Tetrology/Truncus arteriosus/Transposition of Great arteries

Question 1

Embryological cause of Tetrology of Fallot

Answer 1

Embryologically, this is thought to be
due to anterior deviation of the conal
septum

Question 2

Four key features of tetrology of fallot

Answer 2

• Sub pulmonary stenosis
• Ventricular septal defect (VSD)
• Over riding aorta
• Right ventricular hypertrophy (RVH)

Question 3

Common etiology of tetrology of fallot

Answer 3

DiGeorge syndrome (22q11.2 deletion syndrome) is the most common underlying genetic association for tetralogy of Fallot (TOF), seen in 10%-16%.
• Trisomy 21 (Down syndrome) is the next most common associated syndrome with TOF.
• Mutations in NKX2.5, JAG1 (also seen with Allagile’s syndrome), FOG27, trisomy 13, and CHARGE syndrome may be associated with TOF

Question 4

key features of DiGeorge

Answer 4

phenotypic facies*
– developmental delay (IQs 70 to 90)/ learning disabilities/ speech delay
– hypocalcemia (due to parathyroid underdevelopment)
– immune deficiency (related to thymic hypoplasia)

Question 5

routine test for DiGeorge

Answer 5

FISH for 22q11

Question 6

Newborns with TOF may be_______ or may
have physiology consistent with “pink” TOF,
if the ____________
obstruction is minimal.

Answer 6

cyanotic

right ventricular outflow tract (RVOT)

Question 7

Most common signs and symptoms of TOF

Answer 7

1) a heart murmur (systolic ejection murmur
@ left upper sternal border)
2) ± cyanosis
3) ± tachypnea (esp. present when only mild
RVOT obstruction exists and resulting
pulmonary over-circulation occurs, from the
left to right shunting across the VSD)

Question 8

What type of heart murmur do we hear with TOF?

Answer 8

heart murmur (systolic ejection murmur 
@ left upper sternal border)

Question 9

Cyanotic CHD classically include the “5 T’s”

Answer 9

1. Tetralogy of Fallot – the most common cyanotic CHD
2. Truncus arteriosus
3. Transposition of the great arteries (TGA)
4. Tricuspid atresia
5. Total anomalous pulmonary venous return

Question 10

For a cyonotic newborn, a _______ test should be performed to confirm CHD exsists rather than a pulmonary cause of cyanosis

Answer 10

hyperoxia

Question 11

For cyanotic or acyanotic newborn suspected of
having CHD work up will likely include:

Answer 11

ECG for chamber info

chest x-ray

Cardiac cath (no longer done)

karyotipic and FISH analysis

Question 12

On echo of a newborn with suspected TOF… what do we see between the ventricles?

Answer 12

There is a VSD… hole between the right and left ventilces

Question 13

newborn presents with a heart murmur.. systolic ejection at left upper sternal border, is cyonotic and slightly tachypnic. This is what you see on chest xray.. Diagnosis?

Answer 13

Tetrology of Fallot (boot shaped heart)

Question 14

For CYONOTIC newborn with TOF, what is the medical manangement before surgery?

Answer 14

Initiate intravenous prostaglandin (PGE) 0.05-0.1 mcg/kg/minute to maintain patency of the ductus arteriosus (PDA) which will augment pulmonary blood flow.

Question 15

Common side effects of PGE to monitor for include:

Answer 15

Apnea
Fever
Hypotension at higher doses
Increased secretions
Gastric outlet obstruction (chronic use)

Question 16

Operative intervention for TOF includes

Answer 16

Shunt
Complete repair

Question 17

Management of “pink” TOF newborn is different then in cyonotic.. what would you tell the parents

Answer 17

Discharge to home with close follow up in clinic.
with the goal to optimize growth with good nutrition.
• Discuss tetralogy of Fallot spells with parents, as
degree of RVOT obstruction may change with
infant’s growth.
• Plan for operative repair at 3 – 6 months of age

Question 18

You send a ‘pink’ TOF child hold with the parents.. They call a month later and note the baby is tinged blue and rush the baby in. An M3 on totations listens to the heart and doesn’t hear any murmurs and is confused because he knows there is suposed to be a typical ejection systolic murmur. Explain to him what’s going on

Answer 18

During a Tet spell, disappearance of the typical
ejection systolic murmur indicates that RVOT obstruction has become so severe that there is little to no forward blood flow into the branch pulmonary arteries and significant right to left shunting occurs across the ventricular septal defect.

