Accurate arm circumference (AC) measurement is required for accurate blood pressure (BP) readings. Standards stipulate measuring arm circumference at the midpoint between the acromion process (AP) and the olecranon process. However, which part of the AP to use is not stipulated. Furthermore, BP is measured sitting but arm circumference is measured standing. We sought to understand how landmarking during AC measurement and body position affect cuff size selection. Two variations in measurement procedure were studied. First, AC was measured at the top of the acromion (TOA) and compared to the spine of the acromion (SOA). Second, standing versus seated measurements using each landmark were compared. AC was measured to the nearest 0.1 cm at the mid-point of the upper arm by two independent observers, blinded from each other\'s measurements. In 51 participants, the mean (±SD) mid-AC measurement using the anchoring landmarks TOA and SOA in the standing position were 32.4 cm (±6.18) and 32.1 cm (±6.07), respectively (mean difference of 0.3 cm). In the seated position, mean arm circumference was 32.2 (±6.10) using TOA and 31.1 (±6.03) using SOA (mean difference 1.1 cm). Kappa agreement for cuff selection in the standing position between TOA and SOA was 0.94 (p < 0.001). The landmark on the acromion process can change the cuff selection in a small percentage of cases. The overall impact of this landmark selection is small. However, standardizing landmark selection and body position for AC measurement could further reduce variability in cuff size selection during BP measurement and validation studies.

High systolic blood pressure (BP) is the most important modifiable risk factor for cardiovascular disease. Managing systolic hypertension is especially difficult in underserved populations wherein access to cuff BP devices is limited. We showed that ubiquitous smartphones without force sensing can be converted into absolute pulse pressure (PP) monitors. The concept is for the user to perform guided thumb and hand maneuvers with the phone to induce cuff-like actuation and allow built-in sensors to make cuff-like measurements for computing PP. We developed an Android smartphone PP application. The \'app\' could be learned by volunteers and yielded PP with total error < 8 mmHg against cuff PP (N = 24). We also analyzed a large population-level database comprising adults less than 65 years old to show that PP plus other basic information can detect systolic hypertension with ROC AUC of 0.9. The smartphone PP app could ultimately help reduce the burden of systolic hypertension in underserved populations and thus health disparities.

BACKGROUND: This study aimed to evaluate the accuracy of ankle blood pressure measurements in relation to invasive blood pressure in the lateral position.
METHODS: This prospective observational study included adult patients scheduled for elective non-cardiac surgery under general anesthesia in the lateral position. Paired radial artery invasive and ankle noninvasive blood pressure readings were recorded in the lateral position using GE Carescape B650 monitor. The primary outcome was the ability of ankle mean arterial pressure (MAP) to detect hypotension (MAP < 70 mmHg) using area under the receiver operating characteristic curve (AUC) analysis. The secondary outcomes were the ability of ankle systolic blood pressure (SBP) to detect hypertension (SBP > 140 mmHg) as well as bias (invasive measurement - noninvasive measurement), and agreement between the two methods using the Bland-Altman analysis.
RESULTS: We analyzed 415 paired readings from 30 patients. The AUC (95% confidence interval [CI]) of ankle MAP for detecting hypotension was 0.88 (0.83-0.93). An ankle MAP of ≤ 86 mmHg had negative and positive predictive values (95% CI) of 99 (97-100)% and 21 (15-29)%, respectively, for detecting hypotension. The AUC (95% CI) of ankle SBP to detect hypertension was 0.83 (0.79-0.86) with negative and positive predictive values (95% CI) of 95 (92-97)% and 36 (26-46)%, respectively, at a cutoff value of > 144 mmHg. The mean bias between the two methods was - 12 ± 17, 3 ± 12, and - 1 ± 11 mmHg for the SBP, diastolic blood pressure, and MAP, respectively.
CONCLUSIONS: In patients under general anesthesia in the lateral position, ankle blood pressure measurements are not interchangeable with the corresponding invasive measurements. However, an ankle MAP > 86 mmHg can exclude hypotension with 99% accuracy, and an ankle SBP < 144 mmHg can exclude hypertension with 95% accuracy.

