Congenital heart disease Flashcards
Most common congenital malformation and incidence
Congenital heart disease 7-8/1000
Anomaly with fetal lithium exposure
Ebstein’s anomaly
CHD that typically presents in the newborn period (4)
Coarctation of the aorta Transposition of the great arteries Tetralogy of fallot Patent ductus arteriosus
Defects causing left to right shunt (2)
VSD ASD
Obstructive lesions (2)
Aortic stenosis Pulmonary stenosis
CHD presenting with shock, %,, murmur
VSD AVSD PDA
CHD presenting with a murmur, %, murmur
Pulmonary valve stenosis Atrial septal defect
Presenting with cyanosis
Tetralogy of fallot Transposition of the great arteries
Paediatric circulation from placenta
oxygenated blood from placenta–> umbilical vein–> ductus venosus–> IVC–> R atrium–> shunted through foramen ovale–> L atrium–> L ventricle–> aorta–> brain/myocardium/ upper extremities
Paediatric circulation from deoxygenated blood returning via SVC
deoxygenated blood returns via SVC to R atrium–> 1/3 of blood entering R atrium does not flow through foramen ovale and flows to the R ventricle–> pulmonary arteries–> ductus arteriosus–> aorta–> systemic circulation placenta for reoxygenation
Most critical time for fetal heart development
Critical stage at 3-8 weeks
What is the shunt for deoxygenated blood
Ductus arteriosus
What are the shunts for oxygenated blood (2)
Foramen ovale Ductus venosous
What does the ductus venosous connect
Umbilical vein and IVC->bypassing the liver
Changes in circulation at birth
- First breath->lung open-> -ve pulmonary resistance= +pulmonic blood flow 2. Separation of low resistance placenta->systemic circulation becomes high resistance system -> ductus venosus closure 3. Increased pulmonic flow -> +left atrial pressure->foramen ovale closure 4. +oxygen concentration in blood after first breath= -ve prostaglandins-> ductus arteriosus closure 5. Closure of fetal shunts and changes in vascular resistance->infant circulation assumes normal adult adult flow
Epidemiology, common presentations, most common lesio
Number of live briths: 8/1000 Heart murmur Heart failure Cyanosis VSD most common
Investigations
Echo ECG CXR
At what concentration of deoxy Hb does cyanosis occur
At least 3g/dL
Pathogenesis of acyanotic
acyanotic heart disease: (i.e. L to R shunt, obstruction occurring beyond lungs) blood passes through pulmonic circulation g oxygenation takes place –> low levels of deoxygenated blood in systemic circulation –> no cyanosis
Division of acyanotic HD
- Left to right shunt: ASD, VSD, PDA, AVSD 2. Obstructive->CA, AS, PS
Division of cyanotic
- R->L shunt: TOF, ebstein’s anomaly 2. Other: TGA, total anomalous pulmonary venous drainage, tricuspid atresia
Complications/progression of L to R shunt
Pulmonary vascular disease Left ventricular dilatation and dysfunction RV hypertension and hypertrophy R to L shunts
Types of ASD
ostium primum (common in Down syndrome), ostium secundum (most common type, 50-70%), sinus venosus (defect located at entry of superior vena cava into right atrium
How common are ASD
Responsible for 5% CHD
Spontaneous closure rate of ASD
Spontaneous closure in 80-100% when
History of ASD
Asymptomatic common in childhood May present with HF / pulmonary hypertension later in adulthood
Physical examination in ASD: palpation, auscultation
Palpation: Normal, may have RV+ Auscultation: +flow to right, low pitch diastolic, TR, pulmonary ejection murmur Fixed splitting P2 No direct murmur
Investigations in ASD
Echo CXR ECG
Management of ASD
left-to-right shunt 1st line: observation adjunct: corrective closure adjunct: prophylactic antibiotics->after closure for 6 months (amoxicillin) right-to-left shunt reversible 1st line: corrective closure plus: prophylactic antibiotics irreversible (Eisenmenger’s syndrome) 1st line: supportive medical therapy with pulmonary vasodilators->bosentan plus: monitoring and treatment of hyperviscosity plus: prophylactic antibiotics 2nd line: heart-lung transplantation
Why do patients with eisenmenger’s develop a hyperviscocity
To cope with the hypoxemia
Most common CHD
Ventricular septal defect
Causes of VSD
Congenital Alcoholism MI
Most common location of VSD
Interventricular septum
Presentation if small VSD
Asymptomatic, normal growth and development Early/holosystolic murmur, LLSB
