Congenital CardiovascularAnomalies
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Dr. Kalpana MallaMBBS MD (Pediatrics)
Manipal Teaching Hospital
Contents
• General concepts of congenital heart diseases.• Atrial Septal Defect.• Ventricular Septal Defect.
Incidence:
• ~1% in the general population (6-8 per 1000 live births)
• Incidence in stillborns (3-4%), aborted fetus (10-25%), premature infants (2%)
• Diagnosis made in 40-50% by one week of age, in 50-60% by 1 mo of age
Incidence
• Recurrence risk - if h/o one affected sibling – • VSD, PDA 3%• TOF, ASD2.5%• Tricuspid atresia, Ebstein anomaly1%
Relative frequencies of major CHD:
Lesions % of all lesions • VSD 25-30• ASD 6-8• PDA 6-8• Coarctation of Aorta 5-7 • TOF 5-10• Pulmonary valve stenosis 5-7 • Aortic valve stenosis 4-7
Relative frequencies of major CHD
Lesions % of all lesions • TGA 3-5• Hypoplastic left heart 1-3• Truncus Arteriosus, TAPVR, Tricuspid atresia, Single ventricle, Double outlet rt ventricle 1-2
Others 5-10
Etiology –1.Genetic
• Inheritance- Dominant pattern – • ASD, supravalvular aortic stenosis,
cardiomyopathy
• Osteogenesis Imperfecta: Aortic regurgitatio
• Marfan Syndrome: Aortic dilatation, aortic & mitral incompetence
CHD with chromosomal abnormalities
5 % associated with Chromosomal anomalies: • Trisomy 13, 18 (>90%), 21 (50%) • 18 Trisomy - VSD, PDA, DORV • 13 Trisomy - Dextocardia,VSD, PDA• 21 Trisomy Downs syndrome - A-V canal defect,
VSD
CHD with chromosomal abnormalities
• Turner’s syndrome (40%) - Coarctation of aorta, aortic stenosis
• Deletion chromosome 22q11: Di George syn
• Familial cardiomyopathies: HCM, DCM
Etiology: 2.Gender Factors
• Occur equally among males and females, but—–More common in males:
aortic stenosis, coarctation of the aorta
–More common in females: PDA, ASD
Etiology: 3. Environmental
• High altitude• Maternal Dsa) Diabetes: TGA ,VSD, situs inversus, single ventricle, hypoplastic left ventricle b) SLE: Congenital heart block
3. Environmental Factors
3. Maternal Infections:– Rubella: PDA, pulmonary stenosis, VSD, ASD
• Mumps: Endocardial Fibroelastosis4. Maternal Drugs:– Lithium: Tricuspid valve abnormalities, Ebstein’s
Anomaly – Thalidomide– Alcohol abuse: VSD
- warfarin, anticonvulsants, antimetabolites , Phenytoin : Variable
Classification of congenital heart disease:
1. Acyanotic
2. Cyanotic lesions
Acyanotic
• volume load pressure load -L→R shunts obstr. ventric. outflow -ASD - Pulmonary valve stenosis -VSD - AV canal - Aortic valve stenosis-Patent ductus arterisus - Coarctation of aorta
Cyanotic
↑ pulmonary flow ↓ pulmonary flow
• TGA • TOF• Single ventricle • Pulmonary atresia • Truncus arteriosus • Tricuspid atresia• TAPVR w/o obstruction • TAPVR with obstruction
Characteristics of patients with LR shunts:
• Absence of cyanosis• Frequent chest infections -Due to decreased
lung compliance which leads to frequent respiratory tract infections
• Precordial bulge• Excessive sweating - Tendency for CCF
Characteristics of patients with LR shunts:
• Failure to thrive - due to poor oxygen saturation in the growing tissues, persistent heart failure, and frequent respiratory infections with undernutrition
• Cardiomegaly• Shunt & flow murmurs• Plethoric lung fields
Characteristics of patients with obstructive lesions:
• Absence of cyanosis or frequent chest infections
• Normal precordial shape• Forcible/heaving cardiac impulse, without
cardiomegaly• Delayed S2
Obstructive lesions (contd)
• Ejection systolic murmur, with thrill• Absence of diastolic murmurs• Normal sized heart with normal pulmonary
vascularity• Ventricular hypertrophy on ECG• Chest pain- severe aortic stenosis lead to
myocardial ischemia
Characteristics of cyanotic patients:
• Cyanosis- Occurs under following circumstances1. Reduced pulmonary blood flow in defects with
right ventricular outflow tract obstruction 2. R→L as in tetralogy of Fallot 3. Discordant ventriculoarterial connections – TGA 4. Mixing of venous and arterial blood – truncus
arteriosus or single ventricle
Characteristics of cyanotic patients:
• Hypercyanotic Spells Fallot's tetralogy and defects with Fallot's physiology
**Due to pulmonary infundibular stenosis
Characteristics of cyanotic patients:
• Clubbing
• Polycythemia
• Murmurs
• FTT
• Heart Failure occurs in following situations :
• Volume overload- all defects with L →R shunt like VSD,ASD,PDA
• Pressure overload - in pulmonary and aortic valve stenosis
• Intrinsic myocardial diseases -cardiomyopathies, • Decreased or increased diastolic fillings -
tachyarrhythmias and bradyarrhythmias.
