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PubMed This is a summary of 13 peer-reviewed journal articles Updated
Pediatric Cardiology

The 'Friends' of ccTGA: Associated Heart Defects

At a Glance

Most people with ccTGA have associated heart defects, including ventricular septal defects (VSD), pulmonary stenosis, and tricuspid valve abnormalities. While these defects add complexity, some like pulmonary stenosis can actually protect the heart by keeping the left ventricle strong.

While ccTGA describes the basic “swapping” of the heart’s chambers and pipes, it rarely occurs alone. Most patients—about 80% to 90%—have additional heart issues that doctors often refer to as “associated defects” [1][2]. Think of these as “friends” that come along with ccTGA; while they add complexity, understanding them is vital to managing the heart’s long-term health.

The Hole in the Wall: Ventricular Septal Defect (VSD)

A Ventricular Septal Defect (VSD) is a hole in the wall (the septum) that separates the two bottom chambers of the heart [1].

  • In a typical heart: A VSD allows oxygen-rich blood to leak back to the lungs, making the heart work harder.
  • In ccTGA: Because the ventricles are swapped, a VSD allows blood to flow between the morphologic left ventricle (pumping to the lungs) and the morphologic right ventricle (pumping to the body) [3].

If the hole is large, it can cause high pressure in the lungs and may require surgical closure [4]. It is important to know that in ccTGA, the heart’s electrical wiring (the AV node) sits in an abnormal, anterior position right near the edge of this hole. Surgeons must be incredibly careful when placing a patch over a VSD to avoid injuring this fragile electrical wire [5].

The Narrow Door: Pulmonary Stenosis (PS)

Pulmonary Stenosis is a narrowing of the valve or the area leading to the lungs (the pulmonary artery) [1]. While “narrowing” sounds negative, in the world of ccTGA, it can actually be a “protective friend.”

  • The Paradoxical Benefit: Usually, the morphologic left ventricle pumps to the lungs at low pressure. However, if a patient is a candidate for an anatomic repair (a surgery to switch the work back to the “correct” ventricles), that left ventricle needs to be strong enough to pump to the whole body [6].
  • “Training” the Muscle: Pulmonary stenosis creates resistance, forcing the left ventricle to work harder and grow thicker muscle [4][7]. This “trains” the ventricle so it stays strong enough to potentially take over the body’s circulation later in life [6].
  • Pressure Balance: PS can also help balance the pressures within the heart, which may prevent the middle wall (septum) from bowing and causing the systemic valve to leak [8][9].

The Systemic Valve: Tricuspid Issues

In ccTGA, the tricuspid valve is on the left side of the heart, acting as the “door” for the ventricle pumping blood to the body [10]. This valve is under a lot of stress, and it is prone to two main issues:

  1. Ebstein-like Anomaly: Many people with ccTGA are born with a tricuspid valve that is “displaced” or shaped incorrectly—similar to a condition called Ebstein’s Anomaly [1]. The valve may be set deeper into the ventricle than it should be, preventing it from closing tightly.
  2. Regurgitation (Leaking): Because the morphologic right ventricle is pumping to the body, it may stretch or “dilate” over time [11]. As the ventricle stretches, the tricuspid valve gets pulled apart, causing blood to leak backward (regurgitation) [12].

Managing these associated defects is a balancing act. Your medical team monitors the VSD, the “training” provided by PS, and the “tightness” of the tricuspid valve to determine the best timing for any potential interventions [11][13].

Common questions in this guide

What are the most common associated heart defects in ccTGA?
The most common associated defects in ccTGA include a ventricular septal defect (VSD), pulmonary stenosis, and abnormalities of the tricuspid valve, such as leaking or an Ebstein-like anomaly.
How can pulmonary stenosis actually help the heart in ccTGA?
Pulmonary stenosis forces the left ventricle to work harder by creating resistance. This helps train the heart muscle to stay strong, which is beneficial if the patient eventually needs an anatomic repair surgery to switch the heart's workload back to normal.
Why is repairing a ventricular septal defect (VSD) complicated in ccTGA?
In ccTGA, the heart's electrical wiring is located in an abnormal position very close to the edge of the VSD hole. Surgeons must take extreme precautions during a VSD patch repair to avoid injuring this fragile electrical pathway.
Why does the tricuspid valve often leak in ccTGA?
In ccTGA, the tricuspid valve is under high stress because it acts as the door for the ventricle pumping blood to the entire body. Over time, this pressure can stretch the ventricle, pulling the valve apart and causing blood to leak backward.

Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Does the presence of pulmonary stenosis in my/my child's case provide a protective effect for the systemic ventricle?
  2. 2.Is the systemic tricuspid valve showing signs of an Ebstein-like anomaly or 'leakiness' (regurgitation)?
  3. 3.How large is the VSD, and is it causing the two ventricles to work harder than they should?
  4. 4.Because of the abnormal location of the electrical node, what specific precautions would a surgeon take if a VSD repair is needed?
  5. 5.How frequently will we need to monitor the 'bowing' or position of the heart's middle wall (septum)?