Question 19

First line therapy to Tet spell

Answer 19

First-line therapy is to calm the infant and provide supplemental oxygen. Placing the infant or child in the knee-to-chest position can increase systemic venous return to the heart and augment blood flow across the RVOT; it also increases systemic vascular resistance (SVR)

*if child doesn’t have an IV.. give intramuscular morphine… if they have an IV, use bolus of saline

Question 20

Additional meds (besides intramuslcuar morphine or saline bolus) for tet spells

Answer 20

1) IV ketamine
2) IV phenyleprine
3) β blocker therapy (oral propranolol)

Question 21

What complete operative repair options are there for TOF?

Answer 21

1) Patch closure of the ventricular septal defect (VSD), so that the left ventricular chamber
blood flows into the aorta
2) Relief of right ventricular outflow tract obstruction

Question 22

To provide relief of right ventricular outflow tract obstruction: what three options are there?

(in TOF)

Answer 22

a) sub pulmonary muscle resection
b) RVOT patch placement to increase the diameter
of this area, either via a non-transannular patch or
a transannular patch placement (which increases
the size of a hypoplastic pulmonary valve annulus)
c) placement of a right ventricular to pulmonary
arterial conduit (used for atretic pulmonary valve/
main pulmonary artery or when a coronary artery
crosses the RVOT)

Question 23

Mortality/ Morbidity of TOF Repair
]
• Mortality following TOF repair:

• Postoperative inpatient hospitalization is:

Mean length of stay for TOF repair:

Answer 23

1.5% - 3.9% (varies depending on method)

~1 to 2 weeks.

o TOF with ventriculotomy & transannular patch ~ 11.7 d (median 7.0 d)
o TOF repair with conduit ~ 12.7 days (median, 7.0 d)

Question 24

Long term follow up in pts with repaired TOF

Answer 24

have residual pulmonary regurgitation that may become progressively more severe as patients age
–>lead to increasing RV dilation.
• patients with transannular patch repair have significantly more pulmonary regurgitation and larger indexed RV end-diastolic volume than for
those with right ventricular to pulmonary artery conduits.
• RV-PA conduits placed in infancy do not grow
and need to be replaced

Question 25

When prognosis is good for survival, patients with repaired TOF may require re-operation later in life • Re-operation needed if

Answer 25

pulmonary regurgitation becomes significant and leads to right ventricular dilation and dysfunction.

Question 26

Indications for re-operation for PVR in patients with repaired TOF or similar physiology who have moderate or severe pulmonary regurgitation (regurgitation fraction ≥25%) IF pt is asymptomatic: patient is symptomatic:

Answer 26

asymptomatic: need 2+ criteria symptomatic: pt is showing signs attributable to severe RV volume load, exercise intolerance, signs and symptoms of heart failure and syncope

Question 27

QOL in children/adolescents with repaired TOF

Answer 27

is not proportional to the severity of residual disease. • Self-reported QOL appears similar to healthy peers, while parent/proxy reported lower QOL. • For both children and parents, QOL positively correlated with the child's exercise capacity. -have normal B-natruitic peptide and reasonable exercise tolerance

Question 28

Whats going on in Transposition of the great arteries

Answer 28

Atrio-Ventricular concordance • Ventricular-Arterial discordance Aorta arises from the morphologic RV Pulmonary artery from morphologic LV

Question 29

IN TGA we see atrio-ventrcular \_\_\_\_\_\_\_ Ventricular arterial \_\_\_\_\_\_\_

Answer 29

* Atrio-Ventricular concordance * Ventricular-Arterial discordance

Question 30

Complete TGA, the single discordance....

