2.  Defects of the structure and great vessels of the heart
present at birth
 Classified into 2 categories
o Cyanotic
o Acyanotic (left-to-right shunts or obstructive)
 Causes:
o Chromosomal abnormalities e.g. trisomy 13, 18 & 21
o Genetic syndrome e.g. Holt-
Oram, Noonan’s, Williams, 22q11 deletion
o Maternal illnesses e.g. diabetes mellitus, rubella, SLE
(Systemic Lupus Erythematosis)
o Environmental exposure
o Alcohol

3.  ACYANOTIC HEART ANOMALITIES
o Left-to-right shunts
 Oxygenated blood shunts from LH
(atrium, ventricle, aorta) to RH (atrium, ventricle)
or pulmonary artery through opening in the heart
 Blood shunts from left to right due to high
systemic and vascular resistance than pulmonary
pressure and resistance.
 Shunt increases pulmonary artery pressure to a
varying degree.
 Greater the increase, the more severe the
symptoms.
 Small shunt is asymptomatic

4.  High pressure shunts
o Occur at the ventricular or great artery level
o Apparent several days to weeks after birth
 Low pressure shunts
o Atrial septal defect
o Apparent later in life
o If untreated, elevated pulmonary artery pressure
may lead to Eisenmenger’s syndrome (elevated
pulmonary artery pressure may reverse left to
right shunt to right to left shunt.
Deoxygenate d blood gets into systemic circulation
causing hypoxia.)

5.  Large left-to-right shunts
o E.g. large ventricular septal defect, patent
ductus arteriosis causes volume overload
o May lead to heart failure (HF) or failure to
thrive
o Decreases lung compliance, leading to frequent
lower respiratory tract infections

6. o Obstructive lesions
 Blood flow is obstructed without
shunting, causing a pressure gradient across
the obstruction
 Increase in pressure distal to the obstruction
may cause ventricular hypertrophy and HF
 Principle manifestation- heart murmur, result
of turbulent blood flow through obstructed
point.
 E.g. congenital aortic stenosis, congenital
pulmonary stenosis

7.  CYANOTIC HEART ANORMALITIES
o Right-to left shunting
o Deoxygenated venous blood is shunted to the
left heart
o Reduces systemic arterial oxygen saturation
o If >5L/dl of deoxygenated Hb, results in
cyanosis
o Infants with dark pigmentation-difficult to
detect cyanosis

8.  Complications of persistent cyanosis
o Polycythemia (large number of RBC’s in the body)
o Clubbing
o Thromboembolism (including stroke)
o Bleeding disorders
o Brain abscess
o Hyperuricemia (excess uric acid in the blood)
o Pulmonary blood flow may be increased, normal
or reduced (depends on the anormality), resulting
in variety severities of cyanosis

9.  Heart failure
o Some congenital heart defects do not alter
hemodynamics e.g. bicuspid aortic valve, mild
aortic stenosis.
o Others cause pressure or volume overload,
sometimes causing HF
o HF occurs when,
 Low cardiac output to meet body’s metabolic
activities
 Body cannot handle venous return, leading to
pulmonary congestion (in left ventricular failure),
or edema(right ventricular failure)

10.  Signs and symptoms of HF
o Tachycardia
o Tachypnea
o Dyspnea with feeding
o Diaphoresis
o Restlessness
o Irritability

11.  Dyspnea with feeding;
 Causes inadequate intake and poor growth
 May worsen
 Other manifestations
 Circulatory shock- may be the first
manifestation of any anormalities (e.g.
hypoplastic left heart syndrome)
 Critical aortic stenosis
 Interrupted aortic arch
 Chest pains may cause irritability

12. o Murmurs
 Left-to-right shunts and obstructive lesions cause
systolic murmurs
 Systolic murmurs and thrills most prominent at
surface closest to point of origin making diagnosis
helpful
 Mid systolic(ejection systolic) murmur caused by
increased flow across pulmonary or aortic valve
 Holosystolic(pansystolic) murmur caused by
regurgitant flow across atrioventricular valve or
ventricular septal defect (VSD)

13.  PDA (patent ductus arteriosis) causes
continuous murmur, uninterrupted by the
second heart sound because blood floes
through DA during systole and diastole.
o Cyanosis
 Characterized by bluish discoloration of mucus
membranes, nail beds or clubbing of nails,
pulse oxymetry <93-95%

14.  Diagnosis
 Pulse oxymetry
 ECG
 C-xray
 Endocardiography
 Cardiac MRI/CT angigraphy- clarify
anatomical details
 Cardiac catheterization with
angiocardiography- confirm diagnosis/assess
severity of anomality

15.  Medical Rx of HF
 Oxygen
 Diuretics-Furosemide 1mg/kg IV
 ACE inhibitors
 Digoxin
 Dopamine/Dobutamine 5-15
micrograms/kg/min
 Salt restriction
 Surgical repair of anormality