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La acumulación en la intolerancia ortostática crónica: vasoconstricción arterial pero no defectos de cumplimiento
1Department of Pediatrics and Physiology, New York Medical College, Valhalla, NY 10595, USA. stewart@nymc.edu
Circulation
|May 16, 2002
Resumen
La agrupación en pacientes con síndrome de taquicardia postural (POTS) no se debe a un mayor cumplimiento venoso. En cambio, la vasoconstricción arterial embotada causa una redistribución pasiva de la sangre, lo que lleva a síntomas ortostáticos.
Área de la Ciencia:
- Fisiología cardiovascular fisiología cardiovascular.
- Trastornos del sistema nervioso autónomo Trastornos del sistema nervioso autónomo
Sus antecedentes:
- La intolerancia ortostática, caracterizada por el síndrome de taquicardia postural (POTS), implica una taquicardia exagerada y síntomas ortostáticos.
- El POTS está asociado con la "acumulación" de sangre, incluida la acrocyanosis y el edema dependiente, cuando se está erguido.
- Este estudio investigó si el aumento del cumplimiento venoso contribuye a la agrupación en pacientes con POTS.
Objetivo del estudio:
- Para probar la hipótesis de que la agrupación en POTS resulta de un mayor cumplimiento venoso.
- Para comparar el cumplimiento venoso y la regulación del flujo sanguíneo en pacientes con POTS y controles sanos durante el estrés ortostático.
Principales métodos:
- Se utilizó la pletismografía estirometría para medir el flujo sanguíneo en las piernas, la presión venosa (Pv) y el cumplimiento venoso.
- Los sujetos incluyeron 15 pacientes con POTS (de 13 a 19 años) y 11 controles sanos de la misma edad.
- Se realizaron pruebas incrementales de inclinación de la cabeza hacia arriba (hasta 35 grados) mientras se medían los parámetros cardiovasculares.
Principales resultados:
- El cumplimiento venoso fue similar entre los pacientes con POTS (divididos en subgrupos normales y de alta P) y los controles, y no se vio afectado por la ortostasis.
- La resistencia periférica de la pierna supina difería entre los subgrupos de POTS y los controles.
- Durante la inclinación vertical, la resistencia de la pierna disminuyó en el grupo con POTS alto y aumentó en los controles, mientras que P aumentó en pacientes con POTS normales y controles, pero no en el grupo con POTS alto.
Conclusiones:
- La acumulación en POTS se atribuye a la vasoconstricción arterial embotada, no al aumento del cumplimiento venoso.
- Esta vasoconstricción embotada conduce a la redistribución pasiva de la sangre dentro de los lechos de capacidad venosa periférica.
- El cumplimiento venoso en pacientes con POTS es comparable al de individuos sanos.
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