transposition of the great arteries

Transposition of the Transposition of the Great ArteriesGreat Arteries

Eric OsbornEric Osborn

January 27, 2010January 27, 2010

OutlineOutline

DefinitionsDefinitions EmbryologyEmbryology EpidemiologyEpidemiology Complete transposition (D-TGA)Complete transposition (D-TGA) Congenitally corrected transposition Congenitally corrected transposition (L-TGA)(L-TGA)

EchocardiographyEchocardiography

DefinitionsDefinitions

The key anatomic characteristic of The key anatomic characteristic of transposition complexes is transposition complexes is ventriculoarterial discordanceventriculoarterial discordance.. The aorta arises from the morphological The aorta arises from the morphological RVRV

The PA arises from the morphological LVThe PA arises from the morphological LV


Complete transposition (D-TGA)Complete transposition (D-TGA) Atrioventricular concordanceAtrioventricular concordance


Congenitally corrected transposition Congenitally corrected transposition (L-TGA)(L-TGA) Atrioventricular discordanceAtrioventricular discordance

EmbryologyEmbryology

22 days gestation … 22 days gestation …

the primitive straight cardiac tube the primitive straight cardiac tube is formedis formed


23 days gestation … the straight 23 days gestation … the straight cardiac tube elongates and bends cardiac tube elongates and bends forming the cardiac loop.forming the cardiac loop. Cephalic portion bends ventrally, Cephalic portion bends ventrally, caudally, and right-ward.caudally, and right-ward.

Caudal portion moves dorsally, Caudal portion moves dorsally, cranially, and left-ward.cranially, and left-ward.

The rotational motion folding over of The rotational motion folding over of the bulboventricular portion bringing the bulboventricular portion bringing the future ventricles side-by-side.the future ventricles side-by-side.


44thth-7-7thth weeks gestation … the heart weeks gestation … the heart divides into 4 chambers via divides into 4 chambers via formation of swellings (cushions) of formation of swellings (cushions) of tissue that exhibit differential tissue that exhibit differential growth.growth. Endocardial cushions divide the AV Endocardial cushions divide the AV canal forming the mitral and tricuspid canal forming the mitral and tricuspid valves.valves.

Conotruncal cushions form the outflow Conotruncal cushions form the outflow tracts, aortic and pulmonary roots.tracts, aortic and pulmonary roots.

EmbryologyEmbryology 55thth week gestation … the conotruncal week gestation … the conotruncal cushions.cushions. Right superior truncal cushion grows distally Right superior truncal cushion grows distally and left-ward.and left-ward.

Left inferior truncal cushion grows distally Left inferior truncal cushion grows distally and right-ward.and right-ward.

The net effect is a twisting motion.The net effect is a twisting motion. The truncal cushions fuse to form the truncal The truncal cushions fuse to form the truncal septum.septum.

Additional cushions develop in the conus which Additional cushions develop in the conus which grow down and towards each other until they grow down and towards each other until they fuse with the truncal septum to form the RVOT fuse with the truncal septum to form the RVOT and LVOT.and LVOT.


Mechanism of great artery Mechanism of great artery transpositiontransposition Conotruncal cushion defectConotruncal cushion defect Leads to failure of the conotruncal Leads to failure of the conotruncal septum to spiral and instead extends septum to spiral and instead extends straight downwardstraight downward

Aorta fuses with the RV and PA with the Aorta fuses with the RV and PA with the LVLV

EpidemiologyEpidemiology ~0.8% of live births are complicated by a ~0.8% of live births are complicated by a cardiovascular malformationcardiovascular malformation**..

>750,000 adult patients with congenital >750,000 adult patients with congenital heart disease.heart disease.

