Syncopal patients without prodromes exhibit a diverse pattern of adenosine release during head-up tilt test

Abstract Background/Introduction In a significant proportion of patients with neurally-mediated syncope (NMS), the mechanism remains largely undetermined. Adenosine has been proposed as central humoral factor in various forms NMS: high Plasma Levels (ADP) are encountered vasovagal (VVS), low ADP non-prodromes (NPS), while situational SS less well determined. Purpose We sought to assess different clinical syncope, an emphasis on presence or absence prodromal symptoms, relation between and outcomes Head-Up Tilt Table Test (HUTT) test (ADT). Methods Patients types NMS (n=124), i.e., VVS, NPS, SS, were investigated using standard protocol including HUTT ADT. During HUTT, was measured supine position, at table tilting, syncope. Results Baseline did not differ among groups. higher NPS compared VVS (1.55±1.29 vs 0.16±0.05 μM, p=0.03) (0.15±0.05 p=0.02). increased from position time (0.47±0.25 1.55±1.29 p=0.04). only tilt (0.23±0.04 0.35±0.10 μMu, p=0.02), change any stage HUTT. associated cardioinhibitory (OR 3.40, 95% CI 1.05 9.56, p=0.04) positive ADT 4.22, 1.47 11.46, p=0.012). Conclusion(s) A distinct pattern increase is noted during suggesting that excessive may play key role triggering this type presentation independently baseline ADP. Cardioinhibition prevails without clear adenosine involvement. Such observations contribute enhanced understanding pathophysiology which offer possibility tailor management approach appropriately. Funding Acknowledgement Type funding sources: None.