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Consecuencias de la isquemia breve: aturdimiento, precondicionamiento y sus implicaciones clínicas: parte 1
1Heart Institute, Good Samaritan Hospital, Keck School of Medicine, University of Southern California, Los Angeles, CA 90017, USA. rkloner@goodsam.org
Circulation
|December 12, 2001
Resumen
La isquemia breve puede dañar el corazón a través del aturdimiento, causando disfunción prolongada. Sin embargo, también protege el corazón a través del precondicionamiento isquémico, reduciendo el daño de eventos posteriores.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Fisiopatología Miocárdica Fisiopatología del miocardio
Sus antecedentes:
- Las oclusiones breves de las arterias coronarias (hasta 15 minutos) en perros causan lesiones miocíticas reversibles.
- La isquemia induce cambios en el miocardio, incluido el aturdimiento del miocardio, caracterizado por una disfunción contráctil postisquémica prolongada.
- El aturdimiento está relacionado con los radicales de oxígeno, la homeostasis alterada del calcio y los cambios en las proteínas potencialmente contráctiles.
Objetivo del estudio:
- Explorar los efectos duales de los episodios isquémicos breves en la función miocárdica.
- Investigar los mecanismos y la relevancia clínica del aturdimiento miocárdico y el precondicionamiento isquémico.
Principales métodos:
- Estudios experimentales en perros que involucran oclusiones y reperfusión de la arteria coronaria.
- Observación de los escenarios clínicos asociados con el aturdimiento miocárdico.
- Revisión de los datos experimentales y clínicos sobre limpiadores de radicales de oxígeno y bloqueadores de los canales de calcio.
Principales resultados:
- La isquemia breve (5-15 minutos) puede conducir a una lesión reversible, pero también inducir el aturdimiento del miocardio.
- El miocardio aturdido exhibe una disfunción contráctil prolongada.
- El precondicionamiento isquémico, episodios isquémicos cortos seguidos de reperfusión, protege el corazón contra oclusiones posteriores más largas al reducir la necrosis.
Conclusiones:
- La isquemia breve tiene efectos paradójicos: aturdimiento miocárdico (negativo) y precondicionamiento isquémico (protector).
- Los mecanismos involucran radicales de oxígeno, homeostasis de calcio y complejas vías de segundo mensajero.
- La investigación futura tiene como objetivo minimizar el aturdimiento y maximizar el precondicionamiento para el beneficio clínico.
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