Topic 9: ASD / VSD Flashcards
1 year
systolic/diastolic
98-104
55-60
2 year
systolic/diastolic
101-107
59-64
5 year
systolic/diastolic
104-114
69-72
> 36 gestation full term
systolic/diastolic
68/43
ASDs - occurs what two places
Most commonly occur as defects in the septum primum within the fossa ovalis (secundum ASD)
Defect can involve the septum secundum near SVC (sinus venosus defects-less common)
Will cause pressure mediated shunting
L->R *compliant right heart
R->L
ASDs most commonly occur where?
Most commonly occur as defects in the septum primum within the fossa ovalis (secundum ASD)
Compliant right heart with an ASD will cause what kind of shunting?
L –> R
What ratio do you intervene with ASDs (Qp:Qs ratio)
The general rule is shunts that DO NOT cause right heart size (Qp:Qs
Most common ASD called what?
Ostium Secundum -(Mid atrial, Most common)
how is Ostium Secundum formed?
formed by failed growth of the septum secundum or
rapid reabsorption of the septum primum
What is the only type of ASD that allows for percutaneous closure?
Ostium Secundum
ASDs - occurs what two places
Most commonly occur as defects in the septum primum within the fossa ovalis (secundum ASD)
Defect can involve the septum secundum near SVC (sinus venosus defects-less common)
Will cause pressure mediated shunting
L->R *compliant right heart
R->L
ASDs most commonly occur where?
Most commonly occur as defects in the septum primum within the fossa ovalis (secundum ASD)
Compliant right heart with an ASD will cause what kind of shunting?
L –> R
how is Ostium Secundum formed?
formed by failed growth of the septum secundum or
rapid reabsorption of the septum primum
What is the only type of ASD that allows for percutaneous closure?
Ostium Secundum
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
Channel from birth
Normally closes due to pressure changes very early in life
“flap valve”
How does PFO close?
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
In addition, more blood returns from the lungs which increases the pressure in the LA.
The increased LA pressure and decreased RA 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
Ostium Primum ASD - located where?
Located low in the septum
Considered a type of AV Septal Defect (AVSD)
Could have RA saturations lower than RV without a VSD
Sinus Venosis ASD - located where?
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
May have PAPVR
Embryonic/fetal circulation is ____ to the neonatal circulation
different
Embryonic septation forms
separate chambers
One septal “defect” occurs in us all - -which ?
the foramen ovale (between the 2 atria) which in general closes in the neonate over time
Cardiac Septation when ?
Occurs at Day 27 Lasts 10 days The formation of the cardiac septa occur simultaneously During this time, no major changes in external appearance
Atrial Septation - when? how long?
At day 27-28, the paired atria fuse together to form a common atrium.
Atrial septation occurs simultaneously and in
cooperation with ventricular septation
Atrial septation also lasts approximately 10days
what size ASD may result in a clinically remarkable left-to-right shunt?
large ASD (>9mm)
Blood will shunt from the LA to the RA.
This extra blood from the left atrium may cause a volume overload of both the RA and the RV (RA dilatation-> RA fibrosis) .
If untreated, this condition can result in enlargement of the right side of the heart and ultimately heart failure
ASD present -> Increased right sided volume -> _______ -> Tricuspid annular dilatation (TR) -> Pulmonary congestion -> Pulmonary hypertension
Right atrial and ventricular dilatation
ASD present -> Increased right sided volume -> Right atrial and ventricular dilatation -> _______ -> Pulmonary congestion -> Pulmonary hypertension
Tricuspid annular dilatation (TR)
ASD present -> Increased right sided volume -> Right atrial and ventricular dilatation -> Tricuspid annular dilatation (TR) -> Pulmonary congestion -> _______
Pulmonary hypertension
ASD present -> _____ -> Right atrial and ventricular dilatation -> _____ -> Pulmonary congestion -> Pulmonary hypertension
Increased right sided volume
Tricuspid annular dilatation (TR)
Any process that increases the pressure in the
LV can cause worsening of what??
the left-to-right shunt.
It also works on the right heart
Included are systemic HTN which increases the pressure that the LV has to generate in order to open the aortic valve
ASD pathophysiology: The RV will have to push out more blood than the left ventricle due to the L-> R shunt.
This constant overload of the right side of the heart will cause what??? and eventually what?
Qp/Qs??
an overload of the entire pulmonary vasculature.
