Persistent Pulmonary Hypertension of the Newborn (PPHN): failure of the pulmonary vascular resistance to fall after birth
Inborn error of metabolism
What level of DEOXYGENATED Hb gives rise to central cyanosis?
Deoxygenated blood exceeds 5g/dL
In the neonatal period, what are the 2 main categories, causes of cardiac cyanosis?
1. Reduced pulmonary blood flow: infants with duct-dependent pulm circ (relies on DA – so when it closes they become severely cyanosed. They have ROTO so depend on PDA. Severe cyanosis develops when duct closes. Also in Fallot’s get pulmonary stenosis so ROTO
2. Abnormal mixing of systemic venous and pulmonary venous blood: present with cyanosis first 2 days. TGA there must be some mixing.
On chest x-ray, how do you differentiate between the 2 main causes of cyanotic heart disease?
Abnormal mixing: pulmonary vascularity is increased, pulmonary plethora is apparent
Echo: shows defect and poor contractility of ventricles
What does differential cyanosis in the limbs indicate?
R to L shunting across the DA
What are the 2 types of ASD? Which is the more common type?
Ostium Secundum ASD: 80% of ASDs (more common)
Ostium primum ASD (also known as partial AVSD)
Where is the defect in the secundum ASD? And what causes it?
High in the atrial septum
Enlarged Foramen ovale, inadequate growth of septum secundum or xs absorption of septum primum
Which syndrome is affected by primum ASD /pAVSD?
Which murmur is AVSD commonly associated with?
What are the symptoms of ASD?
Recurrent chest infection/wheeze
Arrhythmia: 40s onwards
What is an ASD commonly mistaken for?
Patent foramen ovale
How do you distinguish between an ASD and a patent foramen ovale?
PFO opens only in conditions of raised atrial pressure or volumes
Whereas ASDs are LARGE and ALWAYS open
What % of people have a patent foramen ovale?
What are the 3 physical signs of ASD?
1. Fixed and widely SPLIT 2nd heart sound (as RVSV is equal in both insp and exp)
2. ESM best heard at upper left sternal edge – due to inc flow across RV outflow tract due to L-R shunt
3. With a partial AVSD – apical pansystolic murmur from the AV valve regurgitation
Is there a murmur generated by the flow across the ASD, why?
No because it is LOW VELOCITY
What does CXR of ASD show?
What does ECG of ASD show?
Which Ix is needed to diagnose ASD?
What is the Rx of ASD? And what is it trying to prevent?
Surgical – for secundum insertion of an occlusion device
Prevent cardiac failure, arrhythmia in later life
When is surgery for ASD best done? Where?
3-5 years of age
30% in cardiac catheter lab
Is endocarditis prophylaxis needed for ASD repair?
Not for secundum ASD
How are VSDs classified?
According to size
What are the symptoms of a small VSD?
What are the 2 main signs of a small VSD?
LOUD Pansystolic murmur at lower left sternal edge
Thrill at lower left sternal edge
What do CXR, ECG and echo show in small VSD?
CXR, ECG are normal
Echo shows anatomy of defect.
What is the management of small VSD?
Most close spontaneously
Need antibiotic prophylaxis of bacterial endocarditis before dental extraction
What are the symptoms of a large VSD?
Failure to thrive after 1 week old
What are signs of large VSD?
SOFT pansystolic murmur (because big hole!)
Apical mid diastolic murmur – due to increased flow across mitral valve after blood has circulated through lungs
Loud P2 due to raised pulm art DBP
Enlarged liver – due to heart failure
What does CXR of large VSD show?
Enlarged pulm artery
Increased pulm vasc markings
What does ECG of large VSD show?
LVH and RVH
Signs of pulm HTN
What is the management of a large VSD – remember medical and surgical
Drugs for heart failure: diuretics + captopril (ACEi)
Additional calorie input
Surgery: at 3-6 months of age to manage heart failure, prevent permanent lung damage from high pressures
What is a complication of a VSD – think about having such a big L to R shunt?
Increased flow in pulm vessels → pulmonary hypertension → increased pressure on R heart → reversal of shunt → so then right to left → CYANOSIS!!!
= Eisenmenger’s syndrome
What is the main complication of Eisenmengers syndrome, and when does E occur?
E occurs in 2nd decade of life
What does the DA connect?
Aorta to L pulm artery
When does the DA usually close by?
Fourth day of life
When is a PDA diagnosed?
If duct does not close after 1 month POST TERM
Which direction is the flow of blood in a PDA?
From aorta to pulmonary artery (L→ R)
Following the fall in pulm vasc res after birth
Give 3 risk factors for PDA?
Is the PDA in preterm infants the same as congenital PDA?
What are the 2 main clinical features of a PDA?
