Syncope is an abrupt, transient loss of consciousness and postural tone followed by spontaneous recovery associated with profound anxiety in the patient, family, and, not too infrequently, the clinician. For patients receiving the “rule out” diagnosis of vasovagal syncope (VVS), treatment options are commonly of uncertain value, and often are dissatisfying because they are not typically curative.
Dr. Ankur Vyas of the University of Iowa, and colleagues, conducted a systematic review to shed light on the various options for vasovagal syncope (Int J Cardiol. 2012 May 22 doi:10.1016/j.ijcard.2012.04.144).
Among other studies, their analysis focused on seven randomized controlled trials involving 400 patients. End points for four of the studies looked at repeat positive tilt tests; three evaluated spontaneous symptom recurrence. Among their findings:
• Alpha-adrenergic agonists were found to be effective in preventing recurrence (7 studies, n = 400; OR 0.19, CI 0.06–0.62, P < 0.05). Among the alpha-adrenergic agonists, midodrine was found to be effective (4 studies, n = 136, OR 0.12, CI 0.05–0.26, P < 0.05), but etilefrine was not.
• Beta-blockers were found to be ineffective for reducing VVS when only randomized studies comparing them to non-pharmacologic agents were analyzed (9 studies, n = 583, OR 0.48, CI 0.22–1.04, P = 0.06).
• SSRI’s were ineffective for reducing recurrence (2 studies, n = 131, OR 0.28, CI 0.10–0.74, P< 0.05).
• When only randomized trials were included, tilt training was not found to be effective for reducing recurrence of VVS.
• Pacemakers appeared to be effective for preventing syncope recurrence (6 studies, n = 463, OR 0.13, CI 0.05–0.36, P < 0.05). And specifically, when pacemakers were compared to medical therapy they were more effective at preventing syncope (4 studies, n = 209, OR 0.09, CI 0.04–0.22, P < 0.05).
Vasovagal syncope is clinically challenging especially for our patients who have recurrent symptoms. “High risk” patients, defined as those whose events occur without warning and in any position with no clear precipitating causes, and/or frequent occurrence, need to be counseled against driving. Unfortunately, adherence to this recommendation is low. Only 35% of patients with VVS are symptom free after a median of five years of follow-up, regardless of presenting symptoms or treatment. For patients with VVS, reassurance and education regarding the nature, risks, and prognosis of the condition may be just as important as the medical therapy we provide.
Jon O. Ebbert, M.D., is a professor of medicine and a primary care clinician at the Mayo Clinic in Rochester, Minn. He declares having no conflicts of interest. The opinions expressed are solely those of the author. Contact him at ebbert.jon@mayo.edu.