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Shunt Detection and Quantification . Grossman’s cardiac catheterization, angiography, and intervention. Presenter : 蔣俊彥 Supervisor : 趙庭興 醫師. Outline. Oximetry Run Flow Ratio Early Recirculation of An indicator Angiography . Shunt suspection. Unexplained arterial desaturation

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shunt detection and quantification

Shunt Detection and Quantification

Grossman’s cardiac catheterization, angiography, and intervention

Presenter : 蔣俊彥

Supervisor : 趙庭興 醫師

outline
Outline
  • Oximetry Run
  • Flow Ratio
  • Early Recirculation of An indicator
  • Angiography
shunt suspection
Shunt suspection
  • Unexplained arterial desaturation
  • Unexpectedly high Oxygen content in pulmonary artery
  • Consider an intracardiac shunt
oximetry run
Oximetry Run
  • Obtain a 2-ml sample from each of the following locations:

1. Left and or right pulmonary artery

2. Main pulmonary artery

3. Right Ventricle , outflow tract

4. Right ventricle , mid

5. Right ventricle , tricuspid valve or apex

6. Right atrium , low or near tricuspid valve

7. Right atrium , mild

8. Right atrium , high

9. Superior vena cava , low (near junction with

right atrium)

10. Superior vena cava , high (near junction with

innominate vein)

11. Inferior vena cava , high (just at or below diaphragm)

12. Inferior vena cava , low L4-L5)

13. Left Ventricle

14. Aorta(distal to insertion of ductus )

oximetry run6
Oximetry Run
  • A significant step-up is defined as an increase in blood oxygen content or saturation that exceeds the normal variability that might be observed if multiple samples were drawn from that cardiac chamber.
  • Dexter Criteria in oximtery run :

a. Highest oxygen content in blood samples drawn from the right atrium exceeds the highest content in the venae cavae by 2vol %

slide7

b. a significant step-up at the ventricular level is present if the highest right ventricular sample is 1 vol % higher than the highest right atrial sample.

c. a significant step-up at the level of the pulmonary artery oxygen content is more than 0.5% vol% greater than the highest right ventricular sample.

1 vol% = 1ml O2/100ml blood or 10mlO2/l

example of left to right shunt detection atrial septal defect
Example of Left-to-Right Shunt Detection:Atrial Septal Defect
  • Vena Cava SPO2=

(3x67.5+1x73)/4=69%

  • Right Atrium SPO2=

(74+84+79)/3=79%

  • A significant step-up

79%-69%=10% >=7%

84%-68%=16%>=11%

  •  SPO2 from SVC to PA

is 12%-13% >8%

slide10
PV O2 content

=0.96(14g Hgb /100ml blood) x (1.36 mlO2/g Hgb)

=18.3 mlO2/100ml blood

=183 mlO2/liter

  • PA O2 content =0.80(14)1.36x10 =152ml O2/liter
  • Qp = O2 consumption (ml/min)/ PVO2 content – PAO2

content

= 240ml O2/min /(183-152) mlO2/L = 7.74 L/min

Qs = 240ml O2/min/ Systemic arterial O2 content – Mixed

venous O2 content

= 240/(0.96-0.69)14(1.36)10=4.6 L/min

  • Qp/Qs=7.74/4.6=1.68

Left-to-right Shunt=7.7-4.7=3L/min

ventricular septal defect
Ventricular Septal Defect
  • Qp =

260/(0.97-0.885)15(1.36)10

= 15 L/min

  • Qs=

260/(0.97-0.66)15(1.36)10

= 4.1 L/min

  • Qp/Qs=15/4.1=3.7

LShunt=15-4.1=10.9 L/min

flow ratio qp qs
Flow Ratio(Qp/Qs)
  • The ratio Qp/Qs gives important physiologic information about the magnitude of a left-to-right shunt
  • A Qp/Qs<1.5 signifies a small left-to-right shunt and is often felt to argue against operative correction ,particularly if the patient has an uncomplicated atrial or ventricular septal defect
  • A Qp/Qs between 1.5 and 2.0 are obviously intermediate in magnitude ; surgical intervention is generally recommended if operation risk is low
  • A Qp/Qs <1.0 indicates a net right-to-left shunt and is often a

sign of the presence of irreversible pulmonary vascular disease.

  • A simplified formula

Qp (SAO2-MVO2)

Qs (PVO2-PAO2)

calculation of bidirectional shunts
Calculation of Bidirectional Shunts
  • Qeff = O2 Consumption (ml/min)

PV O2 content -- MVO2 content

(ml/L) (ml/L)

  • L R = Qp(MVO2 content-PA O2 content )

(MVO2 content-PV O2 content)

  • R  L =Qp(PV O2 content-SAO2 content)(PAO2 content-PVO2 content

(SAO2 content –MV O2 content)x(MVO2 content-PVO2 content)

early recirculation of an indicator
Early Recirculation of An Indicator
  • Standard indicator dilution curves , performed by injection of indocyanine green into the pulmonary artery with sampling in a systemic artery, are rarely done today.
  • The technique can detect left-to-right shunts too small to detected by the oxygen step-up method.
angiography
Angiography
  • Selective angiography is effective in visualizing and localizing the site of left-to-right shunts and useful in localizing the anatomic size of the shunt .
  • Complicated lesions(e.g., endocardial cushion defects, coronary artery/right heart fistula , ruptured aneurysms at the sinus of valsalva) commonly require angiographic delineation before surgical intervention can be undertaken and helps to assess the “routine” more completely.
  • However, Angiography , cannot replace the important physiologic measurements that allow quantitation of flow and vascular resistance
detection of right to left intracardiac shunts
Detection of Right-to-Left Intracardiac Shunts
  • Injection of a dilute solution of saccharin
  • Angiography
  • Oximetry
  • Echocardiographic methods –“bubble study ”
outline22
Outline
  • Atrial septal Defect
  • Ventricular Septal defect
  • Patent Ductus arteriosus
  • Valvar aortic stenosis
  • Valvar Pulmonary stenosis
  • Coarctation of aorta
  • Tetralogy of Fallot
  • DTGA
  • Single Ventricle
  • Postop Fontan
atrial septal defects
Atrial Septal Defects
  • Surgery can be done without catheterization
  • Improving success with umbrella devices for transcatheter closure of central located defects of small or moderate size of ASD
  • Anatomic Types

three main types: ostium secundum (68%) , stium primum

(18%) , sinus venosus defects (6%).

Secundum defects are located in the fossa ovalis below the

limbs band and usually single and central and often

amenable for device closure.

Sinus venosus defects occur in the posterior part of the interatrial

septum , near the superior vena cava , or rarely , the inferior vena

cava and are not amenable to device closure , largely because of

the proximity of nearby right pulmonary veins

slide24
Physiology
  • right ventricular hypertrophydecrease RV compliance ( pulmonary stenosis , pulmonary hypertension ) a smaller left-to-right shunt or a larger right-to-left shunt  reduce left ventricular compliance and produce a larger left-to-right shunt
  • Suggest closing all ASDs at the time of diagnosis
  • Catheterization Technique
  • advance from femoral vein , and pass from right atrium to left atrium
  • An alternate approach is to withdraw the catheter from the SVC to the RA with the tip positioned posteromedially, so that it drops beneath the limbic band into the fossa ovalis (as in a Brockenbrough transseptal puncture ) and then to the RA.
  • Primum defects are located more inferiorly , and sinus venous defects are located more superiorly . Diffiuclty in crossing a known ASD usually implies the presence of the latter type of defect.
  • Oximter Data
slide25
Step-up in oxygen-content of blood in the RA In children ,  10% in oxygen saturation between the high SVC and the RA indicates an abnormal increase .
  • ASD, LV-RA VSD( a VSD and associated tricupid regurgitation)
  • The absence of a measured shunt does not exclude an important ASD.
  • Pressure Data

The absence of transatrial gradient does not make the diagnosis of an ASD ,pericardial tamponade , restrictive physiology

  • Angiography

angiography for pressure equalization across the atria , catheter course , and a step-up at the atrial level is important to make a diagnosis

Both angiography and balloon sizing of atrial defects are carried out to assess whether transcatheter closure is feasible

Suspect ostium primum ASD and perform LV angiogram in a so-called hepatoclavicular view (LAO cranial 40º )

  • Interventional Catheterization

About 50%-60% of patitents with secundum ASDs and those lesions is less than 24 mm diameter , balloon sizing of the defect with a soft , deformable balloon and angiography precede device placement .

