Shortened Head-Up Tilting Test Guided by Systolic Pressure Reductions in Neurocardiogenic Syncope

Background—Asymptomatic reductions in arterial pressure have been reported to occur before the onset of tilt-induced syncope. We investigated the predictive value of these reductions for a positive tilt result. Methods and Results—In a first study, 238 consecutive healthy subjects with unexplained syncope underwent a passive tilt table test. Finger systolic arterial pressure (SAP) recordings made it possible to calculate how many of the beat-to-beat SAP values during the first 15 minutes of tilt were lower than the lowest value recorded at baseline. Neurocardiogenic syncope was diagnosed in 73 subjects; 28 fainted after 15 minutes of tilt and experienced more pressure reductions than did the subjects with a negative test (328400 versus 119284; P0.01). More than 14 SAP reductions during the first 15 minutes of tilt allowed us to predict a positive test with 93 % sensitivity, 58 % specificity, and positive and negative predictive values of 28 % and 98%, respectively. In a second prospective study (80 consecutive subjects), the online analysis of this criterion by visually inspecting a Finapres monitor showed 80 % sensitivity, 85% specificity, and positive and negative predictive values of 57 % and 94%. Conclusions—In healthy subjects with unexplained syncope, the evaluation of SAP reductions during the first 15 minutes of tilt is a marker of systolic pressure instability preceding syncope and constitutes a simple and good predictor of tilt outcome that could be used to guide test duration. (Circulation. 2002;105:146-148.) Key Words: blood pressure syncope cost-benefit analysi