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Reserva de vasodilatador coronario en el miocardio isquémico del perro que hace ejercicio
D D Laxson1, X Z Dai, D C Homans
1Department of Medicine, University of Minnesota, Minneapolis 55455.
Circulation
|January 1, 1992
Resumen
La reserva de vasodilatador coronario persiste en el músculo cardíaco isquémico durante el ejercicio. Esto sugiere que el tono microvascular restante influye en la hipoperfusión de la estenosis coronaria.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Investigación de la isquemia miocárdica Investigación de la isquemia miocárdica.
- Estudios de la circulación coronaria Estudios de la circulación coronaria
Sus antecedentes:
- Estudios previos sugieren que la reserva de vasodilatador coronario puede persistir en el miocardio hipoperfundido.
- Esta investigación investiga el tono vasomotor coronario residual en la isquemia miocárdica inducida por el ejercicio agudo debido a la estenosis coronaria.
Objetivo del estudio:
- Para determinar la presencia y la extensión del tono vasodilatador coronario residual en el miocardio isquémico agudo durante el ejercicio.
- Para evaluar el impacto de la adenosina en el flujo sanguíneo del miocardio y la función en condiciones isquémicas.
Principales métodos:
- Estudios realizados en perros instrumentados durante el ejercicio en cinta de correr con una estenosis coronaria que limita el flujo.
- Flujo sanguíneo miocárdico medido con microsferas radiactivas antes y durante la infusión de adenosina intracoronaria.
- La presión de perfusión coronaria se mantiene constantemente para aislar los efectos de la adenosina.
Principales resultados:
- El ejercicio con estenosis coronaria redujo significativamente el flujo sanguíneo en la región posterior isquémica en comparación con la región anterior no isquémica.
- La adenosina intracoronaria aumentó significativamente el flujo sanguíneo del miocardio en la región isquémica, lo que indica una reserva vasodilatadora persistente.
- El acortamiento del segmento miocárdico en la región isquémica mejoró con adenosina, a pesar de la presión de perfusión sin cambios.
Conclusiones:
- La reserva de vasodilatador coronario sensible a la adenosina está presente durante la isquemia miocárdica inducida por el ejercicio.
- El tono vasoconstrictor microvascular residual puede contribuir a la gravedad de la hipoperfusión miocárdica causada por estenosis coronaria.
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