Investigations in VSD when small and management
CXR and echo are normal Most will close spontaneously
Moderate to large VSD: CHF presentation, clinical history, PE findings
CHF by 2 monthsd Pulmonary hypertension Clinically can have delayed growth, -ve exercise tolerance, recurrent URTI/asthma episodes PE: Holosystolic LLSB S3, S4 +on expiration, Loudness ++when small RV heave
Investigation findings when moderate VSD
CXR: +pulmonary vasculature, ECG: biventricular hypertrophy Cardiomegaly, CHF
Management of moderate VSD
Treat CHF and surgical closure by 1 year old
Complications of VSD
- Endocarditis 2. Progressive aortic regurgitation 3. CHF 4. Pulmonary hypertension and refersal
Management of VSD
congenital: small 1st line: observation adjunct: prophylactic antibiotics congenital: medium or large asymptomatic 1st line: corrective closure adjunct: prophylactic antibiotics symptomatic with left-to-right shunt 1st line: preoperative medical therapy plus: corrective closure adjunct: prophylactic antibiotics symptomatic with right-to-left shunt (Eisenmenger’s syndrome) 1st line: supportive medical therapy with pulmonary vasodilators plus: prophylactic antibiotics adjunct: monitoring and treatment of hyper-viscosity 2nd line: heart-lung transplantation
Functional and anatomical closure of PDA
Functional closure at 15 hours, anatomical closure within first few days
When is closure delayed, and is this different to PDA in term
Delayed in prematurity, different to term
When is spontaneous closure more common
Premature infants
Clinical presentations
If small may be asymptomatic TacyP Failure to thrive SOB +respiratory symptoms of URTI
Risk factors
Prematurity Maternal rubella Female
Clinical examination findings
TacyP Bounding pulse Wide pulse pressure Hyperdynamic praecordium Systolic thrill Continous machinery murmur
Investigations and findings
ECG: deep Q, tall R waves in 2,3,aVF, V5, V6. May have widened P wave suggesting LAE, LVH, RVH CXR: cardiomegaly, +pulmonary vascular markings Echo: Two-dimensional and/or colour Doppler evidence of a PDA. Diastolic forward flow in the pulmonary artery. Left ventricular and/or left atrial enlargement. Diastolic flow reversal in the distal aortic arch
When is surgery contraindicated in PDA
When pulmonary disease, right to left shunt
Management of PDA: premature, term/children, smptomatic and too small
Premature: Indomethacin (or ibuprofen) in premature Surgery->ligation Term and children: Percutaneous catheter closure Frusemide->if not large enough for surgery just yet and are symptomatic- can give time for them to grow Term/symptomatic and too small for percutaneous device closure: surgical ligation
When is surgery for PDA generally indicated
When medical therapy has failed
Is indomethacin ever given prophylactically
Yes, in the very low birth weight infants to avoid the hemodynamic challenges
What is used if the DA needs to be kept open and in what situation may this be required
Prostaglandin E Transposition of the great arteries
How do infants with obstructive lesions present
Pallor Cool extremities Fatigue Reduced urine output Cardiogenic shock
Coarctation of the aorta general features
Narrowing of aorta- most commonly at division of left subclavian/ligamentum arteriosa
Clinical features
- HTN in upper extremities with hypotension in lower extremities 2. Well-developed upper body with underdeveloped lower half 3. Midsystolic murmur heard best over the back 4. Symptoms include headache, cold extremities, claudication with exercise, and leg fatigue. 5. Delayed femoral pulses when compared to radial pulses 6. Prevalence of coarctation of the aorta is increased in patients with Turner’s syndrome
Risk factors for COA
Strong male gender young age Turner’s syndrome DiGeorge’s syndrome Cardiac defects include tetralogy of Fallot, interruption of aortic arch, aortic coarctation, truncus arteriosus, and ventricular septal defects. hypoplastic left heart syndrome Shone’s complex PHACE syndrome
Features of PHACE syndrome
A rare syndrome in which the association: 1. Posterior fossa malformations, 2. Haemangioma, 3. Arterial anomalies, 4. Cardiovascular anomalies 5. Eye abnormalities
CHD seen in Digeorge
Tetralogy of Fallot, interruption of aortic arch, aortic coarctation, truncus arteriosus, and ventricular septal defects.
