Congenital Heart Disease

Mohamed Waheed Elsharief. MBBS, MSc. MD

Objectives 

By the end of this lecture you should be able to  Define congenital heart disease  Differentiate between cyanotic and Acyanotic CHD.  Illustrate how to investigate a child when suspecting CHD  Outline the management of common CHD 

Definition and etiology 

Any deviation in the sequence of embryogenesis structural, functional or positional defect presents at birth which manifest any time after birth.  Normal embryogenesis depend genes, enivroment infections (diabetes, drugs,)

Congenital Heart Disease (CHD) 

Occurs in 8: 1000 of all live births  Simple way to classify is: – L→R shunts (Acyanotic) – Cyanotic CHD (R→L shunts)

– Obstructive lesions

Acyanotic Congenital Heart Disease Left-to-Right Shunt Lesions 

Atrial Septal Defect (ASD)  Ventricular Septal Defect (VSD)  Atrioventricular Septal Defect (AV Canal)  Patent Ductus Arteriosus (PDA)

Atrial Septal Defect 

ASD is an opening in the atrial septum permitting free communication of blood between the atria. Seen in 10% of all CHD.

Atrial Septal Defect 

There are 3 major types:

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Secundum ASD – at the Fossa Ovalis, most common.

• Primum ASD – lower in position & is a form of ASVD, MV cleft.

• Sinus Venosus ASD – high in the atrial septum, associated w/partial anomalous venous return & the least common.

Atrial Septal Defect Clinical Signs & Symptoms  Rarely presents with signs of CHF or other cardiovascular symptoms.

• Most are asymptomatic but may have easy fatigability or mild growth failure.

• Cyanosis does not occur unless pulmonary HTN is present.

Atrial Septal Defect Clinical Signs & Symptoms • Hyperactive precordium, RV heave, fixed widely split S2.

• II-III/VI systolic ejection murmur @ LSB. • Mid-diastolic murmur heard over LLSB.

Atrial Septal Defect Treatment:  Surgical or catherization laboratory closure is generally recommended for secundum ASD • Closure is performed electively between ages 2 & 5 yrs to avoid late complications. Surgical correction is done earlier in children w/ CHF or significant Pulm HTN. Surgery is not indicated if there Pul HTN occur and shunt is reveresed

Ventricular Septal Defect 

VSD – is an abnormal opening in the ventricular septum, which allows free communication between the Rt & Lt ventricles. Accounts for 30% of CHD.

Ventricular Septal Defect 

4 Types

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Perimembranous (or membranous) – Most common.

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Infundibular (subpulmonary or supracristal VSD) – involves the RV outflow tract.

• Muscular VSD – can be single or multiple.

• AVSD – inlet VSD, almost always involves AV valvular abnormalities.

Ventricular Septal Defect Hemodynamics 

The left to right shunt occurs secondary to PVR being < SVR, not the higher pressure in the LV.

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This leads to elevated RV & pulmonary pressures & volume hypertrophy of the LA & LV.

Ventricular Septal Defect Clinical Signs & Symptoms • Small - moderate VSD, >5mm, are usually asymptomatic and 50% will close spontaneously by age 2yrs. • Moderate – 5-10 large VSD, almost always have symptoms and will require surgical repair.

Ventricular Septal Defect Clinical Signs & Symptoms • II-III/VI harsh holosystolic murmur heard along the LSB, more prominent with small VSD, maybe absent with a very Large VSD. • Prominent P2, Diastolic murmur. • CHF, FTT, Respiratory infections, exercise intolerance hyperactive precordium. Symptoms develop between 1 – 6 months

Ventricular Septal Defect Treatment

• Small VSD - no surgical intervention, no physical restrictions, just reassurance and periodic follow-up and endocarditis prophylaxis. • Symptomatic VSD - Medical treatment initially with afterload reducers & diuretics.

Ventricular Septal Defect Treatment 

Indications for Surgical Closure:

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Large VSD w/ medically uncontrolled symptomatology & continued FTT.

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Ages 6-12 mo w/ large VSD & Pulm. HTN

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Age > 24 mo w/ Qp:Qs ratio > 2:1.

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Supracristal VSD of any size, secondary to risk of developing AV insufficiency.

Atrioventricular Septal Defect 

AVSD results from incomplete fusion the the endocardial cushions, which help to form the lower portion of the atrial septum, the membranous portion of the ventricular septum and the septal leaflets of the triscupid and mitral valves.

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They account for 4% OF ALL CHD.

Atrioventricular Septal Defect 

Question: What genetic disease is AVSD more commonly seen in?

• Answer: Down’s Syndrome (Trisomy 21), Seen in 20-25% of cases.

