Catheter ablation of atrial flutter

Typical atrial flutter in humans is the consequence of a stable macro-reent rant circuit produced by the unique right atrial architecture providing ana tomic barriers and functional blocks to conduction. Mapping studies have in dicated that the so-called isthmus between the inferior aspect of the tricu spid annulus and the ostium of the inferior caval vein is a critical zone f or maintenance of atrial flutter. An anatomically guided approach with plac ement of a transmural and contiguous lesion line throughout the isthmus has established as curative treatment of typical atrial flutter. Electrophysic al criteria indicating complete bidirectional isthmus conduction block afte r ablation proved to be superior with respect to redurrences of atrial flut ter compared with the noninducibility criterion. The gold standard for prov e of complete conduction block is the recording of double potentials along the entire isthmus ablation line. Recently, it proved possible to reduce th e period of fluoroscopy during isthmus ablation by using electro-anatomical mapping.