Congenital Heart Disease in Children

Treatment of an ASD

- ASD's smaller than 7-8 mm often close spontaneously - *Surgical closure recommended when ratio of pulmonary to systemic blood flow (qP/qS) is > 2:1.* Can present with CHF, FTT - Elective procedure b/w ages 1 & 3 years for symptomatic children w/ large ASD - *Transcatheter (preferred)* or open procedure FTT - failure to thrive

How does an infant with Tetralogy of Fallot survive after birth?

- In utero have a natural right to left shunt to bypass the lungs - For most of these patients, after birth the ductus arteriosis remains open. - Shunt switches from R to L & becomes a left to right retrograde shunt (which helps them - sending deoxygenated blood back to the lungs) - "Ductus dependent" - depending on some of the ductus ateriosis blood flow to go back into the right ventricle - The amount of time a pt survives w/ tetralogy of fallot is dependent on how long the ductus arteriosis remains open

Treatment for VSD

- Surgery indicated for closure of a VSD associated with CHF & failure to thrive, or pulmonary hypertension. - Prior to surgery, symptoms are managed with *high-calorie diet (150 kcal/kg/d) & diuretics* - Pts with cardiomegaly, poor growth, poor exercise tolerance, or other clinical abnormalities typically undergo surgical repair at 3-6 months

3 major types of VSD

1. Small, hemodynamically insignificant *<3 mm* 2. Moderate VSDs - *3-5 mm* 3. Large VSDs - *6-10 mm*

Cyanotic CHD (R→L)

1. Tetralogy of Fallot 2. Total anomalous pulmonary venous return 3. Transposition of the great arteries 4. Truncus arteriosus 5. Eisenmenger's syndrome

Associated findings in Ebstein's Anomaly

1. aortic valve atresia - No opening from the left ventricle into the aorta (valve cannot open properly) 2. coarctation of the aorta 3. bicuspid AV valve 4. Atrial Septal Defect 5. mitral valve prolapse 6. subaortic stenosis 7. hypoplastic pulmonary artery *Associated with maternal use of lithium in the first trimester of pregnancy* "Atresia" refers to a missing heart structure

Class III conditions for Maternal CHD Pregnancy Risk

1. presence of mechanical valve 2. systemic right ventricle 3. Fontan circulation (surgical creation for infants with a common ventricle) 4. unrepaired cyanotic heart disease 5. other complex congenital heart disease 6. aortic dilatation 40-45mm in *Marfan syndrome* 7. aortic dilatation 45-50mm associated with bicuspid aortic valve. Marfan syndrome (MFS) = genetic disorder that affects the connective tissue. Pts tend to be tall and thin, long arms, legs, fingers and toes.

Class IV conditions for Maternal CHD Pregnancy Risk

1. pulmonary arterial hypertension (maternal mortality 17-50%) 2. severe symptomatic LV dysfunction (LVEF<30%, NYHA III-IV) 3. previous peripartum cardiomyopathy with any residual impairment of LV function 4. severe mitral stenosis 5. severe symptomatic aortic stenosis 6. Marfan syndrome with aortic dilatation > 45mm 7. aortic dilatation > 50mm associated with bicuspid aortic valve 8. severe aortic coarctation

Class II conditions for Maternal CHD Pregnancy Risk

1. unoperated atrio-septal defect (ASD) 2. unoperated ventricular septal defect (VSD) 3. repaired Tetralogy of Fallot 4. most arrhyhmias

Coarctation of the Aorta

Narrowing of the thoracic aorta just distal to the left subclavian artery • *Often associated w/ a bicuspid aortic valve (30 - 40%), Turner syndrome, & brain aneurysm* • males > females • Cannot be diagnosed until adulthood, important to check pulses in all extremities in routine pediatric exams (weaker pulses in the lower extremities)

Non-cyanotic CHD with no shunting involved

Obstruction to blood flow 1. Pulmonic stenosis (PS) 2. Aortic stenosis (AS) 3. Aortic coarctation (aka coarctation of the aorta)

