ASDDr. H. Sadeghian

1. ASD ostium secondum: in the central portion of

Atrial septum in the position of foramen ovalis

2. Sinus venosus: in the region of SVC, RA junction

or IVC RA junction

3. Unroofing coronary sinus: between ostium of CS

to RA and LA

septum primum and endocardial cushion defect

4. ASD ostium primum

Rudolph chapter 7

Sinus venosus : 3 – 10%

ASD ostiom serondun: more common

F / M = 2/1

5% ASD + PS (valvuler)

Muller, chapter 22

PVR abn

< 10% AsD ostium secondum

almost always ASD SV

Associates PVRAb

Braunwald

Morphologic and Embriologic considerations

Septum primum grows from posterosuperior

side (SVC side) toward A-V junction where

endocardial cushion separotes Atria from

ventricles. The lower part of the septum

primum is completed by fusion with

endocardial cushion tissue.

Rudolph chapter 7

Some fenestrations develop in midportion of

septum primum. Septum secrodum just

grows in the posterosuperior portion of IAS

(near SVC) but right to the septum primum.

It grows toward the AV junction and it partly

covers the central hole of septum prinum. It

has a semilunar edge which is concave

toward TV.

Rudolph chapter 7

Ostium secondum defects

1. Large hole in septum primum or

2. Inadequite development of septum

secondum

Rudolph chapter 7

1. Sinus venosus defects: septum primum

or secondum

2. Unroofing CS: the well between CS and

LA, may involved a portion of septum or

whole septum and are frequently

associated with LPSVC

Rudolph chapter 7

LAP 1-2 mmHg >RAP

two ventricles fill with one pressure

so RV will be distended.

Rudolph chapter 7

The degree of left to right

Shout depends on the

1- The size of the defect

2- Filling pressure of ventricles

Braunwald

Infants

Large defects: QP/Qs > 2.5 : 1

Produce symptoms

Medium size defects: do not cause symptoms

during infancy and early childhood

Rudolph chapter 7

ASD beyond infancy

The majority of children even those with large

defeats do not experience symptoms.

Unlike VSD most of them tend to be smaller with

growing, ASD usually grows in proportion to

heart size and there is evidence suggesting that

some defects may become larger as age increase.

Rudolph chapter 7

40% ASDs in infants will close

spontonously

ASD < 3 mm in first 3 months always

close

ASD > 8 mm is unlikely to close

Muller, chapter 22

Spontanous closure of ASD may occur

within the 1 year of life.

< 7 mm in neonatal period may reduce

in size and require no intervention

Braunwald

Natural history of growth of ASD ostiun

secondum and implication

Heart 2002, 87, 256-9

104 Patients

Exclusion criteria: multiple ASDs or

fenestrated 91 – 98

3 – 6 mm small ASD

6 – 12 moderate

12 large

65% patients size with ASD 30% > 50% increase in size

spontanous closure in 4 patients

12% 20 mm

Only factor associated with ASD growth was initial size

Heart 2002, 87, 256-9

ASD growth was independent of age of

patients

Conclusion: 2/3 of ASDs growth with time

Heart 2002, 87, 256-9

Defects < 6 mm

66% spontanous closure

Mean age of diagnosis: 4.5 years

F / M / 2.2/1

Heart 2002, 87, 256-9

33% had small defects(34P)

FO

3p closed spontounsly

26% (27p) ASD

1 small mod

3 small large

1.6 mm/y size

Mean FO : 3.2 y

Heart 2002, 87, 256-9

Small ASD group

40 p (38%)

FO 31% mod

3 small

8 large

1.6 mm/y mean FO: 3.3 y

Heart 2002, 87, 256-9

Mod ASD group

30 p (29%) large

43% (45) FO : large

1.9 mm/y FO : 2.9 year

Heart 2002, 87, 256-9

Large ASD defeats

66% ASD size

14% decrease

20% no change

Initial size, final size correlated

Heart 2002, 87, 256-9

The main concerns in individuals

with ASD are

1. PV Resistance

2. Atrial arrhythmia

3. Cardiac failure

Rudolph chapter 7

The association of PVD and ASD are infrequent

during childhood. Singificant PVD is unusual

before age of 25-30 years.

