Efectos miocárdicos directos de levosimendan en humanos con disfunción ventricular izquierda: alteración de las
Michael M Givertz1, Costa Andreou, Chester H Conrad
1Cardiomyopathy Program and Cardiovascular Section, Boston University Medical Center, Boston, Mass, USA. mgivertz@partners.org
Circulation
|March 7, 2007
Resumen
Levosimendan, un sensibilizador de calcio, ofrece leves beneficios inotrópicos y lusitrópicos en pacientes con insuficiencia cardíaca. Mejora la función sistólica y diastólica sin alterar las relaciones fuerza-frecuencia o relajación-frecuencia.
Área de la Ciencia:
- Cardiología Cardiología.
- Farmacología Farmacología.
Sus antecedentes:
- Los sensibilizadores de calcio se exploran para el tratamiento de la insuficiencia cardíaca, pero existen preocupaciones con respecto a la relajación deteriorada.
- Levosimendan mejora la sensibilidad al calcio de los miofilantes al unirse a la troponina C, mostrando efectos positivos inotrópicos y lusitrópicos in vitro.
- Investigar los efectos directos de levosimendan en la insuficiencia cardíaca humana en el miocardio in vivo es crucial.
Objetivo del estudio:
- Para determinar los efectos in vivo de levosimendan en la función sistólica y diastólica en corazones humanos con disfunción ventricular izquierda.
- Para evaluar si los efectos de levosimendan dependen de la frecuencia cardíaca.
Principales métodos:
- Diez pacientes con cardiomiopatía dilatada no isquémica se sometieron a cateterismo ventricular izquierdo y aceleración auricular derecha.
- Se administró levosimendan intracoronario, y se midieron respuestas inotrópicas (+dP/dt) y lusitrópicas (Tau) en varias frecuencias cardíacas.
- Las medidas de control se tomaron con infusión intracoronaria de solución salina.
Principales resultados:
- Levosimendan aumentó el pico +dP/dt y disminuyó el Tau de manera dependiente de la dosis en un rango de frecuencias cardíacas.
- El acelerador auricular por sí solo disminuyó el Tau pero no aumentó +dP/dt.
- Levosimendan no alteró las relaciones fuerza-frecuencia o relajación-frecuencia.
Conclusiones:
- La sensibilización al calcio miocárdico con levosimendan proporciona efectos inotrópicos y lusitrópicos leves en humanos con disfunción ventricular izquierda.
- Los efectos beneficiosos de Levosimendan en la función sistólica y diastólica no están modulados por los cambios en la frecuencia cardíaca.
- El fármaco no altera la dinámica intrínseca de fuerza-frecuencia o de relajación-frecuencia del miocardio humano que está fallando.
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