Orthostatic syncope

Orthostatic syncope refers to syncope resulting from a postural decrease in blood pressure termed as Orthostatic hypotension. Orthostatic syncope refers to syncope resulting from a postural decrease in blood pressure termed as Orthostatic hypotension. Orthostatic hypotension occurs when there is a persistent reduction in blood pressure of at least 20mmHg systolic or 10mmHg diastolic within 3 minutes of standing or being upright to 60 degrees on the head-up tilt table. In people with initial orthostatic hypotension, the decrease in blood pressure occurs within 15 seconds, while in those with delayed orthostatic hypotension it occurs after over 3 minutes of assuming an upright position. Orthostatic syncope may occur suddenly with no warning or may be preceded by symptoms. Associated symptoms are usually because of cerebral hypoperfusion occurring in the upright position and include dizziness, feeling faint or nauseated, diaphoresis, a sense of warmth or blurred vision. Other general symptoms regardless of the position include a feeling of generalized weakness, headache, fatigue, cognitive slowing and shortness of breath. Symptoms may be sudden or gradual, getting progressively worse until the patient loses consciousness. Patients may have a single episode with an identifiable precipitating factor or recurrent episodes without an overt, identifiable, precipitating factor. Blood pressure and heart rate should be measured in supine and standing positions. As described above, orthostatic hypotension diagnosis is when there is a drop of greater than or equal to 20 mmHg or greater or equal to 10 mmHg in systolic and diastolic blood pressures, respectively within 3 minutes of standing. In the case of hypovolemia, there is also a compensatory rise in heart rate of greater than 15 beats/minute. Complications of orthostatic syncope include: There are multiple causes of orthostatic hypotension which could lead to syncope including neurally mediated (neurogenic) and non-neurally mediated causes. Neurally mediated causes include conditions that cause either primary or secondary failure of the autonomic system: Non-neurally mediated causes include: