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Alternantes de potenciales de acción auriculares durante el aleteo auricular como precursor de la fibrilación
Sanjiv M Narayan1, Frank Bode, Pamela L Karasik
1University of California and Veterans Affairs Medical Center, San Diego, Calif, USA.
Circulation
|October 9, 2002
Resumen
Las transiciones de aleteo auricular a la fibrilación a través de alternantes de potencial de acción en el istmo. Esta inestabilidad eléctrica, caracterizada por una mala adaptación de la velocidad y un bloqueo de conducción, puede iniciar la fibrilación auricular y justificar la ablación del istmo.
Área de la Ciencia:
- Electrofisiología y electrofisiología.
- Las arritmias cardíacas son arritmias cardíacas.
Sus antecedentes:
- Los mecanismos que impulsan la transición del aleteo auricular típico (Afl) a la fibrilación auricular (AF) no se comprenden completamente.
- Este estudio investigó el papel de los alternantes de potencial de acción en la conversión de Afl a AF.
Objetivo del estudio:
- Para probar la hipótesis de que el aleteo auricular se desorganiza en fibrilación auricular a través de alternantes de potenciales de acción auriculares.
- Identificar los mecanismos electrofisiológicos subyacentes a la transición de Afl a AF.
Principales métodos:
- Los potenciales de acción monofásicos (MAP) se registraron desde el istmo auricular derecho y otros sitios auriculares derechos en pacientes con AFL durante el ritmo excesivo.
- El ritmo continuó hasta que se alcanzó el inicio de la FA o una duración del ciclo de 160 ms.
- Se analizaron los alternantes de duración y amplitud de MAP y el bloque de conducción en relación con el inicio de AF.
Principales resultados:
- Los pacientes que desarrollaron AF mostraron alternantes de duración y amplitud de MAP en el istmo anterior a la aparición de AF.
- Se observaron alternantes de duración de MAP inducidos por velocidad y bloqueo de conducción 2:1 en el istmo en pacientes en transición a AF.
- Los alternantes de MAP ocurrieron con menos frecuencia y a tasas de ritmo más rápidas en pacientes que no desarrollaron AF.
Conclusiones:
- La mala adaptación en el istmo auricular derecho puede precipitar alternantes y bloqueo de conducción, facilitando la transición a AF.
- Estas propiedades electrofisiológicas del istmo pueden permitir el inicio de la AF a través de la fraccionamiento del frente de onda.
- Los hallazgos apoyan el papel del istmo en la conversión de AF a AF y pueden explicar la eficacia de la ablación del istmo para prevenir la recurrencia de AF.
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