Paed Cardio Flashcards
CHD Incidence
-Incidence 6-8/1000 live births
-80-85% now survive to adulthood
-VSD: 30%
-ASD: 10%
-Pulmonary stenosis: 10%
-PDA: 7%
-Coarctation: 7%
-Tetralogy of Fallot: 7%
-Aortic stenosis: 5%
-Transposition (TGA): 5%
Cardio history for neonates
-Antenatal scan
-Perinatal history
-Cyanosis –consider duct dependent lesions
-Breathlessness
-Collapse, shock-consider duct dependent lesions
-Family history
Cardio exam for neonates
-Dysmorphic features
-Tachycardia
-Tachypnoea
-Cyanosis
-Pulse oximetry
-Peripheral pulses
-Enlarged liver
-Murmurs
History for infants and older children
-Respiratory distress
-Cyanosis
-Cyanotic spell
-Sweating during feeding/poor feeding (HF): L to R
-Poor weight gain
-Exercise intolerance
-Chest pain
-Syncope
-Palpitations
Cardio exam for infants and older children
oedema extra
Investigations in cardio problems
-ECG
-Echocardiogram
-Pulse oximetry
-Blood gas for acid base/ metabolic acidosis/ high lactate – for very sick patients
-Blood tests
-CXR (only symptomatic patients)
-Exercise test
-CT/MRI
-Cardiac catheter
Classification of Congenital Heart Disease
-Acyanotic
=Increased pulmonary blood flow/ L >R shunt (ASD, VSD, patent ductus arteriosus, atrioventricular canal)
=Obstruction to blood flow from ventricles (coarctation of aorta, aortic stenosis, pulmonary stenosis)
-Cyanotic
=Decreased pulmonary blood flow/ R > L shunt (Tetralogy of Fallot, Tricuspid atresia, pulmonary atresia)
=Mixed blood flow (TGA, total anomalous pulmonary venous return, truncus arteriosus, hypoplastic left heart syndrome)
Pathophysiology of L to R shunts
-Passage of oxygenated blood back to pulmonary circulation at atrial, ventricular or great artery level
-Results in
=Increased pulmonary blood flow
=Tendency to develop heart failure and PHT
Pathophysiology of obstructive lesions
-Examples: pulmonary stenosis, aortic stenosis, coarctation of aorta
-Increased pressure in upstream vessel or chamber
-Ventricular hypertrophy
-Risk of ventricular failure (late feature)
-Critical stenosis, coarctation – duct dependent – iv Prostin
Overall presentation of cyanotic HD
-Decreased pulmonary blood flow
=Oligaemic lungs
=Spelling episodes: hyperpnea (rapid/ deep breathing), irritability and prolonged crying, worsening cyanosis, disappearance or reduced intensity of heart murmur
-Mixed blood
=Plethoric lungs
=Heart failure signs: tachypnoeic
Management of cyanotic spell
-ABCDE approach
-100% oxygen (pulmonary vasodilator)
-Auscultate to see if RVOTO murmur is reduced/absent to confirm diagnosis
-Holding infant in the knee-chest position, preferably in parents arm
-Morphine (IV or subcut)
=Quietens the distressed baby & reduces oxygen consumption: Suppresses respiratory centre which abolishes hypernea
-IV Access taking blood gas to check for acidosis
-IV Fluid bolus (10ml/kg) & maintenance IV fluids
-Propranolol PO 0.5mg/kg to 1mg/kg
=Myocardial depression reducing pulmonary infundibulum contraction
=Reducing tachycardia allowing more time for ventricular filling
Overview of ASD
-Atrial septal defects (ASDs) are the most likely congenital heart defect to be found in adulthood. 10%
-They carry a significant mortality, with 50% of patients being dead at 50 years.
-Two types of ASDs are recognised, ostium secundum (failure of septum secundum) and ostium primum (septum primum, leads to AV valve defects and ASD). Ostium secundum are the most common. Patent foramen ovale
-Left to right shunt because left atrium higher pressure so no cyanosis but increased flow to RHS leads to right sided overload and strain so pulmonary hypertension then Eisenmenger syndrome (pulmonary pressure>systemic so shunt reverses so cyanosis)
-P: ejection mid systolic murmur, crescendo-decrescendo loudest at ULSB, fixed splitting of S2 (delayed closure of P2), dynamic precordium, parasternal heave.
=Usually asymptomatic in first 4 decades
=Asymptomatic and present in adulthood with dyspnoea, HF, stroke
=Symptomatic: SOB, difficulty feeding, poor weight gain, LRTI
= Risk of R heart failure, arrhythmias (AF and flutter), pulmonary hypertension, paradoxical embolism (RA to LA across ASD)
-I: CXR (normal or increased CTR, prominent main PA, plethoric lung fields), ECHO best from subcostal window, colour flow Doppler helpful, volume loaded right heart side), angiography
-Ostium secundum (70% of ASDs)
=Associated with Holt-Oram syndrome (tri-phalangeal thumbs)
=ECG: RBBB with RAD
-Ostium primum
=Present earlier than ostium secundum defects
=Associated with abnormal AV valves
=ECG: RBBB with LAD, prolonged PR interval
-M: closure (surgical: low mortality, good long term results/ transvenous catheter closure via femoral vein). Paediatric cardiologist for ongoing management, watchful waiting. Anticoagulants
Overview of VSD
-Most common cause of congenital heart disease 30%. They close spontaneously in around 50% of cases.
