Successful case of complex atrial flutter occurring in a patient with congenitally corrected transposition of the great arteries, aberrant left atrial appendage, and situs inversus

Background Congenitally corrected transposition of great arteries (ccTGA) is a rare congenital cardiac defect with atrioventricular and ventriculoarterial discordance which leads to heart failure and limits patients’ lifespan. The extremely aberrant cardiac structure makes electrophysiological procedure and radiofrequency ablation very difficult to be performed in such patients. Until now, there were only sporadical cases that have reported the successful ablation of atrial flutter in ccTGA patients. Case presentation We report a case of a 36-year-old male who was diagnosed with dextrocardia, atrial septal defect and congenitally corrected transposition of great arteries (ccTGA) at a young age and received atrial septal defect repair and morphological tricuspid valve plasty in 2014. As for reasons of heart failure and atrial flutter, he frequently suffered from progressively worsening dyspnea and recurrent episodes of palpitations. Cardiac anatomic imaging reconstruction before electrophysiological test revealed an unusually huge left atrial appendage in this patient. After high-density mapping of both right atrium and left atrium, activation mapping showed reentry circuit loops were located in left atrium. Successful ablation strategy was performed under the guidance of high-density mapping and entrainment. Conclusion This is a clinical case showing high-density mapping and successful ablation of a complex dual-loop atrial flutter in a patient with ccTGA and aberrant left atrial appendage. The successful procedure corroborates clinical utility of high-density mapping approach in the treatment of the patients with complex congenital heart disease accompanied by rapid arrhythmia, can be simpler, safer and more effective.