Killer dreams.

Emotional stress is a recognized trigger for coronary artery spasm. An association between dreams and sudden death is described in folklore and medical history, and originates from the common experience of being awakened by vivid, frightening dreams, with racing pulse, cold sweats and other physiological responses associated with intense distress. Intense alterations in autonomic activity during dreaming can have dire consequences in patients with cardiovascular disease. Four patients with no evidence of underlying coronary artery disease, where emotional stress produced by nightmares or 'deadly dreams' caused coronary artery dissection in two and vasospasm in the other two, leading to life-threatening cardiac events, are presented. A possible mechanism is speculated.