Paediatric Cardiology Flashcards
What are the 4 defects of tetralogy of fallot
Ventricular septal defect
Overriding aorta
Pulmonary valve stenosis
Right ventricular hypertrophy
RF for tetralogy of fallot
Rubella infection, maternal diabetes, increasing maternal age (>40), alcohol use during pregnancy
What determines the degree of cyanosis in tetralogy of fallot
The degree of pulmonary stenosis
Pathophysiology of tetralogy of fallot
- pulmonary stenosis increases pulmonary resistance
- blood shunts through VSD from right to left and into aorta bypassing the lungs
- the increased pulmonary resistance also causes right ventricular hypertrophy
- the blood does not get oxygenated at the lungs causing cyanosis
Presentation of tetralogy of fallot
Cyanosis, finger clubbing, poor feeding and poor weight gain, Tet spells, ejection systolic murmur in pulmonary area
What are Tet spells
Periods of worsening cyanosis due to decreases in systemic resistance or increases of pulmonary resistance
- for example during exertion there is increased CO2 causing systemic vasodilation
- this worsens the right to left shunt increasing cyanosis
How do Tet spells present
Worsening of cyanosis- irritability, shortness of breath, loss of consciousness, seizures and potentially death
May occur during physical exertion, crying etc
Child may squat or bring knees to chest to increase systemic resistance
How is tetralogy of fallot diagnosed
Echocardiogram and Doppler study of blood flow
Chest X ray- boot sign
How are Tet spells treated
Oxygen, beta blockers, IV fluids, morphine, sodium bicarbonate, phenylephrine infusions
Treatment of Tetralogy of fallot
Neonates- prostaglandin infusion to maintain the ductus arteriosus (aorta-> PA)
Definitive = surgery
Describe what atrial septal defects are
Defects in the septum between the atrium caused by failure of the septum primum or septum secondum to close
Two types of ASD
Ostium primum and ostium secondum
Are ASDs cyanotic?
No - may become if eisenmengers syndrome occurs
Describe how ASDs can become cyanotic
If the left to right shunt is big enough there can be right sided overload.
This can lead to RHF and pulmonary hypertension
This can cause reversal of the left to right shunt so blood bypasses the lungs
RF for ASD
Maternal smoking, family history, maternal diabetes, maternal rubella infection
What is the murmur that is associated with atrial septal defects ?
Mid systolic crescendo decrescendo murmur heard loudest on the upper sternal border
What can happen to the heart sounds in ASDs?
You can have a fixed split second heart sound due to difference in timing of the aortic and pulmonary valves (occurs due to delayed closing of the pulmonary valve as a result of increased blood flow) .
This will not vary with inspiration (its fixed)
How may a child with a ASD present
Shortness of breath, poor feeding, poor weight gain, lower respiratory tract infections
How may ASDs present in adulthood
Dyspnoea, heart failure, stroke
Diagnosis of atrial septal defects
Echo
ECG - RBBB
Treatment of atrial septal defects
If less than 1cm watch and wait
If larger than 1cm - surgical repair (either transvenous catheter closure or open heart surgery)
Treatment of atrial septal defects
If less than 1cm watch and wait
If larger than 1cm - surgery (transvenous catheter closure or open heart surgery
Why may strokes occur in atrial septal defects?
In DVTs emboli usually travel into the lungs and cause PE
In a right to left shunt they can travel into the brain and cause a stroke
Complications of ASDs
Strokes, atrial fibrillation, atrial flutter, right heart failure
Explain what a ventricular septal defect is?
A congenital hole in the the septum between the ventricles
What can cause ventricular septal defects
Genetic condition such as Down’s syndrome, Turner’s syndrome, Edward’s syndrome
Congenital infections
Post-myocardial infarction
Are VSDs cyanotic
No but then can become cyanotic in Eisenmengers
Presentation of a VSDs
Pan-systolic murmur heard loudest in the lower sternal border
Poor feeding
Dyspnoea
Tachypnoea
Failure to thrive
Differentials of a pan systolic murmur
VSDs, mitral regurgitation, tricuspid regurgitation
Diagnosis of VSDs
Echo
Treatment of VSDs
Small- watch and wait
Large - surgical repair (trans catheter, or open)
What are potential ocmplications of VSDs
Aortic regurgitation
Infective endocarditis
RHF
What should be given to patients with VSDs if they have surgery
Prophylactic antibiotics to prevent infective endocarditis
How does a patent ductus arteriosus present on examination
machinery-like murmuer
bounding pulse
widened pulse pressure
What can be given to close a patent ductus arteriosus
indomethacin or ibuprofen
What type of pulse may be heard in a patent DA
collapsing pulse
what type of murmur is not consisten with an innocent murmur
a diastolic murmur
what is ebstein’s anomaly
a congenital cardiac condition where the tricuspif valve leaflets are attached to the walls of the septum of the right ventricle
What are features of a innocent murmur?
