Paeds: Cardio Flashcards
fetal shunts
what are the 3 fetal shunts
- ductus arteriosus
- foramen ovale
- ductus venosus
fetal shunts
what does the ductus venosus connect
the umbilical vein to the IVC
fetal shunts
what does the foramen ovale connect
the RA with the LA
allows blood to bypass the RV and pulmonary circulation
fetal shunts
what does the ductus arteriosus connect
the pulmonary artery with the aorta and allows blood to bypass the pulmonary circulation
fetal shunts
how does the foramen ovale close
baby’s 1st breath –> pulmonary vascular resistance decreases –> RA pressure decreases –> LA pressure is greater than RA –> squashes atrial septum
fetal shunts
what does the foramen ovale become
the fossa ovalis
fetal shunts
how does the ductus arteriosus close
increased blood oxygenation –> drop in circulating prostaglandins –> closure
fetal shunts
what does the ductus arteriosus become
the ligamentum arteriosum
fetal shunts
how does the ductus venosus close
umbilical cord is clamped and there is no flow in the umbilical veins
so structurally closes a few days later
fetal shunts
what does the ductus venosus become
ligamentum venosum
Murmurs
what are innocent murmurs aka
flow murmurs
Murmurs
what are the typical features of innocent murmurs
- soft
- short
- systolic
- symptomless
- situation dependent
Murmurs
what features would prompt further investigations and referral to a paediatric cardiologist
- Murmur louder than 2/6
- Diastolic murmurs
- Louder on standing
- Other symptoms: failure to thrive, feeding difficulty, cyanosis or SOB
Murmurs
what are the differentials of a pan-systolic murmur
- mitral regurg
- tricuspid regurg
- ventricular septal defect
Murmurs
describe a mitral regurg murmur
pan-systolic
heard at the 5th ICS, mid-clavicular line
Murmurs
describe a tricuspid regurg murmur
pan-systolic
heard loudest at the 5th ICS, L sternal border
Murmurs
describe a ventricular septal defect murmur
pan-systolic
heard loudest at the L lower sternal border
Murmurs
differentials of an ejection-systolic murmur
- aortic stenosis
- pulmonary stenosis
- hypertrophic obstructive cardiomyopathy
Murmurs
describe an aortic stenosis murmur
ejection systolic
heart at 2nd ICS, R sternal border
Murmurs
describe a pulmonary stenosis murmur
ejection-systolic murmur
heard at the 2nd ICS, L sternal border
Murmurs
describe a hypertrophic obstructive cardiomyopathy murmur
ejection-systolic murmur
heard at the 4th ICS on the L sternal border
Murmurs
what causes the 2nd heart sound to be ‘split’
inspiration: chest wall
+ diaphragm pull the lungs and heart open.
This is called negative intra-thoracic pressure.
R heart fills faster as it pulls in blood from the venous system.
The increased volume in RV causes it to take longer for the RV to empty during systole, causing a delay in the pulmonary valve closing.
When the pulmonary valve closes slightly later than the aortic valve, this causes the 2nd heart sound to be ‘split’
Cyanotic Heart Disease
what kind of shunt is it
right to left shunt
Cyanotic Heart Disease
what heart defects can cause it
- VSD
- ASD
- PDA
- transposition of the great arteries
Cyanotic Heart Disease
what is Eisenmenger syndrome
left to right shunt becomes a right to left shunt , causing cyanosis
Patent Ductus Arteriosus
reason for it not to close
- may be genetic
- or rubella
- prematurity is a key RF
Patent Ductus Arteriosus
why is there RV hypertrophy
pressure aorta > pulmonary vessels, so blood flows from aorta to pulmonary artery.
This creates a L to R shunt
This increases the pressure in the pulmonary vessels causing pulmonary hypertension
leading to R sided heart strain as the RV struggles to contract against the increased resistance.
