Congenital Heart disease Flashcards
Why does a baby have shunts?
Blood doesnt pass through the pulmonary circulation as lungs not functional with gas exchange in mother
What are the three foetal shunts?
Ductus venosus
Foramen ovale
Ductus arteriosis
Where is the ductus venosus?
Umbilical vein to IVC
What does ductus venosus allow?
Blood to bypass RV and pulmonary circulation
Where is the foramen ovale? What does it allow to bypass?
RA and LA - allows bypass RV and pulmonary circulation
Where is the ductus arteriosis and what does it allow to bypass?
Pulmonary artery with aorta, bypasses pulmonary circulation
How does the foramen ovale ckose after birth?
First breath expands alveoli decreasing pulmonary vascular resistance -> decreased pressure in RA, which means LA has higher pressure, squashing atrial septum and closes foramen ovale
What does the foramen ovale become a few weeks after birth>
Foramen ovalis - weeks (when structurally shut)
What keeps the ductus arteriosus open?
Prostaglandins
What causes the ductus arteriosis to close?
Increased blood oxygenation -> drop in circulating prostaglandins, causing closure of ductus arteriosus
What does the ductus arteriosus become?
Ligamentum arteriosum
Why does the ductus venossu shut immediately after birth?
Umbilical cord clamped, no flow in umbilical veins
Structura;y closese in dyas -> ligamentum venosum
What to remember about presentation of PDA?
Pink and stable - breathless
When does the ductus arteriosus stop functioning vs structurally close?
Stop functioning 2-3 days after birth
Completely closes 2-3 weeks
What causes PDA?
Unclear
Prematurity high risk
Maternal infections? eg rubella
When is PDA asymptomatic?
Small - no functional problems, spontaneous closure
When do adults present with heart failure after PDA?
Undiagnosed PDA because asymptomatic
What direction does the blood flow through the PDA?
Left to right shunt
Aorta to pulmonary vessels
How does PDA lead to HF?
Increased pressure in pulmonary vessels as blood continues passing from the aorta into them
Pulmonary hypertensin
Rs heart strain
-> RV hypertrophy
Increased afterload -> LV hypertrophy
Symptoms of PDA and ASD in childhood
SOB
difficulty feed
Poor weight gain
LRTIs
Murmur heard with significatn PDAs
Continuous cresceno-decrescendo machinery murmur (may continue with second heart sound)
How to diagnose PDA?
ECHO cardiogram
Size and charcteristics of shunt
How long are patients with PDA monitored for?
Until 1 year of age
When is surgery considered for PDA and why?
sYMPTOMATIC
Evicdence of HF as direct consequence of PDA
After one year as then highly unlikely to spontaneously close
What is an atrial septal defect?
Hole in septum between artria - mizing of blood between them
Where do defects a=occur in development to ause ASD?
Problems with septum primum and septum secundum or with them fusing together or with endocardial cushion
What hole should occur in the septum secundum?
Foramen ovale
Which direction does blood move in ASD?
L to R - increased pressure in L pushes
How cna RH failure be caused by ASD?
Increased flow to R -> overload and heart strain
-> pulm hypertension and RH failure
What can pulmonary hypertension lead to long term?
Eisenmonger syndrome
What is eisenmonger syndrome?
Pulmonary pressure > systemic
Shunt reverses - R to L across ASD
Blood bypasses lungs
Patient becomes cyantoics
What could you suspect in a patient with long term ASD where they become cyanotic?
Eisenmonger syndrome - reversla in direction of ASD shunt
Most to least common ASDs
Ostium secondum (primum secundum fails to close)
Patent foramen ovale
Ostium primum -> Atrioventricular septal defect
Complications from ASD
Stroke in ctonext of VTE
Atrial fibrillation or flutter
Pulm hypertension and RSH failure
Eisenmonger syndrome
What is a DVT likely to cause in a patient with ASD?
Stroke
Why do patients with ASD have a stroke from a VTE rather than a PE?
Embolus from DVT -> RA -> LA across ASD
Clot -> LV -> aorta -> brain -> stroke
What is heard with an ASD?