soft, systolic, short, symptomless, standing/sitting
what medication should be given initially in babies born with cyanotic congenital heart diseases
prostaglandin E1
what are the 5 cyanotic heart diseases?
tetralogy of fallot
transposition of the great vessels
tricuspid atresia
total anomalous pulmonary venous return
truncus arteriosus
What test can be used to differentiate between cardiac and non-cardiac causes of cynosis in neonates
nitrogen washout test - neonate is given 100% O2 for 10 mins and then an ABG is taken- pO2 of less than 15 indicates cyanotic heart disease
If a cyanotic heart defect presents in the first few days of life what is the likely cause
transposition of the great arteries
if a cyanotic heart disease presents after 1-2 months of life, what is the most likely cause?
tetralogy of fallot
when is indomethacin given to a newborn for PDA
afte an echo shows PDA one week after delivery
is ventricular tachycardia a shockable rhythm
yes
what size VSD can be treated conservatively
less than 3mm
murmur of a patent ductus arteriosus
continuous machinery like murmer in the left sternal edge
in tetralogy of fallot what defect causes the murmur
pulmonary stenosis
what does transposition of the great arteries look like on x ray
egg on a string appearance
What are the cyanotic congenital heart diseases?
transposition of the great arteries
tetralogy of fallot
What is transposition of the great arteries?
a cyanotic heart disease where the origins of the aorta and the pulmonary artery are transposed
RF of transposition of the great arteries
maternal diabetes
maternal rubella infection in pregnancy
alcohol use
increased maternal age
family history
other structural heart defects (VSD, ASD)
Pathophysiology of transposition of the great arteries
normally in embryology there is spiralling of the great arteries however in GA the spiraling fails to occur
how does transposition of the great arteries present?
cyanosis at birth- worsens after closure of the ductus arteriosus, improves if a septal defect is present
rapid breathing
poor weight gain
heart murmur- systolic if VSD also prsent
loud single S2
How is transposition of the great arteries diagnosed
often antenatal diagnosis on USS
echo
xray- eggs on a string appearance.
How is transposition of the great arteries treated?
surgical correction in the first few months
what treatment can be given prior to surgery in transposition of the great arteries and why?
prostaglandin E1 - keeps the ductus arteriosus open
What is coarctation of the aorta
a congential heart disease where there is narrowing of the aorta, typically just before the ductus arteriosus
What genetic condition is coarctation of the aorta associated with?
Turner’s syndrome
How does coarctation of the aorta present?
can be asymptomatic if mild
systolic murmur- loudest between the scapula
radiofemoral delay
hypertension of the upper limbs
can present as shock once the ductus arteriosus shuts
How is coarctation of the aorta diagnosed?
Echo
BP - increased in upper and lower in the lower limbs
ECG- may show evidence of left ventricular hypertrophy
How is severe coarctation of the aorta treated
1st line- balloon angioplasty and stent insertion
2nd line- surgical correction
What is rheumatic fever?
an immunological response to recent streptococcus pyogenes infection
How soon after infection does rheumatic fever occur?
2-4 weeks
What condition often is associated with rheumatic fever
tonisilitis caused by strep pyogenes
Pathophysiology of rheumatic fever
Infection with strep pyogenes activates the innate immune system causing IgM and IgG production and activation of CD4+ T cells
There is a type 2 hypersensitivity reaction where antibodies to a antigen on the cell wall of strep pyogenes (M protein) cross react with myosin and smooth muscle of arteries
What diagnostic criteria can be used for rheumatic fever?
the Jones criteria
What components make up the jones criteria
RF is diagnosed when there is evidence of a recent streptococcal infection (positive throat swab, raised ASOT, raised DNase B titre)
plus two major criteria or one major and 2 minor criteria
Major criteria:
- joint arthritis
- organ inflammation (carditis)
- Nodules
- Erythema marginatum rahs
- Sydenham chorea
Minor:
– Fever
- ECG changes without carditis (prolonged PR interval)
- arthralgia without arthritis
- raised inflammatory markers (CRP and ESR)
How is arthritis associated with rheumatic fever describeD?
migratory arthritis of the large joints- joint are hot and swollen then improve nad move to next joint)
What is sydenham’s chorea
irregular uncontrolled rapid movmements of the limbs along with emotional disturbance and muscle weakenss
Often worse on one side and ceases during sleep
What ECG change may be associated with rheumatic fever
prolonged PR interval
describe the rash associated with rheumatic fever
erythema marginatum - pink rings of varying sizes on torso and proximal limbs
How is rheumatic fever treated
pen V 10 days when streptococcal infection
NSAIDs
prophylactic antibiotics may be used into adulthood to preent further strep infections- oral or IM penicillin
what type of bacteria causes rheumatic fever?
group A beta haemolytic streptococci- strep pyogenes
What complications can occur in rheumatic fever?
valvular heart disease- particularly mitral stenosis
chronic heart failure
recurrence
