By: Dr. Shkar R. Saeed

Etiologic Basis of Congenital Heart Diseases

1. Primary genetic factor (10%) 1) Chromosomal; 5-10% 2) Single mutant gene; 3% Recessive Dominant 2. Genetic-environmental interaction (90%) 1) Multifactorial inheritance; majority 2) Risks to offspring of an affected parent 3) Environmental contribution Drugs Infections Maternal conditions

Potential Cardiovascular Teratogens

1. Drugs Alcohol Amphetamines

Anticonvulsants Chemotherapy Sex hormone Thalidomide Retinoic acid

2. Infections Rubella Coxsakie virus 3. Maternal

conditions Old age Diabetes Lupus Phenylketonuria 4. Others

Maternal Risk FactorsFactors Malformation Advanced age Trisomy 21

Maternal CHD Various Diabetes mellitus VSD, TGA,

cardiomyopathy SLE Heart block Phenylketonuria TOF, VSD, COA, HLHS Viruses Teratogenic,

myocarditis (*cytomegalovirus, herpes, coxsacki B, parvovirus)

Maternal Drug ExposuresDrug Malformation• Diphenylhydantoin PS, AS• Trimetadione VSD, TOF, TGA,

HLHS• Thalidomode TOF, Truncus

arteriosus • Lithium Ebstein anomalies• Alcohol VSD, ASD, PDA, TOF• Amphetamine VSD, ASD, PDA, TGA• Birth control pills VSD, TOF, TGA

classification of Congenital Heart Diseasesclassification of Congenital Heart Diseases

1. Lt to Rt Shunt ( 53 % ) PDA 17 % ASD 16.5 % VSD 13 % AVSD 3.5 %

2. Rt to Lt Shunt (11 % ) TOF 4.5 % TA 3 % PA+VSD 2.5 % PA+IVS 0.5 %

3. Admixture Lesion ( 15 % )

TGA 5 % Univ. Ht. 5 % DORV < 2 % Truncus 0.8 % Corrected TGA < 0.5 %

4. Obstructive Lesion ( 15 % )

Coarctation 9.5 % PS 2 % MS etc. 1.5 % LVOTO 1.3 % HLHS 0.9 % IAA 0.6 % 5. Valvular Lesion Ebstein < 1 % AR < 0.5 % MR < 0.5 % 6. Miscellaneous Arrhythmia 5 % Vascular ring 0.5 %

Evaluation of CHD by History Taking

1. Infants 1) Murmur 2) Symptoms of CHF poor feeding, low weight gain, tachypnea, tachycardia, sweating, anxiety, irritability, frequent

URI 3) Symptoms of

hypoxemia cyanosis, hypoxic spell

2. Children 1) Murmur 2) Symptoms of CHF exercise intolerance, dyspnea on exertion, frequent URI, palpitation 3) Syncope, chest pain 4) Symptoms of

Hypoxemia cyanosis, hypoxic

spell,clubbing

Investigations1.CXRIntegral part of evaluationTOF(boot shaped heart)TGA(egg on side)Dilated PA (PHTN)2.Echo(TTE,TEE)3. MRI4. Cardiac catheterization(exact anatomy, PA pressure messurements,Qp/QA messure, occluders and dilators

To Be Corrected in Neonate

Critical ASHypoplastic left heart syndrome Interrupted aortic archSymptomatic COATGATruncus ArteriosusOther symptomatic complex heart diseases

To Be Corrected in Infancy Cardiac anomalies with pulmonary

outflow tract obstruction

• Critical PS• Tricuspid atresia• TGA• TOF• PA with or without VSD• Corrected TGA

Palliative SurgerySystemic – pulmonary artery shunt Blalock-Taussig shunt

Cavopulmonary shunt (BCPS) Hemifontan & Fontan proceduresRVOT reconstruction Valvotomy

Patch widening Valved conduitPulmonary artery bandingAtrial septectomy

Systemic–Pulmonary Artery Shunt ( Qp<Qs i.e cyanosis)

Systemic–pulmonary artery shunt is indicated due to age, size, anatomy or other conditions when:

Complex anomaly with severe cyanosis, irritability, hypoxic episode

Critically ill neonates or infants due to decreased pulmonary flow

Facilitating growth of hypoplastic pulmonary artery

Pulmonary Artery BandingQp>Qs i.e more Pulm. flow

Pulmonary artery banding is indicated to decrease pulmonary blood flow & protect vascular disease

when:• Control of congestive heart failure Complex or multiple VSD (+/- coarctation) CPB medically contraindicated• Protection of pulmonary vascular bed

Atrial Septectomy For the increasing of effective pulmonary flow and systemic oxygen saturation

Indication of atrial septectomy : TGA Tricuspid atresia Pulmonary atresia MV and LV hypoplasiaDecreasing tendency of indication due to

early total correction or intervention

Reparative Surgery Non-open heart surgeryOpen heart surgery

Palliative procedure Corrective procedure

Anatomic correction Physiologic correction

Non-open Heart Surgery

Corrective procedurePDACOAVascular ring and slingCoronary artery anomaliesStenotic valvular diseases

Instrumental dilatation

Patent Ductus ArteriosusOpen communication usually between upper

descending Aorta and proximal portion of LPA

Significant PDA : indicated after 1st monthProphylactic closure : 6-12 monthsSymptoms of heart failure or failure to

thrive: indicated at any timeSevere pulmonary vascular disease:

contraindicated

Coarctation of the AortaCongenital narrowing of upper thoracic aorta

adjacent to the ductus arteriosus

Operation is indicated when : Reduction of luminal diameter > 50% Upper body HT > 150mmHg in young

infant With CHF at any age COA with VSD COA with other important intracardiac defects One stage repair

ASD with or without PAPVRA hole of variable size in the atrial septum and ismost common cardiac malformation with variouslocation of defect, fossa ovalis, posterior, ostium, primum, coronary sinus, subcaval (sinus venosus)

Uncomplicated ASD or of PAPVC with RV volume overload (Qp/Qs>1.5 or 2.0) : is an indication of

surgery.• Optimal age : under 5 years but recently 1-2 years

to avoid RV volume overload

Total Anomalous Pulmonary Venous Connection

These are no direct connection between anypulmonary vein and the LA. But rather, all thepulmonary veins connect to the RA or one of itstributaries

Diagnosis is an indication of operation• Immediate repair with Diagnosis in any ill neonate : Preoperative preparation is not needed• Repair should be done nearly always before 6 months• Diagnosis at 6-12 months: prompt repair is indicated

Ventricular Septal Defect A hole (or multiple holes) between Lt & Rt

ventricle

• Symptomatic large VSD : an indication of operation

• Before 3 months: indicated in large VSDs with CHF or respiratory symptoms

• Moderate sized VSDs (Qp/Qs < 3.0) with few symptoms : observation during infancy

• Small VSDs (Qp/Qs < 1.5) : not indicated, risk of bacterial endocarditis• Subarterial type : early repair is indicated before

childhood

Atrioventricular Septal DefectAbnormalities of atrioventricular valve form

& function and interatrial & interventricular communication from maldevelopment of the endocardial cushions

Presence of AVSD : indicated with Diagnosis• Partial AVSD : 1-2 years of age except CHF or

growth failure• Complete AVSD with good condition : 3-6

months

• Development of pulmonary vascular obstructive disease : not indicated

Congenital Aortic StenosisThe various forms of LVOTO occur in combination with

other cardiac lesions (IAA, COA, MV anomalies, LV hypoplasia) and obstructive types are supravalvular, valvular, subvalvular, intraventricular

• Critical AS in neonates : urgent (severe CHF, LV dilatation, hypertrophy)

• Infants and children Pressure gradient > 75mmHg Symtoms of angina, syncope, exercise intolerance,

LVH, pressure gradient > 50mmHg Pressure gradient over 40mmHg in subvalvular lesion to prevent progression

Ebsteins anomaly A congenital defect of tricuspid valve in which the

origin of septal and posterior leaflets or both are displaced downward into the right ventricle and the leaflets are variably deformed

Symptomatic Ebstein’s anomaly is an indication • Valve repair and ASD closure : with important TR, moderate and severe

cyanosis• WPW syndromes : ablation of accessory conduction pathway

Pulmonary Stenosis A form of RV outflow obstruction in which

stenosis is usually valvar or both valvar & subvalvularor only subvalvular

• Critical PS in neonate : indicated with Dx

Percutaneous balloon valvotomy Valvotomy with CPB Transannular RVOT patch widening

• PS in infants and children : indicated with Symptoms & Pr gradient over 50mmHg

• Surgical treatment is not indicated with mild stenosis

Tetralogy of FallotCharacterized by underdevelopment of RV

outflow

Diagnosis is an indication of operation• Symptomatic complicated in early life : Early total correction or Shunt (1-2 months) and total correction (1

year)• Asymptomatic uncomplicated : Total correction at 3-24 months• Multiple VSDs, LAD from RCA : Initial shunt and total correction

Double Outlet Right Ventricle A congenital cardiac anomalies which both great

arteries rise wholly or in large part from the RV. It is, then, a type of ventriculoarterial connection.

Dx is an indication of operation• Simple DORV with subaortic VSD : repair by 6

mo with PS --- repair like TOF• DORV with subpulmonic VSD (Taussig-Bing

heart) : arterial switch operation within 1 mo

Transposition of Great Arteries A cardiac anomaly in which the Aorta arises

entirely or in large part from the RV, and PA from LV (atrioventricular concordant connection and ventriculoarterial discordant connection)

• Simple TGA in neonate : arterial switch operation within 1 months• Simple TGA beyond 30 days :

atrial switch operation (Mustard, Senning)• TGA with VSD :

arterial switch operation as early

Tricuspid Atresia A cardiac anomaly in which RV fails to open

into a ventricle through a AV valve. There is thus a univentricular AV connection PVR is an important indicator

> 4 unit -- contraindication2-4 unit -- BCPS< 2 unit -- Fontan operation

• Symptomatic in early life early shunt or PAB

BCPS or hemi-Fontan at 6-12 monthsFontan at 12-24 months

• AsymptomaticFontan candidate : 12-30 months

Congenitally Corrected TGA A cardiac anomaly with ventriculoarterial

discordant connection & atrioventricular discordant connection. The circulatory pathways are therefore in series

The presence of CCTGA per se is not an indication.• With VSD : indications for VSD• With VSD + PS : indications for TOF• With complete heart block : pacing• Double Switch operation : anatomic correction