Measuring orthostatic hypotension with the Finometer device: is a blood pressure drop of one heartbeat clinically relevant?

OBJECTIVE: The role of orthostatic hypotension in falls in older people is generally accepted. Because of the high degree of intra- and interobserver variability in conventional measurements of orthostatic hypotension, application of continuous measurement systems has been proposed. The clinical relevance of a blood pressure drop lasting one heartbeat, however, is unknown. We therefore investigated which time average of continuous-finger-blood-pressure measurement (Finometer) showed the best association between orthostatic hypotension and falls. This was also compared with conventional sphygmomanometer measurements. METHODS: In 217 geriatric outpatients supine and standing (finger) blood pressure to diagnose orthostatic hypotension was monitored with Finometry (beat-to-beat and 1, 5, 10, 15, 20 and 30 s averages) and sphygmomanometry. History of fall incidents (previous year) was registered. RESULTS: The best association (C=0.22, P=0.003) with falls history was found for the 5-s average of Finometry, whereas falls and orthostatic hypotension assessed by sphygmomanometry did not correlate. The odds ratio of a fall according to orthostatic hypotension using the 5-s average was 2.54 (95% CI: 1.37 to 4.71). CONCLUSIONS: Orthostatic hypotension and falls are correlated when using Finometry, with the best association found when using 5-s averages. As the etiology of falls is often multifactorial, orthostatic hypotension and falls are poorly correlated, irrespective of the method or time average that is applied.