Answer 30

The single discordance makes the transpotision physiologically complete

Question 32

Genetics of TGA: * Represents \_\_\_\_of CHD * Chromosomal and extracardiac abnormalities rare thus it is likely\_\_\_\_\_\_ * Male/female ratio \_\_\_\_\_ * Seen more commonly in infants of \_\_\_\_\_\_

Answer 32

5% sporadic 2:1 diabetic mothers

Question 33

What happens embroyologically to account for formation of TGA?

Answer 33

TGA probably results from abnormal conotruncal rotation as septation occurs

Question 34

In TGA, babies are fine in utero.. but what happens at birth?

Answer 34

blue babies with immediate cyaosis. Normal circulation is in series.. in TGA, the circuation is in parellel

Question 35

Survival in transposition of the great arteries depends on

Answer 35

intercirculatory mixing – PV blood → Aorta (effective systemic blood flow) – SVC/IVC blood → PA (effective pulmonary blood flow)

Question 36

What are the potential sources of intercirculatory mixing? – Atrial Level : – Ventricular Level: – Arterial Level :

Answer 36

– Atrial Level (patent foramen ovale, ASD) – Ventricular Level (VSD – present in 40-45% of all TGA) – Arterial Level (patent ductus arteriosus)

Question 37

In TGA physiology: Postnatal circulation –What happens to SVR as placenta removed? – What happens to PVR with ventilation?

Answer 37

SVR↑ PVR↓ \*\*Understand difference between shunting and mixing

Question 38

An option to maintain intercirculatory mixing in TGA is keeping the PDA open by:

Answer 38

giving PGE1.. but this alone may not always help!

Question 39

What associated lesions are present in TGA?

Answer 39

• 50% of TGA have other cardiac anomalies – Ventricular septal defect (40-45%) – LV outflow tract obstruction (5%) – Coarctation of aorta or Interrupted aortic arch – Coronary artery abnormalities

Question 40

Do all TGA cases have associated lesions?

Answer 40

50% of TGA have an intact ventricular septum and PFO or PDA – with no other cardiac anomalies

Question 41

Our patient has TGA with VSD.. does this affect our treatment to maintain intermixing? What is our most common VSD in TGA?

Answer 41

• May not require PGE1 to maintain PDA Perimembranous VSD

Question 42

Coronary arteries usually arise from the aortic sinuses that face the pulmonary artery – Most commonly the LCA arises from left sinus, and RCA from right sinus – Many other variants: circumflex from RCA, single RCA or LCA, inverted origins Why does this matter in TGA?

Answer 42

Because if you have low degree of mixing, one side of the heart will have adequate oxygen perfusion, while the other doesn't. In TGA, the left side will be perfused, while the right side won't.. may affect cardiac ischemia patterns ( I think)

Question 43

How does the presentation of TGA differ from other types of cyanotic heart disease?

Answer 43

• Cyanosis immediately after birth, degree can be variable depending on associated lesions, but it is usually profound • Murmur may be absent • Loud single S2 (due to anterior location of aorta) • Hyperoxia test • Neonatal pulse oximetry screening?

Question 44

What weird heart sound do we get with TGA?

Answer 44

loud single S2 (due to anterior location of aorta) --may not have a murmur

Question 45

Your attending has you look at a chest xray of a newborn with a congentital heart defect. The Xray is descirbed as "egg on a string" Dx?

Answer 45

Transposition of the great arteries

Question 46

What accounts for the findings of 'egg on a string' on chest xray in TGA?

Answer 46

Oval or “egg-shaped” cardiac silhouette with narrow superior mediastinum. (code word “egg on a string”) • Mild cardiomegaly • Increased pulmonary vascular markings

Question 47

Diagnostic procedure of choice for TGA?

Answer 47

Echo

Question 48

Management of Transposition of Great arteries

Answer 48

* Oxygen * Volume (IV fluids) * Correct metabolic abnormalities

Question 49

Two ways to maintain intercirculatory mixing in TGA?

