Cardiac Disorders: Transposition of Great Arteries

Questions and Answers

What is the Van Praagh classification?

This classifies the heart into 3 segmental sets: atria/viscera situs, ventricular looping, and arterial situs.

What is the normal relationship of the aorta to the pulmonary artery?

The aorta is normally posterior and to the right of the pulmonary artery in arterial situs solitus.

What is Complete Transposition of the Great Arteries (TGA)?

Physiologic uncorrected ventriculoarterial discordance (the aorta arises from the RV, the PA arises from the LV).

What is the Van Praagh classification for TGA?

SDD. Signup and view all the answers

What pathology is the second most common cyanotic lesion?

TGA Signup and view all the answers

What is the embryologic malformation that occurs with TGA?

There is abnormal division of truncus arteriosus which leads to the vessels being parallel (0 degree rotation). Signup and view all the answers

What patient population is more susceptible to TGA?

Males with diabetic mothers. Signup and view all the answers

Circulation in a patient with TGA can be described as which of the following?

Two parallel circuits Signup and view all the answers

What happens to a baby when they have TGA and their PDA closes?

Sudden death. Signup and view all the answers

List some commonly associated conditions with TGA.

VSD, PDA, coarctation, LVOT obstruction, coronary anomalies. Signup and view all the answers

What are some typical features of TGA?

More common in males, newborn will be cyanotic WITHOUT respiratory distress. Signup and view all the answers

What are the surgical treatments for TGA?

Surgical treatments: Jatene: arterial switch (switch outflows), Mustard Senning: atrial switch (switch inflows) - less common. Signup and view all the answers

What is the Le Compte maneuver?

A procedure that repositions the PA to be anterior to the aorta. Signup and view all the answers

With transposition of the great arteries, which of the following increases systemic oxygen saturation?

Left to right PFO Signup and view all the answers

What does the Jatene procedure do?

Jatene procedure is used for TGA; it switches the great arteries (they only move the arteries not the valves). Signup and view all the answers

The clinical presentation of a child with congenitally corrected transposition of the great arteries is usually dependent on what factor?

The severity of associated defects. Signup and view all the answers

What is congenitally corrected transposition of the great arteries?

Atrioventricular discordance AND ventriculoarterial discordance. Signup and view all the answers

What is the Van Praagh classification for congenitally corrected TGA?

S, L, L or I, D, D. Signup and view all the answers

What is the embryologic malformation that occurs with congenitally corrected TGA?

The primitive heart tube loops left instead of right. Signup and view all the answers

What is the most common associated defect with congenitally corrected TGA?

Tricuspid abnormalities. Signup and view all the answers

What treatments are used for congenitally corrected TGA?

Treatment is focused on associated defects. Signup and view all the answers

What is double outlet right ventricle?

Ventriculoarterial connection in which both of the great vessels arise entirely or predominately from the RV. Signup and view all the answers

What is the 50% rule?

PA and more than 50% of the aorta arise from the right ventricle. Signup and view all the answers

What is the embryologic malformation that occurs with DORV?

Failure to achieve conotruncal inversion and leftward shift of the conus. Signup and view all the answers

What are the different great vessel relationships associated with DORV?

Normal relationship: PA is anterior and to the left of the Ao, Side by Side: aorta to the right (most common relationship), Dextromalposition: aorta is anterior and to the right, Levomalposition: aorta is anterior and to the left. Signup and view all the answers

The clinical presentation of DORV is dependent on which of the following?

The location of VSD in relationship to the great arteries and degree of POTO Signup and view all the answers

What are the different types of DORV? How are they classified?

VSD type: subaortic or doubly committed VSD WITHOUT POTO, TOF type: subaortic or doubly committed VSD with POTO, TGA type: sub-pulmonary VSD (Taussig-Bing anomaly), Remote: non-committed VSD can be with or without POTO. Signup and view all the answers

What is the most common type of VSD that is considered a remote VSD in DORV?

Inlet type of VSD. Signup and view all the answers

What is the most common type of VSD with DORV? What is the least common?

