Congenital defects: ASD

Question 1

is ASD cyanotic

Answer 1

• no
• left to right shunt
• females 3:1

Question 2

most common defect in

Answer 2

Holt-Oram syndrome (12q21-22 TBX5)

Question 3

most common location

Answer 3

ostium secundum (normal AV valves, may be large defects)

Question 4

abnormal transcription

Answer 4

NKx2.5, TBX, GATA4 (activates MYH6)

Question 5

shunt is determined by

Answer 5

size
RV compliance
PVR

Question 6

ASD locations

Answer 6

Fossa Ovale type (midportion)
Ostium primum type (lowest portion)
sinus venosus type (uppermost portion)

Question 7

what can bee seen with ASD

Answer 7

RAH
RVH
enlarged pulmonary artery

Question 8

clinical presentation of ASD

Answer 8

-usually asymptomatic and noted on PE after 2 years of age
-even large ASD cause subtle exercise intolerance, recognize after surgical repair
-normal peripheral pulse
-RV systolic lift palpable along LSB
loud S1 (pulmonic ejection click heard)
soft systolic ejection murmur at 2nd L interspace
fixed widely split second heart sound
diastolic rumble at lower left sternal border (if shunt >2:1)

Question 9

CXR shows

Answer 9

enlarged RV, RA, main pulmonary artery and increased pulmonary markings

Question 10

ECG shows

Answer 10

RV hypertrophy

R axis deviation (atrial dysrhythmias or even fibrillation if late diagnosis)

Question 11

Echo shows

Answer 11

• septal motion with increased RV will move anterior in systolic
• show size and location of defect
• shunt evaluated by doppler
• mitral valve and pulmonary resistance
• evaluated pulmonary venous return

Question 12

cardiac cath shows

Answer 12

• delineate the lesion and shunt

- can be necessary in adults to determine pulmonary HTN

Question 13

MRI shows

Answer 13

show show
anomalous pulmonary veins
quantify ventricular volume
pulmonary and systemic flow

Question 14

prognosis for ASD

Answer 14

• asymptomatic in childhood

- pregnancy may trigger complications: Paradoxical emboli

Question 15

pos-op complications

Answer 15

atrial fibrillation
late heart failure (after 20 years of age)
bacterial endocarditis rare

Question 16

untreated ASD

Answer 16

atrial dysrhythmias
tricuspid or mitral insufficiency 
heart failure
embolism
recurrent pulmonary infections
pulmonary HTN
Eisenmonger's physiology possible

Question 17

treatment ASD

Answer 17

• 2:1 shunt should be closed surgically
• most done between 1-5 years of age
• open heart surgery closure
• or close by atrial septal occlusion devices inserted transvenously at cardiac catheterization

Question 18

treatment ASD continued

Answer 18

• closure allows recover of RV size, full exercise tolerance, improved growth and prevents late complications of arrhythmias and heart failure
• small shunts currently untreated (except deep sea divers)