Download Congenital Heart Disease

Congenital Heart Disease
Chronic Exam One: 4 questions
Wong: pgs. 936-65
L. Jones
1
Congenital Heart Disease
Incidence and Etiology
 Occurs in approximately 8 out of 1000 live births
 Rate is higher in preterm infants-PDA most common in preterm
 Most common defect is VSD
 Most cases the cause is unknown
Incidence: Factors Associated with Higher Incidence
 Inheritance
 Genetic predisposition
 Viruses
 Alcohol
 Drugs
 Poor maternal nutrition
 Chromosomal aberration-e.g Trisomy XXI, XIII, XVIII, Turner’s Syndrome
Pediatric Differences
 Heart and great vessels develop during the first weeks of gestation-14th-55th day
 Heart sounds of the young infant have a higher pitch and are of greater intensity
than in the adult
 Pulse rate is higher in the infant
 Chest wall of the infant and young child is relatively thin
 Innocuous murmurs can be auscultated in structurally normally hearts-e.g.
innocent murmurs
Diagnostic Tests
 History taking
 Physical examination including cardiac auscultation and blood pressure of all 4
extremities-In infants: Check bp in upper arms and lower legs (calves—not
thighs)!
 ECG
 CXR
 Echocardiography
 MRI-can visualize tumors, shunts, etc.
 Cardiac catheterization-invasive—used under fluoroscopy. Can check
oxygenation, use dye or contrast media, often use right-sided cath and go through
foramen ovale to check the left side of the heart.
Fetal Circulation-In Utero
 Pressure increased on right side of heart-b/c no need to exchange gasses
 Pressure decreased on left side of heart
 Pulmonary is high pressure system
 Open foramen ovale and patent ductus arteriosus (PDA)-PDA is between the
pulmonary artery and the aorta.
Congenital Heart Disease
Chronic Exam One: 4 questions
Wong: pgs. 936-65
L. Jones
2
Pressure Changes after Birth
 Pulmonary becomes low pressure system
 Pressure decreases on right side of heart
 Pressure increases on left side of heart
 PDA closes due to oxygen constricting the ductus
 Foramen ovale (opening between the atria) closes due to pressure changes in the
heart
Heart Pressures: Newborn
 Right atrium 2-4 mmHg
 Right ventricle 20-35 mmHg
 Left atrium 8-14 mmHg
 Left ventricle 60-90 mmHg
Newborn pressures in Heart Chambers
Atria
Rt. At. 2-4 mm Hg
Lft. At. 8-14 mm Hg.
Ventricles
Rt. Vent. 20-35 mm Hg
Lft Vent. 60-90 mm Hg
(whatever systolic bp is)
Changes in Vessels in Lungs
 With each defect, need to determine if blood flow is going to the lungs
 Under increased pressure
 With increased flow
 If hypoxia exist
 All three cause pulmonary vasoconstriction
Changes in Vessels in Lungs
 If only increased flow, it takes a longer time to get irreversible pulmonary
hypertension (15 to 30 years)—e.g. as with an atrial/septal defect
 If increased flow and increased pressure, irreversible damage can result after only
one to two years
 Check pics on handout that accompanied this lecture!
Acyanotic Heart Defects
 Patent Ductus Arteriosus (PDA)
 Atrial Septal Defect (ASD)
 Ventricular Septal Defect (VSD)
 Coarctation of the Aorta (COA)
Congenital Heart Disease
Chronic Exam One: 4 questions
Wong: pgs. 936-65
L. Jones
3
1. PDA: Patent Ductus Arteriosus
 Connection between pulmonary artery and aorta
 Normal pathway in fetal circulation
 Functional closure occurs within a few hours after birth
 Permanent closure occurs in the first few weeks of life
 Failure of ductus arteriosus to close results in a left to right shunt
 Lungs are receiving increased blood flow under increased pressure
 If not corrected, irreversible pulmonary vascular disease can result
 Common in premature infants
o Symptoms
 Murmur - machinery-like
 Widened pulse pressure
 Bounding peripheral pulses-btw. 20-50 mm Hg
 Frequent respiratory infections
 FTT-failure to thrive
 S/S of CHF –b/c of increased flow to lungs and pulmonary edema
o Older Child
 If found in 12-year-old who is asymptomatic would still fix b/c of
possible bacterial endocarditis development.