Investigations:
1. Chest X-ray: shape & size of heart, vascularity, pulmonary edema, lung & thoracic anomalies
2. ECG: Hypertrophy3. Hematology: anemia (? Physiological, iron
deficiency), polycythemia
Investigations
5. Echocardiography/Doppler Echo: intracardiac
anatomy of all structural defects , hemodynamic data regarding pressure gradients across valves, cardiac contractility, flow, vegetations
Investigations
6.Cardiac catheterisation: calculates 02
saturation, shunt volumes, pressures, etc • Indications • Preoperative identification of the lesions• Peroperative physiological assessment of
pulmonary artery pressure and press gradient
Cardiac Catheterization
• Therapeutic interventional procedures1.Baloon dilatation of stenotic valve and
coarctation of aorta2. Blade and baloon atrial septoplasty3. Non- surgical closure of PDA ,ASD4.Catheter ablation of arrythmogenic focus by
pacemaker implantation
Investigations (contd):
7. Exercise testing8. MRI9. Angiocardiography10.Interventional catheterisation
Management:
• Early identification of problem• Supportive management:1. Treatment of heart failure2. Prevent frequent RTIs3. Maintain required weight , Hb4. Infective endocarditis prophylaxis5. Regular follow-ups• Surgical management
Atrial Septal Defect
– Defect in atrial septum
– 6-8 % of all CHDs
– Male : female ratio is 1:2
ASD - classification• Three major types– Ostium secundum• most common- 50-70%, • In the middle of the septum in the region of the
foramen ovale– Ostium primum -30%• Low position• Form of AV septal defect
ASD - classification
– Sinus venosus• Least common-10% • Site-at entry of superior venacava into right
atrium• Mitral valve prolapse associated in ~20% with
ostium secundum or sinus venosus defect
Hemodynamics
• L -R shunt at minor pressure difference-silent• Rt atrium receive blood from SVC,IVC + left
atrium - rt atrium enlarges in size -passes through normal sized tricuspid valve -delayed diastolic murmur at lower left sternal border -rt.ventricle also enlarges -normal pulmonary valve -pulmonary ejection systolic murmur, prolonged ejection phase of rt ventricle P2 delayed
Hemodynamics
• S2 normally is single in expiration ( both component is superimposed on each other) & split in inspiration( A2 component slightly early P2 component is delayed)
• In ASD-S2 is widely split and fixed- as rt ventricle fully loaded further increase in rt ventricular volume during inspiration cannot occur
Clinical manifestations:
• Usually asymptomatic• Mild effort intolerance, frequent chest
infections may be +• CCF - rare
Physical examination
• Slender built• Parasternal impulse +• Systolic thrill 2nd Lt. interspace – 10%
Auscultation• S1 :normal or accentuated due to loud tricuspid
component• S2: Widely split & fixed S2 with P2 accentuatedMurmur –• Shunt murmur – absent• Flow murmurs – 1. Pulmonary – ejection systolic grade 2- 3/6 at 2nd and 3rd lt interspace-widey transmitted all over chest 2. tricuspid –delayed diastolic at lt lower sternal border
Investigations:
1. CXR- mild to moderate cardiomegaly with enlarged right atrium & right ventricle, prominent pulmonary artery segment, increased pulmonary vascular markings
2. ECG- RAD, RVH or RBBB with rsR’ pattern in V1 LAD - suggest O. primum defect
3. Echo- position, size, signs of LR shunt, flow
Natural history:• Spontaneous closure in ~87% of ostium secundum
defects
1. ASD <3 mm size, diagnosed before 3 months of age, spontaneous closure in 100% by 1.5 years of age
