Congenital Heart Defects PDF

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Congenital Heart Defects...

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● Older classifications of CHD ○ Acyanotic(lt---> rt shunt) – can become cyanotic ■ 1) ASD ■ 2) VSD ■ 3) PDA ○ Cyanotic – can be pink/can develop ○ (5 T's, with 1-5 mnemonic) ■ Truncus arteriosus (1 vessel) ■ Transposition of the great vessels (2 vessels switched) ■ Tricuspid valve atresia (3 valve cusps) ■ Tetralogy of Fallot (4 components) ■ Total anomalous pulmonary venous return (5 words) ● Newer Classification of CHD ○ Hemodynamic characteristics ■ Increased pulmonary blood flow ■ Decreased pulmonary blood flow ■ Obstruction of blood flow out of the heart ■ Mixed blood flow ● Classification of Congenital Heart Defects

● Increased pulmonary blood flow defects (acyanotic-oxygenation is not an issue) ○ Abnormal connection between the two sides of the heart ■ Either the septum or the great vessels ○ Result = Increased blood volume on the right side of the heart ○ Leads to Increased pulmonary blood flow

○ Leads to Decreased systemic blood flow ○ result=Heart Failure Symptoms ● Atrial Septal Defect - ASD ○ Defect between the left and right atrium ■ Blood flows back into the right atrium ● Adds to the lungs--HF symptoms ○ Increased blood volume on the right side of the heart. ○ Increased pulmonary blood flow ○ Decreased systemic blood flow ○ Clinically: ■ Asymptomatic OR Heart Failure Symptoms ■ + Murmur ● Smaller the hole the louder the murmur will be, softer the bigger the hole (resistance) ● swishes ● Fixable ○ surgery or cardiac cath ● Good prognosis ○ Result= Heart failure symptoms (volume overload)

● Ventricular Septal Defect (Most Common)- VSD ○ Oxygenated blood is flowing back into the right ventricle ■ Right sided HF due to the over workload ○ Increased blood volume on the right side of the heart. ○ Increased pulmonary blood flow ○ Decreased systemic blood flow ○ Clinically: ■ Heart Failure Symptoms (common) ● Fluid on the lungs, weight gain, swelling, increased pulmonary blood flow, decreased systemic blood flow ■ + Loud Holosystolic Murmur ● Smaller the hole the louder the murmur ● Bigger the hole the more symptomatic ■ Fixable (surgery) ● Might just close on its own ○ Every kid is different

■ Many close spontaneously in 1st year of life ■ Prognosis depends on location, #, and other associated defects (single membranous = good prognosis) ○ Result= Heart Failure symptoms (volume overload)

● Patent Ductus Arteriosus -PDA ○ Failure of fetal ductus arteriosus to close. ○ Blood flows from the aorta to pulm artery ○ Added more blood flow to the lungs ○ Left-> Right shunt ○ Clinically: ■ Asymptomatic or heart failure ■ + Machine murmur ■ Indomethacin (prostaglandin inhibitor) may be given to try to close ■ Fixable (surgery or cardiac cath) ■ Good prognosis ○ Result= heart failure symptoms (volume overload is large) ● Atrioventricular Canal Defect -ACD ○ Low ASD + high VSD with mitral & tricuspid valve involvement = large central AV area. ■ Looks like a doughnut ● A hole between the atriums and the ventricles ● Can involve the valves now ● Depends on the individual ○ Flow determined by individual hemodynamics but typically left ----> right. ■ Worse HF symptoms ■ No push of the valves as well (may or may not) ○ Most common defect in Trisomy 21(Down Syndrome) ○ Clinically: ■ Moderate to severe Heart Failure ■ + Loud Systolic Murmur ● There's an additive effects due to the holes in the values ■ Mild cyanosis that increases with crying ● Its so big ■ Surgery to repair, potential post-op problems ○ Result= heart failure symptoms

