Paediatrics Cardiology Flashcards
What are the 3 fetal shunts?
Ductus venosus: bypass liver (umbilical vein to IVC)
Foramen ovale: bypass right ventricle and pulmonary circulation (connects right and left atriums)
Ductus arteriosus: bypass pulmonary circulation (connects pulmonary artery with aorta)
What happens when a baby takes its first breath at birth?
First breaths the baby takes expands the alveoli which decreases the pulmonary vascular resistance causing a fall in pressure in the right atrium.
At this point the left atrial pressure is greater than the right atrial pressure - squashed the atrial septum causing foramen ovale to close
What happens to the foramen ovale?
Gets sealed shut structurally after a few weeks becoming the fossa ovalis
What happens to the ductus arteriosus?
Prostaglandins are required to keep the ductus arteriosus open and an increase in blood oxygenation causes a drop in circulating prostaglandins causing closure of the ductus arteriosus which becomes the ligamentum arteriosum
What happens to the ductus venosus?
Immediately after birth the ductus venosus stops functioning because the umbilical cord is clamped and there is no flow in the umbilical veins (ductus venosus structurally closes a few days later and becomes the ligamentum venosum)
What are innocent murmurs also known as?
Flow murmurs (caused by blood flow through various areas of the heart during systole)
What are the features of innocent murmurs?
Soft
Short
Systolic
Symptomless
Situation dependent (if the murmur is quieter with standing or only appears when the child is unwell or feverish)
When should a murmur be referred to a paediatric cardiologist?
- Murmur louder than 2/6
- Diastolic murmur
- Louder on standing
- Other symptoms such as failure to thrive, feeding difficulty, cyanosis or SoB
What are the key investigations for a suspious murmur in a child?
ECG
Chest X-Ray
Echocardiography
What are the differentials for a pan systolic murmur? How are they differentiated?
Mitral regurgitation - heard at mitral area (5th intercostal space, mid-clavicular line)
Tricuspid regurgitation - heard at tricuspid area (5th intercostal space, left sternal border)
Ventricular septal defect - heard at left lower sternal border
What are the differentials for an ejection systolic murmur? How are they differentiated?
Aortic stenosis - heard at the aortic area (2nd intercostal space, right sternal border)
Pulmonary stenosis - heard at the pulmonary area (2nd intercostal space, left sternal border)
Hypertrophic obstructive cardiomyopathy heard at the 4th intercostal space on the left sternal border
What causes splitting of the second heart sound?
Inspiration = heart is pulled open (negative intra-thoracic pressure)
Causes the right side of the heart to fill faster as it pulls in blood from the venous system
Increased volume in the right ventricle causes it to take longer for the right ventricle to empty during systole causing a delay in the pulmonary valve closing (when this closes slightly later than the aortic valve this causes the heart sound to be split)
What type of murmur does an atrial septal defect cause?
Mid-systolic, crescendo-decrescendo murmur lousest at the upper left sternal border with a fixed split second heart sound
What is a fixed split second heart sound?
Split doesnt change with inspiration and expiration
Why does a fixed split second heart sound occur in an atrial septal defect?
Because blood is flowing from the left atrium across the atrial septal defect increasing the volume of bloos that the right ventricle has to empty before the pulmonary valve can close (doesn’t vary with respiration)
How does a patent ductus arteriosus sound?
Continuous crescendo-decrescendo “machinery” murmur that may continue during the second heart sound making it difficult to hear
How does the murmur in tetralogy of fallot sound?
Arises from pulmonary stenosis giving an ejection systolic murmur which is loudest at the pulmonary area (second intercostal space, left sternal border)
When does cyanotic heart disease occur?
On a right to left shunt
What can cause cyanotic heart disease?
Ventricular septal defect (VSD)
Atrial septal defect (ASD)
Patent ductus arteriosus (PDA)
Transposition of the great arteries
What is Eisenmenger syndrome?
If the pulmonary pressure increased beyond the systemic pressure then blood with start to flow from right-to-left across the defect causing cyanosis
Why does a patent ductus arteriosus occur?
Unclear, may be genetic or related to maternal infections e.g. rubella (prematurity is a key factor)
How may a small PDA present?
Asymptomatic throughout childhood then present in adulthood with signs of heart failure
What is the result of a patent ductus arteriosus?
Pressure in the aorta is higher than in the pulmonary vessels- blood flows from the aorta to the pulmonary artery (creating a left to right shunt)
Increases pressure in the pulmonary vessels causing pulmonary hypertension leading to right sided heart strain causing right ventricular hypertrophy.
