Underestimation of sensorimotor task-induced blood-pressure changes by posttask sphygmomanometry.

For assessment of cardiovascular effects of sensorimotor work, blood pressure is commonly measured by arm sphygmomanometry. A technique introduced by Penaz makes it feasible to monitor blood pressure noninvasively and continuously from the finger artery which measures give high correlations with intraarterial measurement. This study compared blood-pressure changes induced by a standard sensorimotor task using sphygmomanometry and the Penaz-method. It was investigated whether sphygmomanometrically recorded blood pressure can be used to estimate task-induced blood-pressure changes and whether inflating the cuff to different maximum pressures induces blood-pressure changes. 46 normotensive individuals were randomly assigned to the discomfort group (maximum arm-cuff pressure of 280 mmHg) or to the control group (maximum arm-cuff pressure of 160 mmHg). The experiment consisted of six tasks of 4 min. each. Results indicated that sphygmomanometries under-estimated task-induced blood-pressure changes and that phasic systolic and diastolic blood-pressure elevations during the task were leveled off shortly after the end of the task. Effects of 'cuff-inflation hypertension' were not found. The Penaz-method appears to be more appropriate than sphygmomanometry if dynamic aspects of blood pressure are of interest.