Congenital Heart Defects: ASD/VSD

Question 1

ASD most commonly occur as defects in the

Answer 1

septum primum within the fossa ovalis (secundum ASD)

Question 2

ASD can also occur

Answer 2

can involve the septum secundum near SVC (sinus venosus defects-less common)

Question 3

cyanotic shunt

Answer 3

R -> L. worse for a kid

Question 4

acyanotic shunt

Answer 4

L->R

Question 5

Blood Flow is quantitated in terms of:

Answer 5

PULMONARY BLOOD FLOW (Qp)
 SYSTEMIC BLOOD FLOW (Qs)
 This gives us a ratio of Qp/Qs  This will equal 1:1 (or 1) in a normal individual

Question 6

The general rule is shunts that DO NOT cause increase in right heart size

Answer 6

(Qp:Qs

Question 7

Ostium Secundum

Answer 7

most common
formed by failed growth of the septum secundum or
rapid reabsorption of the septum primum

Question 8

OSTIUM SECUNDUM LOCATION

Answer 8

mid-atrial

Question 9

PFO

Answer 9

A patent foramen ovale (PFO) is a small channel that has little hemodynamic consequence; it is a remnant of the fetal foramen ovale.
 In some cases the PFO can be larger and require treatment

Question 10

PFO closure from right side

Answer 10

The initial inflation of the lungs causes changes:
 Decreases PVR results in increased blood flow from PA.
 That increased amount of blood flows from the RA to the RV and into the PA’s and less blood flows through the foramen ovale to the left atrium.

Question 11

PFO closure from right side

Answer 11

The initial inflation of the lungs causes changes:
 Decreases PVR results in increased blood flow from PA.
 That increased amount of blood flows from the RA to the RV and into the PA’s and less blood flows through the foramen ovale to the left atrium.

Question 12

PFO closure due to left side

Answer 12

In addition, more blood returns from the lungs which increases the pressure in the LA.
 The increased LA pressure and decreased right atrial pressure (due to pulmonary resistance) forces blood against the septum primum causing the foramen ovale to close.
This action functionally completes the separation of the heart into two pumps

Question 13

ostium primum location

Answer 13

located low in the septum and can be considered a type of AV septal defect.

Question 14

ostium primum sat.

Answer 14

could have normal sat. in upper atrium but higher in lower atrium

Question 15

sinus venosus location and associated with

Answer 15

located high in the septum where the vena cava intersects with the right atrium, frequently associated with partial anomalous venous return (PAPVR)
 May be inferior and/or superior

Question 16

Cardiac Septation - review

 Occurs at ______ and lasts

Answer 16

day 27 and lasts 10 days

Question 17

At day ____ the paired atria fuse together to form a

common atrium.

Answer 17

27-28

Question 18

clinically remarkable left-to-right shunt

Answer 18

ASD > 9MM

Question 19

Any process that increases the pressure in the LV can

Answer 19

cause worsening of the left-to-right shunt. It also works on the right heart

Question 20

IF ASD LEFT uncorrected

Answer 20

ressure in the right heart > left heart.
 RA pressure > LA pressure
 The pressure gradient reverses across the ASD the shunt will reverse
 a right-to-left shunt (R->L) will now exist.

Question 21

This shunt reversal phenomena is known as

Answer 21

Eisenmenger’s syndrome

Question 22

Once right-to-left shunting occurs

Answer 22

oxygen-poor blood gets shunted to the left side of the heart.
This will cause signs of cyanosis.

Question 23

percutaneous closure of ASD aka

Answer 23

(Amplatzer)

Question 24

types of surgical closure

Answer 24

Primary Closure  Patch Closure

Question 25

Surgical Correction of ASD’s |  Incision:

Answer 25

 Mediansternotomy  Right thoracotomy (going between the ribs on the right side)  Sub-mammary (under the breast tissue on the right front of the chest)-very difficult

Question 26

Surgical Correction of ASD’s  Surgical Closure  Primary

Answer 26

– Closure by direct vision suture

Question 27

Surgical Correction of ASD’s |  Surgical Closure patch

Answer 27

– Uses pericardial tissue or Gore-Tex patch for closure

Question 28

Surgical Correction of ASD’s |  Surgical Closure patch

Answer 28

– Uses pericardial tissue or Gore-Tex patch for closure

Question 29

ASD cannulation and VENTING

Answer 29

Arterial: Aortic  Venous: Bicaval (total CPB)  Single Atrial if the infant is small and DHCA is anticipated  Venting: may use direct venting with a flexible since the heart is open