Increase in blood flowing through the pulmonary vessels and returning to the left side of the hear leads to left ventricular hypertrophy
How does a patent ductus arteriosus present?
- Shortness of breath
- Difficulty feeding
- Poor weight gain
- Lower respiratory tract infections
How is a patent ductus arteriosus diagnosed?
Echocardiogram (doppler flow studies during the echo can assess the size and characteristics of the shunt - echo can also assess hypertrophy of the heart)
How are patients with a patent ductus arteriosus managed?
Monitored until 1 year of age using echocardiograms- after 1 year of age its unlikely that the PDA will close spontaneously and atranscatheterorsurgical closure can be performed
Symptomatic patients or those with evidence of heart failure as a reault of PDA are treated earlier
How do the atria develop?
During development left and right atria are connected - two walls grow downwards from the top of the heart and then fuse together with the endocardial cushion in the miss of the heart to separate the atria
2 walls = septum primum and septum secundum
Which atrial wall is the foramen ovale in?
Septum secondum
What can cause atrial septal defects?
Ostium secondum where the septum secondum fails to close full, leaving a hole in the wall
Patent foramen ovale where the foramen ovale fails to close (although this isnt strictly classed as an ASD)
Ostium primum where the septum primum fails to fully close, leaving a hole in the wall - leading to atrioventricular valve defects making it an atrioventricular septal defect
What is a complication of an artial septal defect?
Stroke (in the context of a VTE)
Atrial fibrillation or atrial flutter
Pulmonary hypertension and right sided heart failure
Eisenmenger syndrome
What kind of murmur does an atrial septal defect cause?
Mid-systolic, crescendo-decrescendo murmus loudest at the upper left sternal border with a fixed split second heart sound
How may an ASD present in adulthood?
Dyspnoea
Heart failure
Stroke
What are the symptoms in childhood for ASD?
- SoB
- Difficulty feeding
- Poor weight gain
- Lower respiratory tract infections
What is the interesting link with patent foramen ovale?
Have been linked to migraine with aura
What is the management of ASD?
- Referral to paediatric cardiologist
- Corrected surgically using a transvenous catheter closure (via femoral vein) or via open heart surgery
- Anticoagulants (such as aspirin, warfarin and NOACs) used to reduce the risk of clots and stokes in adults
What is a ventricular septal defect?
Congenital hole in the septum between the two ventricles (vary in size from tiny to the entire septum forming one large ventricle)
What are ventricular septal defects associated with?
Down’s syndrome
Turner’s syndrome
What does a ventricula septal defect lead to?
Right sided overload, right heart failure and increased flow into the pulmonary vessels
What eventually can a VSD lead to?
Eisenmenger Syndrome
How does VSD appear in childhood?
Poor feeding
Dyspnoea
Tachypnoea
Poor feeding
Failure to thrive
How does a VSD sound?
Pan-systolic murmur
What else can cause a pan-systolic murmur?
VSD
Mitral regurgitation
Tricuspid regurgitation
How should VSDs be managed?
What are patients with a VSD at increased risk of?
Infective endocarditis - antibiotic prophylaxis should be considered during surgical procedures to reduce the risk of developing infective endocarditis
What are the three underlying lesions which can cause Eisenmenger’s syndrome?
ASD
VSD
Patent ductus arteriosus
How long does Eisenmenger’s syndrome take to develop?
1-2 years with large shunts or in adulthodd with small shunts (can develop more quickly during pregnancy)
What are the blood changes seen in Eisenmenger’s syndrome?
Bone marrow responds to low oxygen saturations by producing more red blood cells and haemoglobin to increase the oxygen carrying capacity of the blood , leading to polycythaemia which is a high concentration of haemoglobin in the blood
How does polycythaemia make patients appear?
Plethoric complexion (blood is more viscous = more blood clots)
What are the examination findings in Eisenmenger’s syndrome?
Pulmonary hypertension causes:
- Right ventricular heave (right ventricle contracts forcefully against increased pressure in the lungs)
- Loud P2: loud second heart sound due to forceful shutting of the pulmonary valve
- Raised JVP
- Peripheral oedema
How may the septal defect present in Eisenmenger’s ?
Atrial septal defect: mid-systolic, crescendo-decrescendo murmur loudest at the upper left sternal boarder
Ventricular septal defect: pan-systolic murmur loudest at the left lower sternal boarder
Patent ductus arteriosus: continuous crescendo-decrescendo “machinery” murmur
Arrhythmias
How may the chronic hypoxia present in Eisenmenger’s?