Transposition of the great arteries occurs Transposition of the great arteries occurs in approximately 1 per 5,000 live births.in approximately 1 per 5,000 live births. More common in malesMore common in males

Diagnosis possible in utero with fetal Diagnosis possible in utero with fetal echocardiographyechocardiography Transvaginal ultrasound at 13-14 weeks (limited Transvaginal ultrasound at 13-14 weeks (limited views)views)

Transabdominal ultrasound at 16 weeksTransabdominal ultrasound at 16 weeks

*not including bicuspid aortic valve and mitral valve prolapse*not including bicuspid aortic valve and mitral valve prolapse

Complete transposition Complete transposition (D-TGA)(D-TGA)

Pulmonary and systemic circulations Pulmonary and systemic circulations are in parallelare in parallel

Lethal, if no mixing (ASD, PDA, VSD)Lethal, if no mixing (ASD, PDA, VSD) ¾¾ are are simplesimple with no major associated with no major associated abnormalitiesabnormalities

¼¼ are are complexcomplex VSD (16%)VSD (16%) Pulmonary/subpulmonary stenosis (9%)Pulmonary/subpulmonary stenosis (9%) Coarctation of the aorta (4%)Coarctation of the aorta (4%)

Complete transposition (D-Complete transposition (D-TGA)TGA)

Clinical Presentation and Clinical Presentation and OutcomesOutcomes Larger size and weight at birthLarger size and weight at birth

Dyspnea and cyanosisDyspnea and cyanosis Progressive hypoxemiaProgressive hypoxemia Congestive heart failureCongestive heart failure

Without treatment, the outlook is Without treatment, the outlook is dismaldismal 30% mortality within the 130% mortality within the 1stst week week 90% mortality within the 190% mortality within the 1stst year year

Complete transposition (D-Complete transposition (D-TGA)TGA)

ManagementManagement Prostaglandin E1 to maintain the PDAProstaglandin E1 to maintain the PDA Atrial septostomy (balloon or Atrial septostomy (balloon or surgical)surgical) Palliative prior to corrective surgeryPalliative prior to corrective surgery

Repair within the first days to weeks Repair within the first days to weeks of lifeof life 2-4% mortality with 90% 1 year survival2-4% mortality with 90% 1 year survival Atrial switchAtrial switch

Mustard or SenningMustard or Senning Arterial switchArterial switch Rastelli procedureRastelli procedure

Complete transposition (D-Complete transposition (D-TGA) TGA) Atrial switch Atrial switch (Mustard/Senning)(Mustard/Senning)

Developed in the 1950sDeveloped in the 1950s Baffle directs venous return to Baffle directs venous return to contralateral ventriclecontralateral ventricle

Complete transposition (D-Complete transposition (D-TGA) TGA)

Atrial switch (Mustard/Senning)Atrial switch (Mustard/Senning) DisadvantagesDisadvantages

RV functions as the systemic ventricleRV functions as the systemic ventricle Several significant long term complicationsSeveral significant long term complications

Congestive heart failureCongestive heart failure ArrhythmiasArrhythmias Baffle leaks and obstructionBaffle leaks and obstruction Pulmonary hypertensionPulmonary hypertension Paradoxial embolusParadoxial embolus EndocarditisEndocarditis

Overall survival 75% at 25 yearsOverall survival 75% at 25 years Senning may be better than Mustard [Moons et al, Senning may be better than Mustard [Moons et al, HeartHeart 2004] 2004]

340 patients (~340 patients (~⅔⅔ Senning) compared Senning) compared Less obstruction (1 vs. 15%) and better functional Less obstruction (1 vs. 15%) and better functional class with Senningclass with Senning

No significant mortality benefit No significant mortality benefit


Atrial switch (Mustard/Senning)Atrial switch (Mustard/Senning)ArrhythmiasArrhythmias

Palpitations, presyncope, and syncope are not uncommonPalpitations, presyncope, and syncope are not uncommon Both brady and tachyarrythmias frequently seenBoth brady and tachyarrythmias frequently seen

50% develop sinus node dysfunction50% develop sinus node dysfunction Physical damage during surgery and baffle constructionPhysical damage during surgery and baffle construction Disruption of blood supply leading to ischemiaDisruption of blood supply leading to ischemia

