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Efecto de la administración de nitroglicerina intracoronaria en el patrón de fase y la distribución transmural del
M Goto1, A E Flynn, J W Doucette
1Department of Medical Engineering and Systems Cardiology, Kawasaki Medical School, Kurashiki, Japan.
Circulation
|June 1, 1992
Resumen
La nitroglicerina intracoronaria puede no aliviar la angina debido al aumento del flujo sistólico inverso, lo que afecta el flujo sanguíneo subendocárdico a pesar del aumento del flujo subepicárdico en los corazones isquémicos.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Farmacología Farmacología.
Sus antecedentes:
- La nitroglicerina alivia eficazmente la isquemia del miocardio.
- La nitroglicerina intracoronaria puede no aliviar la angina de pecho y puede afectar negativamente el flujo sanguíneo subendocárdico.
- Los mecanismos subyacentes a estos efectos requieren investigación.
Objetivo del estudio:
- Investigar los efectos directos de la nitroglicerina en la circulación coronaria en los corazones isquémicos.
- Para aclarar la relación entre la administración de nitroglicerina y los patrones de flujo sanguíneo coronario.
Principales métodos:
- Utilizó un medidor de flujo de ultrasonido Doppler pulsado de 80 canales y 20 MHz para medir el flujo arterial coronario intramiocárdico.
- Empleó microsferas radiactivas para evaluar la distribución del flujo sanguíneo transmyocardiano.
- Efectos estudiados en perros de pecho abierto anestesiados con estenosis inducida de la arteria coronaria.
Principales resultados:
- La administración de nitroglicerina disminuyó las presiones sistólica y diastólica distales en las arterias coronarias estenosadas.
- La nitroglicerina aumentó el flujo diastólico hacia adelante, pero aumentó significativamente el flujo sistólico inverso.
- El flujo subepicárdico aumentó con nitroglicerina, mientras que el flujo subendocárdico no lo hizo, lo que lleva a una reducción de la relación de flujo subendocárdico a subepicárdico.
Conclusiones:
- El aumento del flujo sistólico inverso después de la nitroglicerina intracoronaria es un factor clave.
- Este aumento del flujo sistólico inverso está estrechamente relacionado con el fracaso del flujo sanguíneo subendocárdico para mejorar.
- Los hallazgos sugieren un mecanismo potencial para la eficacia limitada de la nitroglicerina en ciertas condiciones isquémicas.
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