Care of the Adult with Congenital Heart Disease

Optimize usual cardiac RFs: HTN, lipids, DM Depending on the specific lesion(s) & repair, at risk for 1. Pulmonary vascular disease/ HTN 2. Aortic dissection & aneurysm (bicuspid AV, coarctation) 3. *Erythrocytosis* (due to chronic hypoxemia) 4. Poor pregnancy outcome - *Women with aortic coarctation or pulmonary HTN should not become pregnant* - *OC's are contraindicated* for women w/ cyanotic congenital HD due to increased risk for thrombosis Pediatric cardiologists are the only ones who deal w/ congenital heart disease Cardiologists do not see pts w/ congenital heart disease

Clinical Presentation of Atrial Septal Defects

usually asymptomatic • Order 2D echo if ASD is suspected Features suggesting ASD: 1. *Fixed splitting of the 2nd heart sound (90%)* 2. *A midsystolic pulmonary flow or ejection murmur (94%)* 3. Right ventricular conduction delay on ECG (79%) 4. Enlargement of the right atrium & right ventricle on imaging studies Variability to the widening of S2 when a person breathes in & out Will remain fixed when a person has ASD

Clinical Findings in Tetralogy of Fallot

vary depending on degree of RVOFT obstruction • *Hypoxemic spells ("tet spells")* - hallmark of severe tetralogy • Tet spells commonly start ~4-6 months of age & are characterized by: 1. *Sudden onset or deepening of cyanosis* 2. *Sudden onset of dyspnea* 3. *Alterations of consciousness* 4. *Decrease in intensity of systolic murmur* Older child with tet spell will *"stop & squat"* in order to *increase afterload on the LV thereby increasing proportion of blood moving from left to right.* changing the pressure gradient in the heart so that more blood will go into the pulmonary artery

Congenital Heart Disease

• *Cardiac anomalies are the most common type of structural birth defect* • Most are diagnosed in *first month of life* • 15% are potentially life-threatening. • Some are diagnosed prenatally, allowing for more time to plan for care after birth. • Many pts survive well into adulthood w/ prompt diagnosis & treatment.

Incidence of Patent Ductus Arteriosis

• Accounts for ~10% of all cases of CHD • *higher incidence of PDA in infants born at high altitudes* (over 10,000 feet) - lower partial pressure of O2 at higher altitude • *more common in females* Need more blood flow One way to get more blood flow to the lungs is through a patent arterioles

Incidence of Congenital Heart Disease

• CHD prevalence 6 - 10/1000 live births • Premature infants have ~2X the rate of CHD as full term infants • ~7% have identifiable chromosomal abnormalities • 22% have extra-cardiac anomalies

Moderate VSDs

- 3-5 mm in diameter - Least common group of children (3-5%) - w/o evidence of CHF or pulmonary HTN, can be followed until spontaneous closure occurs

Repairing Defects in Tetralogy of Fallot

1. Repair can be staged - modified Blalock-Taussig Shunt (BT shunt) or 2. Complete (repair of small PV tet Ductus arteriosis (becomes ligamentum arteriosum) is also fixed during the repair

Presentation of CHD in Infants & Children

In infants: lethargy, poor feeding, poor weight gain, respiratory distress or cyanosis with feeding, grunting respirations In children: easy fatigue, respiratory distress, diaphoresis with minimal exertion, poor weight gain

Large VSDs

- *Might not have much of a murmur, less turbulent flow b/c the defect is larger* - 6-10 mm in diameter - *Requires surgery*, otherwise... - Will develop failure to thrive & CHF by age 3-6 months.

Paradoxical Embolism

*Asymptomatic adults w/ ASD or PFO can develop embolic stroke during Valsalva-type maneuvers due to a reversal in pressure gradient b/w the RA & LA* - This momentary shift allows a clot to pass to the *left side* of the circulation & into the brain. - *In people <50 y/o, this is the most common cause of cryptogenic stroke* & should be investigated with echo (look for congenital heart defect) - Treatment: *anti-platelet Tx, anticoagulation, closure* This can happen w/ Eisenmengers syndrome (clot in the right side of the heart becomes dislodged) during Valsalva maneuver

