儿科心脏病学先心病（32p）

Paediatric Cardiology Congenital Heart Defects Amarpal S. Bilkhu 5th Year Medical Student University of Glasgow 0705287bstudent.gla.ac.uk 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 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 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) 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 Case Scenario Investigations: ECG normal CXR cardiomegaly, enlarged pulmonary arteries and increased pulmonary vascular markings Echocardiography large ventricular septal defect USS Showing VSD, and Doppler showing left to right shunt during systole (blue) /fetal-heart.htm#VSD_(Ventricular_Septal_Defect) 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 (Eisenmengers syndrome) Case Scenario Eisenmengers 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 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 Downs syndrome/FH of congenital defects 8/1000 newborns have congenital heart defects Some associated with syndromes: Downs AVSD Turners aortic valve stenosis, coarctation of the aorta Edwards syndrome (trisomy 18) complex defects 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% 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 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 USS Showing VSD, and Doppler showing left to right shunt during systole (blue) 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 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 Downs syndrome Clinical features Commonly asymptomatic Recurrent chest infections/wheeze HF Arrhythmias in adulthood 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 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 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 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 USS Showing VSD, and Doppler showing left to right shunt during systole (blue) 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 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 USS Showing VSD, and Doppler showing left to right shunt during systole (blue) 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 USS Showing VSD, and Doppler showing left to right shunt during systole (blue) Cyanotic Complete AVSD Most commonly in children with Downs 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 Downs USS Management: HF management Surgical repair at 3-6 months 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 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 Thril