Electroanatomic Mapping of Focal Atrial Tachycardia : Reproducibility ofActivation Time Measurement and Focus Localization

• Background: Different algorithms of estimating local activation time (LAT) can be usedduring the mapping of focal atrial tachycardia (FAT). Objective: The impact of these algorithms on the reproducibility of LAT measurementand the location of the focus. Methods: Fifteen patients (48 ± 17 yrs) with FAT were studied. Three independentobservers reviewed 1438 bipolar electrograms and successively assigned the LAT on thepeak amplitude (Bi-peak), the steepest downslope (Bi-dslope), and the onset (Bi-on) ofthe electrograms. The reproducibility of LAT measurement was estimated. Results: The mean interobserver absolute differences in LAT for the three algorithmswere 1.47 ± 2.75 ms (Bi-peak) vs. 2.15 ± 3.89 ms (Bi-dslope) vs. 2.87 ± 3.47 (Bi-on) (p <0.0001). The corresponding intraobserver differences were 2.29 ± 3.74 ms (Bi-peak) vs2.47 ± 4.17 ms (Bi-dslope) vs 3.16 ± 4.49 ms (Bi-on) (p < 0.0001). The interobserverdifferences in the location of the focus were 3.57 ± 3.81 mm (Bi-peak) vs 5.47 ± 4.98mm (Bi-dslope) vs 6.57 ± 6.94 mm (Bi-on) (p = 0.03), with differences of up to 13 mm(Bi-peak), 16 mm (Bi-dslope), and 25 mm (Bi-on). However, regardless of the method ofLAT determination, the foci computed by the three observers clustered within regions oflow-amplitude fractionated electrograms. Conclusions: Significant observer variability exists among the three algorithms, whichtend to compute different LAT and foci with different locations. However, the foci aresituated in regions of low voltage fractionated electrograms.

Nyckelord

Ectopic atrial tachycardia; catheter ablation; atrial electrogram

MEDICINE

MEDICIN

Publikations- och innehållstyp

vet (ämneskategori)

art (ämneskategori)