Honarbakhsh, S;
Schilling, RJ;
Orini, M;
Providencia, R;
Keating, E;
Finlay, M;
Sporton, S;
... Hunter, RJ; + view all
(2019)
Structural remodeling and conduction velocity dynamics in the human left atrium: relationship with reentrant mechanisms sustaining atrial fibrillation.
Heart Rhythm
, 16
(1)
pp. 18-25.
10.1016/j.hrthm.2018.07.019.
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Bebiano Da Providencia E Costa VoR 1-s2.0-S1547527118306969-main.pdf - Published Version Download (1MB) | Preview |
Abstract
BACKGROUND: Rate-dependent conduction velocity (CV) slowing is associated with atrial fibrillation (AF) initiation and reentry mechanisms. OBJECTIVES: Assess the relationship between bipolar voltage, CV dynamics and AF drivers. METHODS: Patients undergoing catheter ablation for persistent AF (<24 months) were enrolled. Unipolar electrograms were recorded with a 64-pole basket catheter during atrial pacing at four pacing intervals (PIs) during sinus rhythm. CVs were measured between pole pairs along the wavefront path and correlated with underlying bipolar voltage. CV dynamics within low voltage zones (LVZs<0.5mV) were compared to those of non-LVZs (≥0.5mV) and were correlated to driver sites mapped using CARTOFINDER. RESULTS: Eighteen patients were included (age 62±10yrs). Mean CV at 600ms was 1.59±0.13m/s vs. 0.98±0.23m/s, in non-LVZs and LVZs respectively (p<0.001). CV decreased incrementally over all four-PIs in LVZs whilst in non-LVZs a substantial decrease in CV was only seen between PI 300-250ms CLs (0.59±0.09m/s; p<0.001). Rate-dependent CV slowing sites measurements, defined as exhibiting a CV reduction ≥20% more than the mean CV reduction seen between PIs 600-250ms for that voltage zone were predominantly in LVZs (0.2-0.5mV, 75.6±15.5%; p<0.001). Confirmed rotational drivers were mapped to these sites in 94.1% of cases (sensitivity 94.1%, 95%CI 71.3- 99.9% and specificity 77.9%, 95%CI 74.9-80.7%). CONCLUSIONS: CV dynamics are determined largely by the extent of remodeling. Rate-dependent CV slowing sites are predominantly confined to LVZs [0.2-0.5 mV] and the resultant CV heterogeneity may promote driver formation in AF.
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