Congenital Heart Disease Flashcards
Describe the normal foetal circulation and how it changes at birth?
- Foramen Ovale allows mixing of blood between left and right atria with Ductus Arteriosus allowing mixing between the Pulmonary Artery and the Aorta to by-pass the pulmonary circulation and supply the systemic circulation with oxygenated blood.
- Ductus Venosus connects the umbilical vein carrying oxygenated blood from the placenta to the IVC
- Right ventricular pressure is high in the foetus as it recieves both systemic and placetal blood flow
- Left ventricular pressure is low as their is little venous return fvia the left atria from the pulmonary circulation
- At birth, crying opens the lungs reducing resistance in the pulmonary circulation -> increased blood flow and venous return to the left atria via the pulmonary circulation
- At the same time, venous return to the right atria decreases at the blood flow from the placenta is lost
- The net affect is closure of the Foramen ovale as left side pressure > right side pressure
- Over the next few days, decreased PgE2 from the placenta and increased ppO2/Bradykinin -> contraction of sphincters that closes the DA with eventual remodelling forming the ligamentum arteriosum
Describe the Epidemiology of Congenital Heart Disease
Cingenital Heart Disease is the most common group of Congenital abnormalities affecting 8/1000 live births. 30% of these require intervention during the 1st year of life. 1/10 still-births are due to heart defects.
The leading 9 Congenital Heart defects account for ~80% of cases. These can be divided into 4 main categories.
- Left-to-right shunts = VSD (30%), PDA (12%) and ASD (7%)
- Right-to-left shunts = ToF and Transposition of the great arteries (5% each)
- Common mixing = AVSD = 2%
- Outflow obstruction = Pulmonary stenosis (7%), Aortic Stenosis (5%) and Coarctation of the Aorta (5%)
Neonates are more likely to have heart failure secondary to left ventricular outflow obstruction, infants due to high pulmonary pressures and older children due to compensatory mechanisms such as Cardiomyopathy or Eisenmenger’s
Describe the term duct-dependent?
Duct-dependent refers to the requirement of a patent Ductus Arteriosus to maintain either systemic or pulmonary circulation
Describe the characteristic of an incidental murmur and when do they occur?
Innocent murmurs are: asymptomatic, soft, systolic, at the sternal edge and do not radiate
- They are commonly found in children due exertion, anxiety or illness when CO increases
A 4 y/o presents with SOB and a cough. He has a Hx of reccurent chest infections and a wheeze. O/E you hear an ejection systolic murmur at the upper left sternal border. FBC and CRP normal, ECG shows M QRS complex in V1 and W QRS complex in V6. Lead 1 is -Ve and Leads 2/3 are +Ve. CXR shows cardiomegaly, dilated pulmonary vessels and increased vascular markings. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- ASD
This is a secundum ASD owing to the ejection systolic murmur at the upper left sternal border and the RBBB and RAD on ECG. CXR shows signs of left ventricle dysfunction. Primum would present with a pansystolic murmur and a superior QRS showing negative deflection in AVF.
ASDs are left-to-right shunts presenting with signs of LHF and recurrent chest infections. Secundum malformations involve the Foramen Ovale with Primum malformations involving the lower parts of the atria and AV valves.
Ix
- FBC and CRP
- ECG
- CXR
- Echocardiogram
Tx
- Secundum = transcather occlusion device
- Primum = sternotomy for primary closure
A 4 y/o presents with SOB and a cough. They have a Hx of recurrent chest infections. O/E you here a quiet pansystolic murmur at the lower left sternal border, a loud pulmonary component of S2 and a mid-diastolic murmur over the mitral valve. ECG shows an upright T-wave in V1. CXR shows cardiomegaly, dilated pulmonary vessels and increased vascular markings. What is your Dx and how would you manage this patient?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- VSD
The quiet pansystolic murmur at the lower sternal border and mid-diastolic click over the mitral valve suggests a large VSD with rapid LV filling. The upright T-wave in V1 and the Dilated pulmonary arteries are suggestive of PHTN which can occur in larger defects.
Those with small defects have a louder pansystolic murmur and a quiet pulmonary component of S2 but are generally asymptomatic with the VSD closing spontaneously.
