Cardiovascular and sensory responses to forearm ischemia and dynamic hand exercise.

The relationship between cardiovascular responses and pain produced by the submaximal-effort tourniquet procedure was evaluated in healthy humans. Graded increases in ischemic pain were associated with graded elevations in arterial blood pressure, forearm vascular resistance, and venous tone. Many of the vascular responses to muscle ischemia were typical of the cardiovascular components of the defense reaction and correlated with both the sensory and affective aspects of ischemic pain. The cardiovascular responses to arm ischemia were distinguishable from those produced by rhythmic hand exercise used to produce ischemia. Dynamic hand exercise produced a transient increase in arterial blood pressure, heart rate, and measures of hand discomfort. These responses were enhanced when dynamic hand exercise was conducted under ischemic conditions. The tightly coupled and coordinated cardiovascular responses elicited by ischemic pain represent integrated adaptive responses to painful stimulation.