● Obstructive Defects ○ Obstruction of blood flow from ventricles: ■ 1) Coarctation of the aorta ■ 2) Aortic stenosis ■ 3) Pulmonic stenosis ● Coarctation of the Aorta ○ COA= narrowing of the aorta near ductus arteriosus ○ Increased pressure proximal to defect = Increased to head & upper extremities ○ Decreased pressure distal to the defect = Decreased pressure to body & lower extremities ○ Clinically: ■ Hyperdynamic perfusion upper extremities & poor perfusion lower extremities ■ Brachial-Femoral delay ● Brachical vs. femoral (feeling for the misbeat, or strength is different) ■ Infants = HF symptoms even hemodynamically instability ● Bigger the pinch, the more symptoms/problems that well have ■ Older = Dizziness, HA, fainting, nose bleeds d/t hypertension, exercise intolerance, syncopy ● They had a small pinch so they are now an older kid rather than it being caught at infancy ■ Fixed by balloon angioplasty and/or surgery ■ BP is going to be higher in the arms than it is in the legs ■ Poor cardiac output ● Decreased capillary refill on legs ■ Fixed by surgery

● Aortic Stenosis ○ AS = Narrow or strictures of the aortic valve ○ Difficult for blood to eject from left ventricle ○ Decreased cardiac output ○ Left ventricular hypertrophy ○ Pulmonary vascular congestion d/t back up of pressures (lt vent -> lt atria -> pulmonary veins)

○ Clinically: ■ Decreased cardiac output ■ Infants = faint pulses, hypotension, tachycardia, poor feeding ■ Older = Exercise intolerance, chest pain, dizziness. ● Going to look really bad because this is a big defect ■ +/- Systolic ejection murmur ■ Surgery or balloon angioplasty via cardiac cath to repair ■ Pulmonary congestion because everything is getting backed up and only one little car is getting to pass through ■ Poor pulses, cooler extremities, decreased cardiac output

● Pulmonic Stenosis ○ PS=Narrowing at entrance to pulmonary artery. ○ Right ventricular hypertrophy (may lead to rt atrial increase in pressure & reopening of foramen ovale & shunting of unoxygenated blood to left atrium = cyanosis) ○ Decreased pulmonary blood flow ○ Pulmonary Atresia = Extreme pulmonic stenosis = total fusion & no blood flow to the lungs (duct-dependent) ■ Means doesn't exist (road block) ■ WHERE DOES IT MIX? ● PFO STAYS OPEN ○ Clinically: ■ May be asymptomatic ■ Mild cyanosis or HF ■ Progressive narrowing causes increased symptoms ■ Severe narrowing = cyanosis ■ Loud systolic ejection murmur LUSB ■ (murmur may be softer if severe d/t decreased cardiac output & shunting) ■ Cardiomegaly on CXR ■ Surgery or balloon dilation via cardiac cath ● Decreased Pulmonary Blood Flow Defects ○ 1) Tetralogy of Fallot ○ 2) Tricuspid atresia ● Tetralogy of Fallot ○ 4 Defects Involved:

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■ 1). Ventricular Septal Defect (VSD) ■ 2). Pulmonic Stenosis ● Narrowing of pulmonic valve area ● Extra blood trying to push through small opening ■ 3). Rt Ventricular Hypertrophy ● Due to pressure build up ■ 4). Overriding Aorta ● Shifting to the middle Pressures in the right and left ventricles often equal so shunt direction (blood flow direction) depends on the difference between pulmonary and systemic vascular resistance If pulmonary vascular resistance higher = Shunt right ----> left (cyanosis)- TET SPELL ■ If systemic vascular higher = Shunt left ----> right Degree of PS determines degree of cyanosis Clinically: ■ Acute cyanosis at birth or mild cyanosis that progresses as PS worsens ● Mixed SATS- what are their pressures (right vs. left) ■ + Systolic murmur ■ Tet spells/Anoxic spells/hypercyanotic spell = acute episodes of hypoxia & cyanosis. Oxygen requirements exceed blood supply. Usually during crying or feeding ● Calm, left is shunting over and O2 is ok ● Crying, pressure in lungs increases; pressure higher on the right side of the heart and pushes out to the body making oxygen less in the body; O2 is bad ● Increasing the right side pressure by pooping, feeding, playing, any activity ■ I know the pulmonary pressure is higher but can I do to lower the pulmonary or higher systemic pressure? ■ Surgery required. May have palliative shunt (BT shunt) placed before complete repair. BT shunt: Increases pulmonary blood flow which increases oxygen saturation.

