The role of adrenomedullin and galanin in recurrent vasovagal syncope: a case control study

Abstract

Aims. Orthostatic stimuli are known to elicit changes in vasoactive peptide levels. The hypothesis of no difference in adrenomedullin and/or galanin levels in patients with recurrent vasovagal syncope and healthy controls was tested in a passive 35-min head-up tilt test (HUTT). Methods. Twenty eight persons (14 patients and 14 healthy controls) were tested in a 35-min/60° head-up tilt test with telemetry monitoring. Three blood samples were evaluated for each person during the HUTT. Plasma levels of adrenomedullin and galanin were analysed by the Kruskal-Wallis test for all sampling periods. Vagal influence was indirectly assessed by the break index.Results. There were no significant differences between groups in median values for either adrenomedullin or galanin plasma levels (all 6 p-values were greater than 0.4). For adrenomedullin, no significant difference between groups was found. For galanin, the rate of change between the 1st and 2nd measurement was significantly greater for patients (P=0.04), regardless of HUTT result but between the 2 nd and 3 rd measurement it was insignificant (P=0.36). In the group of positive cases, the break index increased significantly (P=0.02). Conclusion. We confirmed that there is a different galanin secretion pattern during orthostatic provocation in patients with recurrent vasovagal syncope than healthy individuals. For adrenomedullin, no significant difference was found. A significant increment of the break index confirmed increased vagal influence in the subgroup of positive cases.

Neuropeptides and peptide hormones in syncope and orthostatic intolerance

“…Plasek et al [20] obtained slightly different results from the Bondanelli et al study [19]. GAL increase differentiated cases from controls better than it differentiated positive and negative responses to HUTT, i.e.…”

“…In this regard, changes in circulatory catecholamines have tended to be of greatest interest given the apparent association of VVS with anxiety or stress states [8][9][10][11][12][13][14]. However, the potential role of NPs has also attracted attention; specifically, BNP [8], vasopressin (VP) [8,15,16], atrial natriuretic peptide (ANP) [8,17], adrenomedullin (ADM) [17][18][19], galanin (GAL) [19,20], and endothelin-1 (ET-1) [17,[21][22][23]. A summary of the primary physiologic effects of these NPs is shown in Table 2.…”

Neurohormones in the Pathophysiology of Vasovagal Syncope in Adults

“…The role of ADM in VVS has been the subject of several reports but currently its impact remains unclear. Plasek et al (40) did not observe a significant difference in ADM levels in a study comparing of 14 HUT-positive patients with a cohort of 14 HUT-negative control group. Gajek et al (41) observed ADM to rise substantially in patients who developed VVS during the passive phase of HUT (but not if nitroglycerin-induced) On the other hand, Hamrefors et al (42) observed that in patients >40 years of age, lower supine MR-pro-ADM predicted asystolic VVS on HUT, although orthostatic levels of the biomarker were not assessed.…”

“…Plasek et al (40) obtained slightly different results. These authors observed an increase in plasma galanin for VVS patients during HUT, regardless of whether they developed syncope or not during the test.…”