Subaortic VSD is the most common. The least common is doubly committed VSDs. Signup and view all the answers

If a newborn presented with respiratory distress and cyanosis, which congenital abnormality would you presume?

Hypoplastic left heart. Signup and view all the answers

If a newborn presented with cyanosis but no respiratory distress, which congenital abnormality would you presume?

Transposition of the Great Arteries. Signup and view all the answers

What is hypoplastic left heart?

Severe underdevelopment of the left heart-aorta complex. Signup and view all the answers

What is the embryologic malformation that occurs to cause hypoplastic left heart?

Underdevelopment of the LV-Ao complex. Signup and view all the answers

Which congenital abnormalities in this chapter are ductal dependent?

Pulmonary atresia with intact IVS Signup and view all the answers

Which congenital abnormality is the most common cause of death from heart disease during the first week of life?

Hypoplastic Left heart. Signup and view all the answers

What are some associated defects with hypoplastic left heart?

Aortic stenosis, aortic hypoplasia, mitral valve stenosis/atresia, VSD, coarctation, incomplete aortic arch. Signup and view all the answers

What is Hypoplastic left heart syndrome (HLHS)?

HLHS is associated with aortic and/or mitral valve atresia, stenosis, or hypoplasia. Signup and view all the answers

How does HLHS differ from Hypoplastic left heart complex (HLHC)?

HLHS tends to only have one ventricle and is ductal dependent, whereas HLHC usually has 2 ventricles and isn't as ductal dependent. Signup and view all the answers

What is Hypoplastic left heart complex (HLHC)?

HLHC is aortic and mitral valve hypoplasia WITHOUT valve stenosis or atresia. Signup and view all the answers

What is hypoplastic left heart syndrome's path of circulation?

SVC/IVC > RA > RV > PA > PA's or PDA; Lungs > Pulmonary veins > LA > PFO > RA; PDA > Ao > Systemic circulation. Signup and view all the answers

What is the direction of shunts in hypoplastic left heart syndrome?

PDA: shunt goes right to left before birth, left to right after birth due to decreased PVR; ASD: shunt goes left to right because there is nowhere for blood to go after LA other than to RA. Signup and view all the answers

What is surgical treatment for hypoplastic left heart? What does it do?

Norwood procedure: multistage reconstructive procedure based on single ventricle physiology. Signup and view all the answers

What is the progression and complications of hypoplastic left heart?

Cyanosis, respiratory failure, hemodynamic failure, metabolic acidosis, and other organ system failure; death in the first month if no intervention. Signup and view all the answers

What congenital abnormality would be implied if a baby presented with cyanosis at birth with a concave pulmonary artery segment and the apex tilted upward?

Pulmonary atresia with intact ventricular septum. Signup and view all the answers

What is the embryologic malformation that occurs with pulmonary atresia with intact IVS?

Malformation of the pulmonary outflow tract occluding all flow out the pulmonary artery. Signup and view all the answers

What is the path of circulation for pulmonary atresia with intact IVS?

RA > TV > RV > stop; RA > PFO/ASD > LA > LV > Ao; Ao > PDA > Lungs > Pulmonary veins > LA; Ao > Systemic circulation. Signup and view all the answers

What are sinusoids?

Sinusoids are fistulas that blood flows from the RV to the Coronary arteries due to stenosis near the coronary artery origin. Signup and view all the answers

What are some associated defects with pulmonary atresia with intact IVS?

Hypoplasia of the PA's, RV, or TV; PDA (required), ASD/PFO (required), and sinusoids (RV to coronary artery fistulas). Signup and view all the answers

What is right ventricular dependent coronary artery circulation?

It means sinusoids are associated with proximal coronary artery stenosis so if RV pressure drops, it can cause ischemia to the heart muscle. Signup and view all the answers

If you have atretic PV with hypoplastic RV & abnormal TV, will you have a higher or lower incidence of sinusoids?

Higher chance of sinusoids. Signup and view all the answers

If you have atretic PV with normal or enlarged RV & significant TR, will you have higher or lower incidence of sinusoids?