Answer 49

Create ASD with balloon atrial septostomy. Maintain ductal patency with PGE1 infusion

Question 50

A procedure called the Senning procedure is done to correct TGA. Describe the surgery

Answer 50

pulmonary artery switched to original root of aorta and aorta switched to original root of pulmonary artery coronary arteries attached to neo-aorta close pda use a patch to cover where the coronary arteries used to be

Question 51

Risks/complications of Senning procedure to correct TGA

Answer 51

• Venous obstruction – Systemic veins – Pulmonary veins • Arrhythmias (related to RV dysfunction and can lead to sudden death) – Atrial arrhythmias – Sinus node dysfunction • Systemic ventricle (RV) dysfunction

Question 52

What procedure is being done below on pt with TGA?

Answer 52

Arterial switch ## Footnote The aorta and pulmonary artery are detached from their native roots and reattached to the opposite root; thus, the pulmonary root becomes the neo-aorta, and the aortic root becomes the neo-pulmonary artery. The coronary arteries are transplanted from the aorta/neo-pulmonary artery to the pulmonary artery/neo-aorta.

Question 53

History of surgery of TGA

Answer 53

The History of Surgery in TGA • 1950’s - Palliation only (atrial septectomy); survival \< 6 months • 1960’s - Atrial switch (Mustard/Senning repair) – Long-term problems: RV dysfunction, sudden death related to arrhythmias • 1980’s - Arterial switch (Jatene) • 1990-2000s - Improvements in surgical technique have decreased surgical mortality \<2%; excellent long-term survival and quality of life

Question 54

Risks associated with arterial switch/Jatene surgery to correct TGA?

Answer 54

coronary issues aortic root dilation aortic insufficiency branch pulmonary artery stenosis

Question 55

You are on your newborn nursery rotation and a full term infant is born to a mother with poorly controlled Type 1 Diabetes. The nurse appreciates a murmur.  VS HR 140 RR 40 Sat 80% RA ◦ Mild cyanosis, mild tachypnea but no increased WOB ◦ Hyperactive precordium ◦ S1, single S2 ◦ Gr II/VI harsh systolic ejection murmur at LUSB ◦ Gr II/IV diastolic murmur at LSB ◦ Otherwise normal What do the heart sounds suggest? What do the murmurs suggest?

Answer 55

Truncus arteriousus We have one common valve that is abnormal ...This great vessel usually has one large valve which may have between two and five leaflets. Usually this great vessel sits over both the left and right ventricle.

Question 56

Pathology of Trunucs arteriosus Characterized by: ◦\_\_\_\_\_\_\_ semilunar valve

Answer 56

Single\*\*\*\*\* Differentiates from aortic or pulmonary atresia

Question 57

Pathology of truncus arteriosus: Single arterial vessel giving rise to:

Answer 57

 Pulmonary arteries  Coronary arteries  Systemic artery (aorta)

Question 58

Pathology of Truncus arteriorsus associated with:

Answer 58

Single semilunar valve single arterial vessel giving rise to: pulmonary arteries/coronary arteries/systemic artery (aorta) Infundibular VSD

Question 59

In truncus arteriosus, we have complete mixing of systemic and pulmonary venous return at the ________ and \_\_\_\_\_\_\_ ==\> causes cyanosis

Answer 59

VSD and truncal valve

Question 60

In trunucus arteriosus, what does the degree of cyanosis depend on?

Answer 60

“Qp/Qs”- ratio of blood flow to lungs compare to body

Question 61

Pathophysiology of trunucs arteriosus: As pulmonary vascular resistance decreases after birth… ◦ If no anatomic obstruction, blood flow prefers to go

Answer 61

to lungs- “heart failure” or pulmonary overcirculation

Question 62

What are the two categories of clincical manifestations that will present in trunucs arteriosus?

Answer 62

Increased pulmonary blood flow and decreased pulmonary blood flow

Question 63

In trunucs areteriousus, the baby is found to have increased pulmonary blood flow ◦ What are the symptoms?