Beyond this age, PVD occurred in 5-10% ASDs and

is related to high altitude PVD f/M : 2 : 1

Altitude > 4000 ft PVD in earlier ages

Rudolph chapter 7

PVR

PVR in ASD usually is normal ,

1 unit / m2

3 considerable

Rudolph chapter 7

Atrial arrhythmia

Af , Flutter , PAT occurs commonly in older

patients. They are probably related to

large shunts.

< 20 y 1 - 2%

> 20 y 15 - 50%

Rudolph chapter 7

Cardiac failure

>20 y , Right sided

Failure

Rudolph chapter 7

ECG

SV defects: P ware 0

AV may be moderately prolonged with large defects

QRS Axis: RAD (90 to 180)

rsR or rSR , incomplete RBBB

R in right precordial 10 – 15 mm

> PVD

Rudolph chapter 7

Negative P in Inferior leads

ASD SV below SVC

Braunwald

Echo

1. RV Enlargement

2. QP/QS

3. PVR , SVR

4. PAP , TR , PAPm , d

5. RV function

Rudolph chapter 7

Subcostal : bicaval

Pressures

15 – 30 mmHg Pressure RV-PA

10 – 15 mmHg MPA , branches

Rudolph chapter 7

30% of the patients have effort dyspnea

in third decade and more than 73%

by fifth decade

Braunwald

SV arrhythmia and RSF 10%> 40y

Paradoxical embolic may occur

Braunwald

1- Isenmenger

2- Prominent eustachien valve which leads IVC flow to ASD

3- ASD SV below IVC

Braunwald

Cyanosis

Management

Large ASD

QP/Qs < 2 : 1

QP/QS < 1.5 : 1 Follow up

Rudolph chapter 7

The presence of RSF + ASD > 5 mm with no sign of spontaneous closure

18 month 3/4 ASDs may close spontaneously

Muller and Hoffman

Indications for Intervention

QP QS < 1.5 : don’t want

Closure except for paradoxical emboli

Braunwald

Significant ASD : QP / QS > 1.5 : 1

Or RV volume overload intervention

P HTN : PAP > 2/3 systemic

Or

PVR > 2/3 SVR

1- QP / QS > 1.5 / 1

2- Challenge to O2 or No

3- Lung biopsy reversibility

ASD closure

Braunwald

Stretch diameter < 41 mm

Adequate rim

Complications : embolization

thronbus formation < 1%

atrial perforation

Comparing surgery to device closure :

1- better preservation RV function

2- lower complication rate

Braunwald

Device closure

- Sinus venosus

- Ostium primum

- Ostium serondum not suitable for device

closure

Mortality < 1%

Braunwald

Surgery

ASD with P HTN

PVR > 8 – 12 unit / m2 : high mortality

PVR > 12 unit / m2 FO

PVR 4 – 8 unit / m2 mortality 10%

Rudolph chapter 7

- Aspirin 6 mouths

- Prophylaxis of IE 6 mouths

Braunwald

After device closure

1- ASD SV : Caval or PV stenosis

2- RV Failure

3- Atrial arrhythmia

Braunwald

Long surveillance

< 10% ASD PHTN

PPHTN in association with ASD

> 50% patients > 45y AF

Muller, chapter 22

Post op Atrial arrhythmia

Soon after surgery to later years 30 – 50%

incidence

PAT , AF and flutter but brady-tachy

arrhythmia pace

Transcatheter closure incidence arrhythmia?

Rudolph chapter 7

AF 25% patients > 20 y

5% patients < 20 y

Late post operative arrhythmia :

2 - 9 % children

2 - 33% adults

Early after repair : 14% Atrial arrhthmia

espicially in SV defects

Muller

Rim < 3m : deficient

Anteroinferior : mitral to ASD apical 4C

Antero superior : Aort

Postero superior :RUPV in Apical 4C back wall LA

Superior : SVC (90)

Postero inferior : IVC

Mathewson et al

JASE 2004