20% develop atrial flutter20% develop atrial flutter

Sensitive to nodal agents due to conduction system diseaseSensitive to nodal agents due to conduction system disease 11% required pacemakers at 20 years [Gelatt et al, 11% required pacemakers at 20 years [Gelatt et al, J Am Coll J Am Coll

CardiolCardiol 1997] 1997]

Pacemakers are difficult to place due to distorted anatomyPacemakers are difficult to place due to distorted anatomy Should be avoided if residual intracardiac communications due Should be avoided if residual intracardiac communications due

to risk of paradoxical embolus and stroketo risk of paradoxical embolus and stroke


Atrial switch (Mustard/Senning)Atrial switch (Mustard/Senning)Congestive heart failureCongestive heart failure

Most adult patients develop congestive heart failureMost adult patients develop congestive heart failure By 20 years most are NYHA Class I or IIBy 20 years most are NYHA Class I or II

RV filling compromised due to defects in baffle constructionRV filling compromised due to defects in baffle construction Baffle leaks (Mustard>Senning)Baffle leaks (Mustard>Senning)

Left-to-right shunts with pulmonary hypertension (7%)Left-to-right shunts with pulmonary hypertension (7%) Risk of paradoxical embolus and strokeRisk of paradoxical embolus and stroke Indications for intervention include >1.5:1 left-to-right shunt or any Indications for intervention include >1.5:1 left-to-right shunt or any

right-to-left shuntright-to-left shunt Baffle obstruction (5-15%, Mustard>Senning)Baffle obstruction (5-15%, Mustard>Senning)

SVC>IVC manifesting as SVC syndrome or hepatic congestion/cirrhosisSVC>IVC manifesting as SVC syndrome or hepatic congestion/cirrhosis Often undetected due to collateral venous drainage (e.g. azygous vein)Often undetected due to collateral venous drainage (e.g. azygous vein)

40% develop right ventricular dysfunction40% develop right ventricular dysfunction

10-40% develop 210-40% develop 2++ or greater tricuspid (systemic AV valve) or greater tricuspid (systemic AV valve) regurgitationregurgitation

Annular dilatation from RV failureAnnular dilatation from RV failure Damage from surgery or endocarditisDamage from surgery or endocarditis


Suggested Follow-upSuggested Follow-up


Arterial switchArterial switch Developed in the 1980sDeveloped in the 1980s Great arteries and coronaries are Great arteries and coronaries are transected and re-anastamosedtransected and re-anastamosed


Arterial switchArterial switch AdvantagesAdvantages

LV is the systemic pumpLV is the systemic pump No disruption of atrial conduction (sinus rhythm)No disruption of atrial conduction (sinus rhythm)

Fewer long term complications compared to Fewer long term complications compared to atrial switchatrial switch Coronary ostial stenosisCoronary ostial stenosis Supravalvular pulmonary/aortic stenosisSupravalvular pulmonary/aortic stenosis

Intervention indicated for RVOT gradient >50 mmHgIntervention indicated for RVOT gradient >50 mmHg Neoaortic regurgitationNeoaortic regurgitation ArrhythmiasArrhythmias

Follow up with normal LV function and good Follow up with normal LV function and good exercise capacityexercise capacity


Rastelli procedureRastelli procedure TGA with VSD and LVOT obstruction TGA with VSD and LVOT obstruction

OutcomesOutcomes RV-PA conduit obstructionRV-PA conduit obstruction

Exercise intolerance/anginaExercise intolerance/angina RV failureRV failure Intervention for RV-PA Intervention for RV-PA

gradient >50 mmHggradient >50 mmHg LV-Ao patch obstructionLV-Ao patch obstruction

Dyspnea or syncopeDyspnea or syncope


RV Failure after Atrial SwitchRV Failure after Atrial Switch Standard heart failure therapies are Standard heart failure therapies are unprovenunproven

The two-stage arterial switchThe two-stage arterial switch Stage 1 – the PA is banded to ‘re-train’ the Stage 1 – the PA is banded to ‘re-train’ the LV to handle systemic pressuresLV to handle systemic pressures

Stage 2 – the atrial baffles and pulmonary Stage 2 – the atrial baffles and pulmonary band are taken down and an arterial switch is band are taken down and an arterial switch is performedperformed

50% survival at 8 years in early results50% survival at 8 years in early results Appears to be more successful in patients Appears to be more successful in patients under 12under 12

Congenitally corrected Congenitally corrected transposition (L-TGA)transposition (L-TGA)

A rare disorder that may present in A rare disorder that may present in adulthood.adulthood.