1. Bounding pulse due to wide pulse pressure
2. Machinery murmur
(if large duct then may get pulm HTN)
Describe the change in murmur type in PDA
Then as pulmonary vasc res falls – a continuous run off from the aorta to the pulm artery occurs with a continuous MACHINERY MURMUR
Hear it beneath the clavicle
Why does the murmur in PDA continue into diastole?
Because the pressure in the pulm artery is lower than that in the aorta throughout the cardiac cycle
Normally the ECG and CXR features of PDA are normal but if large what are the features similar to?
What is the management of a PDA?
If asymptomatic PDA – must close ALL to prevent bacterial endocarditis (higher risk of pulm vasc dis and BE from PDA than VSD! )
Coil or occlusion device via cardiac catheter at 1yr age
If large PDA may need surgical close at 1-3 months
Usually PDAs are asymptomatic, but if the duct is large what can happen?
L→ R shunt as pulm vasc res falls
What are the 3 types of outflow obstruction in the WELL child?
Adult type coarctation of the aorta
If you see aortic stenosis, what other things do you have to exclude?
Mitral valve stenosis
Coarctation of aorta
How does mild aortic stenosis present?
How does severe stenosis present?
Reduced exercise tolerance
Chest pain on exertion
In the neonatal period how many AS present?
Severe heart failure
Duct dependent SYSTEMIC circulation leading to shock
What causes aortic stenosis?
Partial FUSION of the aortic valve leaflets – so restricted LV exit
What is the pulse like in aortic stenosis?
Small volume, slow rising pulses
What type of murmur do you get in aortic stenosis? And where do you hear it?
Ejection systolic murmur radiating to neck
Murmur in ‘A’ – upper right sternal edge
What 2 features do you get of the heart sounds in AS?
Delayed and soft aortic S2
Apical ejection click
What do you see on CXR of AS?
Normal or prominent LV
Post stenotic dilatation of aorta
What do you see on ECG of AS? (2 main things)
LVH – deep S wave in V2 and tall R wave in V6 (>45mm)
Downward T wave suggests LV strain and severe AS
What is the management of AS?
If symptomatic or high resting pressure gradient across aortic valve need
If there is significant AS what will the children eventually need?
What is the pathology of pulmonary stenosis?
Pulmonary valve leaflets are partly fused together – restrictive RV exit
What type of pulmonary circulation may some neonates with pulmonary stenosis have?
Duct dependent pulmonary circulation
So they present in first few days of life
What type of murmur do you get in aortic stenosis? And where do you hear it?
Ejection systolic murmur
Murmur in ‘P’ – upper left sternal edge
Where do you hear an ejection click in pulm stenosis?
Upper left sternal edge
What happens to HS in pulm stenosis?
Soft or absent P2
What may you see on CXR of pulm stenosis?
Or post stenotic dilatation of pulm artery
What does ECG of pulm stenosis show?
RVH – upright T wave in V1 indicates RVH in children
Although most children with PS are asymptomatic, what will eventually occur to them?
Reduced exercise tolerance
What is management of pulm stenosis?
Transcatheter balloon dilatation
Why must you palpate for femoral pulses in cardiovascular examination of any child?
Detect coarctation of aorta
Which of the 3 outflow obstruction heart defects in a WELL child is not duct dependent?
coarctation of the aorta
how is coarctation of aorta classified?
Preductal: symptomatic infants
Postductal: asymptomatic chidren
What is the prognosis of coarctation of the aorta?
Gradually becomes more severe over many years
What are symptoms of coarctation of the aorta?
May have leg pains or headache
What do you find on cardiac examination in coarctation of the aorta? – think systematically
Pulse: radiofemoral delay (due to blood bypassing the obstruction via collateral vessels in the chest wall – hence pulse in legs is delayed)
BP: always systemic hypertension in the R arm
Heart: ESM at upper sternal edge
What 2 things do you see on CXR of coarctation of aorta?
Rib NOTCHING due to development of large collateral intercostal arteries under the ribs posteriorly to bypass obstruction
3 sign: aortic knob → notch where coarctation is →post stenotic dilatation
What does ECG of coarcation show?
What is management of coarctation, when does this happen?
When the condition becomes severe (assess by echo), then STENT at cardiac catheter
May need surgical repair
What is the other name for adult type coarctation of the aorta?
Post ductal coarctation
What is the other name for interruption of the aortic arch?
Pre ductal coarctation
What is the problem with pre ductal coarctation?
No connection between aorta PROXIMAL and DISTAL to the arterial DUCT
What other heart defect is commonly seen with preductal coarctation?
When does preductal coarctation present? With what features?
Neonatal – when DA closes get heart failure!
Features of duct dependent systemic circulation
On diagnosis of preductal coarctation what needs to be done?
PG infusion to maintain ductal patency and transfer to cardiac centre for surgery
What is the management of preductal coarctation?
Complete correction with closure of VSD and repair of aortic arch in first few days of life
What other conditions is preductal coarctation associated with?
