Background: The Finometer (FMS, Finapres Measurement Systems, Arnhem, Netherlands), which is the improved successor of the Finapres (TNO Biomedical Instrumentation, Amsterdam, Netherlands), measures finger arterial blood pressure non-invasively and computes other cardiovascular parameters from the computed aortic-flow waveform. The usability of the Finometer would depend on whether it is sensitive enough to detect small cardiovascular changes. The aim was therefore to determine the sensitivity of the Finometer regarding acute and longer-term cardiovascular changes.
Design and methods: The sensitivity of the Finometer regarding the acute effect of 200 mg caffeine was determined with a double-blind, placebo-controlled crossover study which included 38 young male subjects. Finometer recordings were performed during four occasions at fasting level and after 30 min of ingestion. To evaluate the sensitivity of the Finometer in recording longer-term effects of a daily dosage of 1000 mg vitamin C, 800 mg vitamin E and 10 mg folic acid, 14 young males took placebo and 17 took the vitamins for 12 weeks in a double-blind study. Two recordings were performed at baseline and two after 12 weeks.
Results: After caffeine ingestion significantly (P<0.05) higher systolic, diastolic and mean blood pressure values than resting values were obtained. The arterial compliance was significantly lower after caffeine ingestion, whereas heart rate, peripheral resistance, stroke volume and cardiac output did not change significantly. No differences were shown after intake of placebo. Concerning the effects of vitamin intake, the vitamin group indicated a significant decrease in systolic blood pressure (P=0.03) whereas the placebo group indicated no significant differences after 12 weeks.
Conclusions: The results suggest that the improved Finometer might be a sensitive instrument in the recording of relative small acute and longer-term changes in cardiovascular function, but more studies are necessary before final conclusions can be drawn.