A COMPARISON OF NONINVASIVE CONTINUOUS FINGER BLOOD-PRESSURE MEASUREMENT (FINAPRES) WITH INTRAARTERIAL PRESSURE DURING PROLONGED HEAD-UP TILT

Simultaneous intra-radial and non-invasive (Finapres, Ohmeda) blood pr essures were compared during prolonged head-up tilt, in eight patients (mean age 49 years) with malignant vasovagal syncope. Twelve tilts we re performed, of which eight resulted in vasovagal syncope. The mean b ias (difference between Finapres and intra-arterial pressures) for sys tolic pressure was +0.7 mmHg (standard deviation 11.3 mmHg) and for di astolic pressure was +5.4 mmHg (standard deviation 7 mmHg). The within -tilt precision (standard deviation of the bins) of the non-invasive m easurements varied between 2.9-12.4 mmHg (median 4.5 mmHg) for systoli c comparisons, and 1.6-8.4 mmHg (median 4.4 mmHg) for diastolic compar isons. In all but one tilt highly significant positive increases in bo th systolic (median 7.1 mmHg) and diastolic bias (median 8.1 mmHg) occ urred on tilt with respect to resting pre-tilt levels. independent of the absolute level of agreement, the non-invasive measurements followe d changes in intra-arterial pressure closely, with 89% of beat-to-beat changes in systolic pressure, and 95% of beat-to-beat changes in dias tolic pressure followed to within +/- 2 mmHg. This study suggests that the Finapres is well suited for use during diagnostic tilt testing, d emonstrating an acceptable within-tilt precision and closely following pressure changes during vasovagal syncope.