Paediatrics: Cardiology Flashcards
Fetal Circulation: Where does gas exchange occur?
placenta
Fetal circulation: what gets exchanged at the placenta?
- Collect oxygen + nutrients
- Dispose of waste products (CO2 + lactate)
How many shunts are there in the Fetal circulation ? name them?
3
- Ductus venosus
- Foramen ovale
- Ductus arteriosus
Why does blood not go to fetal lungs?
Fetal lungs not developed or functional so shunts allow blood to bypass lungs
From where to where does ductus venous shunt? what does it bypass?
Umbilical vein => Ductus venosus => Inferior vena cava
- Bypass the liver
If there was no ductus venosus, then where would blood flow?
Umbilical vein => portal vein => liver => hepatic vein => inferior vena cava
From where to where does foramen ovale shunt? what does it bypass?
Right atrium => foramen ovale => left atrium
- Bypass RV + pulmonary circulation
From where to where does ductus arteriosus shunt? what does it bypass?
Pulmonary artery => ductus arteriosus => aorta
- Bypass pulmonary circulation
Fetal circulation: what different ways can blood get from RA to aorta?
- RA => foramen ovale => LA => LV => aorta
- RA => RV => pulmonary artery => ductus arteriosus => aorta
At birth describe what happens to foramen ovale? explain
what does it become?
fist breath expands alveoli in lungs => decrease vascular resistance => decrease pressure in RA => LA pressure > RA pressure => closure of foramen ovale (eventually => fossa ovalis)
What is required to keep ductus arteriosus open? be specific
prostaglandins (E1)
At birth describe what happens to ductus arteriosus? explain
What does it become?
At birth: increased blood oxygenation => decreased prostaglandin conc => closure of ductus arteriosus (=> ligament arteriosum)
What are congenital heart defects?
Group of structural abnormalities of the heart the are present at birth
What physiology would cause a cyanotic CHD? briefly
L => R shunt
Give examples of Cyanotic CHD (3)
- Tetralogy of fallot
- Transposition of the great arteries
- Tricuspid atresia
give the 2 categories of cyanotic CHD?
- Shunt lesions
- obstructive lesion
Give examples of shunt lesions? are these cyanotic or not? (3)
VSD, ASD, Patent ductus arteriosus
asyanotc but can beomce cyanotic (Eisenmenger syndrome)
how to obstructive CHD affect the heart?
narrowing/blockage in heart => increase pressure load => hypertrophy
what are innocent murmurs also known as, are they common?
innocent/flow murmurs are common in children
what physiology causes an innocent murmur
caused by fast blood flow through hear in systole
What are the typical features of an innocent murmur?
SSSSSSSSS
- Soft
- Short
- Systolic
- Symptomless
- Situation dependant
When would you want to investigate a murmur in a child? what signs?
- Loud murmur
- diastolic
- louder on standing
- Other symptoms (failure to thrive, feeding difficulty, cyanosis, sob)
Describe a pan systolic murmur?
continue throughout the whole systolic contraction of the heart
What can cause a pnasystolic murmur? (3)
- Mitral regurgitation
- Tricuspid regurgitation
- VSD
What can cause an ejection systolic murmur? (4)
- Aortic stenosis
- Pulmonary stenosis
- ASD
(- tetralogy of Fallot (due to pulmonary stenosis))
What causes splitting of the second heart sound? During which bit of respiration is it normally heard?
Splitting of the second heart sound: normal sound heard on inspiration caused by the negative intrathoracic pressure (generated when chest wall + diaphragm pull lungs open)
- normal on inspiration
What pathology could cause a fixed split second heart sound? describe the murmur associated with this
ASD: ejection systolic, crescendo-descrendo murmur, loudest at the upper left sternal border, with fixed split second heart sound (on inspiration + expiration)
what heart murmur would teroatlofy of fallot present with? what is this due to?
murmur due to pulmonary stenosis => ejection systolic murmur
What is tetralogy of Fallot?
Congenital cardiac condition with 4 co-existing pathologies
what are the 4 pathologies in ToF?
- VSD
- overriding aorta
- Pulmonary stenosis
- Right ventricular hypertrophy
Think of the cowboy riding the aorta, squeezing the pulmonary artery in the boot shaped heart.
Describe the pathophysiology of ToF? of each pathology
VSD allos blod to flow through ventricles
- Overriding aorta means ta entrance to aorta (aortic valve) is placed further ro the right than normal => when RV contracts => more (more deoxy blood sent through aorta)
- Stenosis of pulmonary valve => greater resistance against flow of blood form RV => more blood through VSD into aorta => R to L shunt => cyanosis
- Increased strain on RV + pulmonary stenosis => RV hypertrophy
ToF RF? (4)
- Rubella infection
- Increased maternal age
- Maternal alcohol use
- trisomy 21
ToF presentation?
