AimsIt is unclear how the amplitude of bipolar electrogram relates to the local conduction velocity (CV) in patients with atrial fibrillation (AF). For 50 AF patients (paroxysmal/persistent AF: 40/10 patients), contact bipolar voltage maps of the left atrium (LA) were constructed during sinus rhythm using EnSite version 6.0J in a point-by-point recording fashion. Patients were divided into Groups A (n = 16), B (n = 19), and C (n = 15) according to the level of the lowest electrogram amplitudes: <0.5, 0.5-0.75, and 0.75-1.0 mV, respectively. Low-voltage zone (LVZ) was defined separately for these groups as a bipolar electrogram amplitude of <0.5, 0.5-0.75, and 0.75-1.0 mV, respectively. The local CV through the LVZ and non-LVZ was calculated along the direction of local activation within each zone for all groups.Methods and resultsLow-voltage zone was consistently found at the septal, anterior, and posterior LA in all groups. In Group A, CV through the LVZ was significantly slower compared with the non-LVZ (0.8 ± 0.5 vs. 1.4 ± 0.6 m/s, P = 0.004), but those through the LVZ and non-LVZ were similar in Group B (1.2 ± 0.5 vs. 1.3 ± 0.5 m/s, P = 0.07) and Group C (1.5 ± 0.5 vs. 1.4 ± 0.6 m/s, P = 0.79). The percentage of points showing fractionated or double potentials in the LVZ was significantly more in Group A (76/293 points, 26) than in Group B (11/185 points, 6), and Group C (7/135 points, 5) (P < 0.0001 and P < 0.0001, respectively).ConclusionThere was a significant slowing of local conduction in the LVZ defined as <0.5 mV and was frequently associated with fractionated or double potentials in patients with AF.
CITATION STYLE
Miyamoto, K., Tsuchiya, T., Narita, S., Yamaguchi, T., Nagamoto, Y., Ando, S. I., … Takahashi, N. (2009). Bipolar electrogram amplitudes in the left atrium are related to local conduction velocity in patients with atrial fibrillation. Europace, 11(12), 1597–1605. https://doi.org/10.1093/europace/eup352
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