Cyanosis
Clubbing
Dyspnoea
Plethoric complexion (a red complexion related to polycythaemia)
How long are patients with Eisenmenger’s expected to live?
20 years less compared to healthy individuals
What are the main causes of death in Eisenmenger’s?
Heart failure
Infection
Thromboembolism
Haemorrhage
(Mortality up to 50% in pregnancy)
What is the definitive treatment of Eisenmenger’s?
Heart-lung transplant
What is the medical management of Eisenmenger’s?
Oxygen (does not affect overall outcomes)
Treatment of pulmonary hypertension, for example using sildenafil
Treatment of arrhythmias
Treatment of polycythaemia with venesection
Prevention and treatment of thrombosis with anticoagulation
Prevention of infective endocarditis using prophylactic antibiotics
What is coarctation of the aorta?
Narrowing of the aortic arch usually around the ductus arteriosus
What is coarctation of the aorta typically associated with?
Turner’s syndrome
How does coarctation of the aorta present in neonates?
Weak femoral pulse (high blood pressure in the limbs suppled from arteries which come before the narrowing)
Systolic murmur heard below the left clavicle and below the left scapula
What are the other signs of coarctation of the aorta?
- Tachypnoea and increased work of breathing
- Poor feeding
- Grey and floppy baby
What signs of coarctation of the aorta develop over time?
Left ventricular heave due to ventricualr hypertrophy
Underdeveloped left arm where there is reduced flow to the left subclavian artery
Underdevelopment of the legs
What is the management of coarctation of the aorta?
Varies (some are asymptomatic others require emergency surgery shortly after birth)
- In critical coarctation where there is a risk of heart failure and death shortly after birth prostaglandin E is used to keep the ductus arteriosus open whilst waiting for surgery (IV dinoprostone)
- Surgery = corrects the coarctation and ligate the ductus arteriosus
What is congenital aortic valve stenosis?
Babies are born with a narrow aortic valve
How is the aortic valve usually structured?
Three leaflets = aortic sinuses of Valsalva (patients with aortic valve stenosis may have 1, 2, 3 or 4 leaflets)
How may patients with congenital aortic valve stenosis present?
Asymptomatic or symptoms of fatigue, SoB, dizziness and fainting
Worse on exertion
If severe then presents with heart failure within months of birth
What is the murmur heard in congential aortic valve stenosis?
Ejection systolic murmur heard loudest at the aortic area which is the second intercostal space, right sternal border
It has a crescento-decrescendo character and radiates to the carotids
What other signs are there of aortic stenosis?
Ejection click just before the murmur
Palpable thrill suring systole
Slow rising pulse and narrow pulse pressure
How to diagnose congenital aortic valve stenosis?
Echocardiogram
What does the management of congenital aortic valve stenosis involve?
- Regular follow up under a paediatric cardiologist with echocardiograms, ECGs and exercise testing to monitor the progression of the condition
How can congenital aortic valve stenosis be treated?
- Percutaneous balloon aortic valvoplasty
- Surgical aortic valvotomy
- Valve replacement
What are the complication of congenital aortic valve stenosis?
Left ventricular outflow tract obstruction
Heart failure
Ventricular arrhythmia
Bacterial endocarditis
Sudden death, often on exertion
What can congenital pulmonary valve stenosis be associated with?
Tetralogy of Fallot
William syndrome
Noonan syndrome
Congenital rubella syndrome
How can pulmonary valve stenosis present?
Symptoms of fatigue on exertion
SoB
Dizziness
Fainting
What are the signs of congenital pulmonary stenosis?
Ejection systolic murmur heard loudest at the pulmonary area (second intercostal space, left sternal boarder)
Palpable thrill in the pulmonary area
Right ventricular heave due to right ventricular hypertrophy
Raised JVP with giant a waves
How is pulmonary valve stenosis diagnosed?
Echocardiogram
How is congenital pulmonary stenosis managed?
- If mild then “watching and waiting” approach
- If symptomatic then balloon valvuloplasty via a venous catheter is the treatment of choice (inserting a catheter under xray guidance into the femoral vein through the IVC and right side of the heart to the pulmonary valve and dilating the valve by inflating a balloon)
- If valculoplasty is not appropriate then open-heart surgery can be performed
What are the 4 pathologies of tetralogy of fallot?
- VSD
- Overriding aorta
- Pulmonary valve stenosis
- Right ventricualr hypertrophy
What is the severity of tetralogy of fallot related to?