22q11.2 gene deletion
What are the 2 forms of outflow obstruction in the sick infant?
Interruption of aortic arch (preductal coarctation)
Hypoplastic left heart syndrome
They are both DUCT DEPENDENT
What is hypoplastic left heart syndrome?
Underdevpt of entire L side of heart
What happens when the DA constricts in hypoplastic L heart syndrome?
Profound acidosis and rapid cardiovascular collapse as it is a duct dependent systemic circulation with no L heart!
Therefore need to give PG urgently!
On examination how do you tell between coarctation and hypoplastic left heart syndrome?
Coarctation: weak FEMORAL pulses
Hypoplastic L heart: ALL PERIPHERAL pulses are weak/absent
What is Rx of hypoplastic L heart syndrome?
Norwood procedure – difficult neonatal operation!
In congenital heart disease, what are the 2 causes of CYANOSIS?
1. Decreased pulmonary blood flow, with R to L shunt – FALLOTS
2. Abnormal mixing of systemic and pulmonary venous return – TRANSPOSITION OF GREAT ARTERIES & TRICUSPID ATRESIA
What is the most common cause of cyanotic congenital heart disease?
Tetralogy of fallot
What are the 4 main features of Fallot?
Subpulmonary stenosis → RVOTO
RVH as a result
When are most Fallots diagnosed?
Or after identifying MURMUR in few months of life
What is a HYPERCYANOTIC SPELL?
Rapid increase in cyanosis
Associated with irritability or inconsolable crying due to severe HYPOXIA and BREATHLESSNESS and PALLOR
Due to tissue acidosis
What are signs of Fallots?
Clubbing of fingers and toes – older children
Loud single S2 (only A2)
What type of murmur do you get in Fallots? (remember one of the 4 features…valve one)
ESM at LSE
What happens to heart sound in Fallots?
Single 2nd HS – A2
What causes the murmur to become shorter and cyanosis to increase?
Mainly muscular and BELOW the pulm valve
During a hypercyanotic spell what happens to the murmur in Fallots?
Very short or inaudible
Why is it important to recognise hypercyanotic spells?
They may lead to myocardial infarction, CVA, death if untreated
In fallots what happens on exercise?
Squatting – late in infancy
What is the ECG of Fallots at birth and later?
Later: RAD, RVH – upright T wave in V1 with pure R wave (no S wave)
What is the characteristic feature on CXR of Fallots?
Boot shaped (uptilted apex) heart caused by RVH
As there is pulm stenosis – get decreased pulm blood flow – so dec pulm vasc markings
What is the initial management of Fallots? And when is corrective surgery done? What are the 2 main aspects of surgery
Surgery at 6 months age
1. Patch closure of VSD
2. Widening of RVOT
What needs to be done with neonates who are very cyanosed?
SHUNT to increase pulm blood flow
Artificial tube between subclavian artery and pulm artery – modified Blalock Taussig shunt
Or balloon dilatation of RVOT
What is management of hypercyanotic spells?
Morphine – relieve pain and abolish hyperpnoea
Sodium bicarbonate – correct acidosis
Propranolol – peripheral vasoconstriction to relieve subpulmonary muscular obstruction that is the cause of reduced pulm bld flw.
What can be done to prevent hypercyanotic spells?
What is the problem in transposition of the great arteries?
Aorta is connected to the RV
Pulmonary artery is connected to LV
The blue blood us returned to the body
Pink blood is returned to the lungs
Describe the 2 circulations in TGA? Is it compatible with life?
2 PARALLEL circulations
Unless mixing of blood between the 2 circulations, the condition is incompatible with life
What is the main symptom of TGA?
Can be profound and life threatening
When does TGA usually present?
Day 1-2 of life
When ductal closure leads to a marked reduction in mixing of the desat and sat blood
What other anomalies would make the cyanosis less severe?
Mixing of blood from VSD
What is the heart sound in TGA?
When may you see clubbing in TGA?
Rare child who presents after 1 yr of life
What does CXR of TGA look like?
Narrow upper mediastinum with an egg on side appearance of heart shadow
Increased pulmonary vasc markings
What is the main aspect of management of TGA?
To improve mixing of saturated and desat blood
So maintain PDA – PGE infusion
What is the life saving procedure for TGA?
Balloon atrial septostomy
Catheter with balloon at tip through umb/fem vein to RA and foramen ovale - balloon inflated when in LA then pulled through the atrial septum – tear the septum and makes the flap valve of the foramen ovale incompetent – allow mixing of systemic and pulm venous blood within the atrium
What is the definitive Rx of TGA and when is it done?
Surgery – arterial switch procedure
Done first few days of life
Pulm artery and aorta transected above the valves and switched over
As well as the pulm and aorta which other arteries need to be transferred in surgery for TGA?