Clinical Presentation of Tetralogy of Fallot

*Most common cyanotic lesion* (7-10% of all CHD) Typical features 1. *Cyanosis after the neonatal period* 2. *Hypoxemic spells during infancy* 3. Right-sided aortic arch in 25% of all pts 4. *Systolic ejection murmur at the upper LSB* (at base of heart)

Foramen Ovale

- is a physiologic conduit b/w the right & left atria of every human fetus. Allows blood to bypass the fetal lungs (similar to ductus arteriosus) since fetal lungs do not participate in gas exchange. - A layer of tissue called the *septum primum* acts as a *one way valve* over the foramen ovale during fetal development. - After birth, the *pressure* in the right side of the heart *drops* as the lungs open & begin working, causing the foramen ovale to close entirely. - In ~25% of adults, the foramen ovale does not entirely seal. - *When a newborn takes its first breath, the foramen ovale & ductus arteriosus both close* - *PFO is not a congenital defect* Rather it represents the failure of a normal physiologic event to occur --> Hence, PFO can only occur after birth.

Most Common Heart defects (from greatest to least)

1. *Bicuspid aortic valve >50%* 2. Ventricular septal defect 20-30% (most common intracardiac defect) 3. Atrial septal defect (secundum) 6-8% 4. Patent ductus arteriosus 6-8% 5. Coarctation of aorta 5-7 % 6. Tetralogy of Fallot 5-7 %

Findings requiring urgent referral

1. *Cardiogenic shock*: respiratory distress (tachypnea & wheezing), poor perfusion (deceased capillary refill, cool skin, & decreased distal pulses) & hepatomegaly 2. *Cyanosis*: SpO2 < 85% 3. *Tachyarrhythmias* - HR >220 in infants, >180 in children 4. Syncope esp w/ exertion, chest pain &/or palpitations 5. Septic shock r/o Sepsis from Group B strep, listeria & gram negative organisms in infants

Tetralogy of Fallot

1. *Pulmonic stenosis* 2. *Right Ventricle Hypertrophy* - secondary to pulmonic stenosis 3. *Over-riding Aorta* - displaced so that some of the blood comes from left ventricle & some comes from the right ventricle 4. Ventricular Septal Defect (VSD) Narrow pulmonary valve causes blood to go to the path of least resistance --> through the ventricular septal defect

Clinical Findings in Epsteins Anomaly

1. *S3 & S4 gallops* 2. *holosystolic murmur along the LLSB* 3. RV conduction defects 4. *P pulmonale - "Himalayan" P waves* - P waves are tall 5. tachy-dysrhythmias including *WPW* Depending on severity of the malformation & direction of flow through the ASD, can be cyanotic or non-cyanotic.

Noncyanotic CHD (L --> R)

1. Atrial septal defects (ASD) 2. Patent foramen ovale (PFO) 3. Ventricular septal defects (VSD) 4. Patent ductus arteriosus (PDA)

Defects in the Wall of the Atrium

2 main defects that occur b/w the atria: 1. *atrial septal defect (ASD)* - always abnormal - usually *bigger* than a PFO (size is the difference b/w the 2) 2. *patent foramen ovale (PFO)* - called "patent" when it fails to close after birth - Although both are "holes" in the atrial septae, their causes are quite different. - Under resting conditions, neither presents with murmur due to *small pressure differentials* - *A secundum ASD* is the failure of the septal tissue to form b/w the atria during embryogenesis (--> Congenital defect) don't have a lot of turbulence & blood flow flowing through the holes which is why you don't here much of a murmur

Atrial Septal Defect (ASD)

= noncyanotic • Connection b/w right & left atria • *Can be entirely asymptomatic* • Large defects can cause heart failure • Symptoms can worsen w/ age esp if pulmonary hypertension develops (i.e. from emphysema) • Treatment, if needed, can be a *surgical patch or transcatheter closure*

Ebstein's Anomaly

A congenital heart defect in which the *septal & posterior leaflets of the tricuspid valve are displaced towards the apex of the right ventricle of the heart* while the *annulus of the valve remains in its normal position* • To a varying degree, the valve leaflets attach to the walls & septum of the right ventricle. • Consequently, *"atrialization"* of the upper segment of the right ventricle occurs. This *causes the right atrium to be large & the anatomic right ventricle to be small in size*

