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Efectos de la terapia de bloqueo beta-adrenérgico en las propiedades de relajación diastólica del ventrículo
1University of Michigan and Veterans Affairs Medical Centers, Ann Arbor, MI 48105, USA.
Circulation
|August 18, 1999
Resumen
La terapia con metoprolol mejora la función diastólica ventricular izquierda (LV) en pacientes con cardiomiopatía. Este tratamiento con beta-bloqueantes mejora la relajación del miocardio, lo que lleva a una reducción de la presión diastólica final de LV y mejora las propiedades diastólicas.
Área de la Ciencia:
- Cardiología Cardiología.
- Farmacología Farmacología.
- Fisiología Fisiología Fisiología.
Sus antecedentes:
- El mecanismo por el cual los agentes bloqueadores beta-adrenérgicos mejoran la presión ventricular izquierda (LV) end-diastólica en la cardiomiopatía es objeto de debate.
- Este estudio investiga si la terapia con metoprolol mejora las propiedades de relajación diastólica.
Objetivo del estudio:
- Para determinar si la terapia con metoprolol mejora la relajación diastólica en pacientes con cardiomiopatía.
- Para dilucidar el mecanismo hemodinámico detrás de la reducción de la presión diastólica terminal de LV con el tratamiento con beta-bloqueantes.
Principales métodos:
- 14 pacientes con cardiomiopatía recibieron 6 meses de terapia con metoprolol.
- Se utilizó la micromanometría simultánea y la cineventriculografía biplano.
- Un grupo de control de 4 pacientes con cardiomiopatía no recibió metoprolol.
Principales resultados:
- El metoprolol disminuyó significativamente la presión diastólica terminal de LV (P = 0,001).
- Los principales parámetros diastólicos mejoraron: índice de relajación isovolúmica (tau(ln), P=0,03), constante de rigidez de la cámara LV (kappa, P=0,02), elasticidad del volumen LV (P=0,04) y constante de rigidez miocárdica (kappa(e), P=0,02).
- Los pacientes de control no mostraron mejoría en estas propiedades diastólicas.
Conclusiones:
- La reducción de la presión diastólica terminal de LV con metoprolol indica una mejora de las propiedades diastólicas de LV.
- La terapia con metoprolol promueve una relajación miocárdica más completa en la cardiomiopatía.
- Los hallazgos aclaran los beneficios hemodinámicos de los betabloqueantes en el manejo de la insuficiencia cardíaca.
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