Reversed Septal Motion in ccTGA: A Potential Mechanism for Tricuspid Regurgitation

Area of Science:

• Cardiology
• Pediatric Cardiology
• Cardiac Imaging

Background:

• Congenitally corrected transposition of the great arteries (ccTGA) presents complex cardiac anatomy.
• Tricuspid regurgitation (TR) is a common complication in ccTGA, but its underlying mechanisms are not fully understood.
• Interventricular septal motion (IVSm) abnormalities are frequently observed in ccTGA.

Purpose of the Study:

• To investigate the association between interventricular septal motion (IVSm) and the severity of tricuspid regurgitation (TR) in patients with ccTGA.
• To determine if IVSm patterns can predict the development or progression of severe TR.
• To explore the role of IVSm in the pathophysiology of TR in ccTGA.

Main Methods:

• Retrospective analysis of echocardiographic data from 406 ccTGA patients.
• Stratification of patients based on TR grade (≥3 vs. ≤2) at initial evaluation.
• Categorization of IVSm as normal, reversed, or bidirectional, with subgroup analyses for patients undergoing pulmonary artery banding (PAB) and those without prior surgery.

Main Results:

• A significantly higher prevalence of reversed IVSm was observed in patients with severe TR (83.49%) compared to those with mild/moderate TR (2.02%).
• In the PAB subgroup, TR severity decreased, and IVSm normalized post-procedure.
• Reversed IVSm was a strong predictor of severe TR (AUC 0.77) and independently associated with its development (HR 28.35), with 10.29% of non-surgically treated patients developing progressive TR secondary to reversed IVSm.

Conclusions:

• Reversed interventricular septal motion is significantly associated with severe tricuspid regurgitation in ccTGA.
• Abnormal IVSm may contribute mechanistically to the development of severe TR.
• Reversed IVSm serves as a valuable predictive marker for TR progression in ccTGA patients.