ventricular septal defects
Ventricular Septal Defects
  • Loud murmur permit diagnosis of the patient with a VSD at an early age ; large defects produce symptoms early in life and demand early closure , and small defects tend to get smaller with advancing age.
  • “ fish or cut bait” in patients with VSDs by 2 years of age , or certainly by age 5.
  • Most single, clinically significant VSDs are reparied surgically without catheterization , particularly in infancy , there are patients with congenital , posoperative , posttraumatic or postinfarction VSD who require diagnostic or interventional cardiac catheterization or both.
  • Anatomic Types
  • Most congenital VSDs are defects in or about the membranous septum ; “ perimembranous “ type are located just underneath the aortic valve.
  • Atrioventricular canal –type VSDs are less common, are developmentally related to ostium primum defects , and occur in the posterior interventricuklar septum adjacent to the atrioventricular valves. EKG tend to be associated with a counterclock wise superior QRS in the ECG frontal plane and are see more commonly in patients

Down syndrome .

slide27
Subpulmonary VSDs result from deficiency of the conal septum , occur more commonly in Asian patients, and are frequently associated with prolapse of the right coronary cusp and aortic regurgitation. In Caucasian patients, aortic regurgitation also occurs but it is more commonly associated with membranous defects and often with prolapse of noncoronary cusp alone or in conjunction with right cusp.
  • Muscular VSDs can occur anywhere in the interventricular septum ; most are “mid muscular ” , located just below the moderator band in the RV.
  • Swiss-cheese VSDs, have large openings on the LV side of septum but then are divided into myriad of channels by muscle bundles on the RV side.
  • Physiology

Shunt direction are determined by the afterload that each ventricule faces.

  • Left-to-Right Shunt

increase LV afterload (e.g., hypertension, coarctation)

Decrease RV afterload ( pulmonary resistance occur in early infant )

  • Left-to-right Shunt or a Right-to-Left Shunt

Decrease LV afterload (vasodilator therapy)

Increase RV afterload ( the development of pulmonary stenosis or

pulmonary vascular disease)

slide28
A strong natural tendency for VSDs to close with advancing age.
  • Medical and not surgical management is generally advised initally for any restrictive VSD in any asymptomatic patient.
  • Catheterization Technique
  • Catheter passage through a VSD was avoided for the most part, because it was unnecessary in making the diagnosis or estimating the size of shunt.
  • Increase successfully efforts to close certain VSDs using a transcatheter umbrella approach.
  • For perimembranous defects near the tricuspid valve, the catheter is advanced into the RV and turned posteriorly (clockwise) to cross VSD into the LV outflow tract. Midmuscular and apical VSDs, most easily crossed with balloon floating catheterization from LV. Anterior muscular VSDs are best crossed from RV to LV with precurved stiff catheters and soft torque –control wires.
  • A “reactive” pulmonary vascular bed
  • Pressure Data

Small VSDs have a large pressure gradient acrosss the interventricular septum. A large VSD is not to be a large defect. Small defects with associated pulmonary hypertension may mimic the pressure findings in a large defect.

slide29
Angiography
  • the membranous , conoventricular , middle and apical portions of

interventricular septum are best seen in LAO veiw.

  • anterior portion of the septum is best seen with AP veiw.
  • Posterior portion of the septum (the location of atrioventricular canal defects and posterior muscular defects) is best seen with a four-chamber view.
  • Injection of contrast material into the high-pressure chamber (LV) is required and inject nonionic contrast volumes(1to 1.5 ml/kg) at rapid rates( <1 second) to outline the defects
  • Interventional Cardiology
  • Apical and anterior muscular defects and for most residual postoperative defects is treated by transcatheter closure
  • Considering that the aortic and tricuspid valves are close to the edges of most perimembranous VSDs, surgery remains the mainstay of management for these patients.
patent ductus arteriosus
Patent Ductus Arteriosus
  • PDA is usually diagnosed in children and correct at the time of diagnosis. PDA is maintained before birth by the production of PGE. Premature babies may have an incidence of PDA as high as 40%. These are readily closed by administration of the cyclooxygenase inhibitor indomethacin.
  • The diagnosis of a PDA is made on the basis of physical examination and echocardiography. PDA is closed surgically and catheterization is reserved for those patients with unusal findings or suspected pulmonary hypertension. Alternatively, the PDA can be closed surgically by the video-assisted thoroscopy (VATS) technique.
  • PDAs are almost always located off the underside of the aortic arch just distal to the origin of the left subclavicle artery, left of the trachea, and proximal to the left main stem bronchus.
  • Physiology
  • rarely large except in patients with Down syndrome and live at

high altitude.

