Syncope - the sudden loss of consciousness caused by a passing ischemia of a brain.

Etiology, pathogenesis. The leading factor in a genesis of a syncope is depression of arterial pressure to a level at which mechanisms of a cerebral circulation cannot provide sufficient blood supply of a brain. Allocate 3 basic pathogenetic parts of development of a syncope:
1). Falling of arterial pressure owing to decrease of peripheric vascular resistance (the psychogenic syncopes caused by hyperactivity of the wandering nerve, an orthostatic hypotension);
2). Disturbance of activity of heart (aortal defects);
3). Decrease of the maintenance in a blood of oxygen (cardiopulmonary diseases).

Signs, current. The syncope begins with feeling of faintness, a ring in ears; then the loss of consciousness follows. The patient slowly falls ("settles"), sharp paleness of integuments is marked. Pulse small or is not defined at all. Arterial pressure is sharply lowered, respiration superficial. Duration of a loss of consciousness of 10-30 seconds. After a syncope some time is kept the general delicacy, a nausea.