Mid-systolic, crescendo-decrescendo murmur loudest at L sternal border with fized slit second heart sound
What is a fixed split S2?
Split does not change with inspriation or expiration (normally get normal split on inspiration)
Why is their a fixed split heard in ASD?
RV has more blood to empty due to shunt before pulmonary valve can close
How can ASDs present in al=dulthood?
Dyspnoea
Heart failure
Stroke
How can PDAs be treated surgically
Transcatheter
Surgical valve closure
How can ASDs be surgically fixed
Transvenous catheter closure via femoral vein
Open heart surgery
Management for ASD options
Watch and wait - small and asymtpomatic
Anticoagulatns - reduce risk clots in adults
Surgery
What colour do patients present with eisenmenger syndrome?
Blue, unstable
What underlying lesions can cause eisenmenger syndrome?
ASD
Ventricular septal defect
PDA
How long does eisenmenger syndrome take to develop large vs small shunts?
Large - 1-2 years
Small - Adulthood
When monitor for eisenmenger syndrome in pregnant women?
Develops more quickly in pregancy
history of hole in heart
ECHO
Close cardiologist monitoring
Main causes of death with eisenmengers
HF
Infection
VTE
haemorrhage
Main causes of death with eisenmengers
HF
Infection
VTE
haemorrhage
Mortality in eisenmengers
20 year reduced life expectancy
50% mortality in pregnancy
What shunts cause deoxygenation vs not
L to R shunt does NOT cause cyanosis 0 blood stull travels to lungs and is oxygenated
R to L shunt - blood is removed from pulmonary circultation, not enough gets oxygenated to provide for body -> cyanosis
Mechanism allowing chagning direction of shunt in eisenmengers?
Extra blood into R system causing pulmonary HPTN -> eventually succeeds systemic pressure, changes blood flow R to L
Allows deoxygenated blood back into the body circulation.
What does chronically loe oxygen saturations lead to?
Bone marrow responds by producing more RBCs and haemoglogbin to increase oxygen carrying capacity of blood
Leads to polycythaemia
What is polycythameia?
High conc of heamoglobin in the blood
What complexion does polycythameia give patients?
Plethoric (red)
What does polycythaemia increase the risk of?
VTE
What examination findings are linked to pulmonary hypertension?
RV heave
loud S2
Raised JVP
Peripheral oedema
What examination findings are linked to underlying atrial septal defect?
Mid systolic
crescendo-decrescendo
@ upper L sternal border
What examination findings are linked to underlying ventruclar septal defect?
Pan systolic murmur loudest @ L lower sternal border
Examination findings linked to R to L shunt and chronic hypoxia?
Cyanosis
Clubbing
Dysonoea
Plethoric complexion
Management of eisenmengers
Prevent development of increased pulmonary pressure and therefore swithcing of shunt direction
Cannot reverse once blood has changed direction at a certain pulmonary pressure
Definitive treatment - heart-lung transplant
Why don’t always offer heart lung transplant for eisenmengers
High mortality
Medical management for eisenmenger syndrome?
Oxygen - manage symptoms
Treat pulmonary HPTN eg with sildenafil
Treat arrhythmias
Treatment of polycythaemia with venesection
Prevention and treatment of thrombosis with venesection
Prevention and treatment of thrombosis with anticoagulation
Prevention of infective endocarditis using prophylactic antibiotics
What is a ventricular septal defect?
Congenital hole in septum between two ventricles - tiny to entire septum (one large ventricle)
What are VSDs often linked to
Underlying genetic condition
Commonly ass with Downs syndrome and Turners syndrome
When can VSDs be picked up?
Antenatal scans
Murmur heard during newborn baby check
Typical time for presentation of VSD
6-8 weeks
Typical symptoms of VSD
Poor feeding
Dyspnoea
Tachypnoea
FTT
What examination signs do patients with VSD have?
Pan-systolic murmur
L lower sternal border
3rd + 4th intercostal spaces
Systolic thrill on palpation
May be scattered wheeze
What murmurs can a pan systolic murmur be?
