Successful ablation in a case with atypical, double-loop right atrial flutter

Some atypical right atrial flutters present as a double-loop reentry. This kind of arrhythmia usually occurs after a cardiac operation leaving behind a right atrial scar tissue, with one reentry loop turning around the tricuspid valve, and the other around the scar tissue. It is extremely difficult to detect the presence and localization of these reentry loops by conventional electrophysiologic studies. Only three-dimensional mapping techniques provide identification of these reentry loops. Herein, we presented a 55-year-old woman who developed persistent atrial flutter after mitral valve surgery. Conventional electrophysiologic study showed macroreentry in the right atrium, but ablation target could not be determined. With the use of a three-dimensional mapping technique, a double-loop reentry was delineated in the right atrium and ablation of the common isthmus resulted in the disappearance of tachycardia.