Congenital Heart Disease Flashcards
What is congenital heart disease?
A structural abnormality of the heart or intra-thoracic great vessels that is present at birth and of functional importance
Describe the prevalence of CHD
8-9 per 1000 live births and 10-20% of still births and miscarriages
Describe the 4 stages at which CHD is identified
- Foetus
- Neonate
- Child
- Adult
Describe 3 ways in which CHD may present in a newborn
- Cyanosis
- Congestive cardiac failure
- Cardiac murmur
What are 4 associations of CHD in a newborn?
- Chromosomal defects
- Syndromes
- Extracardiac defects
- Teratogens
What is a common teratogen which may cause CHD in a newborn?
Sodium valproate
What are 3 categories of cyanotic congenital heart disease?
- Abnormal connections
- Right to left shunts
- Abnormal mixing
What is the most common abnormal connections which may cause cyanotic CHD?
Transposition of great arteries
Describe simple transposition of great arteries leading to cyanotic CHD
Aorta is connected to the right ventricle and the pulmonary artery is connected to the left ventricle meaning blood in the aorta is deoxygenated
Describe the treatment of transposition of the great arteries
- Infants present as very cyanotic and only survive if there is mixing of blood
- Stabilised initially using prostaglandin
- Arterial switch repair is carried out usually within 2 weeks
What is a common condition which causes right to left shunts of blood in the heart?
Tetralogy of Fallot
Describe Tetralogy of Fallot
- Lesion occurs between left and right ventricles
- Narrowing of pulmonary valve
- Aorta shifts more rightward
- Hypertrophy of right ventricle
What condition can lead to abnormal mixing of blood in cyanotic CHD?
Univentricular heart
What are 3 associations with a univentricular heart?
- Pulmonary stenosis
- Subaortic stenosis
- Coarctation of aorta
Name 3 symptoms of heart failure in adults
- Swollen ankles
- Peripheral oedema
- Cracking in the lungs
Name 3 symptoms of heart failure in infants
- Tachypnoea (breathlessness)
- Tachycardia
- Hepatomegaly
What is hepatomegaly?
Increased size of liver
Describe 2 causes of heart failure in infancy
- Left to right shunts
2. Obstructive lesions of left heart
Name 4 types of left to right shunts
- Ventricular Septal Defect
- Atrioventricular Septal Defect
- Atrial Septal Defect
- Patent Ductus Arteriosus
What is the most common left to right shunt in:
a) the normal population
b) children with downs syndrome
a) Ventricular Septal Defect
b) Atrioventricular Septal Defect
Describe a ventricular septal defect
There is a defect between the ventricles, causing blood to flow to area of least resistance which causes left to right shunt
What is the main symptom of atrial septal defects?
Breathlessness
What are 2 associations with atrial septal defects?
- Mitral regurgitation (primum type)
2. Partial anomalous pulmonary venous drainage (S.V. type)
What is coarctation of aorta?
A fibrous ridge of tissue encroaches into the lumen of aorta which prevents blood flow through the vessel
Name 3 associations of coarctation of aorta
- Bicuspid aortic valve
- Ventricular septal defect
- Subaortic stenosis
Describe the classic sign of coarctation of the aorta
Hypertension in the upper body and lower tension in the lower body
Describe aortic stenosis
Narrowing of the aortic valve which causes hypertrophy of the left ventricle, leaving it more susceptible to arrhythmias
What are 3 associations of aortic stenosis?
- Mitral valve abnormalities
- Coarctation of aorta
- Left ventricular hypoplasia
What are 2 categories of asymptomatic heart murmurs in childhood?
- Innocent cardiac murmur
2. Asymptomatic CHD
What is the definition of an innocent cardiac murmur?
Any murmur produced by a normal cardiovascular system under normal resting conditions
Describe the characteristics of an innocent cardiac murmur
- No symptoms
- Normal heart sounds
- No added sounds
- Normal ECG / chest x-ray
Name 4 prosthetic materials used in cardiac surgery
- Dacron (patch closure of VSD)
- Gortex (shunts and conduits)
- Prosthetic valves (aortic and mitral)
- Pacemaker leads
What is the primary interventional procedure in paediatric cardiology with regards to CHD?
Device closure
Name an example of a device which may be used to close atrial septal defect
ASD Amplatzer Device
Describe the characteristics of infective endocarditis
- Rare in childhood
- Vast majority have underlying heart disease
- Serious potential cause of morbidity and mortality
Name 4 lesions in the heart which are commonly complicated by endocarditis
- Ventricular Septal Defects
- Aortic stenosis or incompetence
- Tetralogy of Fallot
- Patent Ductus Arteriosus
Why does infective endocarditis tend to be more commonly seen in smaller ventricular septal defects?
Smaller defects cause an increased velocity of flow which causes the endothelium to become more damaged
What are the 3 main types of microorganisms involved in infective endocarditis?
- Streptococci (viridans more than enterococci)
- Staphylococcus Aureus
- Staphylococcus Epidermis
Describe the diagnosis of endocarditis
- Isolation of infecting organism from blood culture is important
- Two to three blood cultures over 24 hour period usually adequate
- Echocardiography
If blood cultures are negative during the diagnosis of potential endocarditis what may be considered?
Candida infection
Describe 5 clinical features of endocarditis
- Fever
- General malaise
- Splenomegaly
- Heart failure
- Blood present in urine
Why is echocardiography useful in the diagnosis of endocarditis?
It demonstrates the vegetations attached to affected valves in most cases
Describe the treatment of endocarditis caused by Streptococcus Viridans
Combination of penicillin and gentamycin given intravenously
Describe the treatment of endocarditis caused by Streptococcus Faecalis
Combination of amoxycillin and gentamycin is used
Describe the treatment of endocarditis caused by staphylococcal infection
Flucloxacillin and gentamycin
Describe the treatment of endocarditis caused by candida infection
It is difficult to treat and may require a combination of amphotericin and flucytosine