(Pulmonary over-circulation)
Qp/Qs > 1.5/1.0 is a problem
Eventually pulmonary HTN will develop
In an ASD – The pulmonary hypertension will cause the heart to have what two things increased – ??
The pulmonary hypertension will cause the
RV to face increased afterload (PVR) in addition to the increased preload that the shunted blood from the LA to RA caused
In an ASD - The RV will be forced to generate higher tension/pressures to try to overcome the pulmonary HTN.
This may lead to what???
right ventricular failure
dilatation and decreased systolic function of the RV
If an ASD is left uncorrected?
Pressure in the right heart___left heart
RA pressure___ LA pressure
Pressure 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.
This shunt reversal phenomena is known as Eisenmenger’s syndrome
Once right-to-left shunting occurs, oxygen-poor blood gets shunted to the left side of the heart.
This will cause signs of cyanosis.
Eisenmenger’s syndrome?
The pressure gradient reverses across the ASD the shunt will reverse a right-to-left shunt (R->L) will now exist.
This shunt reversal phenomena is known as Eisenmenger’s syndrome
Once right-to-left shunting occurs, oxygen-poor blood gets shunted to the left side of the heart.
This will cause signs of cyanosis.
Surgical Correction of ASD how??
Percutaneous closure (Amplatzer)
Surgical Closure
Primary Closure
Patch Closure
Percutaneous closure (Amplatzer) - for what kind of ASD?
Ostium Secundum
Surgical correction of ASD – where to you have the incision?
Median sternotomy
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
Surgical Closure
Primary–
Closure by direct vision suture
Surgical Closure
Patch closure
–Uses pericardial tissue or Gore-Tex patch for closure
Cannulation for ASD surgical procedure
Arterial -?
Venous: ? 2 options?
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
for ASD surgical procedure
CPG??
Case time? Temp?
Cardioplegia: Antegrade, usually a single dose will suffice
: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)
The ventricular septum consists of??
Inferior muscular portion
Superior membranous portion
A ventricular septal defect (VSD) is a defect in the?
ventricular septum, the wall dividing the left and right ventricles of the heart.
Regions of VSDs?
Inlet
Outlet (supracristal)
Peri-membranous Septum
Muscular Septum
VSD %s?
Membranous
Muscular %
Supracristal (Outflow) %
75%
20%
5%
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)
Membranous VSD located where?
The membranous portion, which is close to the atrioventricular node, is most common in adults and older children
Membranous VSDs are located near the heart valves
These VSDs can close at any time
Supracristal is what type of VSD? and where are they found?
outflow tract VSD sub-valvular in nature
Outlet VSDs are found in the part of the ventricle where blood leaves the heart.
These are the rarest type of VSD.
In supracristal VSDS – what two things can be considered synonymous?
The crista supraventricularis can be considered synonymous with the infundibular (or conus) ventricular septum
Rarest type of VSD?
Outlet VSD (supracristal VSD)
The infundibular (or conus) septum separates what two things?
the tricuspid and pulmonary valves and accounts for the more superior placement of the pulmonary valve relative to the aortic valve.
infundibular (or conus) septum provides what ??
This portion of the septum also provides muscular rigid support for the aortic valve, especially the right coronary cusp (think prolapse)
VSD -
During systole, some of the blood from the ___ leaks into the right ventricle, passes through the lungs and reenters the___ via the pulmonary veins and left atrium
left ventricle
left ventricle
2 net effects of 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
When are VSD effects more noticeable ?
This effect 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.
Cardiac Septation
Occurs at Day 27 Lasts 10 days The formation of the cardiac septa occur simultaneously During this time, no major changes in external appearance
Ventricular septation - how is it formed?
The ventricular septum is formed by the outgrowth of the muscular ridge at the interventricular foramen.
The ventricular septum grows upward from the apex of the heart to the base of the heart
VSD Cannulation
Arterial?
Venous?
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
VSD – CPG? Temp? Time?
Cardioplegia: Antegrade, usually a single dose will suffice
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
Ventricular function may be related to of the length of time the VSD has been present
What type of closure will you most likely not see with a VSD?
Surgical Closure - Probably will not see primary closures
What type of closure may be tough to do percutaneously with a VSD?
Percutaneous closure (Amplatzer) Can be tough to close VSD’s percutaneously
options to fix a VSD?
Surgical Correction Percutaneous closure (Amplatzer) Surgical Closure Primary closure Patch Closure