UNASSIGNED: Erroneous blood pressure measurement could lead to improper treatment and hence progression of chronic kidney disease (CKD). In routine clinical practice, there is poor adherence to the various steps to be followed during blood pressure measurement. Automated oscillometric BP measurement is difficult to perform in routine clinical practice due to several practical limitations.
UNASSIGNED: To evaluate the quality of blood pressure measurement and to compare routine office blood pressure measurement with standardized attended manually activated oscillometric blood pressure measurement in patients with CKD attending the nephrology outpatient department (OPD) of a tertiary care referral center.
UNASSIGNED: This cross-sectional study was conducted in patients aged more than 18 years with CKD stage 3-5ND, and previously diagnosed hypertension, in the nephrology OPD of a tertiary care referral center between July 2022 and September 2022.
UNASSIGNED: The quality of blood pressure measurement was evaluated using a questionnaire. The study participants had their blood pressure checked by both methods-routine office blood pressure and standardized attended manually activated oscillometric blood pressure.
UNASSIGNED: Standardized attended manually activated oscillometric blood pressure measurement yielded a significantly higher systolic blood pressure (SBP) compared to routine office blood pressure measurement (Mean SBP: 139.53 ± 29.1 vs 132.57 ± 23.59; P < 0.001). However, the diastolic blood pressure did not differ significantly between the two methods of measurement.
UNASSIGNED: Standardized attended manually activated oscillometric BP measurement yields a higher systolic BP compared to routine office BP measurement. Further studies are required to compare the standardized attended oscillometric BP measurement used in this study with unattended automated oscillometric BP measurement and ambulatory BP measurement.

BACKGROUND: The current standard approach to measuring home blood pressure (BP) involves taking measurements while sitting in a chair. In cultures where floor sitting is common, including Korea, assessing BP while sitting on the floor would be more feasible. However, there is still a lack of research investigating whether BP measurements obtained while seated in a chair and while sitting on the floor can be regarded as interchangeable. The aim of the study was to evaluate whether there is a difference between BP measurements taken while sitting in a chair and while sitting on the floor in a Korean adult.
METHODS: Among the participants who visited for evaluation of pulse wave velocity, a total of 116 participants who agreed to participate in the study were randomly selected. All subjects rested for 5 min, and BP measurements were taken at 1-min intervals according to a randomly assigned order of standard method (chair-sitting) and BP in a seated on the floor (floor-sitting).
RESULTS: Of the 116 participants, the median age was 68 (with an interquartile range of 59 to 75), and 82% were men. There were no significant differences in systolic BP (SBP, 129.1 ± 17.8 mmHg in chair-sitting and 130.1 ± 18.9 mmHg in floor-sitting, P = 0.228) and diastolic BP (DBP, 73.9 ± 11.4 mmHg in chair-sitting and 73.7 ± 11.4 mmHg in floor-sitting, P = 0.839) between the two positions. In addition, there was a high level of agreement between BP measurements taken in the two positions (intraclass correlation coefficients: 0.882 for SBP and 0.890 for DBP).
CONCLUSIONS: These findings provide important insights into securing the reliability of home BP measurements through the commonly practiced floor-sitting posture in cultures where floor sitting is common. Furthermore, this could serve as substantial evidence for providing specific home BP measurement guidelines to patients who adhere to a floor-sitting lifestyle.

Arterial occlusion pressure (AOP) is influenced by the characteristics of the cuff used to measure AOP. Doppler ultrasound was used to measure AOP of the brachial and superficial femoral arteries using straight and curved blood flow restriction cuffs in 21 males and 21 females. Vessel diameter and blood flow were evaluated as independent predictors of AOP. Overall, there were no significant differences in AOP when using the straight and curved cuffs in the brachial (129 mmHg vs. 128 mmHg) or superficial femoral artery (202 mmHg vs. 200 mmHg), respectively. Overall, AOP was greater (p < 0.05) in males than in females in the arm (135 mmHg, 123 mmHg) and leg (211 mmHg, 191 mmHg). Brachial (0.376 mm, 0.323 mm) and superficial femoral (0.547 mm, 0.486 mm) arteries were larger (p = 0.016) in males than in females, respectively. Systolic blood pressure (SBP) and arm circumference were predictive of brachial artery AOP, whereas SBP, diastolic blood pressure, thigh circumference, and vessel diameter were predictive of superficial femoral artery AOP. Straight and curved cuffs are efficacious in the measurement of AOP in the arm and leg. Differences in vessel size may contribute to sex differences in AOP but this requires further investigation.

Comprehending the regulatory mechanisms influencing blood pressure control is pivotal for continuous monitoring of this parameter. Implementing a personalized machine learning model, utilizing data-driven features, presents an opportunity to facilitate tracking blood pressure fluctuations in various conditions. In this work, data-driven photoplethysmograph features extracted from the brachial and digital arteries of 28 healthy subjects were used to feed a random forest classifier in an attempt to develop a system capable of tracking blood pressure. We evaluated the behavior of this latter classifier according to the different sizes of the training set and degrees of personalization used. Aggregated accuracy, precision, recall, and F1-score were equal to 95.1%, 95.2%, 95%, and 95.4% when 30% of a target subject\'s pulse waveforms were combined with five randomly selected source subjects available in the dataset. Experimental findings illustrated that incorporating a pre-training stage with data from different subjects made it viable to discern morphological distinctions in beat-to-beat pulse waveforms under conditions of cognitive or physical workload.