Questions For You

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References

References (13)
  1. 1

    Contemporary management and outcomes in congenitally corrected transposition of the great arteries.

    Kutty S, Danford DA, Diller GP, Tutarel O

    Heart (British Cardiac Society) 2018; (104(14)):1148-1155 doi:10.1136/heartjnl-2016-311032.

    PMID: 29326110
  2. 2

    Complete heart block in a young adult with non-isolated congenitally corrected transposition of the great arteries: Case report.

    Faraj R, Bachar A, Sidaty O, et al.

    Annals of medicine and surgery (2012) 2022; (76()):103500 doi:10.1016/j.amsu.2022.103500.

    PMID: 35340322
  3. 3

    Cardiac Conduction System in Congenitally Corrected Transposition of the Great Arteries and Its Clinical Relevance.

    Baruteau AE, Abrams DJ, Ho SY, et al.

    Journal of the American Heart Association 2017; (6(12)) doi:10.1161/JAHA.117.007759.

    PMID: 29269355
  4. 4

    Urgent double switch operation in a patient with congenitally corrected transposition of great arteries and an untrained systemic ventricle.

    Bilal MS, Özyüksel A, Avşar MK, Yıldırım Ö

    Turk gogus kalp damar cerrahisi dergisi 2020; (28(1)):197-200 doi:10.5606/tgkdc.dergisi.2020.18109.

    PMID: 32175162
  5. 5

    Incessant bundle branch reentrant ventricular tachycardia in a patient with corrected transposition of the great arteries.

    Kato K, Yagishita D, Ejima K, et al.

    HeartRhythm case reports 2015; (1(6)):434-438 doi:10.1016/j.hrcr.2015.05.009.

    PMID: 28491600
  6. 6

    Anatomic and Physiologic Repair of Congenitally Corrected Transposition of the Great Arteries.

    Jacob KA, Hörer J, Hraska V, et al.

    Journal of the American College of Cardiology 2024; (84(25)):2471-2486 doi:10.1016/j.jacc.2024.07.056.

    PMID: 39570245
  7. 7

    Echocardiography-Derived Left Ventricular Outflow Tract Gradient and Left Ventricular Posterior Wall Thickening Are Associated with Outcomes for Anatomic Repair in Congenitally Corrected Transposition of the Great Arteries.

    Moodley S, Balasubramanian S, Tacy TA, et al.

    Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography 2017; (30(8)):807-814 doi:10.1016/j.echo.2017.03.019.

    PMID: 28579248
  8. 8

    Congenitally Corrected Transposition of the Great Arteries in a Septuagenarian from the Developing Country of Pakistan.

    Shahab H, Ashiqali S, Atiq M

    Cureus 2018; (10(6)):e2737 doi:10.7759/cureus.2737.

    PMID: 30087813
  9. 9

    Hemodynamically balanced congenitally corrected transposition of the great arteries with a large ventricular septal defect, and subvalvular pulmonic stenosis: a case report.

    Cho SY, Yoon YE, Lee W, et al.

    Journal of medical case reports 2019; (13(1)):219 doi:10.1186/s13256-019-2145-1.

    PMID: 31319891
  10. 10

    Congenitally corrected transposition of the great arteries (CCTGA).

    Grech N, Borg A, Sammut MA, Caruana M

    BMJ case reports 2021; (14(6)) doi:10.1136/bcr-2021-242069.

    PMID: 34108155
  11. 11

    Outcomes of treatment pathways in 240 patients with congenitally corrected transposition of great arteries.

    Barrios PA, Zia A, Pettersson G, et al.

    The Journal of thoracic and cardiovascular surgery 2021; (161(3)):1080-1093.e4 doi:10.1016/j.jtcvs.2020.11.164.

    PMID: 33436290
  12. 12

    Reversed septal motion in congenital corrected transposition of the great arteries: A potential mechanism for tricuspid regurgitation.

    Pang K, Xing J, Xu N, et al.

    The Journal of thoracic and cardiovascular surgery 2025; (170(5)):1196-1205.e8 doi:10.1016/j.jtcvs.2025.06.005.

    PMID: 40513814
  13. 13

    Management Options for Congenitally Corrected Transposition: Which, When, and for Whom?

    Miller JR, Sebastian V, Eghtesady P

    Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual 2022; (25()):38-47 doi:10.1053/j.pcsu.2022.04.001.

    PMID: 35835515

This page explains associated heart defects in ccTGA for educational purposes only. Always consult your pediatric cardiologist or cardiothoracic surgeon to understand your or your child's specific heart anatomy and treatment options.

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