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Efectos electrofisiológicos de la hipertrofia ventricular izquierda. Efecto del bloqueo de los canales de calcio y
P R Kowey1, T D Friechling, J Sewter
1Cardiovascular Research Laboratory, Medical College of Pennsylvania, Philadelphia.
Circulation
|June 1, 1991
Resumen
La hipertrofia ventricular izquierda (LVH) aumenta la vulnerabilidad a la fibrilación ventricular al alterar la recuperación eléctrica. El bloqueo de los canales de potasio, pero no los canales de calcio, protege contra esta arritmia.
Área de la Ciencia:
- Cardiología Cardiología.
- Electrofisiología y electrofisiología.
- Farmacología Farmacología.
Sus antecedentes:
- La hipertrofia ventricular izquierda (LVH) puede conducir a arritmias cardíacas.
- Los efectos aritmogénicos de la LVH requieren una investigación electrofisiológica detallada.
Objetivo del estudio:
- Para definir los efectos aritmogénicos de LVH en un modelo de corazón intacto.
- Evaluar el impacto del bloqueo de los canales de calcio y potasio en las arritmias inducidas por LVH.
Principales métodos:
- Evaluación electrofisiológica en un modelo felino de bandaje aórtico de LVH.
- Medición de los tiempos de conducción, excitabilidad, refractividad y duración del potencial de acción.
- Evaluación de la vulnerabilidad y los umbrales de la fibrilación ventricular (VF).
Principales resultados:
- Los gatos con LVH mostraron una mayor vulnerabilidad a la fibrilación ventricular, la fibrilación ventricular espontánea y umbrales de fibrilación ventricular más bajos en comparación con los controles.
- La LVH causó una mayor dispersión del período refractario efectivo y la duración del potencial de acción.
- La risotilida (bloqueante de los canales de potasio) redujo la dispersión y la vulnerabilidad ventricular; el verapamil (bloqueante de los canales de calcio) no tuvo un efecto significativo.
Conclusiones:
- La LVH aumenta significativamente la vulnerabilidad ventricular a la fibrilación al promover la dispersión de la refractividad y la repolarización.
- El bloqueo de los canales de potasio dependiente de la tensión mitiga la arritmogénesis inducida por LVH.
- El bloqueo lento de los canales de calcio hacia adentro no protege contra la fibrilación ventricular relacionada con la LVH.
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