ASD/TOF

Question 1

What are the most important clinically important examples of L to R shunts?

Answer 1

• Atrial septal defect (ASD)
• Ventricular septal defect (VSD)
• Atrioventricular Septal Defect (AV canal)
• Patent ductus arteriosus (PDA)

Question 2

What is the most common form of congenital heart dz seen in adults?

Answer 2

ASD

Question 3

What is ASD?

Answer 3

• Abnormal, fixed opening in the atrial septum due to incomplete tissue formation. Usually asymptomatic until adulthood.

Question 4

What can ASD be confused with?

Answer 4

• PFO (patent foramen ovale) – failure to close foramen ovale.

Question 5

What does ASD affect?

Answer 5

• Increase RV and pulmonary outflow volumes

Question 6

What are the 3 major types of ASD?

Answer 6

• Secundum ASD – at the Fossa Ovalis (most common); OS ASD
• Primum ASD – lower in position and is a form of ASVD, can be associated with cleft mitral valve. OP ASD
• Sinus Venosus ASD – high in the atrial septum, associated w/ partial anomalous venous return (least common) SV ASD

Question 7

What are the clinical signs and symptoms for ASD?

Answer 7

• Rarely, pts present with signs of CHF or other cardiovascular symptoms
• Most are asymptomatic, easy fatigue, mild growth failure
• Cyanosis does NOT occur unless pulmonary htn is present.

Question 8

What are PE findings of ASD?

Answer 8

Hyperactive precordium

RV heave

Question 9

What causes the systolic and diastolic murmurs of ASD?

Answer 9

• Systolic murmur
o Caused by increased flow across the pulmonary valve NOT the ASD
• Diastolic murmur is caused by increased flow across the tricuspid valve.

Question 10

What are the tx options for secundum ASD?

Answer 10

• Surgical or catheterization laboratory closure

Question 11

When is surgical intevention performed electively for ASD?

Answer 11

• Between ages 2 and 5 yrs to avoid late complications

* Done earlier in children with CHF or significant pulmonary htn.

Question 12

When is it too late for surgical intervention with ASD?

Answer 12

• Once pulmonary htn with shunt reversal occurs.

Question 13

What are the dzs that cause early cyanosis?

Answer 13

• Tetralogy of Fallot
• Transposition of great arteries
• Persistent truncus arteriosus
• Tricuspid atresia
• Total anomalous pulmonary venous connection

Question 14

what are the 4 cardinal features of TOF?

Answer 14

• Narrowing of pulmonary valve
• Displacement of aorta over ventricular septal defect
• Thickening of RV
• Ventricular septal defect – opening between the L and R ventricles

Question 15

What are the key sxs of TOF?

Answer 15

Cyanosis “Tet spells”: cyanosis after feeding, bowel movement, upon awakening
SOB, tachypnea, respiratory distress (crying baby)

Question 16

What is the characteristic heart murmur for TOF?

Answer 16

harsh systolic ejection murmur @LSB

Question 17

What is the CXR finding of TOF?

Answer 17

BOOT SHAPED HEART

Question 18

What is the compensatory mechanism in pts with TOF?

Answer 18

squatting or knee to chest position in order to increase PVR and thus decreases the magnitude of the R to L shunt across the VSD

Question 19

What would EKG of TOF show

Answer 19

RVH

Question 20

What is the characteristic murmur for ASD?

Answer 20

• Fixed widely split S2
• 2-3/6systolic ejection murmur @ L sternal border
• Mid-diastolic murmur heard over LLSB

Question 21

what kind of shunt is ASD?

Answer 21

L to R shunt

Question 22

what technique can be used as a screening tool for ASD?

Answer 22

Valsalva maneuver

Question 23

What happens when ASD pts do valsalva maneuver?

Answer 23

results in increased intrathoracic blood volume, allowing adequate cardiac output to continue despite temporary obstruction of venous return

Question 24

What is valsalva maneuver?

Answer 24

forceful “exhalation” with mouth closed (nose pinched).