Tilt testing for syncope: a reappraisal

PURPOSE OF REVIEW: Tilt-table tests have provided a diagnostic window on the most common cause of syncope, the common faint. The purpose of this review is to summarize the major contributions of tilt tests and provide a critical assessment of the true validity and usefulness of this diagnostic test. RECENT FINDINGS: Tilt-table tests have provided mixed benefits in the field of neurally mediated syncope. They have greatly improved informed care of syncope patients and have led to a revived interest in the field. They have provided study populations having at least one objective finding in common for diagnostic studies, long-term observational studies, and randomized clinical trials. Tilt tests have been used as platforms for physiologic studies and pilot treatment studies. However, more specific benefits have proven illusive. The main problem is that the neurally mediated syncope syndrome is defined by the test, rather than by evidence-based and widely accepted clinical criteria. Tilt tests have a complex mix of significant methodological variables, have not been validated against gold standard populations, are only moderately reproducible, do not provide prognostic predictive power, and have not been shown useful in selecting efficacious therapies. It may be difficult to achieve important advances in the field until a clinical reflex syncope syndrome is defined by evidence-based diagnostic criteria. SUMMARY: Tilt tests have made neurally mediated syncope amenable to clinical study, but their true usefulness will only be known when an evidence-based, widely accepted definition of this syndrome is developed.