Investigations and findings in COA
- ECG shows LVH. 2. CXR a. Notching of the ribs b. “Figure 3” appearance due to indentation of the aorta at site of coarctation, with dilation before and after the stenosis 3. Echo: discrete narrowing in the thoracic aorta; pressure gradient across narrowing
Complications of COA
Severe treatment resistant hypertension Rupture of cerebral aneurysms Infective endocarditis Aortic dissection/aneurysm
Management: critical in neonates, non critical 1y, recurrent
Critical: alprostadil + surgical repair Non critical: 1y: surgical repair or percutaneous angioplasty with or without stent implantation Recurrent: percutaneous angioplasty
Types of aortic stenosis
- valvular (75%) 2. subvalvular (20%), 3. supravalvular 4. idiopathic hypertrophic subaortic stenosis (IHSS) (5%)
Clinical presentation of AS
presence of risk factors dyspnoea chest pain syncope
Risk factors for AS
Strong age >60 years congenitally bicuspid aortic valve rheumatic heart disease chronic kidney disease->calcification
Examination findings AS
systolic murmur ≥3/6, with a diamond-shaped crescendo-decrescendo pattern that peaks in mid-systole and radiates to the carotid arteries. RUSB A2 prolonged Expiration, the pulmonic sound (P2) is heard before A2 in severe
Can people with AS bleed more
Yes, can develop an acquired vWD
Grading of murmurs
Murmurs are generally graded on a scale of 1 to 6: Grade 1: murmur is faint and heard only with effort Grade 2: murmur is faint but easily detected Grade 3: murmur is loud Grade 4: murmur is very loud and associated with a palpable thrill Grade 5: murmur is so loud that it can be heard with only the edge of the stethoscope Grade 6: murmur is extremely loud and heard even when the stethoscope is no longer in contact with the patient.
Severity of AS classification
Mild: Jet velocity 1.5 cm^2 Moderate: Jet velocity 3.0 to 4.0 m/second Mean pressure gradient 25 to 40 mmHg Valve area 1.0 to 1.5 cm^2 Severe: Jet velocity >4.0 m/second Mean pressure gradient >40 mmHg Valve area
Investigations and findings in AS
Transthoracic echo: elevated aortic pressure gradient; measurement of valve area and left ventricular ejection function ECG: may demonstrate left ventricular hypertrophy and absent Q waves, AV block, hemiblock, or bundle branch block
Management overview AS
- Surgical valve replacement 2. Anticoagulation 3. Endocarditis prophylaxis
General characteristics of TOF
Overriding aorta Pulmonary steonsis VSD Right ventricular hypertrophy
Clinical features in TOF
Cyanosis Tachypnoea Tet spells Murmur is typically crescendo–decrescendo in nature and heard best at the left upper sterna border. Parasternal impulse, heave
What are Tet spells and what is their purpose
Patient with TOF will squat following exertion (exercise, crying)->+SVR->able to shunt blood to the lungs rather than the aorta
Investigations and findings in TOF
Pulse oximetry: low oxygenation CXR: boot shaped Echo: overriding aorta, RVH, pulmonary stenosis, VSD ECG: RVH with a rightwards axis, R in V1 and S in V6 above age-appropriate normals
Management of hypercyanotic spells
Manouevres to +venous return->knees to chest Supportive: fluids, morphine to calm, oxygen (but try not to ++activity) 2nd line: beta blockers 3rd line: phenylephrine
How are beta blockers thought to help during hypercyanotic spells
helps to decrease the infundibular obstruction by decreasing the heart rate, prolonging diastolic filling, and decreasing contractility
How does phenylephrine work to help in hypercyanotic spells of TOF
It increases SVR->shunting more blood to lungs
Management of infant with unremitting cyanosis of TOF
surgical shunt + extracorporeal membrane oxygenation (ECMO)
