Cardiology Flashcards
Name three shunts facilitating transfer of waste (Co2, lactate) and nutrients (oxygen etc.) in the foetal circulation?
- Ductus venosus
- Foramen ovale
- Ductus arteriosus
What does the ductus venosus facilitate?
Blood to bypass the liver:
Umbilical vein –> IVC
What does the foramen ovale facilitate?
Blood to bypass the RV and pulmonary circulation
Right –> Left atrium
What does the ductus arteriosus facilitate?
Blood to bypass the pulmonary circulation
Pulmonary artery –> aorta
What does the ductus venosus become at birth?
Ligamentum venosum
What does the ductus arteriosus become at birth?
Ligamentum arteriosum
How does the ductus arteriosus become X at birth?
Becomes ligamentum arteriosum by increased blood oxygenation causing drop of circulating prostaglandins
What does the foramen ovale become at birth?
Fossa ovalis
How does the foramen ovale become the fossa ovalis at birth?
- 1st breath expands alveoli
- Decreases PVR
- Causes fall in RAP
- LAP > RAP
- Atrial septum squashed
- Foramen ovale forced shut
What is a patent ductus arteriosus?
Failure of ductus arteriosus to close (normally does so in 1st 2-3 weeks of life)
Patent ductus arteriosus pathophysiological process (and which direction the shunt is):
- Aorta Pa > pulmonary vessels Pa
- Left to right shunt (blood flow from aorta to pulmonary artery)
- Pulmonary hypertension
- RS heart strain as contract against greater resistance
- RVH
- LVH
Clinical presentation of baby with patent ductus arteriosus?
Note: some patients ASx until adulthood when they present in HF
SOB, poor WG and feeding, lower RTI
What murmur is heard in patent ductus arteriosus?
Normal 1st heart sound with continuous crescendo-decrescendo “machinery” murmur :. 2nd heart sound hard to hear.
How do you diagnose patent ductus arteriosus?
Echocardiogram
Assess effect on heart and L –> R shunt
Management for patent ductus arteriosus?
Monitor until 1 year old, hoping spontaneous closure
Trans-catheter or surgical closure
What is an atrial septal defect?
Defect in septum between two atria
Simple pathophysiology of atrial septal defects?
Septum primum and septum secundum should fuse with endocardial cushion to separate atria, but do not which is ASD
Pathophysiology of atrial septal defects? Think about the process (and which direction the shunt is)
- Septum primum and septum secundum do not fuse with endocardial cushion to separate atria
- LAP > RAP
- Left to right shunt
- Blood continues to flow to pulmonary vessels and lungs for oxygenation
- Yet leads to RHS overload and strain
–> 6. PH and RSHF
What can atrial septal defects result in as a secondary complication (name of the syndrome and what is occurring)?
Eisenmenger syndrome - shunt reversal to be right to left and bypassing the lungs
Why might a patient with an atrial septal defect suffer a stroke? (previously ASx and undetected)
- Clot to the RHS of the heart
- Then goes to the lungs becoming a pulmonary embolus
- Back to heart then through the right to the left atrium across the septal defect
- Clot to RV, aorta then brain
- STROKE
Complications of atrial septal defect?
Stroke, Eisenmenger syndrome (reversal of left to right shunt to become right to left), PH, RSHF, AF
What is the murmur associated with atrial septal defect?
Mid-systolic, crescendo-decrescendo murmur at upper left sternal border with fixed split-second heart sound.
Clinical presentation of atrial septal defect?
Infant and adult separately
Infant: SOB, difficulty feeding, poor WG, lower RTI
Adult: Dyspnoea, HF, stroke
Management of atrial septal defect? Paeds and adults
Paeds: Transvenous catheter closure - correction, or open-heart surgery
Adults: Anticoagulants (aspirin, warfarin, NOACs).
Why does Eisenmenger Syndrome occur for ASD?
Reversal of left to right shunt to be R to L, due to pulmonary pressure being greater than the systemic pressure.
Patient cyanotic
What are the three classifications of ASD?
Ostium secondum
Patent foramen ovale (though not strictly a ASD)
Ostium primum
Pathophysiology of ventricular septal defect (what does it lead to)?
- Hole between the ventricles
- Left to right blood flow due to increased LV pressure
- Acyanotic as blood still oxygenated
- Long-term pressure rise; right>left so right to left shunt occurs (Eisenmenger syndrome)
Clinical presentation of ventricular septal defect?
Failure to thrive
Poor feed
Dysnpnoea
ASx; often pick up later when progress to PH, RSHF, RS overload.
What are the long-term complications of ventricular septal defect?
RHF, right side overload, PH.
What is the murmur observed in ventricular septal defect?
Pan-systolic at left lower sternal border in 3rd/4th ICS.
Treatment for VSD?
Watchful wait - spont. closure
Surgical - tranvenous cath., open heart surgery
Abx Px due to high IE risk
What is coarctation of the aorta?
Narrowing of aortic arch around the ductus arteriosus
What infection are ventricular septal defect babies at risk of?
Infective endocarditis
Pathophysiology of coarctation of the aorta?
- Reduces pressure of blood flowing to arteries distal to narrowing
- Increases pressure of blood in area proximal to narrowing e.g. heart and aorta three branches
Clinical presentation of coarctation of aorta?
- Pulses
- Limbs
- Murmur
- Baby looks like
- Weak femoral pulses
- Four limb blood pressure - higher in arteries pre-narrowing, lower in arteries post-narrowing
- Systolic murmur in left infraclavicular area
- Grey, floppy, poor feed, underdeveloped, increased work of breathing. Left vent heave
What is given to keep the ductus arteriosus open whilst a baby with coarctation of the aorta awaits surgery?
Prostaglandin E
What is congenital aortic valve stenosis?
Narrow aortic valve restricting blood flow from the LV into the aorta
Gold standard diagnosis for congenital heart defect, especially congenital aortic valve stenosis?
Echocardiogram
What murmur is observed in congenital aortic valve stenosis?
Ejection systolic murmur loudest at 2nd IC, right sternal border
Crescendo-decrescendo radiating to carotids
Palpable thrill, slow rising pulse, ejection click
What murmur is associated with pulmonary stenosis?
Ejection systolic loudest at pulmonary area (2nd IC, left sternal border)
What occurs in congenital pulmonary stenosis?
3 pulmonary leaflets thicken and fused resulting in narrow opening between RV and PA
Treatment for significant congenital pulmonary stenosis?
Balloon valvuloplasty via venous catheter (dilation of valve by balloon inflation)
What causes Eisenmenger’s syndrome?
Atrial septal defect (ASD), patent ductus arteriosus (PDA), ventral septal defect (VSD).
Pathophysiology Eisenmenger’s syndrome?
- ASD, VSD so left –> right shunt
- Pulmonary hypertension
- Eventually pulmonary Pa > systemic Pa
- Right –> left shunt
What examination findings result from the right to left shunt observed in Eisenmenger’s syndrome?
Cyanosis, clubbing, dyspnoea, plethoric complexion
Also RV heave, raised JVP, loud P2
Complications of Eisenmenger’s syndrome?
HF, infection, TE, haemorrhage
Management of Eisenmenger’s syndrome?
PH, polycythemia, other?
Heart-lung transplant (high mortality)
Sildenafil for PH, prophylactic antibiotics, venesection, treat arrythmia.
What are the four co-existing pathologies of tetralogy of the fallot?
- Ventral septal defect
- Overriding aorta
- Pulmonary valve stenosis (causes RV outflow tract obstruction)
- RVH
Cyanotic congenital heart disease due to which direction shunt?
Right to left so blood does not pass through the lungs to become oxygenated
What is a tet spell?
Child squatting to increase SVR
Tetralogy of fallot murmur?
Loud, harsh ejection systolic murmur at left sternal edge
A child in a tet spell undergoing activity will have what Sx?
SOB, increased cyanosis, LoC, irritable
–>risk of hypoxic brain injury
What physiological process occurs during a tet spell?
- Exercise generates carbon dioxide (vasodilator)
- Vasodilator causes systemic vasodilation
- Reduced SVR
- Blood takes path of least resistance
- RV to aorta (not pulmonary vessels) so is oxygen deficient
Tetralogy of fallot investigations on chest radiography/
Small heart
RVH causing uptilted apex
Decreased pulmonary vascular markings
What is the gold standard to diagnose tetralogy of the fallot?
Echocardiography
How do you treat tetralogy of the fallot ‘tet’ spell?
- Supplementary oxygen
- Beta blockers (IV propranolol) to relax RV to increase flow to pulmonary vessels.
- Morphine: decrease respiratory drive and more effective breathing
- Sodium bicarbonate - buffer metabolic acidosis.
Tetralogy of fallot, what occurs at 6 months old?
Open heart surgery for total surgical repair
What occurs in transposition of the great arteries?
Aorta is connected to the RV
Pulmonary artery connected to the LV
What are the clinical features of transposition of the great arteries?
Cyanosis - on day 2 of life the ductal closure leads to the mixing of blood resulting in associated abnormalities
Single 2nd heart sound, no murmur usually
In transposition of the great arteries what is observed in chest radiography?
- Narrow upper mediastinum with egg on side appearance
- Increased pulmonary vascular markings due to increased BF
What other investigations are required to diagnose transposition of the great arteries?
Ultrasound, ECG, echocardiogram
Management of transposition of great arteries? (and why)
- PROSTAGLANDIN INFUSION - maintain ductus arteriosus to allow blood flow to the pulmonary arteries for oxygenation
- BALLOON SEPTOSTOMY - large ASD created; allows blood to return to the lungs
- OPEN HEART SURGERY - cardiopulmonary bypass machine performs arterial switch (w/in few days of birth)
What is hypoplastic LH syndrome?
Underdevelopment of the left side of the heart
What will detect hypoplastic LH syndrome?
Antenatal USS screening
Describe the physiology that is characteristic of hypoplastic left heart syndrome:
Mitral valve small or atresia (lacks opening)
LV diminutive
Aortic valve atresia
What are the names of the three operations and when which are carried out to treat hypoplastic left heart syndrome:
Neonatal operation - Norwood procedure
6-month operation - Glenn or hemi-Fontan
3 year operation - Fontan
Pulses in hypoplastic left heart syndrome?
Weakness or absence of all peripheral pulses
What are the 4xSs of innocent murmurs?
Soft
Systolic
aSymptomatic
left Sternal edge
What are some possible signs of HF in an neonate, infant or adolescent?
Poor feed
Poor weight gain, faltering growth
Breathlessness
Sweating
Recurrent chest infection
Tachypnoea, tachycardia
Hepatomegaly
Cardiomegaly
Cool peripheries
What causes rheumatic fever?
Abnormal immune response to a preceding infection with group A beta-haemolytic steptococcus (e.g. tonsillitis)
How long after a previous Beta-haemolytic strep infection is rheumatic fever observed?
2-4 weeks and is multisystemic
What is the clinical presentation of rheumatic fever (give 4 regions which are involved)?
- Joint involvement: migratory arthritis
- Heart involvement: carditis leading to tachycardia, bradycardia, murmurs, pericardial rub on auscultation, HF
- Skin involvement: SC nodules, erythema marginatum rash
- Nervous system involvement: Sydenham chorea
Jones criteria for rheumatic fever diagnosis major criteria:
J - joint arthritis
O - organ inflammation e.g. carditis
N - nodules
E - erythema marginatum rash
S - Sydenham chorea
Jones criteria for rheumatic fever diagnosis minor criteria:
F - fever
E - ECG changes without carditis - prolonged PR interval
A - arthralgia without arthritis
R - raised inflammatory markers (CRP and ESR)
What is required for a diagnosis of rheumatic fever?
2 major or 1 major and 2 minor
What are the Jones criteria for diagnosis of rheumatic fever
Major:
J - joint arthritis
O - organ inflammation (carditis)
N - nodules
E - erythema marginatum rash
S - Sydenham chorea
Minor:
F - fever
E - ECG changes w/out carditis - prolonged PR interval
A - arthralgia w/out arthritis
R - raised inflam. markers (CRP, ESR)
Treatment for rheumatic fever?
Abx, then consider other issues associated
- Penicillin V - phenoxymethylpenicillin
- NSAIDs for joint pain
- Aspirin and steroids to treat carditis
- Prophylactic antibodies: PO/IM penicillin to prevent future streptococcal infections and recurrence of RF
What are risk factors for infective endocarditis in infants? (x2)
- Turbulent jet blood (due to VSD, coarctation of aorta, persistent ductus arteriosus)
- Prosthetic material inserted at surgery
What causes infective endocarditis?
Alpha-haemolytic streptococcus (strep viridans)
What are signs of infective endocarditis?
Splinter hemorrhage
Janeway lesion
Osler’s nodes
Roth spots
Finger clubbing
Splenomegaly
New or changing heart murmur
Petechiae
Fever, anaemia, pallor, malaise
What is the management of infective endocarditis?
Treat with high dose PENICILLIN in combination with aminoglycoside (6 wks IV therapy and check serum levels of abx)
What should be given if a patient is suffering from a supraventricular tachycardia?
IV adenosine, vagal stimulating manoeuvres
What is observed on ECG for supraventricular tachycardia?
Narrow complex tachycardia, p waves after QRS complex. T wave inversion visible in lateral precordial waves
What is required for congenital heart block patients who are symptomatic?
Endocardial pacemaker
Which antibodies in the maternal serum is congenital heart block related to?
anti-Ro or anti-La antibodies
What is the purpose of a prostaglandin infusion in a paediatric patient?
Keep the ductus arteriosus patent to promote the mixing of the systemic and pulmonary circulation blood to maintain peripheral perfusion (prior to balloon angioplasty and surgery)
