Aims

Fractionated electrograms are ofttimes noted during function of focal atrial tachycardia (FAT). This uncovering suggests slummy cell-to-cell coupling, which is intellection to be an essential responsibility in the impact of ectopic forcefulness institution and propagation. The determine of the inform think was to set the electrogram fractionation in the neighborhood of the early activation place and in the remaining atrium in these patients.

Methods and results

Thirteen patients with FAT (age 48 ± 17 years) who underwent catheter operation were investigated. Mapping was performed with the CARTO system. Electrogram fractionation was assessed on the foundation of the sort of perverse deflections, both in the location close the early activation place and in the remaining atrium. Unipolar and bipolar peak-to-peak emf and bipolar electrogram continuance were also studied. All patients underwent flourishing radiofrequency ablation. A higher honor of electrogram fractionation existed in the location close the early activation place and reactive within the prototypal 15 ms when compared with the remaining atrium (incidence of bipolar electrograms with binary perverse deflections: 88 vs. 79%, P < 0.0001; frequency of unipolar electrograms with binary perverse deflections: 56 vs. 43%, P = 0.0001). The peak-to-peak emf in the location reactive within the prototypal 15 ms was inferior than that in the remaining atrium (bipolar voltage: 1.33 ± 0.99 vs. 1.61 ± 1.11 mV, P < 0.001; unipolar voltage: 1.75 ± 0.92 vs. 1.95 ± 1.11 mV, P = 0.0188). There were no momentous differences in bipolar electrogram duration. Within the location reactive during the prototypal 15 ms, from the bound to the early activation site, there was a sloping process in electrogram fractionation (incidence of bipolar electrograms with binary perverse deflections gradually crescendo from 82 to 100% and frequency of unipolar electrograms with binary perverse deflections crescendo from 56 to 90%), as substantially as a sloping modification in peak-to-peak emf (bipolar emf gradually detractive from 1.47 ± 1.06 to 0.89 ± 0.54 mV, P < 0.0001; unipolar emf gradually detractive from 1.89 ± 0.94 to 1.30 ± 0.63 mV, P < 0.0001). Irregular, intimately distributed isochrones were also noted in the location reactive during the prototypal 15 ms. The Atlantic of this location was 4.88 ± 3.59 cm².

Conclusion

Increased electrogram fractionation exists within a relatively panoramic location around the tachycardia lineage when compared with the remaining atrium. Moreover, this location is electrically heterogeneous, as advisable by the fact that the honor of electrogram fractionation increases gradually whereas the electrogram emf decreases gradually towards the early activation site. These findings declare that a non-discrete atrial location with gradually dynamical electrophysiological properties haw lie the stratum of FAT.

Tags: Bipolar, Initiation, NCR, Nip