- Mostly picked up antenately, or ejection systolic murmur at NIPE
- cyanosis, clubbing, poor feeding, poor weight gain
- tet spells
What are Tet spells?
intermittent spells wehre R => L shunt temporarily worsens => cyanotic episode
What causes tet spells ? (physiology)
Due to increase in pulmonary vas resistance or decrease in systemic resistance
Features of tet spells? (3)
- Rapid, deep respiration
- Irritability
- Increasing cyanosis
Management of ToF? medical and surgical?
medical: squatting, prostaglandin infusion, BB, morphine
- Surgical (definitive): total surgical repair by open heart surgery
what is the common CXR finding of ToF
boot shaped heart
What is PDA?
Patent Ductus Arteriosus
- Failure of closure of the ductus arteriosus
when does normal functional and structural closure of ductus arteriosus occur?
Functional: 1-3 days
Structural: 2-3 weeks
PDA RF? (2)
- Prematurity
- Maternal rubella
what kind of shunt in PDA? describe the pressures briefly ?
L => R shunt
- Pressure in aorta > pressure in pulmonary vessels
what does the shunt in PDA cause? describe the steps
L to R shunt => increased blood flow through pulmonary circulation => pulmonary hypertension + R sided heart strain => R sided hypertrophy => pulmonary pressure greater than systemic => eisenmengers syndrome => cyanosis
PDA presentation in infants?
- SOB
- difficulty feeding
- Poor weight gain
- Recurrent LRTI
- murmur
What heard on auscultation of patient with PDA?
continuous crevscendo-descrencend machinery murmur during 2nd heart sound
when might PDA first be picked up?
murmur on newborn exam
what is the gold standard investigation of PDA?
transthoracic echo + doppler (to assess size and character of L=>R shunt)
describe the management of PDA?
- monitor up until 1 yr (unless severe)
- After 1 yr it is unlikely to close spontaneously so surgery: transcatheter, open heart surgery
What is an atrial septal defect?
When the septum between the R + L atria is not formed properly?
what is the most common CHD?
VSD
(ASD is second)
describe what forms and makes up the atrial septum? ahem the layers?
2 walls grow downward to fuse with endocardial tissue to separate atria
- septum primum + septum secondum
what makes up the foramen ovale?
small space formed between septum primum + secondum
what kind of shunt does ASD cause ? cyanotic ?
LA => RA shunt (a-cyanotic)
describe what the shunt in ASD can cause?
shunt LA to RA => R sided overload + R heart strain => pulmonary hypertension + RHF => Eisenmenger Syndrome (where pulmonary pressure is greater than systemic pressure) => shunt reverse (R=>L) => cyanosis
what are the 3 types of ASD?
- Ostium primum
- Ostium Secondum
- PFO (technically not ASD)
what is the most common type of ASD?
Ostium Secundum (I think)
Patient presents with DVT that develops a large stroke. What condition should be on your mind? why?
ASD
- DVT enters systemic circulation through shunt and goes to brain
What are some complications of ASD?
- Stroke
- AF
- Atrial flutter
- Pulmonary hypertension
- R sided HF
- Eisenmenger Syndrome
ASD RF?
- Maternal smoking (1st trimester)
- Maternal diabetes
- Maternal rubella
ASD presentation? childhood?
vast majority of ASD are asymptomatic
- SOB
- Difficulty feeding
- Poor weight gain
- Recurrent LRTI
ASD presentation? Adulthood?
- Stroke
- HF
- Dyspnoea
ASD gold standard investigation ?
transthoracic echo (gold standard)
management for small ASD?
Just keep watching it
what medical management might you have for ASD? why?
anticoags (aspirin, warfarin, NOACs) to reduce stroke risk
ASD definitive management?
surgical
- transvenous Catheter (via femoral vein) or open heart surgery
What is VSD?
congenital hold in the septum between the 2 ventricles
what is VSD often associated with?
underlying genetic condition (downs, turners)
what type of shunt in VSD?
L to R shunt (acyanotic)
what does the shunt in VSD lead to?
L to R shunt => R sided overload + RHF + increased flow to pulmonary vessels => pulmonary hypertension => R to L shunt (eisenmengers) => cyanosis
VSD RF?
- genetic: Downs, Turners
- GDM
- FAS
- VSD FHx
What does septal defect presentation depend on
the size of the defect
VSD most common presentation
asymptomatic
VSD presentation in babies?
