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La hipertermia moderada altera la autorregulación cerebral dinámica pero no su sensibilidad direccional
Mahmoudreza Taghizadeh1,2, Marc-Antoine Roy1,2, Shahrzad Soleimani Dehnavi1,2
1Department of Kinesiology, Faculty of Medicine, Université Laval, Québec, QC, Canada.
Journal of applied physiology (Bethesda, Md. : 1985)
|February 19, 2026
Resumen
La hipertermia moderada altera la autorregulación cerebral dinámica (dCA) al reducir la capacidad de amortiguación del flujo sanguíneo, especialmente a frecuencias más altas. Sin embargo, preserva la sensibilidad direccional de las relaciones de presión-flujo cerebral.
Área de la Ciencia:
- Fisiología; Neurociencia; Investigación Cardiovascular
Sus antecedentes:
- La autorregulación cerebral dinámica (dCA) es crucial para mantener un flujo sanguíneo cerebral (CBF) estable en medio de fluctuaciones de la presión arterial.; La hipertermia de todo el cuerpo puede alterar la regulación del CBF al aumentar la resistencia cerebrovascular.; El impacto de la hipertermia en la sensibilidad direccional de la dCA sigue sin estar claro.
Objetivo del estudio:
- Investigar los efectos de la hipertermia moderada en la dCA y su sensibilidad direccional.; Determinar si la hipertermia altera la capacidad de amortiguación cerebrovascular durante cambios rápidos de la presión arterial.
Principales métodos:
- Veinte adultos sanos se sometieron a presión negativa oscilatoria en la parte inferior del cuerpo (OLBNP) a 0.05 Hz y 0.10 Hz en condiciones normotérmicas e hipertérmicas.; Se cuantificaron las métricas de dCA mediante análisis de función de transferencia (TFA) y análisis de sensibilidad direccional.; Se monitorizó continuamente la velocidad media de la arteria cerebral media (MCAvmean) y la presión arterial media (MAP).
Principales resultados:
- La hipertermia alteró la dCA, evidenciada por una mayor coherencia de la TFA, una menor fase de la TFA y un aumento de la ganancia de la TFA a 0.10 Hz.; El análisis de sensibilidad direccional reveló patrones direccionales preservados (%MCAvmeanT/%MAPT) en ambas frecuencias bajo hipertermia.; Se observó sensibilidad direccional absoluta (∆MCAvmeanT/∆MAPT) solo a 0.10 Hz, sin un efecto térmico significativo.
Conclusiones:
- La hipertermia moderada atenúa la capacidad de amortiguación dinámica de la vasculatura cerebral, especialmente a frecuencias más altas.; La sensibilidad direccional inherente de la relación presión-flujo cerebral se mantiene durante la hipertermia moderada.; Mecanismos regulatorios distintos probablemente rigen los aspectos dinámicos y direccionales de la autorregulación cerebral.
Palabras clave:
análisis de sensibilidad direccionalestrés por calorarteria cerebral mediapresión negativa oscilatoria en la parte inferior del cuerpoanálisis de función de transferenciaMás Videos Relacionados
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