Treatment of vasovagal syncope: an update

Vasovagal syncope (VVS) remains the most common cause of syncope and transient loss of consciousness in all age groups. The treatment of VVS focuses on measures that interrupt or prevent its pathophysiologic mechanism, as well as on avoidance of triggers. Although the evidence supporting an increase in salt and water intake is weak, it is a cost-effective and safe strategy that should always be used as first-line therapy. Patients should be educated on how to respond to further episodes of syncope, especially if they experience prodromal warning signs. In these cases, counterpressure maneuvers in younger patients are clearly effective. Orthostatic training exercises may improve symptoms in patients with recurrent VVS; however, this strategy is only effective in younger, highly motivated patients. Multiple medications have been tested in small trials, and there is sparse evidence on efficacy. β-Adrenergic antagonists and selective serotonin reuptake inhibitors have shown contradictory results on efficacy in a variety of studies; thus, their use should be restricted. Midodrine is the only drug proven to prevent VVS recurrence; however, no consistent prescription guidelines exist. The ongoing Second Prevention of Syncope Trial (POST II) is investigating the benefits of fludrocortisone in this population. In the meantime, measures such as increased salt and water intake and counterpressure maneuvers should be used in all cases if no contraindications are present. Pharmacologic treatment should be restricted to midodrine and fludrocortisone, with the other treatments as options in highly refractory cases. Implantation of a permanent pacemaker should be a measure of last resort in highly refractory cases, particularly in the cardioinhibitory type of VVS.