neurocardiogenic

Neurocardiogenic syncope, also known as neurally mediated or vasovagal syncope, refers to transient loss of consciousness caused by a reflex interaction between the heart and the autonomic nervous system. It is the most common cause of fainting and often occurs in otherwise healthy individuals. The episode is usually brief, with rapid recovery after lying down or sitting.

The pathophysiology involves a reflex that reduces sympathetic tone and increases parasympathetic activity, leading to vasodilation and sometimes bradycardia. The resulting decrease in cerebral blood flow can cause fainting. Triggers commonly include prolonged standing, emotional stress, pain, heat exposure, dehydration, and standing in crowds. Prodromal symptoms such as lightheadedness, nausea, pallor, sweating, and blurred vision may precede the loss of consciousness.

Diagnosis starts with a clinical history and physical examination to exclude cardiac or neurological disease. Orthostatic vital signs are often checked. An electrocardiogram (ECG) is used to screen for rhythm abnormalities, and further testing such as tilt-table testing may be considered in uncertain cases. Imaging or long-term monitoring is not routine but may be employed if there are red flags or persistent concern for another diagnosis.

Management emphasizes prevention and safety. Nonpharmacologic strategies include recognizing prodromal symptoms, staying hydrated, maintaining adequate salt intake when appropriate, and avoiding known triggers. Physical counterpressure maneuvers can abort an impending episode. For recurrent cases, pharmacologic options such as fludrocortisone or midodrine may be considered on an individualized basis, with careful monitoring. Education and structured follow-up are important components of care.

Prognosis is generally favorable, with most episodes being benign and self-limited. Recurrence can occur, but the condition does not typically indicate progressive heart disease.