From the Guidelines
Vasovagal syncope is characterized by a sudden drop in blood pressure and heart rate leading to temporary loss of consciousness, typically triggered by emotional stress, pain, prolonged standing, or the sight of blood, and is often preceded by prodromal symptoms such as lightheadedness, nausea, sweating, pallor, and visual disturbances. The key features of vasovagal syncope include:
- A sudden drop in blood pressure and heart rate
- Temporary loss of consciousness, usually less than a minute
- Rapid and complete recovery afterward
- Prodromal symptoms such as lightheadedness, nausea, sweating, pallor, and visual disturbances
- Triggers including emotional stress, pain, prolonged standing, or the sight of blood
- An inappropriate autonomic response where the vagus nerve overactivates, causing blood vessels to dilate and heart rate to slow simultaneously 1. Management of vasovagal syncope typically involves:
- Avoiding triggers
- Increasing fluid and salt intake
- Physical counterpressure maneuvers (like leg crossing or muscle tensing) 1
- In severe recurrent cases, medications such as fludrocortisone, midodrine, or beta-blockers might be prescribed. It is essential to note that while vasovagal syncope is generally benign, it can be dangerous if it occurs during activities like driving or swimming, and most patients have an excellent prognosis with proper education and preventive measures 1.
From the Research
Features of Vasovagal Syncope
- Vasovagal syncope is a common disorder that affects at least 20% of people at some time in their lives 2
- It is characterized by an abrupt loss of consciousness in response to reduced perfusion to the brain 3
- The population of patients with vasovagal syncope is highly heterogeneous 4
- Triggers of vasovagal syncope are likely to be protean, and many potential central and peripheral triggers have been identified 4
Diagnosis and Treatment
- Tilt-table testing is a widely used diagnostic tool 4
- The cornerstone of the treatment of vasovagal syncope is lifestyle modifications, including drinking 2 to 3 liters of fluids per day, consuming 10 grams of NaCl per day, and practicing counter-pressure maneuvers 5
- Pharmacological interventions, such as midodrine and fludrocortisone, may be necessary for patients who incur life-disturbing attacks despite compliance with lifestyle modifications 5, 2, 6, 3
- Midodrine is considered the first-line therapy for patients having frequent presyncope or syncope or for those with brief or no prodromes 6
- The routine use of beta-blockers, serotonin-specific reuptake inhibitors, fludrocortisone, and pacemakers is discouraged 6