A lower incidence of sinusoids will be associated. Signup and view all the answers

Which direction will the shunt be for pulmonary atresia with intact IVS with the PDA and ASD/PFO?

PDA: left to right, ASD/PFO: right to left. Signup and view all the answers

What is the Fontan procedure?

It is a single ventricle repair procedure. Signup and view all the answers

Tricuspid atresia is considered a type of single ventricle.

True Signup and view all the answers

What is the embryologic malformation that occurs with tricuspid atresia?

Malalignment between the ventricular loop and atria or abnormal development of the TV. Signup and view all the answers

With tricuspid atresia, which ventricle is the main systemic ventricle?

The left ventricle. Signup and view all the answers

What is the embryologic malformation that occurs with single ventricle heart?

Failure of AV canal shift and/or arrest the development of the IVS. Signup and view all the answers

What are some associated conditions with single ventricle heart?

Complete TGA (most common), RVOT/LVOT obstructions, heterotaxy (asplenia or polysplenia). Signup and view all the answers

What is the most common type of single ventricle heart?

LV type with L-looping. Signup and view all the answers

What is heterotaxy?

Malposition of cardiac and abdominal visceral structures. Signup and view all the answers

What is the variant of single ventricle heart with two separate AV valves and dominant morphologic LV?

Double inlet left ventricle. Signup and view all the answers

What is a single ventricle heart with one common AV valve and a dominant morphologic RV?

Unbalanced right dominant complete AV defect. Signup and view all the answers

What is the variant of single ventricle heart with two separate AV valves and a dominant morphologic RV?

Double inlet right ventricle. Signup and view all the answers

What is a restrictive bulboventricular foramen?

An opening between the dominate chamber and the smaller outlet chamber with a pressure gradient across it in a single ventricle heart. Signup and view all the answers

A patient presents with pulmonary atresia (with intact IVS). The TV appears to be significantly hypoplastic. What is the likelihood you will find cardiac sinusoids?

Very likely. Signup and view all the answers

What is considered to be hypoplastic aorta?

< 5mm Signup and view all the answers

Study Notes

Van Praagh Classification

Classifies hearts into three segmental sets: atria/viscera situs, ventricular looping, and arterial situs.
A normal heart classification is S,D,S (situs solitus, d-looping, situs solitus).

Aorta and Pulmonary Artery Relationship

In a normal heart, the aorta is posterior and to the right of the pulmonary artery.

Complete Transposition of the Great Arteries (TGA)

Characterized by physiologic uncorrected ventriculoarterial discordance.
Aorta arises from the right ventricle, pulmonary artery from the left ventricle; aorta typically anterior to the pulmonary artery.

Classification for TGA

Van Praagh classification for TGA is SDD (situs solitus, d-looping, right-sided aorta).

Common Cyanotic Lesion

TGA is the second most common cyanotic lesion affecting newborns.

Embryologic Malformation in TGA

Caused by abnormal division of truncus arteriosus, leading to parallel vessel arrangement (0-degree rotation).

Patient Population at Risk for TGA

Increased susceptibility observed in males with diabetic mothers.

Circulation Description in TGA

Circulation consists of two parallel circuits, dependent on PDA, VSD, and ASD for systemic oxygenation.

Prognosis with PDA Closure in TGA

Closure of the PDA can result in sudden death due to lack of oxygenated blood delivery.

Associated Conditions with TGA

Commonly associated defects include VSD, PDA, coarctation, left ventricular outflow obstruction, and coronary anomalies.

Typical Features of TGA

More prevalent in males; newborns may exhibit cyanosis without respiratory distress.

Surgical Treatment Options for TGA

Jatene procedure: arterial switch; Mustard/Senning procedure: atrial switch (less common).
Palliative treatments include prostaglandins, balloon atrial septostomy, and PA banding.

Le Compte Maneuver

A surgical procedure that repositions the pulmonary artery to anteriorly place it relative to the aorta in cases of TGA.

Increasing Systemic Oxygen Saturation in TGA

A left-to-right PFO can enhance systemic oxygen saturation by promoting oxygenated blood flow from the lungs to systemic circulation.

Jatene Procedure

Focuses on switching the outflows of the aorta and pulmonary artery, without rearranging valves.

Congenitally Corrected Transposition of the Great Arteries

Exhibits atrioventricular and ventriculoarterial discordance with abnormal positioning of the aorta (anterior and to the left).

Van Praagh Classification for Congenitally Corrected TGA

Classified as SLL (situs solitus, left looping, left-sided aorta).

Embryologic Malformation in Congenitally Corrected TGA

Characterized by the primitive heart tube looping left instead of right.

Common Defects with Congenitally Corrected TGA

Tricuspid abnormalities (~90%), VSD (~75%), and coarctation of the aorta are frequently associated.

Congenitally Corrected TGA Treatment

Treatment focuses on correcting associated defects, including managing CHF and potential heart transplant.

Double Outlet Right Ventricle (DORV)

Defined by both great vessels arising predominantly from the right ventricle.

50% Rule in DORV

Indicates that both the pulmonary artery and over 50% of the aorta derive from the right ventricle.

Embryologic Malformation in DORV

Stemming from failure to achieve conotruncal inversion and a leftward shift of conus.

Great Vessel Relationships in DORV

Relationships include normal positioning, side-by-side, dextroposition, and levo positioning.

Clinical Presentation of DORV

Depends on the location of VSD relative to great arteries and degree of left/right ventricular outflow tract obstruction.

Types of DORV

Classified based on VSD type (subaortic, doubly committed) and specific circulatory requirements (with or without POTO).

Most Common Type of VSD in DORV

The subaortic VSD is the most common; the doubly committed VSD is the rarest.

Hypoplastic Left Heart Syndrome (HLHS)

Characterized by severe underdevelopment of left heart structures, leading to complicated hemodynamics at birth.

Embryologic Malformation in HLHS

Caused by inadequate development of the left ventricle and aorta.

Ductal Dependent Conditions

Conditions include HLHS, TGA, and pulmonary atresia with intact ventricular septum.

Leading Cause of Neonatal Death Due to Heart Disease

HLHS is the most common cause during the first week of life.

Associated Abnormalities with HLHS

Defects include aortic stenosis, coarctation, VSD, and mitral valve atresia.

Differentiating HLHS and HLHC

HLHS is associated with valve atresia; HLHC encompasses cases without atresia but still shows significant ventricular hypoplasia.

Surgical Pathway for HLHS

The Norwood procedure serves as a multistage reconstructive strategy to redirect systemic and pulmonary flow.

Complications of HLHS

Potential complications include respiratory failure, metabolic acidosis, and multi-organ failure, leading to high mortality without intervention.

Implications of Cyanosis with Distinct Cardiac Features

Cyanosis at birth with specific pulmonary artery appearances indicates conditions like pulmonary atresia with intact ventricular septum.

Sinusoids in Pulmonary Atresia with Intact IVS

These are fistulas allowing RV blood to perfuse coronary arteries due to stenosis at the coronary origins.

Essential Components in Pulmonary Atresia with Intact IVS

Requires a PDA and/or ASD for adequate systemic and pulmonary blood circulation.

Right Ventricular Dependent Coronary Artery Circulation

Highlights risks associated with pressure fluctuations in the RV, affecting coronary artery perfusion.

Tricuspid Atresia Association

Recognized as a form of single ventricle heart disease, primarily reliant on the left ventricle for systemic flow.

Single Ventricle Heart Anomalies

Examples include LV type single ventricle and variant structures like double inlet left/right ventricle, depending on atrioventricular valve morphology.

Restrictive Bulboventricular Foramen

Identified as a pressure gradient opening between main and outlet chambers in single ventricle hearts.

Hypoplastic Aorta Classification

Defined as aorta measuring less than 5mm in diameter.

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Description

Explore the classification and implications of Complete Transposition of the Great Arteries (TGA) in this quiz. Understand the Van Praagh classification system, the normal aorta and pulmonary artery relationship, and the embryologic malformations involved. Test your knowledge on cyanotic lesions and their impact on newborns.