Transposition of the Great Arteries (Vessels)

Aorta & pulmonary artery mixed up Dependent on ductus arteriosis remaining open on birth

Small, hemodynamically insignificant VSD

B/w 80-85% of all VSDs • < 3 mm in diameter • All close spontaneously - 50% by 2 years - 90% by 6 years - 10% during school years

Non-cyanotic Congenital Heart Disease

Blood from L --> R • No issues w/ cyanosis & desaturation (blood is not bypassing pulmonary circulation) • However, *the added volume of blood being dumped into the pulmonary circulation overloads the vasculature resulting in pulmonary HTN*

Cyanotic vs Non-cyanotic Congenital Heart Disease

Cyanotic (R --> L) & Non-cyanotic (L --> R) varieties are based on the direction of shunting.

Clinical findings for VSD

Grade II-IV/VI, *medium- to high-pitched, harsh pansystolic murmur* heard best at the *left sternal border* with radiation over the entire *precordium*

Risk of pregnancy by medical condition (Modified WHO Classification of Maternal Conditions)

I - No detectable increased risk of maternal mortality and no/mild increase in morbidity. II - Small increased risk of maternal mortality or moderate increase in morbidity. *III* - *Significantly increased risk* of maternal mortality or severe morbidity. If pregnancy is decided upon, intensive specialist cardiac & obstetric monitoring needed throughout pregnancy, childbirth, and the puerperium. *IV* - *Extremely high risk* of maternal mortality or severe morbidity; pregnancy contraindicated. Elective sterilization should be discussed. If pregnancy occurs, termination can be discussed. If pregnancy continues, care as for class III.

Eisenmenger's Syndrome

Long-standing left-to-right cardiac shunt caused by a congenital heart defect (typically VSD, ASD, or less commonly, PDA) eventually leads to pulmonary hypertension of sufficient severity to produce reversal of the shunt from right to left, producing a cyanotic condition. This phenomenon is known as Eisenmenger's syndrome. blood starts flowing from right to left - go from non-cyanotic to cyanotic

Clinical Presentation of VSD

Moderate to large VSD's often manifest signs of heart failure *by 3-4 weeks of age* Treatment depends on severity: - Lesser symptoms can often be well managed with medications. - More severe symptoms require surgical repair. Timing of surgery is an individualized decision. Medications that reduce the afterload in the left side (reduce PVR in circulation) lower the resistance of the aorta - so blood will follow this route Vasodilator --> 1. CCB (Amlodipine) acts on the vessels & not on the heart (do not want one w/ negative inotropic effects) 2. ACE or ARB

ASD/PFO in Adults

Pts w/ uncorrected, moderate to large ASDs, experience L-to-R shunting that increases w/ age & becomes symptomatic CHF often before 40 • S&S include *atrial arrhythmias* (the most frequent presenting symptom), *exercise intolerance, dyspnea, & fatigue* • A link b/w PFO & migraine headache has been proposed but not proven. (HA resolved when the PFO was closed) PFO can be the source of an embolus, can activate platelets & the coagulation cascade --> risk is thrombosis & embolus

Anticoagulation of the Patient with CHD

This is an enormous subject The need for, duration of, & type of anti-coagulation (anti-platelet vs. anti-cofactor) depends on: 1. the age of the pt 2. whether or not the pt has undergone correction of the abnormality 3. the type of procedure that was performed 4. the presence of dysrhythmias, artificial valves or artificial patch materials - patch material is more thrombogenic**

Truncus Arteriosus

Truncus arteriosus is a rare type of congenital heart disease, in which a single blood vessel (*truncus arteriosus*) comes out of the right & left ventricles. - Associated with a ventricular septal defect infant is dependent on the septal defect for life

Ventricular Septal Defect (VSD)

VSD - noncyanotic • opening b/w right & left ventricles • *most common intra-cardiac defect* (20-30%) • Can be isolated or occur in combination w/ other cardiac defects. • Most are detected in the 1st month of life. • Small VSD's can be asymptomatic except for a murmur & usually close spontaneously

