Oscillometric Method Research Articles

Oscillometric blood pressure measurements on smartphones using vibrometric force estimation

This paper proposes a smartphone-based method for measuring Blood Pressure (BP) using the oscillometric method. For oscillometry, it is necessary to measure (1) the pressure applied to the artery and (2) the local blood volume change. This is accomplished by performing an oscillometric measurement at the finger’s digital artery, whereby a user presses down on the phone’s camera with steadily increasing force. The camera is used to capture the blood volume change using photoplethysmography. We devised a novel method for measuring the force applied of the finger without the use of specialized smartphone hardware with a technique called Vibrometric Force Estimation (VFE). The fundamental concept of VFE relies on a phenomenon where a vibrating object is dampened when an external force is applied on to it. This phenomenon can be recreated using the phone’s own vibration motor and measured using the phone’s Inertial Measurement Unit (IMU). A cross device reliability study with three smartphones of different manufacturers, shape, and prices results in similar force estimation performance across all smartphone models. In an N = 24 proof of concept study of the BP measurement, the smartphone technique achieves a mean absolute error of 9.21 mmHg and 7.77 mmHg of systolic and diastolic BP, respectively, compared to an FDA approved BP cuff. The vision for this technology is not necessarily to replace existing BP monitoring solutions, but rather to introduce a downloadable smartphone software application that could serve as a low-barrier hypertension screening measurement fit for widespread adoption.

Undiagnosed impaired glucose tolerance/diabetes mellitus and relationship with aortic stiffness in patients with acute coronary syndromes

Abstract Background Patients admitted with an acute coronary syndrome (ACS) often have unknown cardiovascular risk factors, such as impaired glucose tolerance (IGT) or diabetes mellitus (DM). Detecting these conditions is crucial to intensify appropriate therapies. Increased aortic stiffness, assessed by aortic pulse wave velocity (PWV), is associated with higher mortality in patients at high cardiovascular risk. Purpose Estimating the prevalence of IGT and DM and their relationship with increased aortic stiffness in patients admitted with an ACS. Methods Seventy-five consecutive patients admitted for ACS (21% women, mean age 63.6±11.1 ys), with fasting plasma glucose (PG) and glycated hemoglobin (HbA1c) not diagnostic for diabetes mellitus, underwent a fully standardized oral glucose tolerance test. All patients were also evaluated with the Arteriograph device, which applies a brachial cuff-based oscillometric method for the estimation of aortic PWV and arterial pulse waveform features. The automated vascular studies and OGTTs were performed after patient stabilization, at least 96 hours after admission. Results Forty-one patients (55% of the total study population) showed an abnormal OGTT response: 14 patients had a 2-h PG-OGTT ≥ 200 mg/dL, uncovering a diagnosis of DM, and 27 patients had a 2-h PG-OGTT ≥ 140 mg/dL, uncovering a diagnosis of IGT. Patients with DM showed no differences in terms of age, cardiovascular risk factors, Framingham risk score, C-reactive protein values, whereas a significant difference was observed in the number of diseased coronary vessels (2.2±0.8 vs 1.6±0.9, p=0.016) and PWV values (10.0±1.3 vs 8.8±1.6 m/s, p=0.028). Similarly, when considering all patients with an abnormal OGTT, a significant difference was observed in PWV values compared to patients with a normal OGTT (9.5±1.5 vs 8.4±1.7 m/s, p=0.032), as well as in estimated glomerular filtration rate (78±18 vs 83±23 mL/min/1.73mq, p=0.05), and peak troponin values (3698±2905 vs 2124±2561 ng/ml, p=0.02). At follow-up (mean time 51.7 months), no patients had died, but 5 patients had a new major cardiovascular event. Aortic pulse wave velocity values were different between patients with and without events (10.6±2.3 vs 8.6±1.4 m/s, p=0.024), and PWV was a significant predictor of events at univariate regression analysis (hazard ratio 1.93; 95 confidence intervals 1.01-3.69, p=0.047). Conclusions An unknown diagnosis of DM and/or IGT is very frequent in patients with ACS. Undiagnosed dysglycemic conditions are linked to a higher prevalence of coronary multivessel disease and increased aortic stiffness, which is also predictive of future cardiovascular events. A systematic screening with OGTT may help identifying patients at even higher cardiovascular risk, and tailoring secondary prevention strategies through personalized aggressive therapeutic interventions.