2. ASD 3-8 mm size, spontaneous closure in 80% by 1.5 years of age
3. ASD > 8mm rarely closes spontaneously
Natural history:
• Mostly asymptomatic and active
• CHF & pulmonary HTN develop in untreated cases in their 20s to 30s
• Atrial arrhythmias may occur in adulthood
• Infective endocarditis rarely occurs, with isolated ASDs
Management:
• Medical: for CHF, chest infections non-surgical closure-Clamshell device,
Sideris button device, Angel Wings, etc
• Surgical closure: delayed till 3-4 years of age Indications: LR shunt Qp/Qs ratio:>1.5:1
VSD
• Communication b/t two ventricles
VSD
• May occur alone or with other abnormalities
• About one-third of small VSDs close spontaneously
Ventricular Septal Defect
• Commonest acyanotic CHD (~25%)
• Associated with-Down Syndrome Fetal hydantoin syndrome Fetal alcohol syndrome Trisomy 13, 18 Apert syndrome
Anatomy
• Compartments of ventricular septum: - Membranous septum - Inlet septum - Trabecular septum - Outlet or infundibular septum • Defects result from a deficiency of growth or
failure of alignment or fusion of component parts
Classification-pathology
1.Membranous VSD- (perimembranous, paramembranous , conoventricular, infracristal, subaortic) – Most common (90%)
2.Muscular VSD- (Swiss cheese ,inlet, trabecular, central, apical, marginal ,or outlet types)
3. Supracristal VSD- (subpulmonary, outlet, infundibular, or conoseptal. subarterial defect) Least common
Hemodynamics:
• L→R shunt in ventricles occur with high pressure gradient throughout systole – pansystolic murmur
• Blood to normal pulmonary valve – ejection systolic murmur
• Large vol of blood to lungs – pul plethora• Blood to left atrium – Lt. atrial enlrgement• Blood to normal mitral valve – delayed
diastolic murmur at apex
Hemodynamics
• Lt ventricles to outlets – empties relatively early – early A2
• Rt ventricle & pul artery – increased ejection time – delayed P2-S2 widely split &variable
Hemodynamics
• Depends on: a) size of the shunt b) PVR
• Based on size of VSD: - Restrictive VSD(<0.5 cm2 ) - Moderately restrictive VSD - Non-restrictive (>1 cm2 )
Restrictive VSD
• Small, hemodynamically insignificant • Size <0.5 cm2
• Between 80% and 85% of all VSDs• All close spontanously 50% by 2 years 90% by 6 years 10% during school years• Muscular close sooner than membranous
A moderately restrictive VSD
• Size -> 0.5 cm2 (>5mm) in diameter
• Moderate shunt (Qp:Qs = 1.5-2.5:1.0) • May lead to left atrial and LV dilation and
dysfunction, as well as a variable increase in pulmonary vascular resistance
Large nonrestrictive VSDs
• Large VSDs with normal PVR
• Usually >1.0 (>10 mm) in diameter
• Usually requires surgery
• Will develop CHF and FTT by age 3-6 months
PVR (Pulmonary vascular R)
• At birth - PVR is higher than normal so pul arterial pressure is equal to systemic pressure→the L → R shunt is limited → no clinical symptoms
• First few weeks of life (normal involution of the media of small pulmonary arterioles) → fall in PVR → L → R shunt increases and clinical symptoms become apparent
• In some with a large VSD -pulm arteriolar medial thickness never decreases – so, continued exposure of the pulmonary vascular bed to high systolic pressure→ high flow → pulm vascular obstructive disease develops
• When the ratio of pulm to systemic resistance is 1:1, the shunt becomes bidirectional and the patient becomes cyanotic (Eisenmenger physiology).
