Paediatric Cardiology Congenital Heart Defects

1. Paediatric CardiologyCongenital Heart Defects Amarpal S. Bilkhu 5th Year Medical Student University of Glasgow 0705287b@student.gla.ac.uk

2. Learning Objectives • Understand basic cardiac physiology in the newborn • To describe common congenital heart defects • Recognise the clinical features of congenital heart defects • Understand the management options available • To be able to perform CV examination and detect congenital defects in children

3. Case Scenario • 6 week old baby girl presents in A&E with difficulty feeding, wheezing and poor weight gain for the past couple of weeks • She can become breathless, cries alot and sweats whilst feeding and becomes irritable • Routine neonatal examination was normal • No other significant history

4. Case Scenario • On examination: • RR – 55 breaths/min • HR – 180 beats/min • Respiratory: • Subcostal and intercostal recessions • No cyanosis, but cold peripheries • Wheeze throughout lung fields • CVS: • Thrill • Loud pansystolic murmur at the lower left sternal edge, accentuated 2nd heart sound • Pulses normal (femoral pulses present)

5. Case Scenario • On examination: • Abdomen: • Liver edge palpable about 2 fingerbreadths below the costal margin • No other masses felt • Clinical features suggestive of heart failure

6. Case Scenario • Investigations: • ECG – normal • CXR – cardiomegaly, enlarged pulmonary arteries and increased pulmonary vascular markings • Echocardiography – large ventricular septal defect

7. USS Showing VSD, and Doppler showing left to right shunt during systole (blue) http://www.ultrasound-images.com/fetal-heart.htm#VSD_(Ventricular_Septal_Defect)

8. Case Scenario • Diagnosis – heart failure due to VSD • Management: • Diuretics for heart failure • Often combined with ACE inhibitors – captopril • Support nutrition via NG feeds to prevent weight faltering • Definitive management is through surgical closure of the VSD • Normally performed at around 3-6 months of age to manage HF, encourage growth and prevent pulmonary complications (Eisenmenger’s syndrome)

9. Case Scenario • Eisenmenger’s syndrome • If VSD with left  right shunts left untreated • Chronically raised pulmonary arterial pressure leads to increased pulmonary vascular resistance • May lead to heart-lung transplant in the second decade of life

10. Congenital Heart Defects • Most now identified on antenatal USS • Fetal anomaly scan performed at 18-20 weeks gestation • USS is the mainstay of diagnostic imaging • At risk newborn babies are always checked e.g. Those with Down’s syndrome/FH of congenital defects • 8/1000 newborns have congenital heart defects • Some associated with syndromes: • Down’s – AVSD • Turner’s – aortic valve stenosis, coarctation of the aorta • Edward’s syndrome (trisomy 18) – complex defects

11. Congenital Heart Defects • Commonly divided into acyanotic and cyanotic • 9 common conditions ACYANOTIC LEFT  RIGHT SHUNTS Ventricular septal defect (30%) Patent ductus arteriosus (12%) Atrial septal defect (7%) OUTFLOW OBSTRUCTION Pulmonary stenosis (7%) Aortic stenosis (5%) Coarctation of the aorta (5%) CYANOTIC Tetralogy of Fallot (5%) Transposition of the great arteries (5%) Atrioventricular septal defect – complete (2%) Other complex – 20%

12. Acyanotic - VSDs • Most common congenital heart defect, 2/1000 births • Usually in the membranous part of the septum • Classified by size: • Small – asymptomatic which normally close spontaneously. May have a thrill, pansystolic murmur at the LLSE • Large – same/bigger than aortic valve. Present with breathlessness, HF, failure to thrive, difficulty feeding, recurrent chest infections after 1 week of age

13. Acyanotic - PDA • Patent ductus arteriosus – when the ductus arteriosus does not close within 72 hours of birth (normally within 48 hours) • Most common in preterm infants • Normally kept open due to low fetal systemic arterial oxygen tension (PaO2) and elevated circulating prostaglandins (from placenta and lungs) • At birth, PaO2 increases, and PG synthesis/supply falls  contraction of oxygen and PG sensitive smooth muscle in the ductus arteriosus

14. USS Showing VSD, and Doppler showing left to right shunt during systole (blue)

15. Acyanotic - PDA • Clinical features: • Continuous ‘machinery’ murmur beneath left clavicle • Increase pulse pressure  bounding/collapsing pulse • HF/pulmonary hypertension in rare, severe cases • Investigations • ECG and CXR usually normal. If large – resembles large VSD • USS to confirm • Management: • Medical – prostaglandin inhibitor, indomethacin (NSAID – reduces PG synthesis) • Surgical ligation or occlusion via cardiac catheter at about 1 year of age

16. Acyanotic - ASD • Two types: • Secundum ASD (80%) • Defect in centre of atrial septum involving foramen ovale# • Foramen ovale closes when baby takes first breath due to increased left atrial pressure • Partial atrioventricular septal defect • Associated with Down’s syndrome • Clinical features • Commonly asymptomatic • Recurrent chest infections/wheeze • HF • Arrhythmias in adulthood

17. Acyanotic - ASD • Clinical features (contd) • Ejection systolic murmur left upper sternal edge • Investigations • CXR – cardiomegaly, enlarged pulmonary arteries, increased pulmonary vascular markings • ECG – partial right bundle branch block with secundum ASD • Partial AVSD – left axis deviatrion (due to defect of AV node) • Management • Occlusion via cardiac catheterisation for secundum • AVSD – open surgical repair at around 3-5 years of age