Foot Sole Temperature Correlates with Ankle-Brachial Index, Pulse Wave Velocity, and Arterial Age in Diabetic Patients Without Diagnosis of Peripheral Arterial Disease.

Background/Objectives: Some vascular alterations such as peripheral arterial disease (PAD) or arterial stiffness can alter perfusion of the limbs, so we wondered if this is reflected in the temperature of the soles of the feet of diabetic patients who did not have a diagnosis of peripheral arterial disease. Foot sole temperature was correlated with the ankle-brachial index (ABI), carotid-femoral pulse wave velocity (cfPWV), brachial-ankle pulse wave velocity (baPWV), and arterial age. Methods: A total of 175 patients with type 2 diabetes mellitus, without a previous diagnosis of PAD, were recruited. Comorbidities, anthropometry, biochemical analysis results, temperature, ABI, cfPWV, baPWV, and arterial age were recorded. Forty-two temperature records were obtained from the sole of the foot with an FLIR T865 thermal imaging camera. ABI, cfPWV, baPWV, and arterial age were obtained using plethysmographic and oscillometric methods. Statistical analysis was performed with SPSS v.29.0 (correlations and multiple linear regression models). Results: All temperature points analyzed correlated negatively with ABI (p < 0.001) and rho values ranged from -0.168 to -0.210. Likewise, cfPWV, baPWV, and arterial age had similar results, since most temperature records showed low rho values and a negative correlation with these parameters. Four models were developed to explain the variables of interest. Temperature was involved in all of them. The temperature of the first toe was included in the prediction of cfPWV, baPWV, and arterial age. Conclusions: There is an inversely proportional relationship between temperature and ABI, cfPWV, baPWV, and arterial age in diabetic patients without a previous diagnosis of arterial disease. Temperature can be a predictor of these hemodynamic variables.

Oscillometric method: what is it and is it suitable for measuring blood pressure in all patients?

The oscillometric method, which is gradually replacing the traditional auscultatory method, is attractive to practitioner due to the possibility of automating blood pressure (BP) measurements. However, there is little literature information about its limitations. The purpose of this review is to address such issues. For this purpose, the main modern information on the maximum amplitude algorithm for BP measurement and location features, in which it is possible to obtain an oscillometric waveform, are preliminarily considered. In addition, the limitations and disadvantages of the method associated with both the equipment and the characteristics of various population groups are analyzed. The list of groups in which blood pressure measuring devices may be inaccurate has expanded significantly in the 2020s compared to the previous decade. This suggests that the reliability of the interpretation of data obtained by the oscillometric method in a certain part of patients is limited.

Is muscle sympathetic nerve activity associated with cerebral blood velocity? A partial coherence analysis.

Despite some evidence, the role of sympathetic nerve activity in the regulation of cerebral blood flow remains controversial. In humans, muscle sympathetic nervous activity (MSNA) is the only direct measure of sympathetic nerve activity that can be recorded with sufficient temporal resolution, to allow association with dynamic regulation of cerebral blood velocity (CBv). This study tested the hypothesis that MSNA is associated with the regulation of CBv at rest and during different physiological maneuvers. Nine healthy subjects underwent two sympathoexcitatory maneuvers: i) isometric handgrip exercise (HGR), and ii) cold pressor test (CPT). Mean arterial pressure (MAP, oscillometric method), CBv (transcranial Doppler ultrasound), and MSNA (microneurography) were measured continuously during experimental protocols. Ordinary and partial coherences of the MAP, CBv and MSNA time series were estimated by transfer function analysis in the low-frequency range (LF: 0.07-0.20 Hz), using MAP and MSNA as inputs and CBv as the output variable. When the influence of MSNA was taken into account, the partial coherences between MAP and CBv were considerably reduced at baseline (P<0.01), HGR (P=0.02), and CPT (P<0.01). Similarly, when the influence of MAP was taken into account, the coherence between MSNA and CBv was considerably reduced at baseline (P<0.01), HGR (P=0.02), and CPT (P=0.01), leading to the conclusion, that MSNA was associated to dynamic regulation of CBv. Partial coherence analysis is a promising method for assessing the influence of the sympathetic nervous system on cerebral hemodynamics.

