Objective: Development and testing of cuffless blood pressure (BP) devices requires methods to increase and decrease BP. This is also required by cuffless BP validation standards. Pharmacological interventions, whilst successful, are not always feasible for all subpopulations or research settings. Non-pharmacological approaches for increasing BP are available, however, methods for decreasing BP are not well described. This study investigates the hyperemic response following bilateral leg-cuff ischemia as a method for acute BP lowering.
Design and method: Participants (n=8, 24±8 years, 6 female) had their BP measured by continuous (finger, Peňáz technique) and intermittent (brachial cuff, oscillometric) methods before, during and following 3-minute leg-ischemia with the participant in an upright position. Total peripheral resistance (TPR) and cardiac output (CO) were calculated from finger BP waveforms. Maxima and minima responses in the variables were extracted and compared to resting conditions by repeated measures analysis of covariance.
Results: During the hyperemic period, systolic BP decreased by -22±3 mmHg (finger) and -6±1 mmHg (brachial). Diastolic BP decreased by -14±5 mmHg (finger) and -4 ±1 mmHg (brachial). Calculated TPR and CO varied, with both decreasing by half and almost doubling during the hyperemic response period.
Conclusions: Leg-cuff ischemia provides a controlled, non-pharmacological intervention for decreasing systemic arterial BP. This removes some of the limitations in testing, development and validation of cuffless BP techniques and devices.