Congenital Heart Defects: ASD/VSD Flashcards Preview

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Flashcards in Congenital Heart Defects: ASD/VSD Deck (56):
1

ASD most commonly occur as defects in the

septum primum within the fossa ovalis (secundum ASD)

2

ASD can also occur

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

3

cyanotic shunt

R -> L. worse for a kid

4

acyanotic shunt

L->R

5

Blood Flow is quantitated in terms of:

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

6

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

(Qp:Qs

7

Ostium Secundum

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

8

OSTIUM SECUNDUM LOCATION

mid-atrial

9

PFO

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

10

PFO closure from right side

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.

11

PFO closure from right side

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.

12

PFO closure due to left side

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

13

ostium primum location

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

14

ostium primum sat.

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

15

sinus venosus location and associated with

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

16

Cardiac Septation - review
 Occurs at ______ and lasts

day 27 and lasts 10 days

17

At day ____ the paired atria fuse together to form a
common atrium.

27-28

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clinically remarkable left-to-right shunt

ASD > 9MM

19

Any process that increases the pressure in the LV can

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

20

IF ASD LEFT uncorrected

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.

21

This shunt reversal phenomena is known as

Eisenmenger's syndrome

22

Once right-to-left shunting occurs

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

23

percutaneous closure of ASD aka

(Amplatzer)

24

types of surgical closure

Primary Closure  Patch Closure

25

Surgical Correction of ASD’s
 Incision:

 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

26

Surgical Correction of ASD’s
 Surgical Closure
 Primary

– Closure by direct vision suture

27

Surgical Correction of ASD’s
 Surgical Closure patch

– Uses pericardial tissue or Gore-Tex patch for closure

28

Surgical Correction of ASD’s
 Surgical Closure patch

– Uses pericardial tissue or Gore-Tex patch for closure

29

ASD cannulation and VENTING

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

30

ASD cardioplegia

Antegrade, usually a single dose will suffice

31

ASD case notes

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)

32

A ventricular septal defect (VSD) is a

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

33

The ventricular septum consists of:

Inferior muscular portion  Superior membranous portion

34

Common Regions of Ventricular Septal Defects

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

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prevalence of VSD

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

36

Muscular ventricular septal defect is found in four locations

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.)

37

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

adults and older children

38

Membranous VSDs are located near

the heart valves

39

membranous VSD can close

at any time.

40

Supracristal is an

outflow tract VSD sub-valvular in nature

41

The crista supraventricularis can be considered

synonymous with the infundibular (or conus) ventricular septum

42

Outlet VSDs are found in

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

43

The infundibular (or conus) septum separates

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

44

The infundibular (or conus) septum also provides

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

45

The infundibular (or conus) septum also provides

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

46

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

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

47

two net effects from VSD

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

48

VSD pathophysiology is more noticeable

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.

49

The ventricular septum is formed by the outgrowth

of the muscular ridge at the interventricular foramen.

50

vsd cannulation and venting

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

51

vsd cannulation and venting

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

52

vsd cardioplegia

Antegrade, usually a single dose will suffice

53

vsd case notes

 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

54

ventricular function after case

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

55

vsd percutaneous closure

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

56

surgical correction of VSD

Probably will not
see primary closure. mostly patch