What is the next step for a patient with neurocardiogenic syncope, confirmed by a tilt-table test, who experiences dizziness, near-syncope, and sinus bradycardia, with symptoms reproduced during the test, including hypotension and bradycardia?

From the Guidelines

The next step for this patient with neurocardiogenic syncope is to initiate non-pharmacological measures including increased salt and fluid intake, physical counterpressure maneuvers, and avoidance of triggers. The patient should increase daily water intake to 2-3 liters and sodium intake to 6-10 grams per day, unless contraindicated by other conditions like hypertension or heart failure, as recommended by the 2017 ACC/AHA/HRS guideline for the evaluation and management of patients with syncope 1. Physical counterpressure maneuvers such as leg crossing, muscle tensing, and squatting should be taught to the patient to perform when prodromal symptoms occur.

If these conservative measures are insufficient, pharmacological therapy with midodrine (starting at 2.5-5 mg three times daily) or fludrocortisone (0.1 mg daily) could be considered, as these medications have been shown to improve symptoms of neurogenic orthostatic hypotension in patients with neurocardiogenic syncope 1. Midodrine increases peripheral vascular resistance while fludrocortisone promotes sodium retention and expands plasma volume.

For patients with significant bradycardia during episodes, as in this case with documented sinus bradycardia and a 2.7-second pause, a beta-blocker like metoprolol (25-100 mg twice daily) may paradoxically help by blunting the sympathetic surge that precedes the vasovagal reaction. However, the use of permanent pacemaker implantation in refractory cases is still a topic of debate, with some studies suggesting its efficacy in reducing symptoms, particularly in patients with little or no prodrome before their syncopal event, those with profound bradycardia or asystole during a documented event, and those in whom other therapies have failed 1.

Key considerations in the management of this patient include:

• Increased salt and fluid intake to improve orthostatic tolerance
• Physical counterpressure maneuvers to increase blood pressure
• Pharmacological therapy with midodrine or fludrocortisone to improve symptoms
• Avoidance of triggers and education on prodromal symptoms
• Consideration of permanent pacemaker implantation in refractory cases with significant bradycardia or asystole.

From the FDA Drug Label

The patient had abnormal tilt test with findings consistent with neurocardiogenic physiology. The next step is to consider treatment for neurocardiogenic syncope.

• Midodrine 2 may be considered as it is used to treat orthostatic hypotension, but caution should be exercised due to potential side effects.
• Fludrocortisone 3 may also be considered as it is used to treat orthostatic hypotension, but caution should be exercised due to potential side effects, particularly in patients with certain medical conditions. However, the FDA drug label does not provide direct guidance on the next step for this specific patient.

From the Research

Next Steps for Patient with Neurocardiogenic Syncope

The patient's symptoms and test results are consistent with neurocardiogenic syncope, also known as vasovagal syncope. The next steps in management can be guided by the following considerations:

• Conservative measures are typically the first line of treatment, but the patient's symptoms have already been reproduced during the tilt-table test, indicating a need for further intervention.
• Pharmacologic treatments can be considered to prevent recurrence of syncope, with options including:
  • Midodrine, which has been shown to be effective in reducing symptoms of neurocardiogenic syncope in several studies 4, 5, 6, 7.
  • Beta-blockers, which may be effective in some patients, but have a lower response rate compared to midodrine 5.
• The choice of treatment should be individualized based on the patient's specific symptoms and medical history.
• Further evaluation and monitoring may be necessary to determine the effectiveness of treatment and to adjust the treatment plan as needed.

Treatment Options

The following treatment options may be considered for the patient:

• Midodrine, starting at a dose of 5 mg three times a day and adjusting as needed to a maximum dose of 15 mg three times a day 6.
• Beta-blockers, such as metoprolol, which may be effective in some patients, but have a lower response rate compared to midodrine 5.
• Other treatments, such as fludrocortisone and sodium chloride, which may be considered in patients who do not respond to midodrine or beta-blockers 4.