Left atrial scarring and conduction velocity dynamics: Rate dependent conduction slowing predicts sites of localized reentrant atrial tachycardias.
Int J Cardiol
; 278: 114-119, 2019 Mar 01.
Article
en En
| MEDLINE
| ID: mdl-30391065
BACKGROUND: Low voltage zones (LVZs) are associated with 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 [≥0.5â¯mV], LVZs [0.2-0.5â¯mV] and very-LVZs [<0.2â¯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 PIâ¯=â¯600â¯ms and 250â¯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⯱â¯10â¯years). Mean CV at 600â¯ms was 1.53⯱â¯0.19â¯m/s in non-LVZs, 1.14⯱â¯0.15â¯m/s in LVZs, and 0.73⯱â¯0.13â¯m/s in very-LVZs respectively (pâ¯<â¯0.001). Rate-dependent CV slowing sites were predominantly in LVZs [0.2-0.5â¯mV] (74.4⯱â¯10.3%; pâ¯<â¯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 [0.2-0.5â¯mV] and the resultant CV heterogeneity may promote reentry mechanisms. These may represent a novel adjunctive target for AT ablation.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fibrilación Atrial
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Ablación por Catéter
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Atrios Cardíacos
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Sistema de Conducción Cardíaco
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Frecuencia Cardíaca
Tipo de estudio:
Observational_studies
/
Prognostic_studies
Límite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Int J Cardiol
Año:
2019
Tipo del documento:
Article
País de afiliación:
Reino Unido
Pais de publicación:
Países Bajos