VSD
Mitral regurgitation
Trciuspid regurgitiation
Treatment for VSD?
Pulmonary HPTN or HF -> transcatherter closure via femoral vein
Open heart surgery
Or close spontaneously
What condition do you have an increased risk with VSD?
Infective endocarditis
Why offer prophylactic antibiotics in patients with VSD undergoing surgical procedures?
Against infective endocarditis as more likely to get
What condition is Turners syndrome often particuarly related to (CHD)?
cOARCTATION of the aorta
What is coarctation of the aorta?
Narrowing of the aortic arch, usually around the ducturs arteriosis
What does coarctation of the aorta cause?
Reduces pressure of blood flow to distal arteries
Increases pressure in proximal areas to narrowing eg heart and first three branches of aorta
What does weak femoral pulses in a neonate indicate?
Coarctation of the aorta
What do you perform to check for coarctation of the aorta in a newborn?
Four limb blood pressure
What is the result from 4 limb blood pressure if coarctation of the aorta?
Will reveal high BO in limbs supplied by arteries before narrowinf
Low BP in limbs supplied by arteries after the narrowing
Murmur with coarctation of the aorta?
Systolic murmur below left clavicle (left infraclavicular area) and L scapula
Coarctation may have other signs in infancy
Signs of coarctation in infancy
Tachypnoea + increased work of breathing
Weak femoral pulses
Poor feeding
Grey and floppy baby
Additiona signs with coarctation of aorta?
LV heave due to LV hypertrophy
Underdeveloped L arm where reduced flow to L subclavian artery
Underdevelopment of the legs
Collapse at 7 dyas old (when ductus arteriosus closes)
Higher BP in arms than legs
Management of coarctation of the aorta
Mild - symptom free until adulthood
Severe - emergency surgery shortly agter birth
Prostaglandin E - crticial coarctation
What use in critical coarctation of the aorta?
Prostaglandin E
What does Prostaglandin E allow in coarctation of the aorta?
Keep ductus arteriosus open while waiting for surgery - allows some blood flow through DA into systemic circulation distal to the coarctation
Surgery - correct coarctation and ligate ductus arteriosus
Which type of shunt in coarctation are more dangerous>
Post ductal because DA can be kept open in preductal to allow some systemic supply, wont really help in post ductal case
Post ductal much more likely to be fatal
What is tetralogy of fallot?
Congenital condition 4 coexisting pathologies:
-Ventricular septal defect
-Overriding aorta
-Pulmonary valve stenosis
-Right ventricular hypertrophy
What is an overriding aorta?
Aortic valve - entrance - placed further R than normal above the VSD
What happens to blood flow in overriding aorta/ how does it cause cyanosis?
RV contracts, blood sent upwards towards aorta. Blood that is sent up is from VSD area therefore mixed between ventricles, greater proportion of deoxygenated blood enters aorta from R side of heart
What does stenosis of the pulmonary valve do>
provides greater resistance against the flow of blood from the right ventricle.
What causes cyanosis in tetralogy of fallot?
Overriding aorta and pulmonary stenosis
How does pulmonary valve stenosis cause cyanosis?
Encourgaes blood to flow through VSD into aorta rather than into pulmonary vessles
What causes RV hypertrophy in tetralogy of fallot?
increased strain on right ventricle as it pump blood against the resistance of the left ventricle and pulmonary stenosis
Why are patients with tetralogy of fallot blue
Cardiac abnormalities cause R to L cardiac shunt
Blood bypasses childs lungs, stays deoxygenated when enters systemic circulation causing cyanosis
What is severity of cyanosis in tetralogy of fallot related to?
Degree of severity of pulmonary stenosis
Risk factors for tetralogy of fallto
Rubella infection
Increased age of mother >40
Alcohol in pregnancy
Diabetic mother
22q1 deletion - Di George syndrome
What CHD is 22q1 deletion - Di George syndrome ass with
Tetralogy of fallot
What will a CXR of tetraolgy of fallot show
Boot shaped heart due to R ventrular thickeing
How to investigate CHD
1st line is always ECHO
What can signal TOF in a newborn baby check?
