From the Guidelines
Vasovagal syncope is a common form of fainting caused by an overreaction of the vagus nerve, resulting in a sudden drop in heart rate and blood pressure that reduces blood flow to the brain, and its management primarily involves education, lifestyle modifications, and physical counterpressure maneuvers, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1.
Characteristics of Vasovagal Syncope
- Typically triggered by emotional stress, pain, prolonged standing, dehydration, or hot environments
- Patients usually experience warning signs before fainting, including lightheadedness, nausea, sweating, and visual changes
- Complete loss of consciousness in vasovagal syncope is usually no longer than 20 s in duration, as noted in a videometric study of 56 episodes of short-lasting severe cerebral hypoxia in adolescents 1
Management of Vasovagal Syncope
- Education and lifestyle modifications are essential, including teaching patients to recognize warning signs and immediately sit or lie down with legs elevated when symptoms begin
- Adequate hydration (2-3 liters of fluid daily), increased salt intake (unless contraindicated), and avoiding trigger situations are essential preventive measures
- Physical counterpressure maneuvers like leg crossing with muscle tensing or hand gripping can help abort an episode by raising blood pressure, as recommended by the 2019 American Heart Association and American Red Cross focused update for first aid 1
- Medication is generally reserved for severe, recurrent cases and may include fludrocortisone, midodrine, or beta-blockers, with midodrine being a reasonable option in patients with recurrent vasovagal syncope and no history of hypertension, heart failure, or urinary retention 1
- Pacemaker implantation is rarely indicated, only considered in cases with documented significant bradycardia during episodes
Key Recommendations
- Patient education on the diagnosis and prognosis of vasovagal syncope is recommended, as stated in the 2017 ACC/AHA/HRS guideline 1
- Physical counter-pressure maneuvers can be useful in patients with vasovagal syncope who have a sufficiently long prodromal period, as noted in the 2019 American Heart Association and American Red Cross focused update for first aid 1
- Midodrine is reasonable in patients with recurrent vasovagal syncope with no history of hypertension, heart failure, or urinary retention, as recommended by the 2017 ACC/AHA/HRS guideline 1
From the Research
Characteristics 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 condition results from a complex neurologic reflex, and treatments aim to modulate aspects of that reflex 3
Management of Vasovagal Syncope
- The cornerstone of treatment 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 4
- Pharmacological interventions, such as midodrine and fludrocortisone, may be necessary for patients who experience life-disturbing attacks despite compliance with lifestyle modifications 4, 3
- Other treatments, such as beta-blockers and norepinephrine transport inhibitors, may also be used to modulate the sympathetic nervous system 3
- Medical or device therapy may be required when syncope is severe and refractory to conservative treatment 5
Treatment Options
- Midodrine has been shown to be effective in reducing recurrence of vasovagal syncope 3, 6
- Fludrocortisone may also be used to increase systemic fluid volume 3, 6
- Beta-blockers and other treatments may be used in certain cases, but more research is needed to determine their effectiveness 3, 6