Tilt-induced vasovagal syncope and psychogenic pseudosyncope: Overlapping clinical entities

To describe the combination of tilt-induced vasovagal syncope (VVS) and psychogenic pseudosyncope (PPS) and aid its clinical recognition.We identified people with tilt-induced VVS/PPS from 2 tertiary syncope referral centers. For each case, 3 controls with tilt-induced VVS were selected at random from the same center. Clinical characteristics were compared between both groups adjusting for multiple comparisons.Of 1,164 tilt-table tests, 23 (2%) resulted in VVS/PPS; these 23 cases were compared with 69 VVS controls. VVS and PPS coincided more often than chance would predict: 2% vs 0.6%, p0.001. Typical VVS prodromes and triggers were reported in all people with VVS/PPS and in controls with VVS. Attack frequency was significantly higher in the VVS/PPS (2 per month, range 0.1-60) than in the VVS group (0.25 per month, range 0.02-4; p0.001). Delayed recovery of consciousness was more frequently reported in the VVS/PPS group (likelihood ratio [+LR] 8.14, 95% confidence interval [CI] 3.94-16.84), as well as episodes without prodromes (+LR 5.57, 95% CI 2.53-12.26), atypical triggers (+LR 5.00, 95% CI 2.04-12.24), eye closure (+LR 3.75, 95% CI 1.68-8.35), and apparent loss of consciousness1 minute (+LR 2.86, 95% CI 1.98-4.13).VVS/PPS presents with a complex phenotype. High attack frequency, delayed recovery of consciousness, apparent loss of consciousness1 minute, ictal eye closure, atypical triggers, and the absence of prodromes may serve as indicators that PPS coincides with VVS.