Congenitally corrected transposition with mirror-image atrial arrangement

Area of Science:

• Cardiology
• Developmental Biology
• Medical Genetics

Background:

• Congenitally corrected transposition with mirror-image atrial arrangement is a rare condition.
• Associated cardiac anomalies in this group are less understood due to limited case numbers.

Purpose of the Study:

• To compare the prevalence and risks of associated cardiac anomalies in patients with congenitally corrected transposition and mirror-image atrial arrangement versus those with usual atrial arrangement.
• To calculate absolute, relative, and attributable risks for specific cardiac defects and their absence.

Main Methods:

• Retrospective analysis of 19 patients with congenitally corrected transposition and mirror-image atrial arrangement.
• Comparison with 39 patients having congenitally corrected transposition with usual atrial arrangement.
• Statistical calculation of risks for subvalvar pulmonary stenosis, ventricular septal defect, tricuspid regurgitation, atrioventricular block, and absence of anomalies.

Main Results:

• Higher absolute risk for subvalvar pulmonary stenosis (68.4% vs. 43.6%) and ventricular septal defect (63.2% vs. 58.9%) in the mirror-image group.
• Mirror-image group showed greater relative risks for subvalvar pulmonary stenosis (1.57) and ventricular septal defect (1.07).
• Usual arrangement group had higher relative risks for tricuspid regurgitation (1.26), atrioventricular block (2.43), and absence of anomalies (1.70).

Conclusions:

• Patients with congenitally corrected transposition and mirror-image atrial arrangement have a significantly increased risk of subvalvar pulmonary stenosis and ventricular septal defects.
• The findings highlight the importance of detailed cardiac evaluation in these rare cases.
• Attributable risks for subvalvar pulmonary stenosis (24.8%) and ventricular septal defect (4.3%) were estimated for the mirror-image group.