CORRESPONDENCE: LETTER TO THE EDITOR
Predicting the Effectiveness of Beta-Blocker Therapy in Vasovagal Syncope
John R. Kapoor, MD, PhD*
* Division of Cardiology, Stanford University, 300 Pasteur Drive, Stanford, California 94305 (Email: jkapoor{at}stanford.edu).
There has been a great deal of interest in the therapeutic role of beta-adrenergic blockade in patients suffering from vasovagal syncope. The efficacy of beta-blockers in these patients may be due to blunting of elevated catecholamine levels that precede vasovagal syncope (1). Notwithstanding the widespread use of beta-blockers in the past, some studies on chronic beta-blocker use have been less than encouraging and may suggest some benefit in older but not in younger patients, as mentioned in the recent article by Tan and Parry (2). That being said, might there be a better way to predict the favorable use of beta-blocker therapy in patients suffering from vasovagal syncope? In one study of patients with confirmed vasovagal syncope, all patients with a negative tilt test response during esmolol infusion had a negative tilt test response with oral metoprolol. Of the remaining patients with a positive tilt test response during esmolol infusion, 90% continued to have a positive response with oral metoprolol (3). In another study, a negative test with esmolol infusion among 112 patients with vasovagal syncope was again found to be an independent predictor for prevention of symptoms with oral metoprolol during follow-up of 2.7 ± 1.2 years (p < 0.0001) (4). Those authors concluded that "acute challenge with esmolol infusion appears to be an accurate predictor of response to chronic beta-blockers." A negative head-up tilt test during propanolol infusion was similarly found to predict favorable responses to oral beta-blocker therapy in other studies, including a prospective trial of 296 patients (5–7). Thus, data on the effectiveness of a beta-blocker challenge during the head-up tilt test in patients with vasovagal syncope may be very helpful in formulating a therapeutic strategy.
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1. Sra JS, Murthy V, Natale A, et al. Circulatory and catecholamine changes during head-up tilt testing in neurocardiogenic (vasovagal) syncope Am J Cardiol 1994;73:33-37.[CrossRef][Web of Science][Medline]2. Tan MP, Parry SW. Vasovagal syncope in the older patient J Am Coll Cardiol 2008;51:599-606.[Abstract/Free Full Text] 3. Sra JS, Murthy VS, Jazayeri MR, et al. Use of intravenous esmolol to predict efficacy of oral beta blocker therapy in patients with neurocardiogenic syncope J Am Coll Cardiol 1992;19:402-408.[Abstract] 4. Natale A, Newby KH, Dhala A, Akhtar M, Sra J. Response to beta blockers in patients with neurocardiogenic syncope: how to predict beneficial effects J Cardiovasc Electrophysiol 1996;7:1154-1158.[Web of Science][Medline] 5. Cox MM, Perlman BA, Mayor MR, et al. Acute and long-term beta-adrenergic blockade for patients with neurocardiogenic syncope J Am Coll Cardiol 1995;26:1293-1298.[Abstract] 6. Gielerak G, Kozlowski D, Dluzniewska E, Roszczyk A, Cholewa M. Value of propranolol-induced heart rate and blood pressure changes in predicting results of tilt testing Kardiol Pol 2003;58:98-108.[Medline] 7. Gielerak G, Makowski K, Cholewa M. Prognostic value of head-up tilt test with intravenous beta-blocker administration in assessing the efficacy of therapy in patients with vasovagal syncope Ann Noninvasive Electrocardiol 2005;10:65-72.[CrossRef][Web of Science][Medline]
Related Article
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Reply
- Maw Pin Tan and Steve W. Parry
J. Am. Coll. Cardiol. 2008 51: 2372-2373.
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