University of Michigan
Department of Pediatrics
Evidence-Based Pediatrics Web Site

Question

• 16 y/o male presented with recurrent episodes of syncope and was found to have a normal EKG, normal cardiac echo, normal EEG, was on no medications, and was not orthostatic. In children or adolescents with syncope of unknown etiology, how good is the tilt table test at diagnosing neurocardiogenic syncope?

Clinical Bottom Lines

• The tilt table test has not been shown to be a sensitive or specific test in children and adolescents. It is expensive, invasive, and the results are not likely to change your management. 
• Pediatric tilt table test is relatively non-specific in the control population with 52% false positive rate in one study. There is low concordance of consecutive tilt tests in the control population. The sensitivity and specificity of the test were 77% and 48% respectively,¹ resulting in LR+ of 1.5 and LR- of 0.48.

Summary of Key Evidence

1. In one retrospective study of 89 children, the sensitivity and specificity of the test were found to be 77% and 48% respectively.  Isoproterenol did not increase the false positive rate in the control population. Shorter tilt period (20 minutes vs. 30 minutes) improved the specificity of the test to 70% but decreased its sensitivity to 58%.¹
2. In another study of 30 patients, the sensitivity and specificity were found to be 75% and 90%. However, this study was limited by significant population bias in that there was a 40% positive family history in the positive responders compared with 0% family history in negative responders and the control population.³
3. One retrospective study found no difference in the recurrence of syncope or the use of conservative measures vs. medications with the results of the tilt table test. They concluded that patients that have history and exam consistent with the diagnosis of neurocardiogenic syncope have comparable outcomes regardless of the tilt table test results.⁴
4. Oral fluid therapy was shown to be an effective treatment for neurocardiogenic syncope diagnosed by positive tilt table tests in children and adolescents. A trial of fluids may obviate the need for further diagnostic testing.⁵

Additional Comments

• At least 15% of all children will experience a syncopal episode before the end of the second decade of life. Neurocardiogenic syncope is reported to be the most common etiology of syncope, accounting for 1/3 of all cases.²
• Exact sensitivity and specificity of tilt table testing are difficult to assess, as the true cause of syncope is unknown, and there is presently no “gold” standard test for the diagnosis of neurocardiogenic syncope.
• Universally accepted tilt table protocol does not exist in children and adolescents.

Citation

1. Berkowitz JB, Auld D, Hulse JE, Campbell RM. Tilt table evaluation for control pediatric patients: Comparison with symptomatic patients. Clinical Cardiology 1195; 18:521-525.
2. Ozme S, Alehan D, Yalaz K. Causes of syncope in children: A prospective study. Int J Cardiol 1993; 40: 111-114.
3. Alehan D, Celiker A, Ozme S. Head-Up tilt test: A highly sensitive, specific test for children with unexplained syncope. Pediatric Cardiology 1996; 17:86-90. 
4. Levine MM. Neurally mediated syncope in children: Results of tile testing, treatment, and long-term follow-up. Cardiology 1999; 20:331-335.
5. Younoszai AK, Franklin WH, Chan DP, Cassidy SC, Allen HD. Oral fluid therapy: A promising treatment for vasodepressor syncope. Arch Pediatric Adolesc Med 1998; 152: 165-168. 

CAT Author: Shadi Imani Miller, MD

CAT Appraisers: Robert Schumacher, MD

Date appraised: November 26, 2001