Congenital Heart Diseases

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

ASD

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

Fairly large perimembranous VSD in

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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