As this is a large VSD with PHTN, this patient requires diuretics and Captopril to reduce afterload until the VSD can be repaired via a patch.
Failure to treat the VSD with result in prolonged PHTN and eventually Eisenmenger’s syndrome where there is irreversible increase in pulmonary resistance -> persistant HTN. The only Tx for this is transplant
A 4 y/o presents with a mild fever. There doesn;t appear to be any concern but to be thorough, you listening to the heart and hear a continuous murmur that is loudest during systole and is best heard nearer the clavicle. The mother reports no SOB, cough or recurrent infections. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- PDA
Small PDAs are often asymptomatic but larger PDAs can cause LHF due to a left-to-right shunt. Advanced disease can result in RHF as well secondary to pulmonary HTN.
PDAs are often found in premature babies but can persist into childhood and are often an incidental finding if small.
Signs of a PDA O/E are a continuous murmur loudest during systole and near the clavicle.
To investigation you would perform an ECG (often normal but may show signs of LV hypertrophy -> RV hypertrophy in advanced disease secondary to pulmonary HTN), a CXR (again may be normal or show hypertrophy, enlarged pulmonary arteries and increased vascular markings) and and Echocardiogram or angiogram to visualise the PDA
Large PDAs require insertion of a coil or occlusion device via a catheter to correct to the left-to-right shunt
A newborn is cyanotic and is put on high flow oxygen but after 10 minutes the cyanosis persists. To the confusion of the team, the baby is otherwise well and is relatively asymptomatic but their oxugen saturation is below 94%. O/E you hear an ejection systolic murmur loudest at the upper left sternal edge. What is your Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- ToF
Persistent cyanosis and/or sats <94% despite 10 minutes of high flow oxygen in an otherwise well child is a positive hyperoxia test indicating Tetrology of Fallot.
The tetrad consists of Pulmonary stenosis (heard here with the ejection systolic murmur), right ventricular hypertrophy, VSD and overriding aorta.
Children with ToF are prone to hypercyanotic spells -> reduced consciousness, MIs, CVAs and AKI.
Ix
- FBC and CRP
- ABG/VBG due to cyanosis
- ECG (often normal but may show RV hypertrophy = absence of S-wave and upright T-wave in V1)
- CXR (small heart, uptilted apex, pulmonary artery bay and oligoaemic vascular markings)
- Echocardiogram
Tx
- High flow oxygen
- PROSTAGLANDINS as they are duct-dependant for pulmonary flow
- if hypercyanotic: Oxygen, analgesia, propanolol + fluid bolus to increase CO and overcome obstruction, bicarbonate if acidotic with severe cases requiring paralysis and ventilation to reduce oxygen demands
- Blolack-Taussig procedure = temporary measure (shunt between sunblavian artery and pulmonary artery)
- Corrective surgery = patch for VSD, correct stenosis and disconnect aorta from RV
A baby had a normal birth but 2 days following delivery they became cyanotic. There were no risk factors for sepsis and O/E you hear a loud S2 heart sound. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- ToGA
ToGA is incompatible with life if it were not for the presence of a ASD/VSD or PDA. It is thus common that if this anomaly is not picked up on antenatal screening that the child will become cyanotic ~2 days after birth once the DA closes with no apparent signs or risk factors for sepsis. Presence of ASD/VSD can delay presentation. O/E you will hear a loud S2 as the aortic and pulmonary components merge.
Ix
- FBC and CRP
- ABG/VBG
- ECG = normal
- CXR = narrow mediastinum, egg-on-side cardiac shadow and increased vascular markings
- Echocardiogram
Tx
- High flow oxygen
- PROSTAGLANDINS as they are duct dependant for systemic flow
- Balloon Septoplasty may be a temporary measure to create a VSD and allow common mixing
- Arterial switch is then conducted ASAP
A 2 day old baby becomes cyanotic. There are no risk factors for sepsis and no abnormal heart sounds heard. ECG reveals a superior QRS complex. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- AVSD
There are two types of AVSD: complete AVSD with a 5 leafket common AV valve or complex heart malformations, the most common of which is tricuspid atresia (common mixing in atria, VSD and Small, non-functional RV).
They are often picked up during antenatal screening
If missed, they can present with cyanosis within the first few days of life or LHF signs 2-3 weeks after birth. Examination is often normal but ECG with show superior QRS with absent S-wave due to superior displacement of the AVN and conduction to the superior parts of the ventricles preferentially.
