Congenital Heart Defects

Question 1

What heart defects are associated with…

Down’s

Turner’s

William’s

Noonan’s

Answer 1

• Down - 50% have cardiac defects; most common is AV septal defects and VS defects
• Turner’s - often L sided obstruction (coarctation of aorta or bicuspid aortic valve)
• William’s - defect in elastin gene so arterial abnormalities; supravalve aortic stenosis (narrow above valve — ascending aorta), renal artery stenosis, pulmonary artery stenosis
• Noonan’s- wide-spaced nipples; pulmonary valve stenosis and hypertrophic cardiomyopathy

Question 2

Acyanotic Septal Defects in General

Answer 2

All involve L—> R shunt which can lead to CHF and pulmonary HTN

+ vol overload –> RAD and RVH on Xray and EKG

Atrial septal, ventricular septal and AV septal defects, patent ductus arteriosus

Question 3

Atrial Septal Defect

Answer 3

• L —> R atria shunt so vol overload in RA and RV
  
  • Parasternal heave
  • R side hypertrophy & inc pulmonary vasculature (X-ray)
  • Fixed split S2 b/c more pulmonary flow so P2 always later
  • Ejection murmur across pulmonary valve
  • Mid-diastolic murmur across tricuspid valve
  • EKG - RAD and R vent hypertrophy (high R waves)
• Diff locations of defect
  
  • Secundum - fossa ovalis in center of atrium
  • Sinus Venosus - higher near superior vena cava
  • Ostium Primum
• Presentation - Usually asymptomatic in childhood; complications in adulthood due to chronic high pulmonary flow (pulmonary HTN, paradoxical emboli, R heart fail, atrial arrhythmias)
• Management - if defect but no volume overload just leave it; but if volume overload - surgical closure or transcatheter closure if secundum

Question 4

Ventricular Septal Defect

Answer 4

• L—>R ventricle shunt so vol overload of L atrium and L vent, L atria and maybe R vent
• Physiology depends on size of defect and pulmonary resistance
  * Larger VSD = more shunting (Pulmonary HTN, CHF, ejection murmur and loud single S2)
  * Smaller VSD= less shunting (Normal S2 and no symptoms but pan-systolic murmur at lower sternal border)
• Larger pulmonary resistance = less shunting
  * When infant is first born they have high pulmonary resistance (less shunting) then by 4 wks pulmonary resistance is way lower than systemic resistance —> more shunting and marked volume overload/pulmonary HTN
• Location determines how likely it is to close on own
  
  • Perimembranous (most common)
  • Muscular - small; high likelihood of closing
  • Supracristal - high; above crust terminus; high incidence of mitral valve prolapse
• Presentation
  
  • Often spontaneously close or decrease in size
  • Complications include CHF, pulmonary HTN, bacterial endocarditis
• Management - surgical repair and treat CHF/pulmonary vascular disease

Question 5

AV Septal Defect

Answer 5

• Defect in center of heart w/ both atrial and ventricular components; L—>R shunt in all chambers; volume overload in all chambers
• Can be partial (low atrial defect and cleft mitral valve) or complete (atrial and vent defect)
• A/V valves also involved - do not form properly
• Presentation
  
  • Most common w/ Down Syndrome
  • If partial - get mitral regurg over cleft mitral; behaves like atrial septal defect
  • If complete - behaves like vent septal defect (pulmonary HTN, CHF)
  • Usually dx by echo
• Management - surgical repair (no cath option)

Question 6

Patent Ductus Arteriosus

Answer 6

• Tube b/n pulmonary artery and aorta stays open after birth
• Aorta —> pulmonary artery (b/c less resistance than systemic) —> LA —> LV
  
  • So only LA and LV overload
• Presentation
  
  • CONTINUOUS murmur at L sternal border and bounding pulses
  • Can lead to pulm HTN and CHF if ductus is large
• Complications - CHF, pulm HTN, endocarditis
• Management - surgical ligation, transcatheter once 1 yr+

Question 7

Acyanotic Obstructions in General

Answer 7

Obstruction –> Pressure overload –> CHF and vent hypertrophy

Pulmonic stenosis, aortic stenosis, coarctation of aorta

Question 8

Pulmonic Stenosis

Answer 8

• Thick pulmonary valve or leaflets fuse so R vent pressure overload/hypertrophy
• Presentation
  
  • Systolic ejection murmur at L sternal border w/ click (mobile valve as child)
  • Dilated pulmonary artery on X ray
• Complications - right heart fail; if foramen ovale still open then R —> L atrial shunting because less resistance than outflow to pulmonary artery (causes cyanosis)
• Management - trans-catheter balloon valvuloplasty

Question 9

Aortic Stenosis

Answer 9

• Thick leaflets or fused leaflets (usually bicuspid) —> block LV outflow/ LV hypertrophy
• Presentation
  
  • Systolic ejection murmur at R sternal border w/ click transmitted to apex
  • Dec pulse amp if severe
  • LVH on EKG
• Complications - more severe b/c dec CO (exertional syncope or sudden death), CHF, endocarditis
• Management - balloon valvuloplasty but usually need surgery later (replace valve)

Question 10

Coarctation of Aorta

Answer 10

• Obstruction of aortic arch (near where ductus arteriosus was) —> P inc in ascending aorta —> inc P in L vent
• Presentation
  • HTN in arms
  • Normal pulses in arms but weak in legs (because pulse pressure becomes blunted at blockage)
  • Any discrepancy in BP b/n upper and lower body
  • LVH on EKG
  • If do not repair for 5 yrs - may see rib notching due to collateral flow through intercostal arteries
  • May see “figure of 3” shape in descending aorta on X ray (see shadow of aorta pinching in)

