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Bloqueo intercaval en los corazones caninos normales: el papel de la cresta terminal
1University of Heidelberg, Department of Cardiology, Heidelberg, Germany. ruediger_becker@med.uni-heidelberg.de
Circulation
|May 23, 2001
Resumen
El bloqueo de conducción intercaval inducible es común en corazones sanos. La cresta terminal de la cresta es el extremo de la cresta terminal.
Área de la Ciencia:
- Cardiología Cardiología.
- Electrofisiología y electrofisiología.
- La anatomía cardíaca anatomía cardíaca.
Sus antecedentes:
- El bloqueo de conducción intercaval durante el típico aleteo auricular sugiere anomalías de conducción preexistentes.
- Investigar el papel de la región de la cresta terminal en el bloque de conducción es crucial.
Objetivo del estudio:
- Para determinar con precisión la ubicación y la base electrofisiológica del bloque de conducción en la región de la cresta terminal.
- Para comprender el papel de la conducción anisotrópica y los gradientes refractarios en el bloque intercaval.
Principales métodos:
- Se utilizaron electrodos de parche de alta densidad (10x10 bipolas) en la cresta terminal y el músculo pectinado en sabuesos.
- Los patrones de activación local y los períodos refractarios efectivos se mapearon durante el ritmo y los estímulos extra.
- Las ubicaciones del bloqueo epicárdico fueron marcadas para la verificación endocardial postmortem.
Principales resultados:
- Se observaron marcadas diferencias direccionales en la activación (anisotropía) en la región de la cresta terminal (1.1+/-0.4 m/s paralelo frente a 0.5+/-0.2 m/s perpendicular al eje intercaval).
- Las velocidades de conducción fueron similares en ambas direcciones dentro de la región del músculo pectinado.
- El bloqueo de conducción paralelo a la cresta terminal fue inducible en el 40% de los perros durante la estimulación S(3).
Conclusiones:
- El bloqueo intercaval inducible es común incluso en corazones normales.
- La conducción anisotrópica y los gradientes refractarios no explican completamente el bloqueo en la cresta terminal.
- Las propiedades anatómicas y electrofisiológicas de la unión entre la cresta terminal y el músculo pectinado probablemente subyacen al bloque de conducción intercaval.
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