Comparison of a shortened isosorbide dinitrate-potentiated head-up tilt testing with the conventional protocol: Tolerance and diagnostic accuracy

Paula G. MacEdo, Samuel J. Asirvatham, Leila Maia, Eustáquio Ferreira Neto, André Zanatta, José Sobral Neto, José Roberto Barreto, Henrique Maia, Edna M. Oliveira, Jairo M. Da Rocha, Carla S. Margalho, Tamer Seixas, Ayrton Peres, Leopoldo Santos-Neto, Luiz R. Leite

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


Background: The head-up tilt test (HUT) is widely used to investigate unexplained syncope; however, in clinical practice, it is long and sometimes not well tolerated. Objectives: To compare the sensitivity, specificity, accuracy, and patients' tolerance of a conventional and shortened HUT. Methods: Patients with a history of vasovagal syndrome (VVS) were randomized to a conventional HUT (group I) consisting of 20-minute passive tilt followed by 25 minutes after administration of sublingual isosorbide dinitrate (ISDN), or a shortened HUT (group II) where ISDN was given immediately after tilt and observed for 25 minutes. The control group consisted of age- and gender-matched subjects without VVS symptoms. A specific questionnaire to evaluate tolerance was applied. Results: Sixty patients (29 ± 10 years, 82% female) were included. In group I, 22/30 patients had a positive HUT compared to 21/30 in group II (73% vs 70%, P = 0.77). There was also no difference in the accuracy between the two protocols (63% vs 73%, P = 0.24). The time to positivity was shorter in group II (13.2 minutes vs 30 minutes, P < 0.001). Within the control group (n = 60), the frequency of false-positives was 47% and 23% for the conventional and shortened HUT, respectively (P = 0.058). After conventional HUT, 65.2% subjects reported that the test was too long compared to 25% subjects after the shortened HUT (P = 0.002). Conclusion: In this study, the HUT without passive phase was not inferior to the conventional HUT regarding sensitivity, specificity, and accuracy. Furthermore, the shortened ISDN-potentiated protocol allowed faster diagnosis and was better tolerated. (PACE 2012; 35:1005-1011)

Original languageEnglish (US)
Pages (from-to)1005-1011
Number of pages7
JournalPACE - Pacing and Clinical Electrophysiology
Issue number8
StatePublished - Aug 2012


  • Head-up tilt testing
  • diagnostic accuracy
  • syncope
  • vasovagal syndrome

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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