 Avoid Subacute Bacterial Endocarditis/Infective Endocarditis
o Management
 Some PDA’s may close spontaneously
 May use indomethacin-a non-steroidal anti-inflammatory that
inhibits prostaglandin synthesis and causes ductus to close. Most
successful when given in 1st 7-10 days of life
 Surgical closure-ligation of defect
 Newer technique called visual assisted thorascopic surgery
(VATS)-clip to be placed on ductus using 3 small thorascopic slits
on chest
2. ASD Atrial-Septal Defect
 12 to 15% of all congenital cardiac defects
 Opening between the right and left atrium
 May be patent foramen ovale
 May involve valve leaflets
 Can vary in size, location in septum
o Characteristics
 Left to right shunt-acyanotic
 Increased flow to lungs without increased pressure
 Grace II/VI ejection systolic murmur; second left intercostal
space.
 Usually asymptomatic
Congenital Heart Disease
Chronic Exam One: 4 questions
Wong: pgs. 936-65
L. Jones
4
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More common in females than males
Murmurs graded I- IV: Grade I, II may not hear. Grade III, IV,
will hear.
o Symptoms
 Growth retardation
 Diaphoresis
 Poor feeding
 Mild fatigue (older child)
 Dyspnea (older child)
 Many patients are asymptomatic
o Management
 Surgical closure/open heart-to close defect with dacron or silastic
or pericardium patch
 Interventional cardiac catheterization/transcatheter closure
 Without surgery child is at risk for infectious endocarditis
 Surgical closure before school age plus antibiotic prophylaxis
before surgery
3.
VSD: Ventricular Septal defect
 The most common defect
 Abnormal opening between left and right ventricles
 Can very in size, location in the septum and number
 Often associated with other more complex defects
o Characteristics
 Left to right shunt
 Increased blood flow going to the lungs under increased pressureb/c of left ventricular pressure
 Approximately 60% will close spontaneously
 Murmur - grade IV/VI loud, harsh, pansystolic murmur; 4th
interspace; left of sternum
 May wait to close these if patient is asymptomatic
o Symptoms
 Growth retardation
 Failure to thrive
 Diaphoresis
 Poor feeding
 Tachypnea
 Frequent respiratory infections
 S/S of CHF
o Management
 May close spontaneously
 Pulmonary artery banding - not used that often-to make it harder
for the blood to flow through
Congenital Heart Disease
Chronic Exam One: 4 questions


Wong: pgs. 936-65
L. Jones
5
Open heart surgery
Device closure-e.g. pursestring suture if very small defect. May
have some leakage and/or conduction disturbances initially after
closure
o Prognosis
 Risks depends on the location of the defect, number of defects and
other associated cardiac defects
 Single membraneous defects - <5% risk of death
 Multiple muscular defects - 20% risk of death
Eismenger’s Complex
 Can occur with any left to right shunt
 When child develops sufficient pulmonary vascular disease and pulmonary
hypertension to cause the shunt to become right to left
 Shunt reversal
 Pressure on the right side has had to increase in order to pump blood to lungs and
shunt reverses to Right-left shunt which is a cyanotic condition. Fatal outcome or
heart and lung transplant is needed.
Coarctation of the Aorta
 Narrowing of the aorta
 Usually located near the insertion of the ductus arteriosus
 Can vary from mild constriction to total occlusion
 The degree of narrowing determines the severity of the symptoms
 Pressure builds proximal to the defect and decreases distal to the defect
 SYMPTOMS
o Upper extremity hypertension
o Bounding pulses in arms
o Weak or absent femoral pulses
o Cool lower extremities
o May be asymptomatic
o Murmur may be present
 Symptoms in Older Child
o Dizziness
o Headache
o Fainting
o Epistaxis-nose bleeds
o Risk for hypertension, ruptured aorta, aortic aneurysm, stroke
 Surgical Treatment
o Resection of the coarcted portion with an end-to-end anastomosis of the
aorta (for children 6+ yrs old)
o Enlargement of the constricted section using a graft of prosthetic material
or a portion of the subclavian artery
o 2 ½ yrs can do subclavian flap repair—take subclavian and use it is a
Congenital Heart Disease
Chronic Exam One: 4 questions
Wong: pgs. 936-65
L. Jones
6
patch over the aorta.