Cyanotic Congenital Heart Disease

When blood is shunted R --> L, it bypasses the lungs & does not participate in gas exchange --> remains de-oxygenated. Deoxygenated blood mixes w/ oxygenated blood (from pulmonary veins) --> O2 stat of hemoglobin falls somewhere in b/w --> Tissues (systemic circulation) will extract as much O2 as needed but, if enough *deoxyhemoglobin is produced, cyanosis will become evident*

Total Anomalous Pulmonary Venous Return

aka Total Anomalous Pulmonary Venous Connection (TAPCV) A cause of cyanotic congenital heart disease & R-->L shunt 4 pulmonary veins form a common pulmonary vein which drains into the SVC or the right atrium (normally drains to left atrium) Often discovered shortly after birth to survive TAPCV, many neonates usually have an atrial septal defect that has a R to L shunt (sending the oxygenated blood from the pulmonary veins to systemic circulation)

Pregnancy in Women with CHD

• High risk for the mother if *pulmonary HTN, LV outflow tract obstruction, CHF or arrhythmia* • The fetus is most at risk with maternal cyanosis, heart failure & pulmonary HTN. • A mother with CHD has *~4% risk of having a baby with CHD. Normal risk for CHD is 1%* • Don't forget pregnancy induced CVD including *peripartum cardiomyopathy, pregnancy induced HTN (PIH), pre-eclampsia, & that secondary to postpartum thyroiditis* etc. These can occur in women with CHD just as in women w/o CHD but the results can be more devastating. • Women who require anticoagulation & become pregnant need to take special precautions. • *Warfarin poses significant risk to the fetus, esp in the first trimester.* Many women on warfarin are switched to *heparin* during the first weeks of pregnancy. *Some might remain on heparin, or be started back on warfarin during the middle of the pregnancy & switched back to heparin for the delivery.*

Patent Ductus Arteriosis

• Persistence of normal fetal vessel joining the pulmonary artery to the aorta. • Closes spontaneously in normal term infants at *3-5 days of age* • *Often does not close spontaneously in premature infants* • Untreated PDA's can lead to right-sided volume overload & pulmonary hypertension.

Clinical Findings in Patent Ductus Arteriosus

• Pulses are bounding & pulse pressure is widened • Characteristically has a rough *"machinery" murmur* which peaks at S2 & becomes a decrescendo murmur & fades before the S1.

Presentation of Aortic Coarctation

• Severely affected infants can present w/ CHF • Children can have *claudication w/ exercise* (have cramps in their legs - stop b/c of pain) • Adolescents & adults classically present w/ *HTN in the upper extremities* • *Cardiomegaly & notched ribs* on CXR (*Why?) • Un-operated pts have a *75% mortality rate by the age of 46, & have HTN, accelerated CAD, CVA & aortic dissection* Blood supply of pt compensates through collaterals --> intercostal arteries, get widening of the arteries that encroaches on lower surface of the ribs --> notched ribs

Treatment for PDA

• Surgical correction when the PDA is large & pts have severe pulmonary HTN • Transcatheter closure of small defects has become standard therapy • *Prostaglandin E1 (PGE₁) treatment can be life saving in pts suffering from ductus dependent congenital heart defect.* • In preterm infants, *indomethacin* 0.2 mg/kg q12h x 3 is used to close a PDA (80-90% success in premature infants > 1200 grams) it is lifesaving b/c it allows the blood to get from right to left side *PGE 1 keeps ductus arteriosis from closing* indomethacin is a non-steroidal, an anti-PGE1 **know which one you give to close & which one 2 open**

Treatment of Aortic Coarctation

• Treatment is surgical at time of dx • Manage & stabilize CHF pre-operatively • Types of procedures include *open surgery & balloon angioplasty* (80-90% success, preferred over age 6 mos) w/ or w/o stent

Physical Exam Findings in CHD

• tachycardia • hypertension, uneven pulses • failure to thrive • poor perfusion • wheezing and/or grunting • murmurs (loud, harsh, diastolic, gallop or rub) • hepatomegaly