Comparison of the Omron HeartGuide to the Welch Allyn ProBP 3400 blood pressure monitor.

Hypertension affects approximately 100 million U.S. adults and is the leading single contributing risk factor to all-cause mortality. Accurate blood pressure (BP) measurement is essential in the treatment of BP, and a number of devices exist for monitoring. Recently, a new watch-type design was released, the Omron HeartGuide (BP8000), with claims to provide clinically accurate BP measurement while also tracking activity and sleep similar to smart watches. The aim of this research was done in two studies: (1) evaluation of the HeartGuide device for measurement of resting BP and heart rate (HR); and (2) assessment of the HeartGuide for BP, HR, step-counting and sleep monitoring during activities of daily living. Study 1 compared the Omron HeartGuide to the previously validated Welch Allyn ProBP 3400 following a modified version of the Universal Standard for validation of BP measuring devices set by the AAMI/ESH/ISO. While resting HR measured by the HeartGuide was similar to Welch Allyn measures, both systolic and diastolic BP were significantly lower ( P ≤0.001), with differences of 10.4 (11.1) and 3.2 (10.0) mmHg, respectively. Study 2 compared HeartGuide measures to Welch Allyn measures for BP, HR, steps and sleep during various body positions (supine, seated, standing), physiological stressors (cold pressor test, lower body submersion, exercise), and free-living. The HeartGuide significantly underestimated BP though provided accurate HR during most conditions. It also significantly underestimated steps, but reported sleep measures similar to those subjectively reported. Based on the significant differences between the HeartGuide and Welch Allyn, our data indicate the HeartGuide is not a suitable replacement for existing BP monitors.

Acute upper and lower limb hemodynamic responses during single sessions of low- versus high-intensity inspiratory muscle strength training.

Inspiratory muscle strength training (IMST) has shown potential to improve both respiratory and cardiovascular function in health and disease. Less is known about acute hemodynamic responses to a single IMST session, therefore we assessed upper and lower limb blood flow via Doppler ultrasound in the brachial and popliteal arteries, respectively. Mean, anterograde, and retrograde blood flow (BF) and shear rate (SR) were assessed relative to baseline during low-intensity (15% maximal inspiratory pressure - PImax) and high-intensity (75% PImax) IMST. During low-intensity IMST, popliteal BF and SR were reduced by ∼10%, and brachial BF and SR were reduced by ∼40%. During high-intensity IMST, popliteal BF and SR were reduced by ∼20%, and brachial BF and SR were reduced by ∼35%. BF and SR responses were not statistically different between low-intensity and high-intensity training for either blood vessel (P > 0.05). In addition, anterograde BF and SR were significantly decreased in the brachial artery for both low-intensity and high-intensity training (P < 0.05), but not the popliteal artery (P > 0.05). Finally, during IMST retrograde BF and SR were significantly increased in both the upper and lower limbs during low-intensity and high-intensity training (P < 0.05). These data provide novel insight into the acute BF and SR responses to a single bout of IMST and may enhance our understanding of the mechanism(s) by which IMST imparts its beneficial chronic effects on cardiovascular function.NEW & NOTEWORTHY Herein, we demonstrate for the first time that upper and lower limb blood flow and shear rate patterns are altered during a single bout of IMST, at low- and high-intensity training. Specifically, anterograde blood flow and shear rate are significantly reduced in the brachial artery, whereas retrograde blood flow is significantly elevated in both the brachial and popliteal arteries. These findings provide insight into the vascular impact of IMST, which may inform future mechanistic studies.

Understanding lower limb blood flow occlusion parameters for use in field-based settings.

Reduction of blood flow to the limb using cuffs before or during exercise has become increasingly popular for training and rehabilitation. Our study tested the effects of cuff brand/width on pressures required to reach limb occlusion pressure (LOP) and developed, cross-validated, and compared accuracy of two LOP prediction equations to previously created methods. Supine LOP was determined in the distal popliteal artery using four different cuff brands/widths in 23 adult participants. Participants then had demographic and resting variables assessed, and two LOP prediction equations were developed from these variables and were compared to five previously developed models and a method using posterior tibial artery palpation for LOP assessment in an independent sample (n = 14 adult runners). For cuff comparison, the widest two cuffs had significantly lower LOP (mean ~149 mmHg) than the narrowest cuffs (mean ~176 mmHg), with the narrowest cuff unable to reach LOP. The eight methods used to predict LOP ranged in accuracy (mean absolute percent errors 3.9-23.0%), with highest accuracy in equations using mean arterial pressure (MAP) and BMI. Practitioners using blood flow reduction methods should be consistent with cuff use due to demonstrated differences across brands/widths. Equations using MAP and BMI appear best for prediction of leg LOP.