Cyanotic Heart Diseases Flashcards
What are the 5 main cyanotic heart diseases
- Truncus arteriosus
- Transposition of the great arteries
- Tricuspid atresia
- Tetralogy of fallot
- Total anomalous pulmonary vascular return (TAPVR)
How does cyanotic heart disease generally present
Blue baby
Feeding problems or failure to thrive
Exertional dyspnoea/tachypnoea
Hypoxaemia
Symptoms of HF
Nail clubbing
What test can be done when a cyanotic baby does not respond to oxygen supplementation
Hyperoxia/nitrogen washout test
1. Infant given 100% O2 for 10 minutes
2. ABG taken
3. PO2 <15kPa = cyanotic heart disease
What are the most likely causes of cyanosis according to timeline
within minutes - TGA
Days - Tricuspid atresia
Months - tetralogy of fallot
Describe truncus arteriosus
Pulmonary artery and aorta become one vessel
Survival depends on the presence of a shunt - VSD
What is transposition of the great arteries and its risk factors
Anatomical reversal of the aorta and pulmonary artery → two closed loop systems
Fatal unless there is a shunt
- intracardiac (PFO/VSD/ASD)
- extracardiac (PDA)
RF: maternal diabetes
How does transposition of the great arteries present (symptoms and signs)
Postnatal cyanosis at rest (within minutes of birth)
Unaffected by supplemental oxygen
Tachypnoea
No murmur heard
Prominent right ventricular impulse
Investigation and Management of Transposition of the great arteries
CXR: Egg on a string sign (cardiomegaly)
Immediate pGE1 infusion e.g. alprostadil
or
Balloon septoplasty (artificial VSD)
→ 2 weeks later - surgery
What is tricuspid atresia
Absence of the tricuspid valve
Fatal unless there is a shunt (ASD + VSD)
How does tricuspid atresia present (Symptoms and Signs)
Central cyanosis
Pansystolic murmur (Due to ASD and VSD)
How is tricuspid atresia managed
Immediate PGE1 infusion e.g. alprostadil
→ 2 weeks - surgery
What is tetralogy of fallot
Simultaneous occurrence of 4 defects:
1. Right ventricular outflow tract obstruction (RVOTO) - pulmonary stenosis
2. Right ventricular hypertrophy
3. Ventricular septal defect (large)
4. Overriding aorta - shifts to sit on top of the VSD
What are the risk factors for tetralogy of fallot
DiGeorge Syndrome
Down’s syndrome
Maternal diabetes and alcohol consumption
How does tetralogy of fallot present (symptoms and signs)
Severe cyanosis (depending on RVOTO extent)
2-4 months: Hypercyanotic tet spells in response to stress (pain, crying, feeding)
Untreated: squatting relieves symptoms
Harsh ejection systolic murmur heard
What are the investigations and management for tetralogy of fallot
CXR: boot-shaped heart
ECG: RVH/Right axis deviation
Knee-chest position
High flow oxygen
Severe: PGE1 → surgical intervention within the 1st year
What is total anomalous pulmonary venous return
The pulmonary veins merge to form a connecting vein that drains into the systemic venous circulation e.g. vena cava instead of the left atrium
Survival depends on a shunt - usually ASD, sometimes PDA
What is Ebstein’s anomaly and what are its risk factors
Atrialisation of the right ventricular, where the tricuspid valve is displaced downwards → small and hypocontractile RV → tricuspid regurg → RA dilation → RHF
In-utero lithium exposure
How does Ebstein’s anomaly present
Depends on the degree of displacement
Mild: cyanosis
Severe: in-utero hydrops fetalis
Pansystolic murmur
Mid-diastolic murmur
Ebstein’s anomaly investigations and management
Echo: confirms
CXR: cardiomegaly (RA enlargement)
Surgery
What are ductal dependent conditions and how are they managed
A heart condition that requires a patent PDA to sustain systemic blood flow
Systemic blood flow:
- Transposition of the great arteries
- Coarctation of the aorta
Pulmonary blood flow:
- Tricuspid atresia
- Severe RVOTO i.e. in tetralogy of fallot
Management = PGE1 infusion