Automated Digital Sfigmomanometer Prototype Testing

Abstract Blood pressure is the pressure of blood flow in the arteries generated by the heart. Abnormal blood pressure can lead to hypertension and hypotension. Hypotension, or low blood pressure, has a prevalence of 5% to 34% among individuals aged 17 to 19, and over 50% in the elderly. Hypertension can cause death in patients with heart disease. About 39.7% of people suffer from hypertension, especially those over the age of 60. Blood pressure measurement needs to be done regularly because it has impact such as early detection of blood pressure health conditions and monitoring of health conditions for those already diagnosed with abnormal blood pressure. Unfortunately, only 59% of the population in Indonesia regularly measure their blood pressure. Accurate blood pressure measurement can be performed using an invasive method. Another method is non-invasive, which can be done using a sphygmomanometer that applies the oscillometric method. This method uses pressure oscillations in the cuff influenced by the pulse in the blood vessels. When using this method, several factors need to be considered, such as body position, cuff size, and the technique used during the measurement. In this study, a fully automatic digital sphygmomanometer has been developed with a cuff attached to the device, equipped with a thermal printer to print out the measurement results and classify blood pressure categories. The advantage of the developed prototype is that it has a smaller relative error value, with 1.03% for systolic blood pressure and 1.45% for diastolic blood pressure, and has already been integrated with a thermal printer to directly print the measurement results.

Association between physical activity performed at different intensities and cardiovascular health in patients with peripheral artery disease: an observational study.

We examined the sedentary behavior and physical activity of 260 patients with peripheral artery disease. Women engaged in more light physical activity than men did. Light physical activity was associated with lower arterial stiffness in men only, while no significant associations were found between sedentary behavior, moderate-vigorous physical activity, and cardiovascular outcomes. ◼ Women with peripheral artery disease exhibited higher blood pressure and arterial stiffness than men. ◼ Low levels of physical activity, particularly moderate to vigorous activity, were observed in individuals with peripheral artery disease. To analyze the association between the time spent in sedentary behavior and physical activity of different intensities with cardiovascular health in men and women with peripheral artery disease. Two hundred and sixty patients with peripheral artery disease and claudication symptoms (65.7% men; 66±1 years; ankle brachial index 0.57±0.18) were evaluated. Physical activity and sedentary behavior were assessed using an accelerometer. Physical activity was classified into light and moderate-vigorous intensities. The cardiovascular outcomes included blood pressure (oscillometric method), cardiac autonomic modulation (heart rate variability), and arterial stiffness (pulse wave velocity). Women spent more time engaged in light physical activity than men (341±14 min/day versus 306±9 min/day; p=0.040, respectively). There was no significant difference in the time spent on sedentary behavior and moderate-vigorous physical activity. Women had a higher systolic blood pressure (p=0.025), higher augmentation index (p<0.001), and lower sympathovagal balance (p=0.047) than men. Pulse wave velocity was only negatively associated with light physical activity (β= -4.66; 95%CI= -8.57; -0.76) in men. Light and moderate-vigorous physical activity and sedentary behavior were not associated with other cardiovascular outcomes. Higher levels of light physical activity were associated with lower arterial stiffness in men with peripheral artery disease.

Innovations in blood pressure measurement and reporting technology: International Society of Hypertension position paper endorsed by the World Hypertension League, European Society of Hypertension, Asian Pacific Society of Hypertension, and Latin American Society of Hypertension.

Blood pressure (BP) is a key contributor to the lifetime risk of preclinical organ damage and cardiovascular disease. Traditional clinic-based BP readings are typically measured infrequently and under standardized/resting conditions and therefore do not capture BP values during normal everyday activity. Therefore, current hypertension guidelines emphasize the importance of incorporating out-of-office BP measurement into strategies for hypertension diagnosis and management. However, conventional home and ambulatory BP monitoring devices use the upper-arm cuff oscillometric method and only provide intermittent BP readings under static conditions or in a limited number of situations. New innovations include technologies for BP estimation based on processing of sensor signals supported by artificial intelligence tools, technologies for remote monitoring, reporting and storage of BP data, and technologies for BP data interpretation and patient interaction designed to improve hypertension management ("digital therapeutics"). The number and volume of data relating to new devices/technologies is increasing rapidly and will continue to grow. This International Society of Hypertension position paper describes the new devices/technologies, presents evidence relating to new BP measurement techniques and related indices, highlights standard for the validation of new devices/technologies, discusses the reliability and utility of novel BP monitoring devices, the association of these metrics with clinical outcomes, and the use of digital therapeutics. It also highlights the challenges and evidence gaps that need to be overcome before these new technologies can be considered as a user-friendly and accurate source of novel BP data to inform clinical hypertension management strategies.

