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Aceleración del miocardio durante la contracción isovolúmica: relación con la contractilidad
Erik Lyseggen1, Stein Inge Rabben, Helge Skulstad
1Institute for Surgical Research and Department of Cardiology, Rikshospitalet University Hospital, Oslo, Norway.
Circulation
|March 9, 2005
Resumen
La aceleración isovolúmica miocárdica (IVA) no refleja de manera confiable la contractilidad regional del músculo cardíaco. Esta medida es dependiente de la carga y puede indicar eventos diastólicos tardíos en lugar de contractilidad durante la isquemia.
Área de la Ciencia:
- Cardiología Cardiología.
- Fisiología Fisiología Fisiología.
- Ingeniería Biomédica Ingeniería Biomédica.
Sus antecedentes:
- La aceleración del anillo mitral durante la contracción isovolúmica se propuso como un índice independiente de la carga de la contractilidad ventricular izquierda (VV) global.
- Este estudio tuvo como objetivo determinar si la aceleración isovolúmica miocárdica (IVA) refleja la contractilidad regional.
Objetivo del estudio:
- Investigar la relación entre la aceleración isovolúmica miocárdica (IVA) y la contractilidad ventricular izquierda (LV) regional.
- Para evaluar la dependencia de carga de IVA.
- Evaluar la utilidad del IVA en la detección de la disfunción miocárdica regional durante la isquemia.
Principales métodos:
- Mediciones de la presión LV, las velocidades del eje largo del miocardio y IVA utilizando imágenes Doppler de tejidos (TDI) y sonomicrometría en perros anestesiados.
- Manipulación de la contractilidad global de LV (dobutamina) y la precarga (carga de volumen).
- Inducción de la isquemia miocárdica regional mediante la reducción del flujo en la arteria coronaria anterior descendente izquierda.
Principales resultados:
- La dobutamina aumentó la AIV y la LV dP/dtmax en paralelo.
- La carga de volumen disminuyó el IVA, pero no cambió la LV dP/dt (max) o la contractilidad regional.
- La isquemia regional deprimía la función regional, mientras que la IVA se mantuvo sin cambios.
- Las mediciones IVA por TDI y sonomicrometría arrojaron resultados consistentes.
Conclusiones:
- El pico IVA no mostró una relación consistente con la contractilidad miocárdica regional.
- El pico IVA fue significativamente dependiente de la carga.
- El pico IVA no reflejó deterioro de la función miocárdica durante la isquemia.
- El pico IVA puede estar influenciado por eventos diastólicos tardíos y oscilaciones de la pared, lo que limita su uso en la evaluación de la función miocárdica regional.
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