Pulmonary hypertension and right sided heart strain lead to RV hypertrophy
Patent Ductus Arteriosus
why is there LV hypertrophy
increased blood flowing through the pulmonary vessels and returning to the L side of the heart
Patent Ductus Arteriosus
murmur
normal first heart sound
with a continuous crescendo-decrescendo “machinery” murmur
that may continue during the second heart sound
making the second heart sound difficult to hear.
Patent Ductus Arteriosus
presentation
- SOB
- difficulty feeding
- poor weight gain
- LRTI
Patent Ductus Arteriosus
diagnostic inx
echocardiogram
Patent Ductus Arteriosus
monitoring
Patients are typically monitored until 1 year of age using echocardiograms.
Patent Ductus Arteriosus
After 1 year of age it is highly unlikely that the PDA will close spontaneously so what is the mnx
trans-catheter or surgical closure can be performed
Atrial Septal Defect
how can it cause Eisenmenger syndrome
eventually, the pulmonary pressure > systemic pressure
the shunt reverses and forms a R to L shunt across the ASD
blood bypasses the lungs and the patient becomes cyanotic.
Atrial Septal Defect
types of ASDs from most to least common
- Ostium secondum
- Patent foramen ovale (not strictly classified as an ASD)
- Ostium primum
Atrial Septal Defect
what is Ostium secondum
where the septum secondum fails to fully close, leaving a hole in the wall
Atrial Septal Defect
what is Ostium primum
the septum primum fails to fully close, leaving a hole in the wall.
This tends to lead to atrioventricular valve defects making it an atrioventricular septal defect.
Atrial Septal Defect
why are ASDs a cause of stroke in pts with a DVT
the clot is able to travel from the RA to the LA
to LV to aorta and up the brain, causing a large stroke
Atrial Septal Defect
describe the murmur
mid-systolic
crescendo-decrescendo murmur
loudest at the upper L sternal border
w/ a fixed split 2nd heart sound
Atrial Septal Defect
what is a fixed split 2nd heart sound
closure of the aortic and pulmonary valves at slightly different times
but the split does not change with inspiration or expiration
increased volume of blood in RV which mean pulmonary valve closes later
Atrial Septal Defect
typical sx in childhood
- SOB
- Difficulty feeding
- Poor weight gain
- LRTI
Atrial Septal Defect
mnx
- refer to paed cardiologist
- transvenous catheter closure (via the femoral vein)
- or open heart surgery
- Anticoagulants (aspirin, warfarin + NOACS) to reduce risk of clots
Ventricular Septal Defects
which conditions are they commonly associated with
Down’s and Turner’s Syndrome
Ventricular Septal Defects
what kind of shunt is it
begins with L –> R (acyanotic) but can lead to R –>L when there is pulmonary hyptertension (Eisenmenger)
Ventricular Septal Defects
presentaion
initially symptomless
- poor feeding
- dyspnoea
- tachypnoea
- failure to thrive
Ventricular Septal Defects
describe the murmur
pan-systolic
heard at the L lower sternal border
in the 3rd and 4th ICS
may be a systolic thrill on palpation
‘holo-systolic murmur’
Ventricular Septal Defects
trx
- watchful waiting if small as they often close spontaneously
- transvenous catheter closure via femoral vein
- open heart surgery
Ventricular Septal Defects
what is there an increased risk of developing
infective endocarditis
abx prophylaxis should be considered during surgical procedures
what is Ebstein’s anomaly
mother taking lithium so child has large right atrium and small right ventricle, usually due to low insertion of the tricuspid valve, which also causes tricuspid incompetence
pan-systolic murmur
Coarctation of the Aorta
what is it
congenital condition where there is narrowing of the aortic arch, usually around the ductus arteriosus
Coarctation of the Aorta
what underlying genetic condition is it associated with
Turner’s syndrome
Coarctation of the Aorta
presentation
- weak femoral pulses
- tachypnoea
- poor feeding
- grey + floppy baby
Coarctation of the Aorta
what would a 4 limb BP reveal
- high BP in limbs supplied from arteries that come before the narrowing
- lower BP in limbs that come after the narrowing
Coarctation of the Aorta
what may the murmur be like
- systolic
- heard below the L clavicle (L infraclavicular area) and below the L scapula
Coarctation of the Aorta
what additional signs may develop over time
- L ventricular heave due to LV hypertrophy
- underdeveloped L arm (reduced flow to L subclavian artery
- underdevelopment of the legs
Coarctation of the Aorta
mnx in cases of critical coarctation where there is a risk of HF and death shortly after birth
Prostaglandin E is used keep the ductus arteriosus open while waiting for surgery to allow some blood flow into the systemic circulation distal to the coarctation
Ebstein’s Anomaly
what is it
a 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.