Pulmonary stenosis
What are the risk factors for tetralogy of fallot?
Rubella infection
Increased age of the mother (over 40 years)
Alcohol consumption in pregnancy
Diabetic mother
What are the investigations for tetralogy of fallot?
Echocardiogram (with doppler flow studies)
C-Xray (characteristic “boot shaped” heart due to right ventricular thickening)
When is tetralogy of fallot picked up?
When the child is born (before the antenatal scans)
Ejection systolic murmur caused by pulmonary stenosis may be heard on the newborn baby check
What are the signs and symptoms of tetralogy of fallot?
Cyanosis
Clubbing
Poor feeding
Poor weight gain
Ejection systolic murmur heard loudest in the pulmonary area (second intercostal space, left sternal boarder)
“Tet spells”
What is a tet spell?
Intermittent symptomatic period where right to left shunt becomes temporarily worse precipitating a cyanotic episode
Occurs when the pulmonary vascular resistance increases or the systemic resistance decreases e.g. on physical exertion they are generating a lot of CO2 (this is a vasodilator which causes systemic vasodilation) and therefore reduces the systemic vascular resistance.
What are tet spell treatment options?
- Squatting (increases systemic vasular resistance encouraging blood to enter the pulmonary vessels)
- Medical
What are the medical treatment options for tet spells?
Supplementary oxygen
Beta blockers can relax the right ventricle and improve flow to the pulmonary vessels.
IV fluids can increase pre-load, increasing the volume of blood flowing to the pulmonary vessels.
Morphine can decrease respiratory drive, resulting in more effective breathing.
Sodium bicarbonate can buffer any metabolic acidosis that occurs.
Phenylephrine infusion can increase systemic vascular resistance.
What are the treatment options for tet spells?
In neonates a prostaglandin infusion can be used to maintain the ductus arteriosus allowing blood to flow from the aorta back into the pulmonary arteries
Total surgical repain by open heart surgery is definitive treatment however mortality from sugery is 5%
Progonsis is poor without surgery
What is Ebstein’s anomaly?
Congenital heart condition where the tricuspid valve is set lower in the right side of the heart (towards the apex) causing a bigger right atrium and a smaller right ventricle (often associated with an atrial septal defect / WPW syndrome)
How does Ebstein’s anomaly present?
Evidence of heart failure (e.g. oedema)
Gallop rhythm heard on auscultation characterised by the addition of the third and fourth heart sounds
Cyanosis
Shortness of breath and tachypnoea
Poor feeding
Collapse or cardiac arrest
When to patients with Ebstein’s anomaly and ASD present?
A few days after birth when the ductus arteriosus closes.
When there is a right to left shunt across an atrial septal defect the ductus arteriosus allows blood to flow from the aorta into the pulmonary vessels to get oxygenated. This minimises the cyanosis. When the duct closes the patient becomes cyanotic and symptomatic.
What are the investigations for Ebstein’s anomaly?
ECG (arrhythmias, right atrial enlargement, right BBB, left axis deviation)
Chest X-ray (cardiomegaly, right atrial enlargement)
Echocardiogram (for confirming the diagnosis)
What is the management for Ebstein’s anomaly?
Medical management including treating arrhythmias and heart failure
Prophylactic antibiotics may be used to prevent infective endocarditis
Definitive managment is by surgical correction of the underlying defect
What is transposition of great arteries?
Attachments of the aorta and the pulmonary trunk to the heart are swapped
What can transposition of the great arteries be associated with?
Ventricular septal defect
Coarctation of the aorta
Pulmonary stenosis
How is immediate survival from transposition of the great arteries possible?
Shunt:
- Patent ductus arteriosus
- Atrial septal defect
- Ventricular septal defect
When is transposition of the great arteries diagnosed?
During pregnancy with antenatal ultrasound scans (woman must give birth in a hospital capable of manageing the condition after birth)
How will transposition of the great arteries present after a few weeks of birth?
Respiratory distress
Tachycardia
Poor feeding
Poor weight gain
Sweating
What is the managment of transposition of the great arteries?
- VSD will provide time for definitive treatment
- Prostaglandin infusion can be used to maintain the ductus arteriosus allowing blood from the aorta to flow to the pumonary arteries for oxygenation
- Balloon septostomy involves inserting a catheter into the foramen ovale via the umbilicus, and inflating a balloon to create a large atrial septal defect (allowing blood to reach the aorta)
- Open heart surgery is the definitive management (cardiopulmonary bypass machine) is used to perform an “arterial switch” procedure within a few days of birth