Associated anomalies (95% of Associated anomalies (95% of patients)patients) VSD (75%, commonly perimembranous)VSD (75%, commonly perimembranous) Pulmonary stenosis (75%, commonly Pulmonary stenosis (75%, commonly subvalvular)subvalvular)

Tricuspid valve anomalies (>75%)Tricuspid valve anomalies (>75%) Congenital complete heart block (5%)Congenital complete heart block (5%)

Congenitally corrected Congenitally corrected

transposition (L-TGA)transposition (L-TGA) OutcomesOutcomes

ArrhythmiasArrhythmias Abnormal AV node and His positionsAbnormal AV node and His positions Dual AV nodesDual AV nodes 2% per year incidence of complete heart 2% per year incidence of complete heart blockblock

Susceptible to fibrosis of conduction systemSusceptible to fibrosis of conduction system

Median survival 40 yearsMedian survival 40 years

Mortality from progressive RV failure Mortality from progressive RV failure or arrhythmiasor arrhythmias

Tricuspid regurgitation is major predictorTricuspid regurgitation is major predictor

Congenitally corrected Congenitally corrected

transposition (L-TGA)transposition (L-TGA) Double Double Switch ProcedureSwitch Procedure

EchocardiographyEchocardiographySegmental approach to congenital Segmental approach to congenital

heart diseaseheart disease1.1. Position of the apexPosition of the apex2.2. Situs of the atriaSitus of the atria

Morphological atria based on anatomic appearance of Morphological atria based on anatomic appearance of their appendagestheir appendages

75% concordance with abdominal situs (aorta and IVC 75% concordance with abdominal situs (aorta and IVC positions)positions)

3.3. Atrioventricular relationshipAtrioventricular relationship Differentiate the morphological RV from LV:Differentiate the morphological RV from LV:

1.1. Trabeculated apexTrabeculated apex2.2. Moderator bandModerator band3.3. Septal attachment of the tricuspid valveSeptal attachment of the tricuspid valve4.4. Lower (apical) insertion of the tricuspid valveLower (apical) insertion of the tricuspid valve

4.4. Ventriculoarterial relationshipVentriculoarterial relationship Pulmonary artery is distinguished by its early Pulmonary artery is distinguished by its early

branching patternbranching pattern Curved contour of the aortic arch with three major Curved contour of the aortic arch with three major

branchesbranches

EchocardiographyEchocardiographyComplete Transposition with Complete Transposition with

Atrial SwitchAtrial Switch Hallmark is parallel great arteries Hallmark is parallel great arteries (parasternal long axis)(parasternal long axis) Aorta is anterior to PAAorta is anterior to PA


Atrial SwitchAtrial Switch Systemic hypertrophied RV septum Systemic hypertrophied RV septum bows into LVbows into LV May impact TR and enhance subpulmonary May impact TR and enhance subpulmonary stenosisstenosis


Atrial SwitchAtrial Switch Aortic and pulmonic valves lie in Aortic and pulmonic valves lie in the same planethe same plane

Aorta is anterior and to the right Aorta is anterior and to the right (parasternal short axis)(parasternal short axis)

EchocardiographyEchocardiographyCongenitally Corrected Congenitally Corrected

TranspositionTransposition Hallmark is reversed offsetting of Hallmark is reversed offsetting of the AV valvesthe AV valves

Aorta is anterior and to the left Aorta is anterior and to the left (parasternal short axis)(parasternal short axis)

EchocardiographyEchocardiographySpecial ConsiderationsSpecial Considerations

Atrial switchAtrial switch RV functionRV function Tricuspid regurgitationTricuspid regurgitation Subpulmonary obstructionSubpulmonary obstruction Baffle leak or obstruction (color Doppler)Baffle leak or obstruction (color Doppler)

