Pregnancy hx/ family hx of CHD *including sudden death
2. Feeding/growth
3. Activity
4. Color
5. Breathing
6. Wake/Sleep
7. Faints/Spells
8. Palpitations
9. Exercise tolerance
10. Chest pain

Question 24

Physical examination -diagnosis CHD

Answer 24

• vital signs including BP 4 limbs
• work of breathing
• vascular congestion/liver/lungs/soft tissues
• cardiac activity/rhythm
• murmur(s) timing and quality
• cyanosis/clubbing

Question 25

Establishing diagnosis before birth

Answer 25

Fetal echocardiography after 17+ weeks pregnancy
Indications:
1. Abnormal 4 chamber view on outside scan
2. Other evidence of syndrome
3. Positive amniocentesis for chromosome abnormality
4. Positive family history of congenital heart disease
5. Major risk factor with drugs/alcohol