EDITORIAL COMMENT Tilt Methodology in Reflex Syncope: Emerging Evidence

Tilt-table testing for patients with unexplained syncope was first described in 1986 by Kenny et al. (1) and later by Almquist et al in the U.S. (2). The tilt protocols proposed differed, with the Westminster Protocol favoring prolonged passive tilt alone (1,3) and the Minneapolis Protocol routinely using isoproterenol provocation (2). Although there is now widespread acceptance of tilt testing, many patients with unexplained syncope still remain undiagnosed (4,5), and a drug challenge during tilt has been part of efforts to raise the sensitivity of the test. Unfortunately, such efforts inevitably reduce specificity, which all tilt protocols lack to a degree (2,3,5,6). During development of the test over the last decade, there is still no universally accepted protocol. Also, many published series have included very different patients, and these two factors together have resulted in uncertainly about the true value of the test. There is controversy over the angle of tilt, the duration of tilt, and the role of drug provocation. Further, it is still unclear what triggers a spontaneous or tilt-induced reflex syncope, why the hemodynamic responses are so variable, why the test is often not reproducible, and what the treatment of the condition should be, if needed at all!