Paeds - Cardiology

Question 1

Murmurs

Innocent Murmurs
Ejection Systolic Murmurs
Pan-Systolic Murmurs
Other Murmurs

Answer 1

1. ) Innocent Murmurs - due to fast blood flow through various areas of the heart during systole
   - very common in children, typical features are (S’s):
   - soft, short, systolic, symptomless, situational
   - they may not require any investigations
   - features of a pathological murmur: loud (>2/6), diastolic, louder on standing, radiates, failure to thrive, poor feeding, cyanosis or SOB
2. ) Ejection Systolic Murmurs - loud in respective areas
   - aortic or pulmonary stenosis
   - HOCM: loudest at the 4th ICS, left sternal border (tricuspid region)
3. ) Pan-Systolic Murmurs - loud in respective areas
   - mitral or tricuspid regurgitation
   - VSD: loudest at the left lower sternal border
4. ) Other Murmurs
   - ASD: mid-systolic murmur loudest at the upper left sternal border, with a fixed split second heart sound
   - PDA (large): continuous/diastolic machinery murmur in the left upper sternal border
   - Tetralogy of Fallot: pulmonary stenosis is the loudest
   - aortic coarctation: crescendo-decrescendo murmur in the upper left sternal border

Question 2

Patent Ductus Arteriosus (PDA)

Pathophysiology
Clinical Features
Effects of PDA on the Heart
Management

Answer 2

1. ) Pathophysiology - failure of the DA to completely close within the first 2-3wks of life (normally stops functioning within 1-3 days of birth)
   - acyanotic heart condition: L–>R shunt
   - risk factors: prematurity, maternal infection, genetics
2. ) Clinical Features
   - SOB, poor feeding, poor weight gain, LRTIs
   - continuous machinery murmur that may make the second heart sound difficult to hear
   - left sub-clavicular thrill, heaving apex beat
   - pulse: large volume, bounding, collapsing, wide pulse pressure
   - a small PDA can be asymptomatic in childhood but may present in adulthood with signs of heart failure
3. ) Effects of PDA on the Heart
   - L–>R shunt increases the pressure in the pulmonary vessels –> pulmonary HTN –> RV hypertrophy
   - increased blood flow returning to the left side of the heart leads to left ventricular hypertrophy
   - Eisenmenger’s syndrome can occur if the pulmonary pressure > systemic pressure, causing blood to flow from R–>L which causes cyanosis
4. ) Management
   - diagnosis can be confirmed by an ECHO
   - ibuprofen/indomethacin (NSAIDs) is given to symptomatic neonates after having an ECHO to inhibit prostaglandins to close the PDA
   - if asymptomatic, monitor for 1yr using ECHO, after 1yr, if still persistent, intervention can be performed
   - tx symptomatic patients or those with evidence of HF with transcatheter or surgical closure of the PDA

Question 3

Atrial Septal Defect (ASD)

Pathophysiology
Clinical Features
Complications
Management

Answer 3

1. ) Pathophysiology - a hole in the atrial septum allows blood to flow from the left –> right atrium (acyanotic)
   - failure of the septum primum or secundum to fully close leaves a hole (ostium primum or secundum)
   - PFO is a form of an ASD
2. ) Clinical Features - majority often asymptomatic
   - often picked up on antenatal scans and the NIPE
   - murmur: mid-systolic murmur loudest at the upper left sternal border with a fixed split second heart sound (fixed means during inspiration and expiration, split is the delay between closure of the aortic and pulmonary valve)
   - sx in childhood (if large): SOB, poor feeding, poor weight gain, recurrent lower respiratory tract infections
   - may present in adulthood w/ SOB, HF or stroke
3. ) Complications
   - stroke/TIA forms instead of a PE from a DVT/VTE
   - AF/flutter, pulmonary HTN + right-sided HF
   - Eisenmenger’s syndrome
4. ) Management - refer to a paediatric cardiologist
   - watchful waiting: for small (<5mm)/asymptomatic
   - surgical correction: if large (>1cm), can use transvenous catheter closure or open-heart surgery
   - anticoagulants used to ↓ the risk of clots and strokes