  • ‘Restrictive’ PDA is characterized by a measurable step-up in PA blood oxygen saturation , perhaps some pulmonary hypertension , and no change in aortic or RV blood oxygen saturation.
slide34
Catheterization Technique
  • The techniques of a standard right-side heart catheter study estimate the hemodynamic effects of a PDA.
  • Transcatheter closure is accomplished eitheter from a venous approach for double-umbrella or coil occlusion or from a retrograde arterial routine fro coil occlusion.
  • Oximetry Data
  • Calculation of the shunt in a patient with a PDA is technique difficult.
  • Left PA blood usually has a higher oxygen saturation than that from

the right PA ; and a “mixed ” PA value cannot be defined accurately.

  • If it is necessary to determinate whether closing of the PDA will result in a fall in PA pressure, one must temporarily balloon-occlude the duct and remeasure saturations and pressures.
  • Pressure Data

Most PDAs do not alter right- or left-side heart pressure unless they are large.

In the face of any left-side heart abnormalities (e.g., poor LV function, aortic stenosis ) , a PDA increases LV systolic pressure , LV diastolic pressure or both .

slide35
Angiography

PDA is best done in a straight lateral view with contrast material injected distal to the PDA.

  • Interventional Catheterization

Most workers use coils in small PDAs and a modification of the double-umbrella technique of Rashkind or a Grifka coil and bag in larger ones.

aortic stenosis
Aortic Stenosis
  • Aortic stenosis, the great majority of which occurs at vavular level, remains a common from of congenital heart disease in both children and adults.
  • The advent of Doppler echocardiography has markedly improved the noninvasive assessment of obstruction severity.
  • Catheterization indication

undertake for balloon vavotomy , which cardiac dysfunction appears in the neonate or the peak-to-peak transvalvar gradient is higher than 50 mmhg , or associated with mild aortic regurgitation in older children,

  • Anatomic Types
  • More than 75% of children with valvar aortic stenosis have a

bicommissural valve with leaflet fusion. The absence of the

intercoronary commissure is most common.

Progression of obstruction occurs in one third of those with valvar

aortic stenosis, making careful follow-up mandatory.

  • In a smlal proportion, the obstruction is subvalvar owing to either a

thin fibrous ridge or fibromuscular dysplasia of the LV outflow tract.

slide38
Surgery is generally indicated for significant stenosis or symptoms in order to protect the aortic valve. It is probably best delayed until after the first decade of life to reduce the risk of recurrence.
  • An hourglass deformity above the aortic valve , so-called supravalvar aortic stenosis. Caused at least partly by thickening of the supracoronary ridge , supravalvar aortic stenosis is often seen in association with Williams syndrome and with branch PA stenosis.
  • Physiology

The clinical findings in all three lesions are similar in these patients with uncompromized LV function.

  • Catheterization Technique
  • Congenitally narrowed valves tend to have an opening in the posterior part of the valve, between the left and noncoronary cusps.
  • Because crossing congenitally stenotic aortic valves can be difficult, sometimes use a side-arm arterial sheath . Beyond infancy, usually place a second arterial catheter in ascending aorta via contralateral femoral artery.
  • Oximetry Data

No oxygen saturation changes in the left or right heart blood

  • Pressure Data

Multiple pigtail catheters are used to enter the LV ; a pullback tracing with these catheters may not localize the presence of subvalvar or supravalvar stenosis, making use of an end-hole catheter necessaryfor the purpose.

slide39
Angiography
  • Aortography and left ventriculography should be obtained in patients with aortic stenosis.
  • Aortography usually in anterioposterior and lateral views assesses the degree of aortic regurgitation as well as anatomy and mobility of the leaflets and coronary artery grossly.
  • Ventriculography (LAO cranial view) is used to measure the annulus diameter to estimate ventricular function, to identify subvalvar pathology and to further outline valvar and supravalvar anatomy.
  • Multiple views may be required to best outline the subvalvar region, including a right anterior oblique view with caudal angulation.