- Poor feeding
- SOB
- failure to thrive
- Tachypnoea
What heart on auscultation of ASD?
Ejection systolic murmur
Heard loudest at the upper left-sternal edge
Widely fixed splitting of the second heart sound
what heard on auscultation of VSD?
pansystollic murmur hear at L lower sternal border
What can a pan-systolic murmur indicate? (3)
- VSD
- MItral regurg
- Tricuspid regurgitaiton
Gold standard investigation for VSD?
transthoracic Echo
what complications associated with VSD?
- Increased risk of IE
- Recurrent LRTI
- Arrhymias
- Growth failure
- Congestive HF
what medications might you consider in VSD?
- Prophylactic Abx (for IE risk)
- Dieretic to relieve pulmonary congestion
When does Eisenmenger Syndrome occure
When blood can flow from R side of heart to L across structural heart lesion
- R=>L shunt means blood bypasses lungs what
3 underlying lesion can cause Eisenmenger Syndrome ?
- ASD
- VSD
- PDA
when does Eisenmenger Syndrome develop ?
can develop after 1-2 years with large shunts + adulthood with small
what condition makes Eisenmenger develop more quickly?
pregnancy so need echo check ups
what is cyanosis and what is this due to?
blue discolouration of the skin due to low level oxy sats
Eisenmenger Syndrome: what is the body’s response to chronic low oxy sats? what does this cause?
Increased RBC + haemoglobin production => polycythaemia => high blood viscosity => more prone to blood clots
what are some signs of pulmonary hypertension on examination?
- R ventricular heave
- Raised JVP
- Peripheral oedema
What are some of the signs you might see related to chronic hypoxia on examination?
- Cyanosis
- Clubbing
- Dyspnoea
- Plethoric completion (red complexion related to polycythaemia)
Pansystolic murmur: what CHD?
VSD
Mid systolic crescendo-descrecendo fixed split heart sound: what CHD?
ASD
Contiunous crescendo-descrendo machiar murmurou during 2nd heart sound: what CHD?
PDA
How does eisenmengers affect life expectancy ?
reduces life expectancy by 20 yrs
Eisengmengers management ?
heart lung transplant
Prostaglandins?
Oxygen?
What is coarctation of the aorta? usually located where?
It is a congenital condition where there is narrowing of the aortic arch (usually located around the ductus arteriosus)
what genetic condition is coarctation of the aorta often associated with?
Turners syndrome
Pathophysioloyf of coarctation of the aorta?
narrowing of aorta => decreased pressure of blood flowing to arteries distal to narrowing + increased pressure to those proximal (heart _ usually fist 3 branches of aorta
Presentation of coarctation of the aorta?
- Weak femoral pulses
- tachypnoea
- Increased work of breathing
- Poor feeding
- Grey floppy baby
what might you find on examination of baby with coarctation of the aorta ?
4 limb blood pressure (increased BP in limbs proximal to narrowing + decreased BP distally)
management of coarctation of aorta?
May live symptom free till adulthood
- If severe emergency surgery
- Prostaglandin
why use prostaglandin in critical management of coarctation of aorta?
Prostaglandin E keeps ductus arteriosus open while waits for surgery (allows bleed flow through DA into systemic circulation distal to coarctation)
What is Congenital Aortic calve stenosis? why bad?
Patients born with a narrow aortic valve => restrict blood flow from LV to aorta
how many leaflets usually in the aortic valve?
3
what are the leaflets of the aortic valve also known as?
aortic sinuses of valsalva
how many leaflets might the aortic valves of patients with congenital aortic valve stenosis have?
1,2,3 or 4 (compared to the normal 3)
how does congenital aortic valve stenosis usually present?
asymptomatic (discovered as incidental murmur on routine checkup)if
symptomatic, how would congenital aortic stenosis present?
- fatigue
- SOB
- dizziness
- Fainting
(all worse on exertion)
describe the murmur associated with congenital aortic stenosis ? hear loudest where?
ejection systolic murmur heard loudest at aortic area
- crescendo-descrenscdo character that radiates to the carotids
where is the aortic area (anatomical) ?
2nd ICS R sternal border
Congenital aortic stenosis complications:
- LV outflow tract obstruction
- HF
- Ventricular arrhythmias
- Sudden death on exertion
how may leaflets are there usually in the pulmonary valve?
3
what causes pulmonary valve stenosis?
when the 3 leaflets of the pulmonary calve develop abnormally => thicken or fuse
pulmonary valve stenosis causes a narrowing from where to where
between RV + pulmonary arteries
what condition is pulmonary valve stenosis associated with?
