Contribution of Head-Up Tilt Testing and ATP Testing in Assessing the Mechanisms of Vasovagal Syndrome

Flammang, Daniel; Erickson, Mark; McCarville, Sally E.; Church, Timothy R.; Hamani, Djamel; Donal, Erwan

doi:10.1161/01.cir.99.18.2427

Cited by 36 publications

(24 citation statements)

References 28 publications

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“…[3][4][5]10 Furthermore, the present study suggests that these patients can be identified, and if further studies could show that syncope is reproduced by exogenous adenosine infusion in these patients, this will favor a causal mechanism of elevated adenosine plasma levels.…”

Section: Study Limitationsmentioning

confidence: 56%

“…Several investigators have hypothesized that adenosine is an important modulator that can trigger vasovagal syncope in susceptible patients. [3][4][5]9 Indeed, the injection of exogenous adenosine or ATP during head-up tilt testing provoked a vasovagal response in those patients with syncope, with a yield comparable to that of isoproterenol. [3][4][5]10 Adenosinesensitive syncope has been identified as a cause of syncope in some patients with an abnormal response to an ATP test.…”

Section: Saadjian Et Al Endogenous Adenosine In Vasovagal Syncopementioning

confidence: 99%

“…[3][4][5]9 Indeed, the injection of exogenous adenosine or ATP during head-up tilt testing provoked a vasovagal response in those patients with syncope, with a yield comparable to that of isoproterenol. [3][4][5]10 Adenosinesensitive syncope has been identified as a cause of syncope in some patients with an abnormal response to an ATP test. 9 More recently, Brignole et al 10 suggested that ATP and head-up tilt tests may identify different patient populations with syncope.…”

Section: Saadjian Et Al Endogenous Adenosine In Vasovagal Syncopementioning

confidence: 99%

“…1 Tilt testing is an established tool for the evaluation of patients with unexplained syncope. 2 Several reports [3][4][5] have shown that exogenous adenosine or ATP is an effective agent for the provocation of neurally mediated syncope in susceptible patients, with a diagnostic yield comparable to that of tilt testing. Therefore, it appeared likely that adenosine might be an endogenous modulator that may play a role in triggering vasovagal syncope in predisposed patients.…”

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confidence: 99%

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Role of Endogenous Adenosine as a Modulator of Syncope Induced During Tilt Testing

et al. 2002

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Background-Previous reports that used head-up tilt testing and adenosine administration have suggested that adenosine may be an important endogenous mediator that may trigger a vasovagal response in susceptible patients. However, little is known regarding endogenous adenosine plasma levels (APLs) during vasovagal syncope provoked by tilt testing. The aim of this study was to determine whether APLs differ in patients with a positive head-up tilt test compared with those with a negative test and whether APLs are modified during tilt-induced vasovagal syncope. Methods and Results-APLs (meanϮSEM) were measured during head-up tilt test in 26 patients who presented with unexplained syncope. In the 15 patients with a negative test, APLs were 0.39Ϯ0.03 mol/L at baseline, 0.22Ϯ0.03 mol/L immediately after tilting, and 0.44Ϯ0.03 mol/L after 45 minutes. APLs were significantly higher in the 11 patients with a positive test (2.66Ϯ0.67 mol/L at baseline and 3.22Ϯ0.85 mol/L immediately after tilting) than in those with a negative test. During tilt testing-induced syncope, APLs increased to reach 4.03Ϯ0.66 mol/L (ie, a 52% increase compared with baseline levels; PϽ0.02). Furthermore, we observed that the higher the APL during syncope, the shorter the time to appearance of symptoms. Conclusions-This study showed that APLs were higher in patients with a positive tilt test than in patients with a negative test and that they increased during tilt testing-induced syncope. These observations suggest that adenosine release may be involved in the triggering mechanism of syncope induced during tilt testing. (Circulation. 2002;106:569-574.)

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Section: Study Limitationsmentioning

confidence: 56%

Section: Saadjian Et Al Endogenous Adenosine In Vasovagal Syncopementioning

confidence: 99%

Section: Saadjian Et Al Endogenous Adenosine In Vasovagal Syncopementioning

confidence: 99%

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confidence: 99%

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Role of Endogenous Adenosine as a Modulator of Syncope Induced During Tilt Testing

et al. 2002

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“…Both ATP and tilt testing were performed in patients with unexplained syncope in two studies [208,209] . Although some overlap of positive responses was observed, this was limited to no more than 20% of cases.…”

Section: Relationship Between Atp and Tilt Testingmentioning

confidence: 99%