Interventional Catheterization

Balloon valvotomy has become the treatment of choice for valvar aortic stenosis at Boston Children Hospital. The results are roughly equivalent to those of surgical valvotomy.

pulmonary stenosis
Pulmonary Stenosis
  • Obstruction to the RV outflow tract usually are seen in association with other congenital lesions, such as TOF, transposition of the great arteries , or single ventricle. Isolated valvar pulmonary stenosis is common beyond the neonatal period.
  • Noninvasive diagnosis and severity assessment are now accurate in almost all circumstances and catheterization is reserved for those who require balloon valvotomy , at any age.
  • Anatomic types
  • Valvar obstruction accounts for more than 80% of isolated pulmonic stenosis.
  • In typical valvar pulmonary stenosisthe annulus is of normal size, the leaflets are thin , the commissures are fused and there is marked poststenotic dilation.
  • Dysplastic pulmonary valves exhibit a different pathology; the annulus is small , the leaflets are markedly thickened, they do not move during systole and they are fused. The main PA is short and narrow.
  • RV muscles bundles occur as anomalously thickened bundles of muscle within the RV cavity and are usually associated with VSD or subvalvar aortic stenosis.
  • The rarest form of pulmonary stenosis is branch PA stenosis. It is often associated with both supravalvar aortic stenosis and Williams syndrome.
slide41
Physiology
  • Severe forms of stenosis in the neonate generally lead to markedly reduced RV compliance with increasing RA pressure and then right-to-left shunting across a PFO.
  • Critical valvar pulmonary stenosis commonly manifests with cyanosis and sometimes with heart failure. Moderate degree of stenosis (e.g., gradients of 40 to 80 mmhg) rarely cause symptoms
  • Patients with moderate pulmonary stenosis have decreased exercise performance at cardiac catheterization. Balloon valvotomy is both safe and successful , most cadiologist now recommend dilation in any patient with more than mild stenosis before 5 years of age.
  • Catheterization Technique

The foramen ovale is usually open , allowing catheter access to the left side of the heart from a femoral venous approach. Arterial catheters usually are required only in ill neonetes and those with severe or more

obstruction. The opening in the pulmonary valve of an infant with severe pulmonary stenosis may be extremely small (less than 1 to 2 mm in diameter)

Do not routinely measure PA pressure directly in infants with critical valvar pulmonary stenosis, rather perform 4 F catheters and a 0.018 inch

torque wire to cross the valve , followed by rapid balloon dilation.

slide42
Oximetry Data
  • Most patient have neither a right-to-left nor a left-to-right shunt . In critical severe valvar pulmonary stenosis, a right-to-left shunt occurs at the atrial level, produceing cyanosis.
  • In patients with both mild pulmonary stenosis and an ASD , with a large left-to-right shunt at the atrial level, the gradient across the pulmonary valve is falsely elevated. Closing the ASD reduces the RV pressure as well as the gradient across the pulmonic valve.
  • Pressure Data

In mild pulmonary stenosis, the RV pressure is normal. As the degree of stenosis increases, the RA a wave increases. With severe pulmonary stenosis , RV systolic pressure approaches or exceeds LV pressure, main PA pressure falls, and the PA pulse pressure dampens. Marked hypertrophy of the RV may cause the infundibular os to close during late systole , resulting in further obstruction.

  • Angiography

Right ventriculography in straight lateral view to outline pulmonary valve and subvalvar region.

A straight AP view with crainal angulation may outline the pulmonary valve, poststenotic dilation of the main PA often obscures the PA branch origin.

coarctation of the aorta
Coarctation of the aorta
  • Catheterization of the patient with isolated coarctation for diagnostic purposes is rarely required before surgery. Improved noninvasive imaging , including MRI allows precise anatomic definition of the lesion.
  • The continued incidence of recurrent coarctation after surgical repair , the common association of coarctation with other forms of congenital heart disease , and increasing use of balloon dilation in discrete nonoperated coarctation
  • Anatomic types

all forms of coarctation occur at or just distal to the left subclavian artery, at or near the level of the old ductus arteriosus

Coarctations have discrete “ curtains ” of tissue indepting the posterior wall of the aorta associated with hypoplasia of the transverse aortic arch.

  • Physiology

The gradient across a coarctation is influenced not only by the degree of obstruction but also the degree of collateral flow around the obstruction

slide46
Upper-extremity hypertension, the primary sequale of a coarctation , usually resolves after surgical correction. In some children, hypertension persists despite adequate anatomic repair. The persist hypertension is more common when repair occur s late in childhood.
  • The general recommendation that coarctation should be diagnosed and corrected before the child reaches 3 years of age.
  • Oximetry Data

no abnormalities in their intracardiac oxygen saturation

  • Pressure Data

The gradient measured by pullback in the catheterization laboatory is frequently smaller than the gradient measured by sphygmomanometer in clinic.