TOF
describe the murmur associated with pulmonary valve stenosis ?
ejection systolic murmur heard loudest in pulmonary areaw
here is the pulmonary area (anatomical)
2nd ICS L sternal border
What is ebsteins anomaly ?
congenital heart condition where the tricuspid valve is set lower in R heart (towards apex)
how does Ebstein’s affect RA + RV ?
bigger RA
smaller RV
( because lower tricuspid valve)
what septal defect is Ebstein’s anomaly associated with?
ASD
What is transposition of the Great Arteries ?
It is where the attachments of the aorta + pulmonary trunk swap (transpose)
in Transposition of the great arteries where to RV and LV pump blood to?
- RV pump blood to aorta
- LV pump blood to pulmonary vessels
why is transposition of the great arteries life threatening?
there is no connection between systems circulation + pulmonary circulation => baby will be cyanosed
what does immediate survival in transposition of the great arteries depend on?
depends on a shunt (PDA, ASD, VSD)
- allows mixing of oxy + deoxy blood
egg on string appearance seen on CXR. what condition is this?
transposition of the great arteries
what is the most common septal defect found in those with Down syndrome ?
AVSD
what CHD is most commonly associated with turners syndrome?
- Coarctation of the aorta
- Bicuspid aortic valve
where is an asd best heard?
This murmur is heard in the second intercostal space at the upper left sternal border (pulmonary area)
(same as AVSD)
In transposition of the great arteries, what is the acid-base status commonly found in these patients that requires correction? explain
Metabolic acidosis
- Distal organs have a low oxygen supply and thus respire anaerobically producing lactate
What is Infective endocarditis ?
it is infection of the endothelium (inner surface) of the heart
- Mostly effects the heart valves
what are the 3 things in the IE triad ? (things required for IE to happen)
- Endothelial damage
- Platelet adhesion
- Microbial adhesion
which bit of IE triad do CHDs increase the risk of?
structural abnormalities of heart or great vessels => endo damage by sheer stress forces
IE RF?
Mostly seen in patients with hx of congenital or acquired cardiac disease
- IVDU (quite low is this population group but higher in adults)
2 most common causative organisms for IE?
- Staphylococcus aureus
- Streptococcus viridans
IE presentation ?
(non-specific)
- Low-grade fever
- malaise
- Fatigue
what would be seen on examination for patient with IE?
- New or changing heart murmur
- Splinter haemorrhages, janeway lesions, oslers nodes, roth spots, finger clubbing, petechiae
what investigations for IE?
- Blood cultures (before Abx)
- Echo (TOE (transoesophageal))
what would be seen on echo of IE
echo (TOE)
- identify vegetations
what score can confirm IE diagnosis?
Modified duke criteria: Has major and minor criteria
IE management ?
- IV broad spectrum Abx (amoxicillin or ceftrioxone)
- Surgery: if HF, or large vegetations, or not responding to Abx
What is Acute rheumatic fever? associated with what other illness?
It is an autoimmune illness that occurs after pharyngitis in some people due to cross reactivity to streptococcus bacteria
which system does rheumatic fever affect?
Multi system disorder
- affects joints, heart, skin, nervous system
which bacteria involved in rheumatic fever? what type of bacteria is this?
group A beta-haemolytic strep (e.g. strep pyogenes)
rheumatic fever pathophysiology ? describe it
type to hypersensitivity reaction
- caused by antibodies created against strep bacteria that also target tissues in body
how long after initial infection will symptoms of rheumatic fever present?
2-4 weeks following strep infection (e.g. tonsillitis)
describe the symptoms rheumatic fever can present with 9think systems)
- Fever
- Joint: arthritis
- heart: pericarditis/myocarditis/endocarditis
- Skin: sub cutaneous nodules, erythema marginatum
- HS: chorea
describe the arthritis associated with rheumatic fever?
migratory arthritis affecting the large joints
what is used to determine a rheumatic fever diagnosis?
Jones criteria (has major - minor criteria)
what investigations would you do for rheumatic fever?
- throat swab for bacterial culture
- ASO antibody titres
- Echo, ECG, CXR (for heart involvement)
rheumatic fever management ?
- the tonsillitis caused by streptococcus should be treated with phenoxymethyl penicillin
- Clinical features of RF: NSAIDs (joint pain), aspirin and steroids (carditis), prophylactic Abx
rheumatic fever complications (3)
- Recurrence of RF
- Valvular heart disease (mitral stenosis)
- Chronic HF