Question 30

ASD cardioplegia

Answer 30

Antegrade, usually a single dose will suffice

Question 31

ASD case notes

Answer 31

Case is very, very quick, 5-10 min pump run  Will XC, Stay warm “drift down temp”  Can be challenging: (on CPB, XC, give CP, warm, correct Ca++,lytes, ABG’s, off CPB-MUF)

Question 32

A ventricular septal defect (VSD) is a

Answer 32

defect in the ventricular septum, the wall dividing the left and right ventricles of the heart.

Question 33

The ventricular septum consists of:

Answer 33

Inferior muscular portion  Superior membranous portion

Question 34

Common Regions of Ventricular Septal Defects

Answer 34

 Inlet  Outlet (supracristal)  Peri-membranous Septum  Muscular Septum

Question 35

prevalence of VSD

Answer 35

Membranous 75%  Muscular 20% Supracristal (Outflow) 5%

Question 36

Muscular ventricular septal defect is found in four locations

Answer 36

anterior, mid-ventricular, posterior, apical. Muscular VSDs are found in the lower part of the septum. They're surrounded by muscle. (most close on their own during early childhood.)

Question 37

the membranous portion, which is close to the atrioventricular node, is most common in

Answer 37

adults and older children

Question 38

Membranous VSDs are located near

Answer 38

the heart valves

Question 39

membranous VSD can close

Answer 39

at any time.

Question 40

Supracristal is an

Answer 40

outflow tract VSD sub-valvular in nature

Question 41

The crista supraventricularis can be considered

Answer 41

synonymous with the infundibular (or conus) ventricular septum

Question 42

Outlet VSDs are found in

Answer 42

the part of the ventricle where blood leaves the heart. These are the rarest type of VSD.

Question 43

The infundibular (or conus) septum separates

Answer 43

the tricuspid and pulmonary valves and accounts for the more superior placement of the pulmonary valve relative to the aortic valve.

Question 44

The infundibular (or conus) septum also provides

Answer 44

muscular rigid support for the aortic valve, especially the right coronary cusp (think prolapse)

Question 45

The infundibular (or conus) septum also provides

Answer 45

muscular rigid support for the aortic valve, especially the right coronary cusp (think prolapse)

Question 46

During systole, some of the blood from the left ventricle leaks

Answer 46

Into the right ventricle, passes through the lungs and reenters the left ventricle via the pulmonary veins and left atrium.

Question 47

two net effects from VSD

Answer 47

First, the circuitous refluxing of blood causes volume overload on the LV.  Second, because the left ventricle normally has a much higher systolic pressure (~120 mm Hg) than the right ventricle (~20 mm Hg), a LR shunt persists this leakage of blood into the right ventricle elevates right ventricular pressure and volume, causing pulmonary hypertension

Question 48

VSD pathophysiology is more noticeable

Answer 48

in patients with larger defects, who may present with breathlessness, poor feeding and failure to thrive in infancy.  Patients with smaller defects may be asymptomatic.

Question 49

The ventricular septum is formed by the outgrowth

Answer 49

of the muscular ridge at the interventricular foramen.

Question 50

vsd cannulation and venting

Answer 50

Arterial: Aortic  Venous: Bicaval (Total CPB)  Single Atrial if the infant is small and DHCA is anticipated  Venting: may use direct venting with a flexible since the heart is open

Question 51

vsd cannulation and venting

Answer 51

Arterial: Aortic  Venous: Bicaval (Total CPB)  Single Atrial if the infant is small and DHCA is anticipated  Venting: may use direct venting with a flexible since the heart is open

Question 52

vsd cardioplegia

Answer 52

Antegrade, usually a single dose will suffice

Question 53

vsd case notes

Answer 53

 Case is quick depending on VSD location  Case may be 32°C, or DHCA if a small infant  Can be challenging, but usually you have more time with VSD

Question 54

ventricular function after case

Answer 54

may be related to of the length of time the VSD has been present

Question 55

vsd percutaneous closure

Answer 55

Percutaneous closure (Amplatzer)  Can be tough to close VSD’s percutaneously

Question 56

surgical correction of VSD

Answer 56

Probably will not | see primary closure. mostly patch