Atrioventricular Septal Defect 

Complete AVSD

Atrioventricular Septal Defect   

  

Clinical Signs & Symptoms Incomplete AVSD maybe indistinguishable from ASD - usually asymptomatic. Congestive heart failure in infancy. Recurrent pulmonary infections. Failure to thrive. Exercise intolerance, easy fatigability. Late cyanosis from pulmonary vascular disease w/ R to L shunt.

Atrioventricular Septal Defect    

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Clinical Signs & Symptoms Hyperactive precordium Normal or accentuated 1st hrt sound Wide, fixed splitting of S2 Pulmonary systolic ejection murmur w/thrill Holosystolic murmur @ apex w/radiation to axilla Mid-diastolic rumbling murmur @ LSB Marked cardiac enlargement on CX-Ray

Atrioventricular Septal Defect Treatment  Surgery is always required. 

Treat congestive symptoms.  Pulmonary banding maybe required in premature infants or infants < 5 kg.  Correction is done during infancy to avoid irreversible pulmonary vascular disease. 

Mortality low w/incomplete 1-2% & as high as 5% with complete AVSD.

Patent Ductus Arteriosus PDA – Persistence of the normal fetal vessel that joins the PA to the Aorta.  Normally closes in the 1st wk of life. 

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Accounts for 10% of all CHD, seen in 10% of  Female : Male ratio of 2:1 

Often associated w/ coarctation & VSD.  PDA is associated with congenital Rubella syndrome

Patent Ductus Arteriosus Hemodynamics  As a result of higher aortic pressure, blood shunts L to R through the ductus from Aorta to PA. 

Extent of the shunt depends on size of the ductus & PVR:SVR.

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Small PDA, pressures in PA, RV, RA are normal.

Patent Ductus Arteriosus Hemodynamics  Large PDA, PA pressures are equal to systemic pressures. In extreme cases 70% of CO is shunted through the ductus to pulmonary circulation. 

Leads to increased pulmonary vascular disease.

Patent Ductus Arteriosus      

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Clinical Signs & Symptoms Small PDA’s are usually asymptomatic Large PDA’s can result in symptoms of CHF, growth restriction, FTT. Bounding arterial pulses Widened pulse pressure Enlarged heart, prominent apical impulse Classic continuous machinary systolic murmur Mid-diastolic murmur at the apex

Patent Ductus Arteriosus Treatment  Indomethacin, inhibitor of prostaglandin synthesis can be used in premature infants.  PDA requires surgical or catheter closure.  Closure is required treatment heart failure & to prevent pulmonary vascular disease.  Usually done by ligation & division or intra vascular coil.  Mortality is < 1%

Obstructive Heart Lesions 

Pulmonary Stenosis

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Aortic Stenosis

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Coarctation of the Aorta

Pulmonary Stenosis 

Pulmonary Stenosis is obstruction in the region of either the pulmonary valve or the subpulmonary ventricular outflow tract. Accounts for 7-10% of all CHD. Most cases are isolated lesions Maybe biscuspid or fusion of 2 or more leaflets. 

Can present w/or w/o an intact ventricular septum.  Associated with Noonan’s syndrome

Pulmonary Stenosis Hemodynamics  RV pressure hypertrophy  RV failure.  RV pressures maybe > systemic pressure.  Post-stenotic dilation of main PA.  W/intact septum & severe stenosis  R-L shunt through PFO  cyanosis.  Cyanosis is indicative of Critical PS.

Pulmonary Stenosis 

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Clinical Signs & Symptoms Depends on the severity of obstruction. Asymptomatic w/ mild PS < 30mmHg. Mod-severe: 30-60mmHg, > 60mmHg Prominent jugular a-wave, RV lift Split 2nd hrt sound w/ a delay Ejection click, followed by systolic murmur. Heart failure & cyanosis seen in severe cases.

Pulmonary Stenosis Treatment  Mild PS no intervention required, close follow-up. 

Mod-severe – require relieve of stenosis.

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Balloon valvuloplasty, treatment of choice.

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Surgical valvotomy is also a consideration.

Aortic Stenosis 

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Aortic Stenosis is an obstruction to the outflow from the left ventricle at or near the aortic valve that causes a systolic pressure gradient of more than 10mmHg. Accounts for 7% of CHD. 3 Types Valvular – Most common. Subvalvular(subaortic) – involves the left outflow tract. Supravalvular – involves the ascending aorta is the least common.

Aortic Stenosis 

Question: Which syndrome is supravalvular stenosis found in?

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Answer: Williams Syndrome

Aortic Stenosis Clinical Signs & Symptoms  Mild AS may present with exercise intolerance, easy fatigabiltity, but usually asymptomatic. 

