Department of Psychology, McGill University, Montreal, QC, Canada.
J Behav Med. 2012 Aug;35(4):393-9. doi: 10.1007/s10865-011-9366-0. Epub 2011 Jul 13.
A recent theory proposes that emotional fainting developed from an earlier adaptive characteristic, fainting in response to hemorrhage. Despite potential loss of consciousness, a dramatic decrease in blood pressure improves chances of survival in animals with severe wounds by reducing blood loss and facilitating clotting. Humans may have developed the characteristic of emotional fainting as a response to anticipated blood loss. This idea suggests that people with stronger fears of blood should be especially susceptible to fainting and milder vasovagal symptoms such as dizziness and lightheadedness. Two samples of young adult blood donors (N = 276 and 663) who completed the Medical Fears Survey (MFS) were studied. Items from the MFS related to fears of blood, needles, and mutilation were used to predict self-reported dizziness and nurse-initiated treatment for vasovagal reactions. In both samples, fears of experiencing or seeing blood loss were more closely associated with both subjective and objective measures of vasovagal reactions, despite the fact that other fears (e.g., fears related to needles) were more common overall. Better understanding of the mechanisms of vasovagal reactions has both theoretical and clinical implications, such as improving means of coping with invasive medical procedures.
最近的一种理论提出，情绪性昏厥可能是从早期对出血的适应特征发展而来的。尽管可能会失去意识，但血压的急剧下降通过减少失血和促进凝血，提高了严重创伤动物的生存机会。人类可能已经发展出了情绪性昏厥的特征，以应对预期的失血。这一观点表明，那些对血液的恐惧更强的人应该特别容易昏厥，并且更容易出现头晕和头晕目眩等较轻的血管迷走神经性症状。对两个年轻成年献血者样本（N=276 和 663）进行了研究，他们完成了医学恐惧调查（MFS）。MFS 中的与对血液、针头和残害的恐惧有关的项目被用来预测自我报告的头晕和护士对血管迷走神经性反应的治疗。在这两个样本中，尽管总体上其他恐惧（例如与针头相关的恐惧）更为常见，但对经历或看到失血的恐惧与血管迷走神经性反应的主观和客观测量都更为密切相关。更好地理解血管迷走神经性反应的机制具有理论和临床意义，例如改善应对有创性医疗程序的方法。
