Neurocardiogenic (Vasovagal) Syncope

Neurocardiogenic syncope is also known as vasovagal or vasodepressor syncope and it is a neurally mediated disorder. It is a common cause of syncope. it most often occurs when the blood pressure is too low (hypotension) and the heart doesn't pump a normal supply of oxygen to the brain.

Causes

• Vasovagal syncope a form of dysautonomia and it is the most common cause of fainting.
• Vasovagal syncope is caused by low heart rate and blood pressure, leading to inadequate circulation. The reduced oxygen supply to the brain results in syncope, or temporary loss of consciousness.
• It may also be caused by emotional stress, pain, pooling of blood in the legs due to sudden changes in body position, overheating, dehydration, heavy sweating or exhaustion.
• It also may result from several heart, neurologic, psychiatric, metabolic and lung disorders.

Symptoms

• A history of identifiable triggering events, including pain, emotional stress, or anxiety related to "fight-or-flight" situations. Previous history of similar episodes.
• Presyncopal or prodromal phase lasting a few seconds to a few minutes is often reported.
• Symptoms during the prodrome include a sense of light, headedness +++, diaphoresis ++, headache or visual changes ++, epigastric discomfort, nausea, and vomiting ++.

Signs

• Normal physical examination is most often noted.
• Decreased heart rate and low blood pressure are noted if the patient is still symptomatic.

Treatment

• Isometric arm counter-pressure maneuvers can increase systolic blood pressure and prevent fainting in some patients with NCS. Patients may perform isometric arm counter-pressure maneuvers by gripping one had with the other and pushing both arms away from their chest.
• Sitting with the head between the knees often is an effective means of preventing syncope.
• Increasing dietary salt may help prevent symptoms associated with neurocardiogenic syncope.
• Drug therapy for patients with neurocardiogenic syncope such as includes beta-blockers, selective serotonin reuptake inhibitors, fludrocortisone, midodrine, theophylline, disopyramide, scopolamine, and hyoscyamine.