Moderate AS – Chest pain, dypsnea on exertion, dizziness & syncope.

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Severe AS – Weak pulses, left sided heart failure, Sudden Death.

Aortic Stenosis Clinical Signs & Symptoms  LV thrust at the Apex. 

Systolic thrill @ rt base/suprasternal notch.

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Ejection click, III-IV/VI systolic murmur @ RSB/LSB w/ radiation to the carotids.

Coarctation of the Aorta 

Coarctation- is narrowing of the aorta at varying points anywhere from the transverse arch to the iliac bifurcation.

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98% of coarctations are juxtaductal

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Male: Female ratio 3:1.

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Accounts for 7 % of all CHD.

Coarctation of the Aorta 

Question: What other heart anomaly is coarctation associated with?

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Answer: Bicuspid aortic valve, seen in > 70% of cases.

Coarctation of the Aorta 

Question: What genetic syndrome is coarctation seen in?

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Answer: Turner’s Syndrome

Coarctation of the Aorta Hemodynamics  Obstruction of left ventricular outflow  pressure hypertrophy of the LV.

Coarctation of the Aorta Clinical Signs & Symptoms  Classic signs of coarctation are diminution or absence of femoral pulses. 

Higher BP in the upper extremities as compared to the lower extremities.

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90% have systolic hypertension of the upper extremities.

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Pulse discrepancy between rt & lt arms.

Coarctation of the Aorta Clinical Signs & Symptoms  With severe coarc. LE hypoperfusion, acidosis, HF and shock. 

Differential cyanosis if ductus is still open

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II/VI systolic ejection murmur @ LSB.

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Cardiomegaly, rib notching on X-ray.

Coarctation of the Aorta Treatment  With severe coarctation maintaining the ductus with prostaglandin E is essential. 

Surgical intervention, to prevent LV dysfunction.

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Angioplasty is used by some centers.

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Re-coarctation can occur, balloon angioplasty is the procedure of choice.

Cyanotic Heart Diseases

Eisenmenger’s Syndrome

Tetralogy of Fallot 

Anatomic Defects – Ventricular septal

defect – Overriding Aorta – Pulmonary artery stenosis – Right ventricular hypertrophy

Picture: www.lpch.org

Tetralogy of Fallot 

Pathophysiology:

Increased resistance by the pulmonary stenosis causes deoxygenated systemic venous return to be diverted from RV, through VSD to the overriding aorta and systemic circulation  systemic hypoxemia and cyanosis Picture: www.lpch.org

Tetralogy of Fallot 

Symptoms: – Dyspnea on exertion or when crying – Tet spells: irritability, cyanosis, hyperventilation

and sometimes syncope or convulsions due to cerebral hypoxemia. – Patients learn to alleviate symptoms by squatting which increases systemic resistance and decreases the right-to-left shunt and directs more blood to the pulmonary circulation.

Tetralogy of Fallot 

Physical exam: – Clubbing of the fingers and toes – Systolic ejection murmur heard at the upper left sternal

border created by turbulent blood flow through stenotic RV outflow tract 

Lab Studies: – – – –

High PCV CXR: prominent RV EKG: RVH, right axis deviation ECHO: displays and quantifies extent of RV outflow tract obstruction

What is the difference between these two films?both are infants with congenital heart disease.

Tetralogy of Fallot 

Treatment: – –

Antibiotic with procedures Surgical closure of the VSD and enlargement of the pulmonary outflow tract

-Patient given beta blockers for prophylaxis against Tet spells

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Treat spells by Position knee chest Oxygen Fluids Morphine B blockers Complications Brain abscess thrombosis, iron deficiency Q can they present with heart failure?

Transposed Great Arteries 

Blue. Presents with cyanosis when the duct closes.

24 Hours to 2 Weeks Cyanotic “Ductal-Dependent” Lesions  CXR

helps in diagnosis

- oligaemic lungfields  PS, pulmonary atresia etc - plethoric lungfields  TGA - congestion  TAPVD

- massive cardiomegaly  Ebstein’s

What is the difference between these two films?both are infants with congenital heart disease.

Cyanotic infant- a lung problem or a heart problem? 

Investigations- suggests heart if: - CXR- clear lung fields and

- ECG- normal and - Hyperoxia test normal ( breathing 100%

oxygen, if pO2 >150mmHg very unlikely to be cyanotic heart disease) - (Echocardiogram is the definitive test)

24 Hours to 2 Weeks Heart failure “Ductal-Dependent” Lesions 

Heart failure is due to left heart obstruction NOT L-R shunts at this age! eg. – Coarctation – Critical Aortic stenosis – Hypoplastic left heart – Mitral stenosis (rare)