Management of infant with severe cyanosis and limited pulmonary flow
Alprostadil and supportive->fluid, morphine, bicarb, oxygen
Ongoing/long term management of TOF
Surgical repair Monitoring with possible pulmonary valve replacement Endocarditis prophylaxis
Endocarditis prophylaxis
Cephalexin in cardiac or amox/ampicillin preferred for dental
What is the most common cyanotic heart disease of the neonate
Transposition of the great arteries
Pathophysiology of TGA
parallel pulmonary and systemic circulations systemic: body RA RV aorta body pulmonary: lungs LA LV pulmonary artery lungs survival is dependent on mixing through PDA and/or atrial or ventricular septal defects
Physical examination in TGA
With closure of the PDA->rapid progression to severe hypoxemia, unresponsive to oxygen therapy VSD: murmur, cyanosis not prominent->progression to CHF in first few weeks No VSD: absent murmur
Investigations and findings in VSD
ECG: RAD/RVH, or may be normal CXR: egg on a string appearance
Management of TGA
symptomatic neonates: prostaglandin E1 infusion to keep ductus open until balloon atrial septostomy followed by switch procedure surgical repair: arterial switch performed in the first two weeks in those without a VSD while LV muscle is still strong
Commonest cause of death from CHD in first month of life
LV hypoplasia may include atretic or stenotic mitral and/or aortic valve, small ascending aorta, and coarctation of the aorta with resultant systemic hypoperfusion systemic circulation is dependent on ductus patency; upon closure of the ductus, infant presents with circulatory shock and metabolic acidosi
Management of Hypoplastic left heart syndrome
Intubate Correct metabolic acidosis IV infusion of alprostadil Surgical palliation or heart transplant
Characteristics of innocent murmurs
Systolic and musical No clinical significance Do not radiate Change with position. Soft <3/6. The rest of the examination is normal
Venous hum
Blowing continuous in systole and diastole Heard below the clavicles Disappears on lying down
Pulmonary flow murmur
Brief high pitched Best heard with child lying down
History taking with a murmur
Fatigue Breathlessness Family history Antenatal->maternal medications, syndromes etc
Physical examination in murmur
Murmur Signs of heart failure-> FTT, poor growth, tachyC/P, crepitations, hepatomegaly Pulse and BO Sternal heave Cyanosis->unlikely finding in children presenting with a murmur
Investigations in CHD
Echocardiograph CXR ECG 24 hr ECG->if palpitations/syncope Cardiac catheterisation
What is this murmur
Aortic stenosis
What is this murmur
Mitral regurgitations
What is this murmur
Aortic insufficiency
What is this murmur
Mitral stenosis
What is this murmur
ASD
What is this murmur
Benign
What is this murmur
VSD
What is this murmur
PDA
What is this murmur
S3
What is this murmur
S4
What is this murmur
Split S2
Why is polycythemia important in cyanosis
Can lead to to more apparent cyanosis
What CHD can cause cyanosis in first 24 hours of life
TGA
Pulmonary atresia
Tricuspid atresia
Which cyanotic CHD is more common in the diabetic mother
TGA is 20 times more common in diabetic mothers
Categories of CHD severity
- Minor
Little ot no hemodynamic impact/no functional impact
Small VSD
Trivial PVS
Bicuspid aortic valve
Small ASD
- Moderate
HemoD impact may produce long term complications, intervention required
ASD w/ V dilation
Coarctation >few months of age
VSD impeding flow
Anomalous pulmonary venous return
- Severe
Major hemodynamic impact
Single ventricle
TGA
TOF
Large VSD
Clinical features in early weeks may suggest CHD
- Cyanosis
- Dusky
- Dysmorphic
- TachyP
- Poor feeding, poor weight gain
- Overactive praecordium
- Murmur