  • Angiography

a straight lateral aortogram usually provides excellent visualization of the coarctation.

  • Interventional Catheterization
  • Although balloon dilation frequently reduces the gradient across an unoperated coarctation site, the results particuly in babies are not generally as good as those seen surgical management.
  • However,balloon dilation of recurrent coarctation has provided clinically

invaluable with or without stent placement.

tetralogy of fallot
Tetralogy of Fallot
  • The association of a malalignment VSD, infundibular and valvar pulmonary stenosis with resultant aortic overriding , and cyanosis is referred to as TOF complex.
  • It remains a difficult and important surgical challenge. Catheterization of infants with the lesion, especially if they are cyanotic , may be hazardous. Therefore, if echocardiography information is adequate in this age group, surgery is undertaken without catheterization.
  • Anatomic Types

(a) branch PA stenosis (5% to 10%)

(b) pulmonary atresia with PDA-dependent pulmpnary blood flow

(5% to 10%)

(c) additional muscular VSDs (5% to 10%)

(d) aortopulmonary collateral arteries supplying blood flow to the

lungs (5% to 10%)

(e) coronary arterial anomalies , especially the left anterior

descending arising from the right coronary artery (1% to 2%)

slide48
Physiology
  • The combination of pulmonary obstruction and a VSD produces a

right-to-left shunt at the ventricular defect.The size of this shunt is

unrelated to the size of the VSD, which in TOF is almost always large

and unrestrictive. The right-to-left shunt and degree of cyanosis are

determined primarily by the degree of pulmonary obstruction and less

by the level of systemic vascular resistance.

  • “tetrad spells” characterized by hyperventilation , acidosis, extreme

desaturation , and unconsciousness. Hypercyanotic episodes may be

provoked by increased pulmonary obstruction or decreased systemic

resistance. They are best treated by sedation, intravenous volume

infusions , and increasing the systemic vascular resistance.

  • Previously , aortopulmonary shunts such as the Blalock-Tassig shunt

were created surgically to increase pulmonary blood flow . Currently , so-

called complete cardiac correction , relieving the pulmonary stenosis, and

closing the VSD, is usually undertaken in infancy , or early childhood.

  • Catheterization Technique
  • enter the left side of the heart from the RA without difficulty.
  • pass the catheter from the RV both to the aorta and into the PA
  • Catheter passage into PA often provoke a hypercyanotic spell and catheter from the RV to aorta often produces transient heart block.
slide49
Oximetry Data
  • No abnormalities in oxygen saturation at the atrial level or ventricular level. The right-to-left shunt is documented only in the aorta.
  • If the cyanosis is severe , a right-to-left shunt may be present at

the atrial level as well, across a PFO. The atrial shunts are signs of substanially decreased RV compliance and suggest long-

standing RV hypertension.

  • Pressure Data

RV and LV pressures are equal in patients with TOF.

PA pressures are decreased in cyanotic patients without surgery.

In the presence of surgically created Waterston or Potts

aortopulmonary shunts , the PA is often distorted and pressures are

elevated but rarely after Blalock-Taussig shunts.

  • Angiography
  • Angiographic definition of anatomic detail is the key element in the

cardiac catheterization of patients with TOF.

  • A biplane RV angiogram with cranial angulation of the anteroposterior

establishes the diagnosis , defines the anatomy of the pulmonary valve

and subpulmonary region , and identifies the main PA and proximal PA

branches.

slide50
An ascending aortogram may be necessary to further delineate coronary artery anatomy, and in particular to identify the origin of the left anterior anterior descending artery.
  • Aortography especially of the descending aorta is also often necessary to see whether any aortopulmonary collaterals are present.
  • Interventional Catheterization
  • Interventional procedures are rarely required before definitive

surgical correction in patients with uncomplicated TOF.