 Postoperative Complications
o Hypertensive response after surgery –vessel has high pressure when
opened up and may spasm
o Post coartectomy syndrome-when GI tract gets a lot of blood and its not
used to it, SPO 2 days to avoid this complication
 NonSurgical Treatment
o Balloon angioplasty
o Is now being performed as a primary intervention for coarctation in some
centers - limited use at present b/c of aneurism formation and b/c of
weakened vessel
 Prognosis
o Surgical mortality is < 5% in patients with isolated coarctation, but
increases in infants with associated defects
o Some children may have continued hypertension after the repair and need
antihypertensive medications
Cyanotic Heart Defects
 Problems
o Decreased oxygen circulating causes increase in RBCs (polycythemia)
o Helps for a while until hematocrit 60 to 70
o Blood becomes too thick and can get emboli and infarcts
o Clubbing-broad fingers and decrease in angle of the nail
 Tetralogy of Fallot Classic form includes 4 defects
o Ventricular septal defect
o Pulmonary stenosis
o Overriding aorta-aorta placed on the right—sits on top of VSD
(Ventricular septal defect)
o Right ventricular hypertrophy
o Pattern of blood flow is determined by the degree of pulmonary stenosis
o Severe pulmonary stenosis will cause right-to-left shunt producing
cyanosis
o Mild pulmonary stenosis will cause left-to-right shunt (pink tetralogy of
fallot)
o With classic TOF, the pulmonary stenosis will become more severe with
time and the child will become more cyanotic as blood flow to the lungs is
decreased
o Clinical Manifestations
 Infants
 Cyanosis
 Murmur
Congenital Heart Disease
Chronic Exam One: 4 questions

Wong: pgs. 936-65
L. Jones
7
Hypoxic or “tet” spells –transient ischemic spells; become
limp and unconscious. Put babies in Knee/chest
position!!!
o Clinical Manifestations
 Children
 Clubbing
 Squatting-b/c it increases blood flow and increases cardiac
output
 Poor growth
o Management
 Palliative Shunt Called the Ballock-Taussig—temporary shunt
 Corrective Surgery - usually performed in the first year of life
 Open pulmonary stenosis
 Patch Ventricular Septal Defect (VSD)-around the aorta b/c
the aorta is displaced.
o Prognosis
 The operative mortality for total correction of TOF is less than 5%.
 With improved surgical techniques there is a lower incidence of
dysrhythmias and sudden death
Transposition of the Great Arteries
 Aorta arises from the right ventricle instead of the left ventricle
 Pulmonary artery arises from the left ventricle instead of the right ventricle
 Altered hemodynamics yields 2 parallel pathways
o Clinical Manifestations
 Depend on the type and size of associated defects
 Cyanosis from birth, hypoxia
 Various murmurs or no murmur
 Symptoms of CHF
o Therapeutic Management
 Need to provide intracardiac mixing
 Mixing of the 2 separate circulations must occur
 If PDA present, medications (Prostaglandin E ) are given to keep it
open
o Palliative Procedure
 Rashkind procedure/atrial balloon septostomy - done to increase
mixing and maintain cardiac output
 Performed during cardiac catheterization
 Enlarge the interatrial communication
o Surgical Correction
 Arterial Switch Procedure
 Procedure of choice performed in first few weeks of life
 Establishes normal circulation
Congenital Heart Disease
Chronic Exam One: 4 questions


Wong: pgs. 936-65
L. Jones
8
 Major vessels are actually switched in position
Mustard/Senning:Don’t see this much anymore
 Atrial switch
 Creates an intra-atrial baffle to direct venous blood to the
mitral valve and pulmonary venous blood to the tricuspid
valve
Prognosis
 Postoperative mortality of arterial switch is 8%
 Some patients will have sudden cardiac death
 Death will occur if condition is not promptly diagnosed and
treated