CATHETER ABLATION FOR THE COMMON TYPE OF ATRIAL-FLUTTER - WHERE DO WESTAND

Atrial flutter is a reentrant tachycardia that originates in the right atrium. The wave front of atrial flutter travels craniocaudally along the anterolateral wall of the right atrium, surrounds the inferior ve na cava, and crosses the region between this structure and the tricusp id ring before closing the circuit after upward septal propagation. Th e area located between the tricuspid annulus and the inferior vena cav a has been proposed as an ideal target for ablation because it appears to he an isthmus that is an obligatory route for closing the inferior part of the arrhythmia circuit. Various publications dealing with rad iofrequency ablation of this tachycardia have dealt with different app roaches, and a wide range of acute and chronic success rates have been reported. The main difficulty in interpreting the results of this ser ies is the lack of a carefully defined patient selection technique des cription, and follow-lip protocol. In almost all of these series it cl early appears that a significant number of late flutter recurrences oc cur in these patients, in addition to the emergence of previously unkn own atrial fibrillation. Many recent reports, where ablation has been targeted at the inferior vena cava-tricuspid annulus isthmus, have sho wn a high rate of acute success. In our experience, the procedure seem s to be facilitated by the use of extra large rip (8-mm) ablation cath erers that allow the use of higher power outputs. Careful mapping of t he ablation site has shown that creation of complete bidirectional blo ck at the isthmus is important for prevention of late recurrences. Fur ther technological improvements should aim at developing energy delive ry systems that allow controlled destruction of wide areas of the atri al myocardium.