Orthostatic hypotension is a disorder that typically manifests itself with feeling light-headed, tired, experiencing blurred vision and syncope. This condition, which is characterized by a reduction of at least 20 mmHg in systolic blood pressure or 10 mmHg in diastolic blood pressure within three minutes of taking a standing position, is the most disabling disorder of patients with vegetative nervous system disease. Moreover, it is often the clinical manifestation of the pathology, the symptom that leads the patient to carry out investigations, as Dr. Vincenzo Tullo, Neurologist and Head of the Outpatient Headache Clinic at Humanitas LAB, explains.
“The characteristic symptoms of orthostatic hypotension are due to cerebral hypoperfusion (i.e. a reduction in cerebral blood flow of 750-1000 ml/min; the brain, even if it represents only 2% of the total body weight, receives 15% of the cardiac output), and develop when the subject is standing and disappear when he assumes the lying position. They are particularly intense after an abundant meal, after demanding exercise or in the morning. Constipation can cause syncopal attacks during the evacuation effort,” explains the specialist.
How is the diagnosis made?
“In the presence of these symptoms, a simple measurement of blood pressure and heart rate is taken with the patient at rest in a supine position for 10 minutes and after 3 minutes of orthostasis (i.e. in an upright position). It is also useful to evaluate the vegetative control of cardiovascular reflexes, by means of some physiological methods (tilt test, Valsalva manoeuvre, deep breath, mental calculation test), biochemical (plasma dosage in clinostatissm and orthostasis of noradrenaline and vasopressin) and pharmacological (infusion of noradrenaline, tyramine, clonidine, edrophonium)”, continues Dr. Tullo.
What to do in case of orthostatic hypotension?
“In patients with symptomatic orthostatic hypotension, drug therapy with fludrocortisone, mydodrin, erythropoietin, dihydroergotamine, indomethacin, desmopressin and octreotide is indicated.
General measures are also necessary, such as: avoiding rapid changes of posture, especially when awake; avoiding remaining in bed for a long time during the day and also maintaining a standing position for a long time; paying attention to efforts during urination and defecation; high ambient temperatures and intense physical exercise. Furthermore, avoid abundant meals and alcohol consumption.
It is advisable to drink a lot, introducing at least two liters of liquids per day; to cure the daily saline contribution; to dedicate oneself to a moderate exercise; to consume small and frequent meals that foresee little carbohydrates; to use air conditioning or fan in summer and elastic stockings”, recommended doctor Tullo.