Correlation of postural blood pressure test and head-up tilt table test in patients with vasovagal syncope

BACKGROUND: Vasovagal syncope is triggered by complex cerebral and cardiovascular reflex mechanisms leading to general vasodilatation and bradycardia resulting in cerebral hypoperfusion.

METHODS: We prospectively studied the correlation of postural blood pressure test (PBT) and head-up tilt table test (TT) in patients with recurrent vasovagal syncope. Sixty-eight patients (37 male, 52.4 +/- 18.6 years) were included in the trial. They were asked to participate in a PBT and a TT. Independent samples t-test, ANOVA and Fisher's exact test were used for statistical analysis. p values <0.05 were considered statistically significant.

RESULTS: Thirty patients (44%) showed a positive TT and thirty-four patients (50%) had a positive PBT. PBT did not show any correlation with TT, although pathophysiological mechanisms in vasovagal syncope and orthostatic hypotension are supposed to be similar. Furthermore neither TT nor PBT nor their combination had any predictive value for the patient's risk of syncope recurrence.

CONCLUSIONS: TT and PBT are not correlated with each other. Both investigations cannot predict the patient's risk of syncope recurrence.