Question 4

Ventricular Septal Defect

Pathophysiology
Clinical Features
Management

Answer 4

1. ) Pathophysiology - a hole in the ventricular septum (often membranous portion) allows blood to flow from the left to right ventricle (acyanotic), most common CHD
   - vary in size, can be tiny or can be the entire septum
   - L–>R shunt –> Rsided overload –> Rsided HF
   - risk factors: trisomy 21/18/13, Turner’s syndrome, maternal DM/rubella/PKU, foetal alcohol syndrome
2. ) Clinical Features - majority often asymptomatic
   - often picked up on antenatal scans and the NIPE
   - pan-systolic murmur loudest in the 3rd/4th ICS left sternal edge, there may be a palpable systolic thrill
   - sx: SOB, ↑RR, poor feeding, poor weight gain, recurrent chest infections, cyanosis (Eisenmenger’s)
   - may present later on in adulthood
3. ) Management - refer to a paediatric cardiologist
   - watchful waiting: if small/asymptomatic
   - consider diuretics and ACEi for HF
   - surgical correction: if symptomatic, can use transvenous catheter closure or open-heart surgery
   - consider antibiotic prophylaxis during surgical procedures due to the ↑risk of infective endocarditis

Question 5

Eisenmenger’s Syndrome

Pathophysiology
Cyanosis
Clinical Features
Management

Answer 5

1. ) Pathophysiology - pulmonary HTN reverses shunt direction across a CHD (ASD/VSD/PDA) when the pulmonary pressure exceeds the systemic pressure
   - this causes cyanosis because deoxygenated blood can now bypass the lungs and enter the body
   - can develop after 1-2yrs w/ large shunts or as an adult with small shunts, develops quicker in pregnancy
2. ) Cyanosis - blue discolouration of skin relating to a low level of oxygen saturation in the blood
   - bone marrow responds to ↑Hb –> polycythemia
   - polycythemia gives a patient a plethoric complexion
   - polycythemia also makes blood more viscous, making patients more prone to developing blood clots
3. ) Clinical Features
   - chronic hypoxia: cyanosis, SOB, plethora, clubbing
   - a murmur of the CHD (ASD, VSD or PDA)
   - pulmonary HTN: ↑JVP, peripheral oedema, RV heave and loud 2nd heart sound (pulmonary valve closing)
4. ) Management
   - correction of the underlying defect
   - O2 therapy, treatment of pulmonary HTN (e.g. sildenafil), arrhythmias, venesection to tx polycythemia
   - anticoagulation to prevent/treat thrombosis
   - prophylactic abx to prevent infective endocarditis
   - cannot reverse the condition, the only definitive treatment is a heart-lung transplant (high mortality)

Question 6

Aortic Coarctation

Pathophysiology
Clinical Features
Management

Answer 6

1. ) Pathophysiology - narrowing of the aortic arch, usually around the DA reduces the pressure of blood flow to the arteries distal to the narrowing
   - ↑pressure in the heart and 1st three aortic branches
   - the severity can vary from mild to severe
   - often associated with esp Turners syndrome
2. ) Clinical Features
   - weak femoral pulses in the neonate
   - 4 limb BP reveals higher BP in the limbs supplied from arteries that come before the narrowing
   - may be a systolic murmur in left infraclavicular area
   - other sx in infancy: ↑RR, poor feeding, grey, floppy
   - additional signs overtime: LV heave (hypertrophy), underdeveloped left side and legs (↓blood flow)
3. ) Management
   - mild: can be asymptomatic until adulthood
   - severe: may require emergency surgery after birth, prostaglandin E1 used to keep DA open whilst waiting for surgery

Question 7

Tetralogy of Fallot

Pathophysiology
Clinical Features
Tet Spells
Management

Answer 7

1. ) Pathophysiology - cyanotic CHD w/ VSD, overriding aorta, pulmonary valve stenosis and RV hypertrophy
   - pulmonary valve stenosis creates an ‘Eisenmenger’ effect with the VSD (the main cause of the cyanosis)
   - ↑pressure in the RV –> RV hypertrophy
   - overriding aorta: aortic valve sits above the VSD so blood in the RV can enter the aorta –> aids cyanosis
   - maternal risk factors: rubella infection, increased age (>40), alcohol consumption, diabetes (GDM)
2. ) Clinical Features
   - majority are picked up on antenatal scans
   - ejection systolic murmur due to pulmonary stenosis
   - sx: cyanosis, clubbing, poor feeding/weight gain, ‘tet’ spells
   - can present as HF before <1yrs in severe cases
3. ) Tet Spells - intermittent hypoxic episodes due to worsening of the R–>L shunt (can be life-threatening)
   - due to ↑pulmonary resistance/↓systemic resistance often from prolonged crying, dehydration, anaemia
   - sx: cyanosis, SOB, irritability, severe spells can cause reduced consciousness, seizures and potentially death
   - Mx: squatting or knee-chest position, O2, propranolol (relaxes RV), IV fluids (↑pre-load), morphine (↓resp drive), sodium bicarbonate, phenylephrine infusion
4. ) Management
   - diagnosed w/ an ECHO, a CXR may show a boot-shaped heart due to RV thickening
   - prostaglandin E1 in neonates to keep the DA open
   - definitive tx is an open heart surgery (5% mortality)
   - prognosis is poor w/o treatment, with corrective surgery, 90% of patients will live into adulthood
   - complications: polycythaemia, cerebral abscess, stroke, infective endocarditis, congestive HF, death

Question 8

Transposition of the Great Arteries (TGA)

Pathophysiology
Clinical Features
Management

Answer 8

1. ) Pathophysiology - cyanotic CHD, the RV attaches to the aorta and the LV attaches to the PA, creating a parallel systemic and pulmonary circulation
   - viable in utero as gas and nutrient exchange occurs in the placenta, immediately life-threatening at birth
   - risk factors: M>F, maternal age >40, GDM, rubella, poor maternal nutrition and alcohol consumption
   - can be associated w/ a VSD, pulmonary stenosis, aortic coarctation and tricuspid atresia
2. ) Clinical Features - often picked up on antenatal US
   - cyanosis at birth or within a few days of birth, TGA is the most common cause of cyanosis in a newborn
   - can initially compensate if a PDA or VSD is present
   - develop signs of congestive HF within a few weeks:
   - resp distress, tachycardia, tachypnoea, sweating, poor feeding/weight gain, failure to thrive
   - hyperoxia test will be positive (<15kPa)
3. ) Management
   - once picked up on the US, labour should happen at a hospital that can manage the condition after birth
   - survival is dependent on a shunt between the two circulations i.e. PDA, ASD/PFO or VSD
   - initial Mx: prostaglandin E1 infusion (keep DA open), atrial balloon septostomy (create large ASD)
   - definitive Mx: is an arterial switch procedure (open-heart surgery) before the age of 4 weeks

Question 9

Congenital Heart Diseases

Cyanotic
Acyanotic 
Common Clinical Features
Investigations
Management

Answer 9

1. ) Cyanotic
   - tetralogy of Fallot (most common), transposition of the great arteries (most common at birth)
   - tricuspid atresia, hypoplastic left heart syndrome
   - pulmonary valve stenosis (often just asymptomatic)
   - Ebstein’s anomaly: RA bigger than RV, coupled w/ an ASD causes an R–>L shunt, associated with WPW
2. ) Acyanotic - VSD (most common), ASD/PFO, PDA
   - can all become cyanotic in Eisenmenger’s syndrome
   - aortic valve stenosis
3. ) Common Clinical Features
   - initial sx: SOB, poor feeding, poor weight gain, recurrent chest infections, cyanosis (dependent obv)
   - acyanotic all associated with a type of murmur
   - signs of heart failure may show up often later on: ↑HR, ↑RR, sweating, respiratory distress, hepatomegaly (due to venous congestion)
4. ) Investigations
   - many are picked on the antenatal ultrasound scan
   - pulse oximetry: cyanosis in cyanotic conditions, may show a difference in pre-ductal and post-ductal SATS
   - hyperoxia test: differentiates cyanosis due to CHD or lung disease, in CHD, pO2 after 15 minutes of 100% oxygen is <15kPa, would be >15kPa if a lung problem
   - imaging: echocardiogram is often used for diagnosis, a CXR or an ECG may show some additional signs
5. ) Management
   - all duct dependent CHDs are temporarily managed with a prostaglandin E1 infusion to keep the DA open
   - definitive management is often surgical correction