Effects of Telmisartan on Intraocular Pressure, Blood Pressure, and Ocular Perfusion Pressure in Normal and Glaucomatous Cats.

To determine the effect of telmisartan on intraocular pressure (IOP), blood pressure (BP), and ocular perfusion pressure (OPP) in normal and glaucomatous cats. A four-week study was conducted in six normal adult cats, followed by a longer six-month study performed in 37 cats with spontaneous glaucoma and 11 age-matched normal cats. Telmisartan (1 mg/kg/day) or placebo-vehicle were administered orally once daily. IOP was measured by rebound tonometry. BP readings were obtained by oscillometric method. OPP was calculated as mean arterial pressure (MAP) - IOP. IOP and BP were obtained three times a week for the first study and weekly for the second study. Baseline IOP was significantly higher, and OPP was significantly lower in glaucomatous cats than in normal cats (P < 0.0001). These differences between glaucomatous and normal cats persisted throughout the study, regardless of treatment (P < 0.001). No significant differences in IOP, BP, or OPP were detected between any study phases in the first, normal feline cohort or between telmisartan- and placebo-treated glaucomatous cats at any timepoint in the second study. Oral telmisartan was well tolerated and did not have a detrimental effect on BP or OPP in cats but did not lower IOP or improve OPP in cats with glaucoma. While showing telmisartan could not be used as a sole therapy for IOP lowering, our data affirmed a lack of detrimental effects of telmisartan on BP and OPP in a translationally-relevant, spontaneous, large animal glaucoma model.

P060 A NOVEL NON-INVASIVE METHOD FOR ESTIMATING CENTRAL SYSTOLIC BLOOD PRESSURE USING AMBULATORY BLOOD PRESSURE MONITORING

Background and Objective: Central blood pressure (BP) holds superior prognostic value compared to peripheral BP in predicting cardiovascular events. Despite its significance, measuring central BP in outpatient settings is impractical. To address this limitation, our research group devised a novel non-invasive method for estimating central systolic blood pressure (cSBP) using peripheral data based on the equation proposed by Chemla et al. However, its validity remains uncertain. The objective was to assess the validity of our new non-invasive method for estimating cSBP by comparing it to a validated brachial oscillometric method. Methods: A cross-sectional study was conducted, involving 132 patients who underwent 24-hour ambulatory blood pressure monitoring (24-h ABPM). A total of 8,112 BP records were obtained. The cSBP was measured during 24-h ABPM using a Custo Screen 310 device (Custo, Ottobrunn, Germany), which has been validated. The cSBP was estimated using the formula: cSBP= MAP2/DBP, where MAP2 represents the estimated mean arterial pressure using the equation: MAP2=(Ts/T) × SBP + (Td/T) × DBP, where T, Ts, and Td denote the cardiac, systolic, and diastolic periods, respectively. The SBP indicate systolic blood pressure and DBP denote diastolic blood pressure. Ts was calculated as: Ts=0.2061+ (Age/2244) + (T/8.17). Results: Among the participants, 53.8% were men, with an average age of 55±16 years. The average height was 1.65±0.1 m, weight 74±12 kg, heart rate 71±12 bpm, SBP 125±19 mmHg, DBP 79±12 mmHg, and cSBP 120±19 mmHg. The agreement of cSBP between the new method and the brachial oscillometric method was very good. Bland-Altman plots revealed that the differences between the methods were randomly distributed along the mean difference line (Figure). Conclusions: The new non-invasive method to estimate cSBP from peripheral BP data, using MAP2 and cardiac periods, has been demonstrated to be valid. The equation, which allows for the estimation of cSBP without a pulse wave, could be easily implemented in conventional 24-h ABPM systems.

Assessment of aortic stiffness during atrial fibrillation: solutions and considerations.