-L to R so Acyanotic so pulmonary hypertension so Eisenmenger syndrome
-Aetiology
=Congenital VSDs are often association with chromosomal disorders
==Down’s syndrome
==Turner’s
==Edward’s syndrome
==Patau syndrome
==Cri-du-chat syndrome
=Congenital infections
=Acquired causes
==Post-myocardial infarction
-VSDs may be detected in utero during the routine 20 week scan. Post-natal presentations include:
=Failure to thrive, poor feeding
=Features of heart failure: Hepatomegaly, Tachypnoea, dyspnoea, Tachycardia, Pallor
=Classically a pan-systolic murmur which is louder in smaller defects, LLSB and 3/4 intercostal, may be systolic thrill on palpation
=Small defects symptoms unusual (can present in childhood), large defects may lead to HF, risk of pulmonary hypertension if not treated
-Management is clearly highly specialised
-Small VSDs that are asymptomatic often close spontaneously and simply require monitoring
-Moderate to large VSDs usually result in a degree of heart failure in the first few months
=Nutritional support
=Medication for heart failure e.g. diuretics
=Surgical closure of the defect (transvenous catheter closure via femoral vein or open heart)
-Complications
=Aortic regurgitation: due to a poorly supported right coronary cusp resulting in cusp prolapse
=Infective endocarditis (prophylactic abx for surgical procedures)
=Eisenmenger’s complex: due to prolonged pulmonary hypertension from the left-to-right shunt, results in right ventricular hypertrophy and increased right ventricular pressure. This eventually exceeds the left ventricular pressure resulting in a reversal of blood flow, this in turn results in cyanosis and clubbing. Eisenmenger’s complex is an indication for a heart-lung transplant
=Right heart failure
=Pulmonary hypertension, pregnancy is contraindicated in women with pulmonary hypertension as it carries a 30-50% risk of mortality
Overview of Patent Ductus Arteriosus
-Acyanotic L to R CHD 7%, however, uncorrected can eventually result in late cyanosis in the lower extremities, termed differential cyanosis
-Connection between the pulmonary trunk and descending aorta- RHS strain leads to ventricular hypertrophy
-Usually, the ductus arteriosus closes with the first breaths due to increased pulmonary flow which enhances prostaglandins clearance. The ductus arteriosus normally stops functioning within 1-3 days of birth, and closes completely within the first 2-3 weeks of life. When it fails to close, this is called a “patent ductus arteriosus”
-More common in premature babies, born at high altitude or maternal rubella infection in the first trimester
-P: left subclavicular thrill, continuous crescendo-decrescendo machinery murmur (left clavicle, back), large volume bounding collapsing pulse wide pulse pressure, heaving apex beat, dynamic precordium. Asymptomatic small (potential for HF in adulthood), large HF
=SOB, difficulty feeding, poor weight gain, LTRI
-I: ECHO (ductal flow easily visualised using colour and continuous-wave Doppler). Hypertrophy?
-M: Monitored untill 1 year using ECHO. Indomethacin or ibuprofen (given to neonate, inhibits prostaglandin synthesis, closes the connection in the majority of cases), diuretics and SBE prophylaxis, if associated with another congenital heart defect amenable to surgery then prostaglandin E1 is useful to keep the duct open until after surgical repair (ligatiob, catheter device occlusion). Surgical after 1 year or symptomatic/ HF
Overview of Coarctation of the Aorta
-7%. Coarctation of the aortic arach usually around ductus arteriosus describes a congenital narrowing of the descending aorta. It is more common in males, despite an association with Turner’s syndrome.
-Narrowing of the aorta reduces the pressure of blood flowing to the arteries that are distal to the narrowing. It increases the pressure in areas proximal to the narrowing, such as the heart and the first three branches of the aorta.
-Associations
=Turner’s syndrome
=Bicuspid aortic valve
=Berry aneurysms
=Neurofibromatosis
-P:
=Infancy: heart failure (tachypnoea, work of breathing, poor feeding, grey and floppy), neonatal collapse, weak femoral pulses (four limb blood pressure will reveal high blood pressure in the limbs supplied from arteries that come before the narrowing, and lower blood pressure in limbs that come after the narrowing)
=Adult: hypertension
=Radio-femoral delay, absent or reduced lower limb pulses, upper limb hypertension, murmur between scapulae (continuous, systolic ejection left infraclavicular area and below left scapula). Left ventricular heave (as left ventricular hypertrophy), underdeveloped left arm where reduced flow to L subclavian artery, underdevelopment of legs
=Mid systolic murmur, maximal over the back
=Apical click from the aortic valve
=Notching of the inferior border of the ribs (due to collateral vessels) is not seen in young children
-M: Surgical repair (end-to-end, patch repair, ligate ductus arteriosus), balloon angioplasty (+/- stent), operative risks (mortality <5%, spinal cord damage <1%, risk of aortic aneurysm). In cases of critical coarctation where there is a risk of heart failure and death shortly after birth Prostaglandin E is used keep the ductus arteriosus open while waiting for surgery