Question 11

How to tell if cyanosis is due to cardiac abnormality

Answer 11

**Normal sat is 95% do not see cyanosis clinically until 85-90%

**Hyperoxia test - give them 100% oxygen and if sat still does not improve than likely cardiac problem

Question 12

3 Types of Cyanotic Defects (+ examples of each)

Answer 12

1- abnormal connections (transposition of great arteries or totally anomalous pulmonary venous return)

2- septal defect w/ obstruction to pulmonary flow (tricuspid atresia, pulmonic atresia, tetralogy of Fallot)
**May be ductal-dependent; use prostaglandins (keep ductus open) if not then may need aorta–>pulm shunt

3- complete mixing (aortic atresia, single ventricle, truncus arteriosus)

Question 13

Transposition of Great Arteries

Answer 13

• Pulmonary artery and aorta connected to wrong chamber
• In utero survive b/c atrial communications —> mixing; so 1st wk after birth Rashkin procedure - enlarge atrial communication (foramen ovale) w/ balloon
• Presentation -
  
  • Cyanotic
  • Normal sound, EKG an Xray
  • Dx via echo
• Management - prostaglandins, balloon septostomy (Rashkin), arterial switch procedure

Question 14

Total Anomalous Pulmonary Venous Return

Answer 14

• Pulmonary veins empty back into R atrium
  
  • Problem in embryology - pulmonary veins go back to confluence behind L atrium but do not enter L atrium; alternative veins will form to connect confluence to systemic circulation so pulmonary flow goes to R atrium NOT L atrium
    
    • Alt vein may go superior vena cava, down to portal circulation OR to coronary sinus
• Compensate w/ foramen ovale —> L ventricle –> mixing
• Complications - inc pulmonary blood flow, if obstruction to pulmonary blood flow thru new veins then get pulmonary edema
• Management - surgical repair; connect confluence to L atrium and ligate alternative veins

Question 15

Tricuspid Atresia

Answer 15

• Do not get flow into R ventricle; so blood goes from R atria —> L atria instead
  
  • Leads to R vent hypotrophy b/c does not get flow in development
• Also have VSD - L ventricle —> small RV —> pulmonic artery (so L vent is source of pulmonary flow)
• Presentation
  
  • More pulmonary blood flow you can achieve = least cyanosis
  • Systolic murmur across pulmonic valve or across VSD
  • Normal heart size but dec pulmonary vascularization
  • LAD and LVH on EKG
• Management - prostaglandins if trying to keep ductus open OR aorta —> pulmonary artery shunt if severe cyanosis

Question 16

Pulmonic Atresia

Answer 16

• Also have R —> L atrial shunt and hypo RV due to less flow
• NO VSD (unlike tricuspid atresia) so get all flow to pulmonary artery from ductus arteriosus (“ductus dependent pulmonary blood flow”)
• Presentation
  
  • Same as tricuspid atresia (LVH, pulmonary inc vascularity)
• Management - use prostaglandins to keep ductus open (natural shunt); then may eventually go in and insert aorta to pulmonary shunt

Question 17

Tetralogy of Fallot

Answer 17

• VSD w/ overriding aorta (too much aorta w/ not enough pulmonic artery)
  
  • Shunt R —> L vent
  • AND obstruction to pulmonary flow (due to valve stenosis - sub-valve stenosis) so R vent outflow —> aorta not pulmonary artery
  • B/c pulmonary stenosis you get RVH
• Differs from tricuspid or pulmonic atresia b/c no RV hypotrophy (RV is fully formed)
• Presentation
  
  • Systolic ejection murmur and split S2 b/c pulmonary stenosis NOT murmur due to VSD flow
    
    • SO… louder murmur = less pulmonic stenosis = still some flow across pulmonic
    • Softer murmur = more pulmonic stenosis = flow goes over VSD instead
  • RVH on EKG
  • Xray shows boot-shaped heart, R aortic arch and dec pulm vasculature
• Management - Usually total repair but if very severe and cannot undergo repair then aorta —> pulmonary shunt

Question 18

Aortic Atresia

Answer 18

• Hypoplastic L heart and L—> R atrial shunt so all L atrial blood goes to R atrium
• Systemic perfusion then depends on ductus (R vent —> Pulm artery —> ductus —> aorta)
• Presentation -
  
  • Cardiogenic shock - dec CO
  • Hyperactive pericordium w/ dec pulses (R vent heaves but low pulse)
  • RVH on EKG and large heart on Xray
• Management - prostaglandins to maintain ductus/maintain systemic perfusion, Norwood operation, eventual heart transplant

Question 19

Single Ventricle

Answer 19

• AV valves both flow into 1 ventricle then can go into either pulmonary artery or aorta which both come off the single ventricle
  
  • So oxygenated and de-oxygenated blood mix
• Which system blood flows into depends entirely on if there is pulmonary stenosis
  
  • Pulm stenosis = favors aorta (cyanosis - may need shunt)
  • No pulm stenosis = favors pulmonary artery (pulmonary HTN, CHF)
  • **Can have balance - just enough pulmonary stenosis that do not need surgical repair

Question 20

Truncus Arteriosus

Answer 20

• Mixing of aorta and pulmonary artery into COMMON TRUNK (pulmonary arteries actually arise from ascending aorta)
  
  • B/c pulmonary system has so much lower pressure you get overload of volume going into pulmonary circulation
  • Accompanied by VSD
• Presentation - pulm HTN and CHF from overload of pulmonary circulation
• Management - surgery (Rastelli Procedure)