Methods to assess aortic stiffness are not validated during ongoing atrial fibrillation (AF) We aimed to determine whether aortic stiffness can be assessed reliably in patients during AF. Carotid-to-femoral and aortic pulse wave velocity (cf/aoPWV), central blood pressure (BP), and augmentation index (AIx) were assessed by a two-site applanation method and a one-site cuff-based oscillometric method in 40 patients with persistent AF and repeated after cardioversion to SR. Mean age was 63 ± 8 years, 73% male, 50% hypertensive. For the two-site method, cfPWV values were slightly higher in AF than in SR (9.3 ± 1.8 vs. 8.5 ± 1.6 m/s, p < 0.001), whereas the one-site method provided similar values in AF and SR (10.1 ± 1.5 vs. 10.0 ± 1.8 m/s).The variability indices from the device was higher in AF for the two-site method (SD 2.5 ± 1.7 vs. 1.0 ± 0.5 m/s, p < 0.001) but similar in AF and SR with the one-site method (SD 0.7 ± 0.2 vs. 0.6 ± 0.2 m/s). Both methods yielded higher central BP (+4.8/+6.6 and +4.1/+5.7 mm Hg) and lower Aix (-6.8 and -9.1 mm Hg) in AF. Aortic stiffness can be assessed during AF. Both methods yielded higher central BP and lower AIx in AF, but similar results for PWV in AF and SR, also when adjusted for BP changes. The two-site method showed high variability necessitating repeated measurements. The one-site method showed lower device-calculated variability and needed fewer repeated measurements.

Different Methods for Measurements and Estimation of Pulse Wave Velocity are not Interchangeable

BackgroundCarotid-femoral pulse wave velocity (c–f PWV) is a gold standard for the arterial stiffness measurement and important biomarker for the assessment of the cardiovascular (CV) risk. Recent studies have focused on 24-h measurements of arterial stiffness and estimated PWV (ePWV). The aim of this study is to analyze agreement of office c–f PWV measurements (SphygmoCor) with 24-h oscillometric measurements (Mobil-O-Graph and Arteriograph), and with ePWV.ResultsThis study included 154 patients with primary hypertension (average age 38.75 ± 12.65). Arterial stiffness has been measured in the office with SphygmoCor and 24 h with two oscillometric methods (Mobil-O-Graph and Arteriograph). ePWV was calculated using validated equation. PWV values obtained in office (SphygmoCor) showed higher average values compared to both 24-h oscillometric measurements of PWV and ePWV. The mean values of 24-h PWV measured by Arteriograph were higher compared to values obtained with Mobil-O-Graph. The measurement of PWV over 24 h using the Arteriograph is the most accurate among the methods that were compared with the office PWV measurements (accuracy of 0.989). However, the most precise method was the Mobil-O-Graph (0.631), and the highest degree of agreement also was shown with the Mobil-O-Graph (concordance coefficient correlation (CCC) = 0.447). The smallest deviation (TDI) and the highest probability of overlapping (CP) were observed with ePWV (TDI = 45.524, CP = 0.322, respectively).ConclusionIn our group of young treated mild hypertensive patients with low CV risk, we found weak agreements between cfPWV and 24-h PWV. These methods are not interchangeable.

Validation of the DBP-8278B Wrist-type Fully Automatic Blood Pressure Monitor in the general population according to the ISO 81060-2:2018/AMD 1:2020 protocol.

The aim of this study was to evaluate the accuracy of the DBP-8278B Wrist-type Fully Automatic Blood Pressure Monitor in the general population according to the AAMI/ESH/ISO Universal Standard (ISO 81060-2 : 2018/AMD 1 : 2020). The test monitor was used to measure SBP and DBP and pulse rate in the wrists using the oscillometric method. According to this protocol using the same-arm sequential blood pressure measurement method, subjects were recruited to fulfill the age, sex, blood pressure, and cuff distribution criteria of the Universal Standard. A single cuff for wrist sizes of 13.5-21.5 cm was used. A total of 85 subjects were included in this study. According to Criterion 1, the mean difference in SBP between the test device and the reference device was 0.89 mmHg, with a SD of 7.76 mmHg. The mean difference of DBP was -1.44 mmHg, with a SD of 6.23 mmHg. The mean difference between SBP and DBP was less than 5.0 mmHg, and the SD was less than 8.0 mmHg, which met the requirements. According to Criterion 2, the SD of the mean differences of SBP between the test device and the reference device per subject was 5.65 mmHg, which was less than 6.88 mmHg and met the requirements. The SD of the mean differences of DBP between the test device and the reference device per subject was 5.61 mmHg, which was less than 6.78 mmHg and met the requirements. The DBP-8278B Wrist-type Fully Automatic Blood Pressure Monitor met the requirements of the AAMI/ESH/ISO Universal Standard (ISO 81060-2 : 2018/AMD 1 : 2020). It can be recommended for home and clinical use.

