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Comparison of Trinitroglycerin and Adenosine As Provocative Agents for Head-Up Tilt Test in Patients With Unexplained Syncope: A Semi-Crossover Randomized Clinical Trial With Prospective Follow-Up Publisher Pubmed



Tajdini M1 ; Aminorroaya A2, 3 ; Rahimi B4 ; Mortazavi SH1 ; Vasheghani Farahani A1 ; Sadeghian S1 ; Easapour Moghadam M1 ; Soltani D1 ; Bozorgi A1
Authors
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Authors Affiliations
  1. 1. Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran
  2. 2. Students’ Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
  3. 3. Universal Scientific Education and Research Network, Tehran, Iran
  4. 4. Department of Cardiology, Urmia University of Medical Sciences, Urmia, Iran

Source: Journal of Interventional Cardiac Electrophysiology Published:2021


Abstract

Purpose: Head-up tilt test (HUTT) is a reasonable diagnostic evaluation for patients with suspected vasovagal syncope; however, its lengthy duration is a remarkable limitation. Although adenosine (AD), as an alternative provocative agent, is a promising option for tackling this shortcoming, it received little appreciation in the literature. We aimed to compare the efficacy and the time to elicit a positive response to HUTT for sublingual trinitroglycerin (TNG) and intravenous AD. Furthermore, we evaluated patients’ outcomes in the follow-up. Methods: Patients with a chief complaint of transient loss of consciousness (TLOC) were evaluated. We randomized patients with the diagnosis of unexplained syncope after diagnostic evaluations, to undergo TNG-augmented HUTT or AD-augmented HUTT. They were crossed over to receive the other medication in case of negative response to the test. In the follow-up, we evaluated traumatic and non-traumatic TLOCs, hospitalization due to syncope, and death in patients. Results: We randomized 132 patients (41.70 ± 19.37 years, 52.3% female) to receive TNG (n = 66) or AD (n = 66). Respectively, the positivity rate of TNG and AD for the first and the crossover-HUTT was 31.1% and 26.7%, and 20.5% and 26.2% with no statistically significant differences in both tests (P ˃ 0.50). The time to positive response was significantly shorter for AD than TNG (P < 0.001). In the follow-up, re-admission was significantly more prevalent in HUTT-negative patients compared to HUTT-positive patients (P = 0.04). Conclusions: We found that diagnostic yield of TNG and AD in HUTT is comparable, while AD acts 4 times faster than TNG in evoking a vasovagal response. © 2019, Springer Science+Business Media, LLC, part of Springer Nature.