● Hypercyanotic Spells (Tet Spells) ○ Goal: Left side heart pressure higher and right side heart pressure to be low ○ Can occur in other cyanotic heart lesions ○ Commonly Precipitated by: crying, feeding, straining (BMs), fevers, dehydration, nap awakening

○ Management: Decrease PVR, Increase SVR, Increase Pulmonary Blood flow ■ 1) Knee-chest position (increases SVR) ● Increase left side heart pressure ■ 2) Calming child ● Drops the PVR to increase the SVR ■ 3) Oxygen – Ask parents baseline SpO2 (could be 88-magic number determined by the cardiologist) ● What is normal for the kid?? ■ 4) Morphine (decreases PVR) ● Tricuspid Atresia ○ Failure of Tricuspid Valve to develop. ○ No blood flow from the right atrium to the right ventricle. ○ Blood flows from an ASD or PFO to get to left atrium then through a VSD to get to rt ventricle to get to lungs. ○ Complete mixing of saturated & unsaturated blood in the left side of heart = Cyanosis & decreased pulmonary blood flow ○ PDA allows blood flow to the pulmonary artery & lungs (duct-dependent). ○ PFO or ASD required so blood can get to left atrium. ○ VSD allows blood flow to the pulmonary artery & lungs. ○ Clinically: ■ Cyanosis ■ Prostaglandin E1 to keep PDA open ■ Individualized staged surgical repairs leading to Modified Fontan Procedure ○ Has to be another hole somewhere

● Mixed Defects ○ Transposition of the great vessels ○ Total anomalous pulmonary venous connection ○ Hypoplastic heart syndrome ■ Right sided ■ Left sided ● Transposition of the Great Arteries or Transposition of the Great Vessels

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Pulmonary artery leaves from left ventricle & aorta leaves from right ventricle. Aorta and pulmonary artery have traded positions No communication between systemic & pulmonary circulation. PDA, PFO, or other defects must be present to allow mixing of blood. Clinically: ■ Presentation depends on associated defects. ■ Newborns with minimal communication have severe cyanosis & poor function. ■ Newborns with PDA or large septal defects less cyanotic but HF symptoms. ■ Heart sounds vary by associated defects. ■ Prostaglandin E1 may be given to keep PDA open to increase mixing. ■ A balloon atrial septostomy may be performed to increase mixing (creates ASD). ■ Definitive surgical repair varies by defects. ■ Can keep the openings open by medication prostaglandin ● The heart wants to close PDA

● Total Anomalous Pulmonary Venous Connection (Return) -DONT NEED ○ -Failure of the pulmonary veins to join the left atrium. Instead, the pulmonary veins are connected to the systemic venous circulation. ○ -Mixed blood returns to right atrium and shunt from rt -> left across an ASD. ○ -Rare defect. ○ Clinically: ■ -Cyanosis ■ -Degree of cyanosis determined by amount of pulmonary blood flow; the more pulmonary blood=the less cyanosis. ■ -Can be asymptomatic early then ■ PVR decreases during infancy, pulmonary blood flow increases & HF develops. ■ -Surgical correction ● Truncus Arteriosus- DONT NEED ○ -Single blood vessel (truncus arteriosus) comes out of the right & left ventricles ○ -Blood from both ventricles mixes in the common great artery. ○ -Blood ejected from the heart prefers the lower pressure pulmonary arteries than aorta leading to increase in pulmonary blood flow & decrease in systemic blood flow ○ Clinically: ■ -Cyanosis ■ -HF

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+Holosystolic murmur +/- diastolic murmur -High association w/ 22q11 deletions -Surgical repair w/ additional surgeries throughout life.

● Hypoplastic Left-Sided Heart Symptoms -DONT NEED ○ -Underdevelopment of left side of the heart leading to hypoplastic left ventricle & aortic atresia. ○ -Blood from left atrium flows into right atrium via ASD or PFO. It then goes to right ventricle & out the pulmonary artery. From the pulmonary artery, blood flows to the lungs & to the descending aorta through the PDA. ○ -The coronary & cerebral vessels rely on retrograde flow through the hypoplastic ascending aorta. ○ Clinically: ■ -Mild cyanosis & HF symptoms until PDA closes then deterioration, cyanosis, & cardiovascular collapse. ■ -Fatal without intervention. ■ -Neonates require stabilization, CMV, & inotropic support. ■ -Prostaglandin E1 infusion needed to keep PDA open to ensure systemic blood flow. ■ -Multi-stage surgical correction. -Transplantation may be needed....