The role of non-invasive oscillometric method to detect aortic stiffness in patients with subclinical hypothyroidism

Introduction Subclinical hypothyroidism (SCH) is a biochemical condition that is diagnosed when peripheral free thyroid hormone levels are within normal reference laboratory range but serum thyroid-stimulating hormone (TSH) levels are mildly elevated. The aim of this study was to investigate the relationship between SCH and arterial stiffness using two different non-invasive methods, including echocardiography and oscillometric arteriography. Material and Methods The study included 33 newly diagnosed SCH patients and 34 age- and gender-matched healthy controls. Systolic and diastolic diameters and elastic parameters of the aorta were calculated by 2D Transthoracic echocardiography (TTE). Central blood pressure and aortic stiffness values of patient groups were measured noninvasively from the brachial artery using Mobil-O-Graph arteriography. Pulse wave velocity (PWV) and augmentation index (AIx) were used as arterial stiffness indicators. Results There was no significant difference between SCH and control groups with regard to age, gender, and body mass index (BMI). Aortic strain and aortic distensibility, were significantly lower in the SCH group than in the control group (p < 0.001). PWV and AIx which measured by Mobil-O-Graph arteriography were found to be significantly higher in the subclinical hypothyroid group compared to the control group (p < 0.05). Conclusion Aortic stiffness assessed by TTE and Mobil-O-Graph arteriography deteriorated in patients with SCH after excluding other cardiovascular risk factors. The assessment of aortic stiffness by the oscillometric method was easy and useful for widespread clinical use.

The Role of Serum Erythropoietin (EPO) and Vascular Endothelial Growth Factor (VEGF) in Pulse Wave Velocity (PWV) Among Hypertensive Patients: A Cross-Sectional Study.

Background and objective While hypertension (HTN) is a major health-related threat globally, it is often an under-reported clinical condition as most of the stage I hypertensive patients do not present with any symptoms. The relationship between endogenous oxygen-sensing protein [erythropoietin (EPO) andvascular endothelial growth factor(VEGF)] levels and vascular stress in hypertensive patients is not fully understood as the mechanistic pathway by which these oxygen-sensing proteins alter the vascular physiology and cause hypertension is still a matter of debate. In light of this, we explored the role of these two proteins in the development of vascular stress including increased pulse wave velocity (PWV). We aimed to examine the correlation between oxygen-sensing proteins and vascular stress markers including PWV in hypertensive patients. Materials and methods We conducted a cross-sectional study involving age-matched participants classified into three groups (group 1: normotensive persons, n=36; group 2: stage I hypertensive patients, n=36; and group 3, stage II hypertensive patients, n=36). Adiposity-related parameters such as waist circumference (WC), hip circumference (HC), BMI, and waist-hip ratio (WHR) were measured. BPwas recorded manually in resting posture by using a sphygmomanometer. PWV, which predicts the progression of BP and the development of HTN, was recorded using a periscope, which works based on the oscillometric method. Vascular stress-induced oxidative stress parameters [serummalondialdehyde(MDA)and serumnitric oxide(NO)] were also estimated by using a UV spectrophotometer. Quantitative estimations of oxygen-sensing proteins (serum EPO and serum VEGF) were done by using the ELISA kit method. The results were expressed as mean ± standard deviation (SD). The correlation between the variables was done using Spearman's correlation. A p-value <0.05 was considered statistically significant. Results Adiposity indices and vascular stiffness parameters were found to be significantly (p <0.05) increased in group 2 and group 3 compared to group 1. The levels of serum MDA were found to be significantly (p<0.05) increased in group 2 and group 3 than group 1, whereasthe levels of serum NO were significantly (p<0.05) decreased in group 3 and group 2 than group 1. A significant (p<0.05) positive correlation was observed between the PWV and EPO (r=0.492) while a significant (p<0.05) negative correlation was observed between PWV and VEGF(r=-0.406) among thestudy population. Conclusion The results are indicative of the influence of vascular stress in stage I and II hypertensive patients. Furthermore, the relationship between oxygen-sensing proteins and vascular stress in hypertensive patients has also been established.

Comparison of invasive blood pressure monitoring vs. non-invasive blood pressure monitoring in critically ill children receiving vasoactive agents-a prospective observational study.

