Left atrial scarring and conduction velocity dynamics: Rate dependent conduction slowing predicts sites of localized reentrant atrial tachycardias

INTERNATIONAL JOURNAL OF CARDIOLOGY

卷:278

Article

Honarbakhsh, S.¹  Schilling, R. J.¹  Orini, M.¹  Providencia, R.¹  Finlay, M.¹  Keating, E.¹  Lambiase, P. D.¹  Chow, A.¹  Earley, M. J.¹  Sporton, S.¹  Hunter, R. J.¹ 

[1] Barts Hlth NHS Trust, Barts Heart Ctr, London, England

关键词: Conduction velocity;    Conduction velocity heterogeneity;    Atrial tachycardia;    Structural remodeling;    Catheter ablation;   

DOI  :  10.1016/j.ijcard.2018.10.072

来源: Elsevier

【 摘 要 】

Background: Low voltage zones (LVZs) are associatedwith conduction velocity (CV) slowing. Rate-dependent CV slowing may play a role in reentry mechanisms. Methods: Patients undergoing catheter ablation for AT were enrolled. Aim was to assess the relationship between rate-dependent CV slowing and sites of localized reentrant atrial tachycardias (AT). On a bipolar voltage map regions were defined as non-LVZs [>= 0.5 mV], LVZs [0.2-0.5 mV] and very-LVZs [<0.2 mV]. Unipolar electrograms were recorded with a 64-pole basket catheter during uninterrupted atrial pacing at four pacing intervals (PIs) during sinus rhythm. CVs were measured between pole pairs along the wavefront path. Sites of rate-dependent CV slowing were defined as exhibiting a reduction in CV between PI = 600 ms and 250 ms of = 20% more than the mean CV reduction seen between these PIs for that voltage zone. Rate-dependent CV slowing sites were correlated to sites of localized reentrant ATs as confirmed with conventional mapping, entrainment and response to ablation. Results: Eighteen patients were included (63 +/- 10 years). Mean CV at 600 ms was 1.53 +/- 0.19 m/s in non-LVZs, 1.14 +/- 0.15 m/s in LVZs, and 0.73 +/- 0.13 m/s in very-LVZs respectively (p < 0.001). Rate-dependent CV slowing sites were predominantly in LVZs [0.2-0.5 mV] (74.4 +/- 10.3%; p < 0.001). Localized reentrant ATs were mapped to these sites in 81.8% of cases (sensitivity 81.8%, 95% CI 48.2-97.9% and specificity 83.9%, 95% CI 81.8-86.0%). Macro-reentrant or focal ATs were not mapped to sites of rate-dependent CV slowing. Conclusions: Rate-dependent CV slowing sites are predominantly confined to LVZs [0.2-0.5mV] and the resultant CV heterogeneity may promote reentry mechanisms. These may represent a novel adjunctive target for AT ablation. (c) 2018 Published by Elsevier B.V.

【 授权许可】

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