If untreated, they can develop PHTN progressing to Eisenmenger’s syndrome (irreversile increase in pulmonary resistance leading to persistant PHTN) for whioch the only Tx is transplant.
Ix
- FBC and CRP
- ECG = superior QRS
- CXR
- Echocardiogram
Tx
- Complete AVSDs are treated as large VSD with diuretics and Captopril to reduce afterload until a patch repair is performed
- Tricuspid atresia is treated temporarily with a Blolack- taussig procedure (shunt between subclavian artery and pulmonary artery) with a Glen procedure at 6 months (connect SVC to pulmonary artery) and Fontan procedure at 3-5yrs (connect IVC to pulmonary artery) to allow LV to supply systemic circulation and central venous pressure to drive pulmonary circulation although functionality is less than ideal!!
A 4 y/o presents with a mild fever. There doesn;t appear to be any concern but to be thorough, you listening to the heart and hear an ejection systolic murmur at the upper left sternal border. The mother reports no SOB, cough or recurrent infections. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- PS
PS in neonates/children is typically caused caused by a bicuspid pulmonary valve.
If duct-dependant for pulmonary flow, PS can present in the first few days of life with cyanosis. However, it is often asymptomatic and thus an incidental finding. If untreated, RV hypertrophy can developed -> RHF
O/E you will here an ejection systolic murmur at the left upper sternal edge. A mid systolic click due to rapid opening of the pulmonary valve secondary to increased RV pressures and a RV heave may also be observed in more advanced disease
Ix
- FBC
- ECG = often normal but may show upright T-waves in V1 if RV hypertrophy
- CXR = may be normal or show dilation of the pulmonary arteries post stenosis
Tx
- Prostaglandins if duct-dependant (cyanosis shortly after birth) with dilatation
- Monitor if asymptomatic until pressure gradient > 64mmHg accross valve -> transcather balloon dilatation
A 4 y/o presents with a mild fever. There doesn’t appear to be any concern but to be thorough, you listening to the heart and hear a cresendo-decresendo, ejection systolic murmur at the upper right sternal border. The mother reports no SOB, cough or recurrent infections. What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- AS
The cause of AS in a neonate/child is typically a bicuspid aortic valve.
Neonates may present with LHF and shock ~2 days of life after closure of the DA if duct-dependant. Older children present with SOB, stable angina and syncope. Some children are asymptomatic and are thus discovered incidentally.
An ejection click best heard at the lower left sternal border may also be present.
AS is also associated with mitral stenosis and coarctation of the aorta so these should be excluded.
Ix
- FBC and CRP
- ECG = LV hypertrophy (deep S in V2 and tall R in V6 with inverted T in V6)
- CXR = LV hypertrophy, post-stenotic dilation of the aorta
- Echocardiogram
Tx
- PROSTANGLANDINS if duct dependent
- If severe stenosis, valve replacement (possible Ross procedure)
- If asymptomatic, monitor until pressure gradient accross valve >64mmHg or SOB upon exertion -> transcather balloon dilatation
A previously well 2 day old baby suddenly enters shock with circulatory collapse. Femoral pulses are absent and the ABG reveals a metabolic acidosis but there are no other signs of sepsis. ECG = normal
What is your most likely Dx and what is your management?
- VSD
- PDA
- ASD
- ToF
- ToGA
- PS
- AS
- Coarctation of the Aorta
- AVSD
- Coarctation of the aorta - child-type
Child-type coarctation of the aorta is more common in neonates and presents ~2 dyas of life when the DA closes. As the DA closes, the aorta also constricts with the coarctation causing obstruction.
Adult-type is less common and typically presents in chidren with progressive LHF. O/E of adult-type, you see right arm HTN, radio-femoral delay and an ejection systolic murmur between shoulder blades + LHF signs
Ix
- FBC and CRP
- ABG/VBG
- ECG = normal in child-type but can show LV hypertrophy in adult type
- CXR = typically normal but may show rib-notching due to collaterals
- Echocardiogram
Tx
- Oxygen
- PROSTAGLANDINS if duct-dependant
- Stent or open-repair of coarctation
