Formal analysis of the optimal duration of tilt testing for the diagnosis of neurally mediated syncope
| Autor: | Marc A. Scheiner, David J. Slotwiner, Suneet Mittal, Steven M. Markowitz, Bruce B. Lerman, Kenneth M. Stein |
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| Rok vydání: | 2001 |
| Předmět: |
Male
medicine.medical_specialty Time Factors Provocation test Population Neurally-mediated syncope Sensitivity and Specificity Severity of Illness Index Tilt-Table Test Internal medicine Prevalence Syncope Vasovagal medicine Humans education Retrospective Studies education.field_of_study business.industry Gold standard (test) Middle Aged Control subjects Surgery Tilt (optics) Duration (music) Data Interpretation Statistical Cardiology Female Test performance Cardiology and Cardiovascular Medicine business |
| Zdroj: | American Heart Journal. 141:282-288 |
| ISSN: | 0002-8703 |
| DOI: | 10.1067/mhj.2001.112236 |
| Popis: | Background Although tilt testing has emerged as the test of choice for assessing patients with suspected neurally mediated syncope, the optimum duration of tilt testing is poorly defined. This in part relates to the absence of a gold standard to assess test performance. Objective Our purpose was to formally estimate the effects of varying duration of drug-free tilt testing on test performance in diagnosing neurally mediated syncope. Design If a test's specificity is known, then in the absence of a gold standard an imputed (estimated) sensitivity may be calculated on the basis of the observed diagnostic yield in a given population as a function of assumed population prevalence. We determined the relationship of specificity to drug-free tilt test duration by use of data from 11 previous studies reporting the results of drug-free tilt testing in a total of 435 control subjects (60 to 80 degrees of tilt, footboard support, 15- to 60-minute duration). Data (weighted for study size) were fit to an exponential function relating specificity to tilt duration. Test yield was evaluated as a function of tilt duration in 213 consecutive patients referred to our laboratory for the evaluation of suspected neurally mediated syncope who underwent passive tilt testing for up to 30 to 60 minutes. Results The estimated specificity of tilt testing was 94% at 30 minutes, 92% at 40 minutes, and 88% after 60 minutes of passive tilt. The cumulative yield of tilt testing was only 17% at 30 minutes, 22% at 40 minutes, and 28% after 60 minutes. On the basis of an estimated population prevalence of 25% to 50% in this referral population, imputed sensitivity is 27% to 48% at 30 minutes, 36% to 64% at 40 minutes, and 43% to 74% after 60 minutes of passive tilt. The overall diagnostic accuracy was not strongly influenced by tilt duration beyond 30 minutes and ranged from 60% to 84%. Conclusions Passive tilt testing (ie, tilt testing without pharmacologic provocation) for durations of up to 60 minutes has limited sensitivity for diagnosing neurally mediated syncope. For populations with a pretest likelihood of 25% to 50%, test results are inaccurate in one to two fifths of patients. (Am Heart J 2001;141:282-8.) |
| Databáze: | OpenAIRE |
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