Answer 63

mild cyanosis/increase pulse pressure/ hyperdynamic precordium/ normal S1 with ejecectionclick and loud S2/ loug pansystolic murmur as LLSB, possible diastlic murmur from truncal insufficiency

Question 64

Baby has trunucus arteriosus with decreased pulmonary blood flow and no regurgitation (RARE); What are the symptoms?

Answer 64

 Often due to PA stenosis or pulmonary vascular disease  Moderate to severe cyanosis  Normal pulses and pulse pressure  Loud S2  Systolic murmur – flow across stenotic PA’s

Question 65

Baby presents with;  Moderate to severe cyanosis  Normal pulses and pulse pressure  Loud S2  Systolic murmur – flow across stenotic PA’s Dx?

Answer 65

Truncus arteriosus with decreased pulmonary blood flow (rare and often due to PA stenosis or pulmonary vascular disease)

Question 66

Baby presents with mild cyanosis and increased pulse pressure  Hyperdynamic precordium  Normal S1 with ejection click; loud single S2  Loud pansystolic murmur at LLSB  Systolic murmur at USB of truncal stenosis Dx?

Answer 66

Truncal stenosis with increased pulmonary flow

Question 67

Genetic implications of truncal arteriosus: ◦ 0.6 to 1.4 per 10,000 births ◦ 40% have what syndrome? ◦ Significant associations: ◦ Trend toward association with:

Answer 67

◦ 40% had 22q11 deletion (DiGeorge syndrome) ◦ Significant associations: right sided arch and abnormal aortic arch branching ◦ Trend toward association with discontinuous PA’s

Question 68

Quick review of natural history of children with truncus arteriosus without intervention

Answer 68

Non-survivable cardiac lesion with low survival beyond infancy without intervention ◦ 15% survive beyond 1year of age  Mean age of death ~ 5 weeks  Infantile death secondary to heart failure  Patients \>4 years died primarily of complications of pulmonary hypertension

Question 69

short pulmonary trunk originating from truncus gives rise to both pulmonary arteries

Answer 69

Type I and A1 of trunucus arteriosus

Question 70

Both pulmonary arteries arise from truncus separately but in close proximity

Answer 70

Type II TA

Question 71

Both pulmonary arteries arise from truncus at some distance from one another

Answer 71

Type III TA

Question 72

Both pulmonary arteries arise from trunucus seperately either close to or far apart

Answer 72

Type A2 truncus arteriosus

Question 73

No true pulmonary arteries, blood flow through collaterals – now believed an error and really PA/VSD

Answer 73

Type IV TA

Question 74

Absence of truncal origin of one pulomonary artery with blood supply to that lung from collateral or PDA

Answer 74

Type A3 TA

Question 75

Associated with underdevelopment of the aortic arch (interrupted aortic arch)

Answer 75

Type A4 TA

Question 76

Anatomy of Truncal valve abnormalities What are the three common ones we see in truncal arteriosus?

Answer 76

◦ Abnormal cusp number (3 most common, could be 2 or 4) ◦ Stenosis ◦ Insufficiency

Question 77

Surgical procedures done to address truncal arteriosus

Answer 77

◦ Separate pulmonary and systemic circulations  “Baffle” VSD so LV pumps to aorta (pathc to cose off VSD so when LV squeezes only goes to aorta)  Find a way to connect RV to PAs --\>RV to PA conduit

Question 78

Post surgical monitoring for Truncal arteriosus in pt with truncal valve

Answer 78

◦ Insufficiency from thickened and nodular dysplastic cusps and annular dilation ◦ Truncal stenosis

Question 79

Post surgical monitoring for Truncal arteriosus in pt with RV-PA conduit

Answer 79

◦ Does not grow with patient thus we will see: ◦ Stenosis/calcification ◦ Insufficiency

Question 80

Post surgical monitoring for Truncal arteriosus in pt with branch pulmonary arteries done

Answer 80

Watch for stenosis at origin into conduit