The primary aim of this study was to compare non-invasive blood pressure (NIBP) measurement using the automated oscillometric method with invasive blood pressure (IBP) measurement using peripheral arterial line insertion in critically ill children receiving vasoactive agents. Single-centre, prospective cohort study. Tertiary care 15 bedded Pediatric ICU in Urban Indian city. All critically ill children between the ages of 1 month to 16 years with shock on vasoactive medications and with IBP monitoring. Forty children with 1,072 paired BP measurements were incorporated in the final analysis. Among all normotensive children (Total number of paired measurements = 623) receiving vasoactive agents, Bland-Altman analysis revealed an acceptable agreement between Invasive mean blood pressure (MBP) and non-invasive MBP with a bias of -2.10 mmHg (SD 11.35). The 95% limits of agreement were from -24.34 to 20.14 mmHg. In children with hypotension (Total number of paired measurements = 449), Bland-Altman analysis showed disagreement between Invasive MBP and non-invasive MBP i.e., a bias of -8.44 mmHg (SD 9.62). The 95% limits of agreement were from -27.29 to 10.41 mmHg. A limited agreement exists between invasive blood pressure (IBP) and non-invasive blood pressure (NIBP) measurements in critically ill children requiring vasoactive agents. This discrepancy can lead to either an underestimation or an overestimation of blood pressure. While NIBP can serve as a screening tool for hemodynamically stable children, those who are hemodynamically unstable and necessitate the initiation of vasoactive agents should undergo IBP monitoring.

Validation of oscillometric ratio and maximum gradient methods for non-invasive blood pressure measurement with intra-arterial blood pressure measurements as reference.

Most non-invasive blood pressure (BP) measurements are carried out using instruments which implement either the Ratio or the Maximum Gradient oscillometric method, mostly during cuff deflation, but more rarely during cuff inflation. Yet, there is little published literature on the relative advantages and accuracy of these two methods. In this study of 40 lightly sedated individuals aged 64.1 ± 9.6 years, we evaluate and compare the performance of the oscillometric ratio (K) and gradient (Grad) methods for the non-invasive estimation of mean pressure, SBP and DBP with reference to invasive intra-arterial values. There was no significant difference between intra-arterial estimates of mean pressure made via Korotkoff sounds (MP-OWE) or the gradient method (MP-Grad). However, 17.7% of MP-OWE and 15% of MP-Grad were in error by more than 10 mmHg. SBP-K and SBP-Grad underestimated SBP by 14 and 18 mmHg, whilst accurately estimating DBP with mean errors of 0.4 ± 5.0 and 1.7 ± 6.1 mmHg, respectively. Relative to the reference standard SBP-K, SBP-Grad and DBP-Grad were estimated with a mean error of -4.5 ± 6.6 and 1.4 ± 5.6 mmHg, respectively, noting that using the full range of recommended ratios introduces errors of 12 and 7 mmHg in SBP and DBP, respectively. We also show that it is possible to find ratios which minimize the root mean square error (RMSE) and the mean error for any particular individual cohort. We developed linear models for estimating SBP and SBP-K from a range of demographic and non-invasive OWE variables with resulting mean errors of 0.15 ± 5.6 and 0.3 ± 5.7 mmHg, acceptable according to the Universal standard.

Assessment of arterial stiffness in paediatric patients with type 1 diabetes mellitus

AimsTo investigate early indicators of cardiovascular disease (CVD) in children and adolescents with type 1 diabetes mellitus (T1DM), focusing on pulse wave velocity (PWV) and its associations with various anthropometric and glycemic parameters. Patients and methodsA total of 124 children and adolescents with T1D (mean age 10.75 ± 3.57 years) were included in this cross-sectional study. Anthropometric data, including height, weight, body mass index (BMI), glycemic parameters, such as HbA1c and time in range (TIR) were assessed. PWV was assessed by oscillometric method using the Mobil-O-Graph PWA device. Univariate and multivariate linear regression were used to explore the association of PWV z-score with anthropometric, demographic, and glycaemic variables. ResultsSignificant negative association between PWV and age and height (β = −0.336, 95 % CI -0.44 to −0.25, p < 0.001 and β = −0.491, 95 % CI -0.62 to −0.36, p < 0.001, respectively), while gender showed a significant positive association with PWV, with females displaying higher PWV values compared to males (β = 0.366, 95 % CI 0.17 to 0.56, p < 0.001). TIR was positively associated with PWV (β = 0.092, 95 % CI 0.01 to 0.16, p = 0.017 only for patients having TIR ≤ 50 %. Finally, systolic blood pressure (SBP) and diastolic blood pressure (DBP) were positively associated with PWV (β = 0.086, 95 % CI 0.02 to 0.14, p = 0.007 and β = 0.152, 95 % CI 0.07 to 0.23, p < 0.001, respectively). ConclusionYouth with T1DM who spend <50 % of time in range exhibit uniquely increased signs of arterial stiffness, indicating that poor glycemic control may contribute to early vascular damage. Differences related to age, gender and height should be considered.