Ebstein’s Anomaly
what is it associated with
- ASD
- WPW syndrome
Ebstein’s Anomaly
presentation
- HF (oedema)
- cyanosis
- SOB + tachypnoea
- poor feeding
- collapse or cardiac arrest
Ebstein’s Anomaly
what is heard on auscultation
gallop rhythm
3rd and 4th heart sound
Ebstein’s Anomaly
diagnosis
echocardiogram
Ebstein’s Anomaly
definitive mnx
surgical correction of the underlying defect.
Ebstein’s Anomaly
medical mnx
- treating arrhythmias and heart failure
- Prophylactic antibiotics may be used to prevent infective endocarditis
what is the most common congenital heart defect if mother is diabetic
Transposition of the great vessels
Transposition of the Great Arteries
what is it
the attachments of the aorta and the pulmonary trunk to the heart are swapped (“transposed”).
the right ventricle pumps blood into the aorta and the left ventricle pumps blood into the pulmonary vessels
Transposition of the Great Arteries
why will the baby be immediately cyanosed
2 separate circulations that don’t mix: one travelling through the systemic system and right side of the heart
and the other traveling through the pulmonary system and left side of the heart
Transposition of the Great Arteries
why is it associated with ASD, VSD and PDA
Immediate survival depends on a shunt between the systemic circulation and pulmonary circulation
Transposition of the Great Arteries
how is it diagnosed
during pregnancy with antenatal USS
Transposition of the Great Arteries
presentation at birth if not detected during pregnancy
- cyanosis within few days of birth
- resp distress, tachycardia, poor feeding, poor weight gain and sweating
Transposition of the Great Arteries
definitive mnx
open heart surgery:
cardiopulmonary bypass machine is used to perform an “arterial switch” procedure within a few days of birth.
If present, a VSD or ASD can be corrected at the same time.
Transposition of the Great Arteries
what is a balloon septostomy
inserting a catheter into the foramen ovale via the umbilicus, and inflating a balloon to create a large ASD
Transposition of the Great Arteries
why may a prostaglandin infusion be useful before defintive mnx
to maintain the patency of the PDA
Tetralogy of Fallot
the 4 coexisting pathologies
- overriding aorta
- pulmonary valve stenosis
- RV hypertrophy
- VSD
Tetralogy of Fallot
what does overriding aorta mean
the aortic valve is placed further to the right than normal, above the VSD.
RV contracts and blood can travel through VSD up into aorta carrying deoxygenated blood
Tetralogy of Fallot
what encourages blood to be shunted from right to left
pulmonary stenosis and overriding aorta
Tetralogy of Fallot
RFs
- rubella
- increased age of mother
- alcohol consumption in pregnancy
- diabetic mother
Tetralogy of Fallot
diagnostic inx
echo
Tetralogy of Fallot
what inx is useful in assessing the severity of the abnormality and shunt
doppler flow studies
Tetralogy of Fallot
what may a chest x-ray show
‘boot shaped’ heart due to RV thickening
Tetralogy of Fallot
what murmur may be heard
ejection systolic (pulmonary stenosis)
Tetralogy of Fallot
severe case presentation
HF before 1y
Tetralogy of Fallot
signs and sx
- cyanosis
- clubbing
- poor feeding
- poor weight gain
- ejection systolic murmur heard loudest in the pulmonary area
- ‘tet spells’
Tetralogy of Fallot
what are tet spells
intermittent symptomatic periods where the R->L shunt becomes temporarily worsened, precipitating a cyanotic episode
Tetralogy of Fallot
when does a tet spell occur
when the pulmonary vascular resistance increases or the systemic resistance decreases
e.g. child physically exerting
Tetralogy of Fallot
why may a tet spell occur after a child physically exerts themselves
CO2 is a vasodilator that causes systemic vasodilation and therefore reduces the systemic vascular resistance
Blood flow will choose the path of least resistance, so blood will be pumped from the RV to the aorta rather than the pulmonary vessels, bypassing the lungs.
