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El ritmo después de choques más fuertes que el límite superior de vulnerabilidad: impacto en la inducción de
N Chattipakorn1, P C Fotuhi, C M Sreenan
1Departments of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA. toon@crml.uab.edu
Circulation
|March 22, 2000
Resumen
La inducción de la fibrilación ventricular (VF) requiere al menos tres ciclos de ritmo rápido después de una descarga eléctrica. Los ciclos anteriores pueden crear las condiciones para que el ciclo final desencadene la VF.
Área de la Ciencia:
- Electrofisiología cardiovascular electrofisiología cardiovascular.
- Investigación de la arritmia cardíaca Investigación de la arritmia cardíaca.
- Tecnología de Dispositivo Médico Tecnología de Dispositivo Médico
Sus antecedentes:
- Los patrones de activación epicárdica después de los choques de onda T son similares ya sea que induzcan o no fibrilación ventricular (VF).
- Múltiples ciclos de ritmo rápido se observan constantemente durante la fibrilación vesicular, pero no durante los episodios que no son de fibrilación vesicular, lo que sugiere su papel en la inducción de la fibrilación vesicular.
Objetivo del estudio:
- Para investigar el papel de los ciclos de ritmo rápido en la inducción de la fibrilación ventricular (VF) después de descargas eléctricas.
- Para determinar el número mínimo de ciclos de ritmo rápido requeridos para iniciar la VF.
Principales métodos:
- Utilizó un calcetín de 504 electrodos para mapear los patrones de activación epicárdica en cerdos.
- Determinados parámetros de choque del límite superior de vulnerabilidad (ULV) y descargas entregadas por encima del ULV.
- Se aplicaron estímulos de ritmo secuenciales (S3-S5) con intervalos de acoplamiento (IC) progresivamente más cortos después de los choques para inducir la FV.
Principales resultados:
- Se necesitaron tres estímulos de ritmo (S3-S5) con CI decreciente para inducir FV; S3 o S3-S4 por sí solos no indujeron FV.
- La inducción de FV se produjo después del estímulo S5 en el 100% de los casos.
- Se observaron dos patrones de activación epicárdica distintos, focales (74%) y reentrantes (26%), después de los choques S5 inducidos por la fibrilación ventricular.
Conclusiones:
- Un mínimo de tres ciclos de ritmo rápido con intervalos cortos de acoplamiento son esenciales para la inducción de VF post-shock.
- Los ciclos intermedios de aceleración (S3-S4) probablemente establezcan el sustrato necesario para el inicio de la fibrilación ventricular en el ciclo final (S5).
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