Impact of Obesity on Cardiac Autonomic System Functioning in Military Police Officers.

Cardiac autonomic system functioning may be altered by obesity leading to cardiovascular diseases and associated complications. Military police officers are exposed to traditional and occupational risk factors for the development of CVD, however data on the cardiovascular health in this population is still scarce. In this cross-sectional study, we investigated the impact of obesity on cardiac autonomic modulation and the hemodynamic profile in male active-duty military police officers. The body composition of the volunteers was assessed by octapolar electrical bioimpedance. Participants were classified as non-obese or obese in accordance with their body fat, with further subgroups as physically active obese or insufficiently active obese using International Physical Activity Questionnaire (IPAQ). Cardiac autonomic modulation was assessed by heart rate variability and the automatic oscillometric method allowed us to assess hemodynamic features. 102 military police officers from the state of São Paulo participated in the study. Cardiac autonomic modulation revealed significant impairment in time and frequency domains and non-linear methods in the obese group compared to the non-obese (p < 0.05). A higher physical activity level did not alter these results in the obese group. However, no significant differences in the hemodynamic profile were observed between groups (p > 0.05). These findings suggest a negative association between obesity and cardiac autonomic modulation in military police officers, unaffected by increased physical activity.

RELATIONSHIP OF DAILY BLOOD PRESSURE PROFILE AND ARTERIAL STIFFNESS

Objective: To study the blood pressure daily profile in patients with hypertension (HNT) depending on the pulse wave velocity (PWV). Design and method: We studied 88 treated patients with HNT. The ambulatory BP monitoring (ABPM) was recorded with a Medicom-combi device (Russia) using the oscillometric method. PWV was determined using the SphygmoCor (AtCor Medical Pty Ltd, Australia). Statistical analysis was performed using the SPSS 24.0 software package. Results: Patients were divided into 2 groups depending on PWV level: the first group had a PWV &lt; 10 m/s, and the second group had a PWV &gt; 10 m/s. The mean PWV in the groups was 7.79±1.38 vs. 14.13±1.85 m/s, respectively (p&lt;0.007). Office SBP and DBP didn’t differ between groups. Patients of the second group had significantly higher mean daily SBP (113.64±16.64 vs 128.23±16.91 mm Hg, p=0.0001), mean daytime SBP (116.77±8.99 vs 129.36±7.8 mm Hg, p=0.0001), and mean nighttime DBP (66.26±9.7 vs 71.64±7.1 mm Hg, p=0.04). The load index (LI) of daytime and nighttime SBP was higher in patients with PWV &gt; 10 m/s. LI of SBP daytime: 9.72±15.82% vs. 27.74±35.24%, respectively, p = 0.001. LI of SBP nighttime: 18.34±26.44% vs. 44.2±38.81%, respectively, p = 0.001. Variability and nocturnal falls of SBP and DBP also didn’t differ between the groups. The number of dippers by SBP and DBP was higher in patients with normal PWV, but not significantly: 18% and 12% vs. 13% and 9%, SBP: χ2 = 0.04, p = 0.83; DBP: χ2 = 0.19, p = 0.45. The number of non-dippers by SBP and DBP was significantly higher in the first group: 65% and 66% vs. 50% and 50%; SBP: χ2 = 4.6, p = 0.032; and DBP: χ2 = 5.25, p &gt; 0.05. However, the number of night-pickers by SBP and DBP significantly prevailed in the second group: 17% and 19% vs. 36.4% and 32%, respectively; SBP: χ2 = 9.2, p = 0.003, DBP: χ2 = 5.58, p = 0.019. There were no over-dippers in both groups. Conclusions: Hypertensive patients with high PWV values had more pronounced disorders in their daily blood pressure profile.