In recent years, hypertension has become one of the leading causes of illness and death worldwide. Changes in lifestyle among the population have led to an increasing prevalence of hypertension. This study proposes a non-contact blood pressure estimation method that allows patients to conveniently monitor their blood pressure values. By utilizing a webcam to track facial features and the region of interest (ROI) for obtaining forehead images, independent component analysis (ICA) is employed to eliminate artifact signals. Subsequently, physiological parameters are calculated using the principle of optical wave reflection. The Nelder-Mead (NM) simplex method is combined with the particle swarm optimization (PSO) algorithm to optimize the empirical parameters, thus enhancing computational efficiency and accurately determining the optimal solution for blood pressure estimation. The influences of light intensity and camera distance on the experimental results are also discussed. Furthermore, the measurement time is only 10 s. The superior accuracy and efficiency of the proposed methodology are demonstrated by comparing them with those in other published literature.

UNASSIGNED: Hypertension, a key modifiable risk factor for cardiovascular disease, is more prevalent among Black and low-income individuals. To address this health disparity, leveraging safety-net emergency departments for scalable mobile health (mHealth) interventions, specifically using text messaging for self-measured blood pressure (SMBP) monitoring, presents a promising strategy. This study investigates patterns of engagement, associated factors, and the impact of engagement on lowering blood pressure (BP) in an underserved population.
UNASSIGNED: We aimed to identify patterns of engagement with prompted SMBP monitoring with feedback, factors associated with engagement, and the association of engagement with lowered BP.
UNASSIGNED: This is a secondary analysis of data from Reach Out, an mHealth, factorial trial among 488 hypertensive patients recruited from a safety-net emergency department in Flint, Michigan. Reach Out participants were randomized to weekly or daily text message prompts to measure their BP and text in their responses. Engagement was defined as a BP response to the prompt. The k-means clustering algorithm and visualization were used to determine the pattern of SMBP engagement by SMBP prompt frequency-weekly or daily. BP was remotely measured at 12 months. For each prompt frequency group, logistic regression models were used to assess the univariate association of demographics, access to care, and comorbidities with high engagement. We then used linear mixed-effects models to explore the association between engagement and systolic BP at 12 months, estimated using average marginal effects.
UNASSIGNED: For both SMBP prompt groups, the optimal number of engagement clusters was 2, which we defined as high and low engagement. Of the 241 weekly participants, 189 (78.4%) were low (response rate: mean 20%, SD 23.4) engagers, and 52 (21.6%) were high (response rate: mean 86%, SD 14.7) engagers. Of the 247 daily participants, 221 (89.5%) were low engagers (response rate: mean 9%, SD 12.2), and 26 (10.5%) were high (response rate: mean 67%, SD 8.7) engagers. Among weekly participants, those who were older (>65 years of age), attended some college (vs no college), married or lived with someone, had Medicare (vs Medicaid), were under the care of a primary care doctor, and took antihypertensive medication in the last 6 months had higher odds of high engagement. Participants who lacked transportation to appointments had lower odds of high engagement. In both prompt frequency groups, participants who were high engagers had a greater decline in BP compared to low engagers.
UNASSIGNED: Participants randomized to weekly SMBP monitoring prompts responded more frequently overall and were more likely to be classed as high engagers compared to participants who received daily prompts. High engagement was associated with a larger decrease in BP. New strategies to encourage engagement are needed for participants with lower access to care.

Central blood pressure confers cardiovascular risk prediction ability, but whether the association between central systolic blood pressure (cSBP) and cardiovascular endpoints is independent of peripheral systolic blood pressure (pSBP) remains controversial. This systematic review and meta-analysis aim to investigate the associations between cSBP and cardiovascular endpoints in models including and excluding pSBP, respectively. Observational studies assessing the risk of composite cardiovascular endpoints with baseline cSBP were searched in PubMed, Embase, Scopus, Web of Science, and Cochrane Library to May 31, 2022. Risk of bias was assessed by the Newcastle-Ottawa Quality Assessment Scale, and random-effects models were used to pool estimates. Finally, 48 200 participants from 19 studies with a mean age of 59.0 ± 6.9 years were included. Per 10 mmHg increase of cSBP was associated with higher risk of composite cardiovascular outcomes (risk ratio [RR]: 1.14 [95%CI 1.08-1.19]) and cardiovascular death (RR: 1.18 [95%CI 1.08-1.30]), and the associations still existed after adjusting for pSBP (RR: 1.13 [95%CI 1.05-1.21] for composite cardiovascular endpoints; RR: 1.25 [95%CI 1.09-1.43] for cardiovascular death). In pSBP-unadjusted studies, increased cSBP was also associated with higher risk of all-cause mortality and stroke, but not in the pSBP-adjusted studies. Both cSBP and pSBP were similarly significantly associated with composite cardiovascular endpoints in models containing them separately and simultaneously. cSBP was significantly associated with cardiovascular events, independently of pSBP. Central or peripheral SBP could supplement cardiovascular risk assessment besides each other.