Ejection systolic murmur caused by pulmonary stenosis
When are most cases of TOF picke up
Antenatal cns
What will severe TOF cause bfore 1?
HF
What suspect in older child with symptoms of HF
Mild tetralogy of fallit
Signs and symptoms of TOF
- Cyanosis (blue discolouration of the skin due to low oxygen saturations) – “goes blue while crying”
- Clubbing
- Poor feeding
- Poor weight gain
- Ejection systolic murmur heard loudest in the pulmonary area (second intercostal space, left sternal border)
- “Tet spells”
What is a tet spell?
Intermittent symptomatic periods where RL shunt worse
Precipitates cyanotic episode
What do children do when a tet spell occurs?
Older - squat
Ypunger - knees to chest
Encourages blood to enter the pulmonary vessels
How to medically manage a tet spell?
Supplementary oxygen
Beta blockers
IV fluids
Morphine
Na bicarbonate
Phenylephrine infusion
What can improve blood flow in pulmonary vessels in a tet spell?
Beta blockers (relax RV)
IV fluids (increase pre-load)
What can be used to treat metabolic acidosis in a tet spell?
Sodium bicarbonate
How does morphine help in a tet spell?
Decrease respiratory drive -> more effective breathing - decrease ulmonary reistance
What does phenylephrine infusion do in a tet spell?
Increase systemic vascular resistance
Emergency reaction to tet spell
Place in knee to chest position
Oxygen
Calm the child
Morphine
Sedation
What colour and stability will transposition of the great vessels present with?
Blue and unstable
What is the prognosis for tetralogy of fallot?
90% survival with surgery
Depends on severity
What is transposition of the great vessels?
Attachments of aorta and pulmonary trunk to heart are swapped -
RV -> aorta
LV -> pulmonary vessels
What conditions can transposition of the great vessels be ass with?
Ventricular septal defect
Coarctation of the aorta
Pumonary stenosis
What does immediate survival in transposition of the great vessels
A shunt - PDA, ASD, VSD
Prognosis of transposition of great vessels
Incompatible with life
When is transposition of the great vessels often picked up?
Antenatal US scans
Presntation of transposition of the great vessles
Cyanosis at birth
PDA or VSD - compensates - allows blood to mix between systemic and pulmonary
after few weeks - respiratory distress, tachycardia, poor feeding, poor weight gain and sweating
How does transposition of great vessels appear on an Xray?
Egg or potato on a string
What is initial management of transposition of the great vessles?
resus with colour, tone, breathing, keep them walm and call the paeds reg.
How is an atrial septal defect created in transposition of the great vessels?
Balloon sepostomy
Insert catheter into foramen ovale via umbilicus, inflate balloon and create large ASD
What is definitive management for transposition of great vessels?
Open heart surgery
Cardiopulmonary bypass machine perform arterial switch within few days birth
Conservative general management for CHDs
High calorie feeding
upright nursing
Supplemental oxygen
Medical management of CHDs
Diuretics
ACEis
PGE2 inhibtors - maintain PDA
Prostaglandin inhibitors - close DA (NSAIDs)
Palliative care for CHDs
Surgical Transcather
Home O2
Curative treatment for CHD
Heart transplant
Surgical
Transcatheter
Curative treatment for CHD
Heart transplant
Surgical
Transcatheter
Causes of HF in paediatrics
CHD
myocarditis
Cardiomyopathy - hyperthrophic or dilated
Endocarditis
Tacharrhtyhmias
IHD - kawasaki disease
HPTN - renal disease
High output - anaemia/thyrotoxicosis
Symptoms of HF in paeds
SOB
Sweat
coguh
poor feed
Recurrent chest infections
Palpitations
Chest pain
Lethargy
Signs of HF in paeds
Tachypnoea
Tachycardia
Heart murmur
Poor weight gain
Faltering growth
Hepatomegaly
Cool peripheries
Radio femoral delay
Thrills
Cyanosis
