An atrial flutter in a 40-year-old woman with situs inversus, transposition of the great arteries, atrial switch, and interruption of the inferior vena cava

Introduction Adult patients with congenital heart disease (CHD) are growing in number with the improvement in corrective techniques. Atrial arrhythmias are a common complication in the long-term follow-up of CHD patients, with a negative impact on morbidity and mortality. Dextro-transposition of the great arteries (d-TGA) is one of the most lifethreatening types of CHD, accounting for approximately 2 cases per 10,000 live births and 3% of all CHD. In d-TGA the aorta arises from the right ventricle (RV) and the pulmonary trunk from the left ventricle, with systemic and pulmonary circulations running in parallel. Therefore, a communication (shunt) between the 2 circulations is mandatory to support life. Since the early 1960s, atrial switch operation, which diverts the systemic venous return to the mitral valve and the pulmonary venous return to the tricuspid valve through baffles, has dramatically improved survival. This extensive atrial surgery creates a substrate for atrial arrhythmias, affecting nearly two-thirds of the population 25 years after surgery. As medical therapy is often limited owing to the concomitant presence of bradyarrhythmias and tachyarrhythmias, catheter ablation has been used in this setting, with excellent success rates. Atrial switch operation was replaced by arterial switch operation by the mid-1980s and is nowadays only seldom performed. Nevertheless, most adults today with d-TGA followed in adult specialized clinics have undergone an atrial switch operation with Mustard or Senning baffles. We report here a case of successful ablation of an atrial flutter in a patient cumulating several malformations, including a d-TGA with an atrial