In the present study, we studied whether analysis of the FAP (finger arterial pressure) waveform during supine rest discriminates subjects with recurrent VVS (vasovagal syncope) from healthy controls. Signal-averaged FAP waveforms (Finapres) were obtained in 32 head-up tilt-test-positive subjects with recurrent VVS (35 +/- 13 years) and in 32 sex- and age-matched healthy controls. The DT (time delay) between the systolic and diastolic peaks of the FAP waveform was measured and large artery SI (stiffness index) was calculated as a ratio of body height and DT. VVS patients had significantly shorter DT compared with controls (303 +/- 31 compared with 329 +/- 18 ms; P < 0.001) and higher SI (5.79 +/- 0.70 compared with 5.20 +/- 0.36 m/s; P < 0.001). The differences were independent of heart rate and blood pressure. SI > 5.45 m/s identified subjects with syncope with a sensitivity of 72% and a specificity of 84%. Age-corrected DT (cDT = DT + age-350) identified subjects with syncope with a sensitivity of 75% and a specificity of 84%. Combined use of cDT <0 ms and SI > 5.45 m/s increased sensitivity and specificity to 81% and 96% respectively. The discriminative power of FAP descriptors improved further when younger subjects were excluded. In subjects aged >30 years (median age), the combination of cDT and SI identified subjects with syncope with a sensitivity of 93% and a specificity of 100%. These results suggest that FAP descriptors during supine rest might be useful in the diagnosis of VVS in middle-aged subjects.