Normal baffle flow is phasic with peak velocity <1 Normal baffle flow is phasic with peak velocity <1 m/secm/sec

Arterial switchArterial switch Neoaortic valve regurgitationNeoaortic valve regurgitation Supraneopulmonary valve stenosisSupraneopulmonary valve stenosis Wall motion abnormalities due to coronary artery Wall motion abnormalities due to coronary artery ostial stenosisostial stenosis

Rastelli procedureRastelli procedure LV-Ao tunnel patch obstructionLV-Ao tunnel patch obstruction RV-PA conduit degeneration RV-PA conduit degeneration (stenosis/regurgitation)(stenosis/regurgitation)

Endocarditis Endocarditis ProphylaxisProphylaxis

ACC/AHA 2008 Guidelines state that ACC/AHA 2008 Guidelines state that antibiotic prophylaxis is reasonable to antibiotic prophylaxis is reasonable to consider for patients at the highest risk consider for patients at the highest risk of adverse outcomes (Class IIa)of adverse outcomes (Class IIa)

Prosthetic valvesProsthetic valves Prior endocarditisPrior endocarditis Congenital heart diseaseCongenital heart disease

Unrepaired cyanotic, including palliative shunts and Unrepaired cyanotic, including palliative shunts and conduitsconduits

Completely repaired with prosthetic material or device (6 Completely repaired with prosthetic material or device (6 months)months)

Repaired with defects at or near a prosthetic deviceRepaired with defects at or near a prosthetic device Post-cardiac transplant with valvular diseasePost-cardiac transplant with valvular disease

Endocarditis Endocarditis ProphylaxisProphylaxis

ReferencesReferences Webb et al., Congenital Heart Disease in Webb et al., Congenital Heart Disease in Braunwald’s Heart Braunwald’s Heart

DiseaseDisease, 8, 8thth ed., Chapter 61, 1561-1624. ed., Chapter 61, 1561-1624. Sadler, Cardiovascular System in Sadler, Cardiovascular System in Langman’s Medical EmbryologyLangman’s Medical Embryology, ,

88thth ed., Chapter 11, 208-259. ed., Chapter 11, 208-259. Otto, The Adult with Congenital Heart Disease in Otto, The Adult with Congenital Heart Disease in Clinical Clinical

EchocardiographyEchocardiography, 4, 4thth ed., Chapter 17, 418-447. ed., Chapter 17, 418-447. Warnes, Transposition of the Great Arteries, Warnes, Transposition of the Great Arteries, CirculationCirculation 2006 2006

114:2699-2709.114:2699-2709. Love et al., Evaluation and Management of the Adult Patient with Love et al., Evaluation and Management of the Adult Patient with

Transposition of the Great Arteries Follow Atrial-level (Senning Transposition of the Great Arteries Follow Atrial-level (Senning or Mustard) Repair, or Mustard) Repair, Nature Clinical Practice Cardiovasc MedNature Clinical Practice Cardiovasc Med 2008 2008 5:454-67.5:454-67.

Verhuegt et al., Long-term Prognosis of Congenital Heart Verhuegt et al., Long-term Prognosis of Congenital Heart Defects: A Systematic Review, Defects: A Systematic Review, Int J CardiolInt J Cardiol 2008 131:25-32. 2008 131:25-32.

Skinner et al., Transposition of the Great Arteries: from Fetus Skinner et al., Transposition of the Great Arteries: from Fetus to Adult, to Adult, HeartHeart 2008 94:1227-35 2008 94:1227-35

ACC/AHA Guidelines for the Management of Adults with Congenital ACC/AHA Guidelines for the Management of Adults with Congenital Heart Disease, Heart Disease, J Am Coll CardiolJ Am Coll Cardiol 2008 52:e1-121. 2008 52:e1-121.

transposition of the great arteries

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conotruncal cushions

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inferior truncal cushion

right superior truncal

weeks of life2