Utility of omnipolar mapping–guided cavotricuspid isthmus block

Figures

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  Figure 1. Representative case in which the block line was completed only by radiofrequency applications (RFAs) at the AAFS during sustained atrial flutter. A: Omnipolar map during sustained atrial flutter, its schema, representative local electrograms, and voltage map. The activation vector converged centripetally within the area bordered by the white dotted lines and then spread centrifugally from the area. This area was identified as an AAFS. Double potentials (indicated by red triangles) were observed at sites a, b, and c. The interval of the double potential at site b was shorter than those at sites a and c. In the voltage map, there was no apparent low-voltage zone around the AAFS. B: Omnipolar map during constant pacing from the CS after RFA at the AAFS and its schema. Conduction block in the cavotricuspid isthmus was completed by RFA only at the AAFS, indicating the presence of preexisting conduction blocks. AAFS = atrial activation focusing site; CS = coronary sinus; IVC = inferior vena cava; TA = tricuspid annulus.

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  Figure 2. Representative case in which the block line was completed only by radiofrequency applications (RFAs) at the AAFS during pacing from the CS. A: Omnipolar map created by annotating local potentials after S1 pacing (S1 map). There was no apparent AAFS. B: Omnipolar map created by annotating local potentials after S2 pacing (S2 map), its schema, representative local electrograms, and voltage map. The activation vector converged centripetally within the area bordered by the white dotted lines and then spread centrifugally from the area. This area was identified as an AAFS. Double potentials (indicated by red triangles) were observed at site a, and fragment potentials were observed at sites b and c. The duration of the local electrogram at site c was longer than that at site b. In the voltage map, there were low-voltage zones in the cavotricuspid isthmus. C: Omnipolar map during constant pacing from the CS after RFA at the AAFS and its schema. Conduction block in the cavotricuspid isthmus was completed by RFA only at the AAFS, indicating the presence of preexisting conduction blocks. Other abbreviations are as in Figure 1.

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  Figure 3. Representative case in which a block line could not be completed by radiofrequency applications (RFAs) at the initial AAFS during sustained atrial flutter (AFL) but was completed by additional RFA at the newly identified AAFS during constant pacing from the CS. A: Omnipolar map during sustained AFL, its schema, representative local electrograms, and voltage map. The activation vector converged centripetally within the area bordered by the white dotted lines and then spread centrifugally from the area. This area was identified as an AAFS. Double potentials (indicated by red triangles) were observed at sites a, b, and c. The interval of the double potential at site b was shorter than those at sites a and c. In the voltage map, there were small low-voltage zones in the cavotricuspid isthmus. B: Omnipolar map during constant pacing from the CS after RFA at the initial AAFS, its schema, and representative local electrograms. A new AAFS was identified at the border with the IVC. Double potential was observed at site d and fragment potential was observed at site e. C: Omnipolar map during pacing from the CS after RFA at the newly identified AAFS and its schema. Conduction block in the…

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  Figure 4. A: Mapping and ablation protocol. B: Distribution of the AAFSs. AAFS = atrial activation focusing site; AF = atrial fibrillation; AFL = atrial flutter; CS = coronary sinus; CTI = cavotricuspid isthmus; OM = omnipolar mapping; RFA = radiofrequency application.