Clinical Manifestations:
1. Small VSD: asymptomatic, normal growth
2. Moderate to large: repeated chest infections, Effort intolerance ,fatigue , failure to thrive, pulmonary HTN
3. If unoperated: Pulmonary HTN, cyanosis and decreased level of activity
Physical examination
1. Small VSD: well developed, acyanotic 2. Moderate VSD: forceful LV impulse ,
prominent systolic thrill along the lower left sternal border
Physical examination
Large VSD: tachypneic, repeated chest infections, poor weight gain, CHF dyspnea, feeding difficulties, poor growth, profuse perspiration, recurrent pulmonary infections, and cardiac failure in early infancy.
Reversal of shunt: cyanosis, clubbing, respiratory distress.
Auscultation
• Heart sounds • S1 : masked by pansystolic murmur• S2: masked but can be heard at 2nd lt ICS –
widely split and variable, with accentuated P2 - single and loud (PAH)
• S3: maybe audible at the apex
Murmurs
• Shunt - loud, harsh, or blowing pansystolic murmur grade 3-5/6 best heard at left 3rd & 4th interspaces is widely transmitted over the precordium at lower LSB
• Flow – • Pulmonary : ejection murmur (drowned)• Mitral : rumbling delayed diastolic murmur at
the cardiac apex, indicates a Qp:Qs of 2:1 or greater
Chest radiography
• Small VSDs -N• Medium- VSDs -minimal cardiomegaly and a
borderline increase in pulmonary vasculature • Large VSDs – gross cardiomegaly . The
pulmonary vascular markings are increased and frank pulmonary edema (Plethoric) if pul arterial HTN
• Oligemic lung fields in reversal of shunt, pul stenosis
Electrocardiography
• Depends on shunt size & degree of pulmonary hypertension
• Small VSDs - N tracing• Medium VSDs – broad, notched P wave ( left
atrial overload), LVH• Large VSDs – RVH with right-axis deviation.
With further progression - biventricular hypertrophy; P waves may be notched or peaked
• RVH in Eisenmenger’s complex
Echocardiography
• Echo - Number, position & size of defect, chamber size
• Two-dimensional echo – site, size of defect ,pul. stenosis or pul HTN
General principles, techniques, and goals
• Small VSDs – reassurance. Surgical repair is currently not recommended
• Protection against IE - antibiotic prophylaxis for dental visits, tonsillectomy, adenoidectomy, and other oropharyngeal surgical procedures , instrumentation of the genitourinary and lower intestinal tracts
Management:• Large VSDs Medical: Treatment of chest infection Control of heart failure Infective endocarditis prophylaxis Dental hygiene Frequent feeding of high calorie formula, correction of
anemia Non-surgical closure with umbrella device
Surgical
• Repair of defect under open heart surgery• Clamshell-type catheter occlusion -closing
apical muscular VSDs. • Transcatheter device closure - trabecular
(muscular) and perimembranous VSDs
Indications of surgery:• Large defects- if CHF not responding to
medical management (within first 6 months of life)
• After 1 year of age, significant LR shunt, Qp: Qs ratio at least 2:1 without pul HTN
• Supracristal VSD of any size because of the high risk of aortic valve regurgitation
Contraindication of surgery
1. Severe pulmonary vascular disease 2.Muscular septum VSDs , particularly apical
defects and multiple (Swiss cheese–type)
Outcomes
• Excellent, and complications (eg, residual ventricular shunts) are rare.
• Post surgery - size of the heart decreases to normal , thrills and murmurs abolished, and pulmonary artery hypertension
• Catch-up growth-over the next 1-2 years• In some cases- systolic ejection murmurs of
low intensity may persist for months.
Natural history• Depends on the size of the defect• Small VSD – Spontaneous closure( 30-50%)
during 1st yr of life (membranous & muscular defects)
• Small muscular VSDs are more likely to close 80% than membranous VSDs 35%
• The vast majority 45% close by age 4 years
Natural history
• Spontaneous closure has been reported in adults
• Spontaneous closure of a perimembranous VSD (from tricuspid leaflet tissue apposition) or of a small muscular VSD during adulthood is uncommon (<10%)
Mod to Large VSDs
• Less commonly close spontaneously• CHF develops in large VSDs after 8 weeks of
age
• Repeated chest infection ,FTT
• IE –independent of VSD size – rare in < 2yrs .risk is 2% above 2 yrs
Natural History:
• Pulmonary hypertension →pulmonary vascular disease (Eisenmenger syndrome
• Aortic valve regurgitation - the greatest risk supracristal VSD
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