Tetralogy of Fallot
what may older children do when a tet spell occurs
squat
it increases the systemic vascular resistance which encourages blood to enter the pulmonary vessels
Tetralogy of Fallot
what may younger children do when a tet spell occurs
positioned with their knees to their chest
Tetralogy of Fallot
tet spell mnx
- O2
- BB
- IV fluids
- morphine
- sodium bicarb
- phenylephrine
Tetralogy of Fallot
how may morphine help in a tet spell
can decrease resp drive, resulting in more effective breathing
Tetralogy of Fallot
how may sodium bicarb help in a tet spell
can buffer any metabolic acidosis that occurs.
Tetralogy of Fallot
how may Phenylephrine infusion help in a tet spell
increase systemic vascular resistance
Tetralogy of Fallot
definitive trx
total surgery repair by open heart surgery
Tetralogy of Fallot
what is used to maintain the ductus arteriosus in nenoates to allow blood to flow from the aorta back to the pulmonary arteries
prostaglandin infusion
Paediatric Aortic Stenosis
how many leaflets is the aortic valve made up of
3, called the aortic sinuses of Valsalva
Paediatric Aortic Stenosis
presentation
- can be asymptomatic
- fatigue
- SOB
- dizziness
- fainting
- worse on exertion
Paediatric Aortic Stenosis
describe the murmur
- ejection systolic
- heard loudest at the aortic area (R sternal border 2nd ICS)
- crescendo-decrescendo
- radiates to the carotids
Paediatric Aortic Stenosis
other signs on examination
- ejection click just before the murmur
- palpable thrill during systole
- slow rising pulse and narrow pulse pressure
Paediatric Aortic Stenosis
gold standard inx
echo
Paediatric Aortic Stenosis
how to monitor it
- echos
- ECG
- exercise testing
Paediatric Aortic Stenosis
options for trx
- percutaneous balloon aortic valvoplasty
- surgical aortic valvotomy
- valve replacement
Paediatric Aortic Stenosis
complications
- LV outflow tract obstruction
- HF
- ventricular arrhythmia
- bacterial endocarditis
- sudden death, often on exertion
Congenital Pulmonary Valve Stenosis
how many leaflets does the pulmonary valve have
3
Congenital Pulmonary Valve Stenosis
what causes it
abnormally developed pulmonary leaflets –> thickened + fused
resulting in a narrow opening
Congenital Pulmonary Valve Stenosis
which conditions is it associated with
- ToF
- William syndrome
- Noonan syndrome
- Congenital rubella syndrome
Congenital Pulmonary Valve Stenosis
sx
often asymptomatic
- fatigue on exertion
- SOB
- dizziness
- fainting
Congenital Pulmonary Valve Stenosis
describe the murmur
- ejection systolic murmur heard loudest at the 2nd ICS, left sternal border
Congenital Pulmonary Valve Stenosis
is there a thrill
palpable thrill in the pulmonary area
Congenital Pulmonary Valve Stenosis
why is there a R ventricular heave
due to RV hypertrophy
Congenital Pulmonary Valve Stenosis
is there a raised JVP
yes with giant a waves
Congenital Pulmonary Valve Stenosis
gold standard inx for establishing a dx
echo
Congenital Pulmonary Valve Stenosis
mnx for mild asymptomatic pts
- none
- follow up with cardiologist with a watch + wait approach
Congenital Pulmonary Valve Stenosis
trx if symptomatic or valve significantly stenosed
balloon valvuloplasty via a venous catheter
last line: open heart surgery