18. Acyanotic - PS • Pulmonary stenosis – partial fusion of pulmonary valve leaflets • Clinical features: • Mostly asymptomatic • Ejection systolic murmur at upper left sternal edge • Soft/absent S2 • Prolonged RV impulse with delayed valve closure in severe cases • Investigations: • ECG – RVH, CXR – post-stenotic dilation of PA may be seen • Management • Transcatheter balloon dilatation when presssue gradient >64 mmHg

19. Acyanotic - AS • Aortic stenosis – partial fusion of aortic valve leaflets (1-3 leaflets) • Clinical features: • Asymptomatic • Chest pain, syncope, reduced exercise tolerance if severe • Low volume, slow rising pulses • Carotid thrill • Ejection systolic murmur at R sternal edge  neck • Investigations: • ECG – LVH, CXR – post-stenotic dilation of aorta may be seen • Management • Transcatheter balloon valvotomy when presssue gradient >64 mmHg

20. Acyanotic - Coarctation • Coarctation of the aorta – constriction in the diameter of the aorta, most usually after the site of the ductus arteriosus • Clinical features: • Can present as neonatal collapse • HF • Weak/absent femoral pulses • In adults: raised BP (particularly R arm), radio-femoral delay, ejection systolic murmur • Management: • Stenting • Surgical repair

21. USS Showing VSD, and Doppler showing left to right shunt during systole (blue)

22. Cyanotic - TOF • Tetralogy of Fallot, most common cyanotic condition • Large VSD • Overriding aorta • Subpulmonary stenosis • Right ventricular hypertrophy • Normally diagnosed antenatally or through murmur in early life. Some present with severe cyanosis in the first few days • Hypercyanotic spells on squatting, feeding etc is now rarer due to early detection • Clinical features: • Clubbing of fingers and toes • Loud harsh ejection systolic murmur at left sternal edge from day 1 • During hypercyanosis, murmur will be quieter/inaudible

23. Cyanotic - TOF • Investigations: • CXR – boot shaped heart (upturned apex due to RVH) • ECG – RVH • Management • Initially medical • Surgical at around 6 months • Cyanosed neonates require a shunt • Hypercyanotic spells > 15 mins: • Sedation and pain relief with morphine • IV propanolol • IV fluids • Bicarbonate to correct acidosis • Ventilation – reduced metabolic demand

24. USS Showing VSD, and Doppler showing left to right shunt during systole (blue)

25. Cyanotic - Transposition • Transposition of the great arteries – aorta connected to the RV, pulmonary artery connected to the LV • Incompatible with life if no mixing of blood – however, often ASD, VSD etc occurring with it • Clinical features: • Cyanosis – profound • Presents day 1-2 of life due to duct closure – reduced mixing • Presentation delayed if there is VSD etc • Single S2 • Investigations • CXR – narrow mediastinum, ‘egg on side’ appearance of cardiac shadow • ECG – usually normal • Management: • PG infusion in neonates to maintain ductus arteriosus patency • Balloon atrial septostomy • Arterial switch surgery in the first few days of life

26. USS Showing VSD, and Doppler showing left to right shunt during systole (blue)

27. Cyanotic – Complete AVSD • Most commonly in children with Down’s syndrome • Septal defect in the middle of the heart with a 5 leaflet valve between the atria and ventricles • HF or cyanosis at 2-3 weeks of life • Usually picked up on antenatal screening/routine Down’s USS • Management: • HF management • Surgical repair at 3-6 months

28. CV Examination Checklist • Initial observations: • Develop rapport with child • Sick or well? • Dysmorphism • Growth and milestones • NG tubes, O2, TPN etc • Inspection • Colour – pallor/cyanosis (central and peripheral) • Clubbing of toes/fingers • Respiratory distress? • Precordial bulge – cardiac enlargement • Ventricular impulse – LVH/hyperdynamic circulation • Scars – sternotomy/left lateral thoracotomy

29. CV Examination Checklist • Palpation • Brachial pulses bilaterally – rate, rhythm, volume • Femoral pulses • Apex beat – 4th/5th intercostal space, mid-clavicular line • Heaves – subxiphoid heave in babies for RVH • Thrills – suprasternal thrill – aortic stenosis • Liver edge – normally 1-2cm below costal margin in infants – enlarged in HF • Auscultation • Diaphragm and bell, praecordium, lung bases, axillae • S1 may be normally split, S2 normally split, S3 can be normal, S4 always abnormal

30. CV Examination Checklist • Murmurs • Loudness graded 1-6. Presence of thrill > 4 • Timing – systolic/diastolic • Duration – ejection/mid/pansystolic • Site where loudest • Radiation • At end of examination • Palpate abdomen • Measure BP • Sacral/lower limb oedema • Nutritional status – state you would like to plot height and weight on a growth chart

31. Signs of HF Poor feeding Failure to thrive Sweating Tachypnoea Tachycardia Gallop rhythm Cardiomegaly Hepatomegaly

32. Innocent Murmurs • Can be heard in 30% of children at some time • Can be ejection murmur or venous hum (turbulent flow in head and neck veins – continuous low pitched rumble beneath clavicles) • Hallmark features: • Asymptomatic • No thrills/heaves • Soft systolic • Varies with position • Localised • Normal heart sounds