Key result
Nitroglycerine-provoked vasovagal syncope exhibited significantly higher sample entropy of systolic blood pressure just before syncope compared to spontaneous passive syncope (0.8 vs 0.51, p=0.0008).
Why the study?
Does the complexity of hemodynamic responses differ between patients with vasovagal syncope provoked passively versus those provoked by nitroglycerine during a tilt test?
Observational (n=80)
No
Does the complexity of hemodynamic responses differ between patients with vasovagal syncope provoked passively versus those provoked by nitroglycerine during a tilt test?
Hemodynamic signal complexity, particularly blood pressure sample entropy, differs significantly just before syncope between patients with passive versus nitroglycerine-provoked vasovagal syncope.
Answers are grounded in this paper and cite their sources.
Differences between passive and provoked tilt responses warrant interpretive caution; leaves open standardization of protocols for vasovagal syncope diagnosis.
The paper presents a comparison of vasovagal syndrome occurrence in a head up tilt table test between patients with a positive result of passive tilt test and those with a positive result after pharmacological provocation. The study group consisted of 80 patients: 57 patients who experienced syncope in the passive phase of the test (43 women (aged: 35.6 ± 16.2) and 14 men (aged: 41.7 ± 15.6) and 23 patients who experienced syncope after pharmacological provocation (17 women (age: 32.3 ± 12) and 6 men (age: 43 ± 15). The main investigation was based on the assessment of monitored signals complexity: heart rate, blood pressure and stroke volume. The analysis of complexity in chosen measurement phases was performed with Sample Entropy. The investigation showed that the reactions of autonomic nervous system during tilt test and before syncope are similar for positive result of passive tilt test and positive result of tilt test with provocation. The differences in supine position occurred only in analysis based on impedance measurement (SV: p = 0.01). Significant differences were denoted for all signals just before the syncope (RRI, sBP, dBP: p = 0,00001 and SV: p = 0.01). In analysis of signals complexity the significant differences occurred just before the syncope for Sample Entropy of blood pressure (SampEn (sBP): p = 0.0008, SampEn (dBP): p = 0,0001).
No takes yet. Share an insight, caveat, or question.
Buszko et al. (2018) conducted an observational in Vasovagal syncope (n=80). Nitroglycerine provocation during head-up tilt test vs. Passive head-up tilt test (spontaneous syncope) was evaluated on Sample Entropy of systolic blood pressure (SampEn sBP) just before syncope (p=0.0008). Nitroglycerine-provoked vasovagal syncope exhibited significantly higher sample entropy of systolic blood pressure just before syncope compared to spontaneous passive syncope (0.8 vs 0.51, p=0.0008).
Synapse has enriched 10 related papers. Consider them for comparative context: