Clinical Study Regarding the Anatomical Structures of the Right Atrial Isthmus Using Intra-Cardiac Echocardiography: Implication for Catheter Ablation of Common Atrial Flutter

Background: The construction of complete bi-directional block in the isthmus (ITH) between the tricuspid annulus and inferior vena cava by radiofrequency energy (RF) applications is sometimes hampered due to anatomical problems such as a thick isthmus or aneurysmal pouch in patients with common atrial flutter (AFL).