  • However, in infants with TOF, pulmonary atresia, and diminutive

Pas, dilation of hypoplastic Pas and coil embolization of

aortopulmonary arteries make up an essential component of

management.

transposition of the great arteries
Transposition of The Great Arteries
  • In transposition of the great arteries (TGA), the great arteries arise from the wrong ventricles (I.e., the aorta from the RV and the PA from LV )
  • Two main types; the more common variety is dextro-TGA(DTGA) and levo-TGA(LTGA)
  • DTGA, the ventricle position is normal (I.e., the RV is right–sided and the LV is left-sided ,with the RV giving rise to a right–sided anterior aorta and the LV to a left-sided posterior PA
  • LTGA, less common , the ventricles are inverted (I.e., the LV is

right-sided and RV is left-sided with the LV giving rise to a right-

sided PA and the RV to a left-sided aorta. The type of

transposition is almost always accompanied by a VSD and

subpulmonary stenosis , is often by tricupid regurgitation and

atrioventricular conduction abnormalities, and is a very difficult

lesion to deal with

slide54
Physiology
  • The pulmonary and systemic circulations in TGArun in parallel:

red blood coming back from the lungs returns to the lungs, and

blue blood coming back the body return to the body. Without a

defect in circulation (e.g., ASD, PDA, VSD) to allow mixing

between the two circuits, the patient would die a few minutes after

birth,

  • The early goal of therapy to make a hole in the atrial septim (BAS),

or between the great arteries (using prostaglandins to open the

PDA)

  • Catheterization Technique

echocardiography definition is so precise and the only reasons to catheterize such neonates are to do a BAS.

  • Angiography
  • RV angiography is standard anteroposterior and lateral views ,

establishes the diagnosis, assess RV function , determines the presence

of a VSD, or a PDA, and assesses tricupid regurgitation.

  • LV angiogram demonstrates LV outflow tract lesions and the location of a

VSD .

  • “laid-back” balloon occlusion aortogram best outlines coronary arterial anatomy.
slide55
Intervention Catheterization

an arterial switch operation is performed electively in the first 10 days of life and perform a BAS in the early neonatal period. Creation of an ASD remain the optimal method for stabilization of cyanotic infants.

single ventricle
Single Ventricle
  • The term “ single ventricle “ refers to a family of lesions and is only one functional ventricular chamber.
  • Since introduction of the Fontan procedure and other proceding palliative procedures such as the Norwood stage 1 and bidirectional Glenn operations, this patient population with its evolving problem is rapidly increasing.
  • Anatomic Types
  • The most common form of single ventricle is the highly lethal

hypoplastic left heart syndrome (HL-HS) , which is caused by

aortic or mitral atresia . LV is diminutive. HLHS died in the past

when PDA close. The pioneering efforts of Norwood et.al, to creat

a new aorta surgically , using the RV as a single ventricle , has

improved the survival.

  • A less common is tricuspid atresia. Patients with aplenia and poly

splenia syndormes , also frequently have single ventricle .

  • Most of the patient’ s catheterized at least twice electively –between the stage 1 and bidirectional Glenn procedures and between the latter and the Fontan operation.
slide58
Catheterization Techniques– Betweenthe stage I and Bidirectional Glenn Procedures.
  • The patient have in common a pulmonary blood flow supplied by

an aortopulmonary shunt , usually a Blalock-Taussig shunt , and

the mandatory catheterization information consists of

measurement of PA pressure, resistance , intracardiac and aortic

pressures, and OA and systemic venous anatomic details. The

catheter is advanced from the descending aorta into the mouth of

the subclavian artery. Then the guidewire is passed from the tip of

the pigtail to the distal PA .

  • An alternative method of PA pressure estimation is to measure the pulmonary venous wedge value , but this is a reliable approximation only when the PA mean is less than 20 mmhg.
  • After the Directional Glenn Procedure and Just Before the Modified Fontan Procedure

Because the SVC has been disconnected from the RA and anastomosed to the PA, another venous line from the left subclavian vein is required in the catheterization of these patients.

, in addition to femoral venous and arterial lines.

slide61
The development of pulmonary arteriovenous fistulas in these

patients is increasingly recognized and is considered to be a

consequence of the hepatic venous blood from the pulmonary

circulation by the bidirectional Glenn procedure.

  • After the Fontan Procedure
  • Many patients after a Fontan procedure have not had a

fenestration placed in the baffle at the time of surgery and who

are doing well are not electively catherized.

  • However, a significant number who had a fenestration placed who

later come to have this communication electively closed with a

double-umbrella device.

  • There are also others who have cyanosis for some other reason or

evidence of congestive heart failure /venous hypertension who

require catheterization for diagnostic and intervention purposes.

  • Excessive aortopulmonary collaterals may be present; they may

lead to ventricular failure and require coil occlusion.

  • Aortic arch obstructions similarly cause ventricular failure and

require dilation and stenting even gradients are small.