Project description:ObjectiveThe objective of this study was to validate the accuracy of beat-to-beat measurements with those taken with an aneroid sphygmomanometer by auscultatory method. A secondary aim was to explore differences between auscultatory and beat-to-beat blood pressure (BP) with daytime ambulatory BP measurements.Participants and methodsA total of 46 participants, comprising 21 males, aged 47±13 years, height 171±8.5 cm and weight 82±16.8 kg attended the Exercise Physiology Laboratory at the University of New England (Armidale, New South Wales, Australia). During the visit, participants had their BP - systolic BP (SBP) and diastolic BP (DBP) - measured using auscultatory methods and a Finometer. An ambulatory BP monitor was fitted during the same visit and worn for a minimum of 12 h.ResultsAuscultatory measurements were slightly higher than beat-to-beat for both SBP and DBP. There was no difference between auscultatory and beat-to-beat SBP with a mean difference of 0.23 mmHg (P=0.87). There were disparities between auscultatory and beat-to-beat DBP, with a mean difference of 4.82 mmHg (P<0.01). Daytime ambulatory BP was higher than both auscultatory and beat-to-beat measurements for both SBP and DBP, with P less than 0.001 for all measures.ConclusionThere was a high level of reliability in the beat-to-beat SBP with that seen by auscultatory; however, there were disparities in DBP measurements using the same devices, which raise concerns over the accuracy of beat-to-beat DBP. Ambulatory systolic and diastolic measures were higher than beat-to-beat and auscultatory; however, they may be more suitable for monitoring diurnal changes in BP, depending upon the research model.
Project description:BackgroundAlthough previous studies have reported differences of blood pressure (BP) according to BP measurement methods, studies in Korean population were scarce. This study aimed to compare BP differences according to different BP measurement methods and assess hypertension phenotype.MethodsThis prospective study recruited 183 individuals (mean 55.9 years; 51.4% males). The BP measurements included office BP (auscultatory attended office BP [ausAOBP], automated attended office BP [aAOBP], and automated unattended office BP [aUAOBP]) and out-of-office BP (home BP [HBP] and ambulatory BP [ABP]) measurements taken within one week of each other.ResultsThe mean systolic/diastolic BP differences between ausAOBP and other BPs according to different BP measurement methods were 3.5/2.3 mmHg for aAOBP; 6.1/2.9 mmHg for aUAOBP; 15.0/7.3 mmHg for daytime ABP; and 10.6/3.4 mmHg for average HBP. The increasing disparity between ausAOBP and other BPs in multivariable regression analysis was significantly associated with increasing BP. The prevalence of white-coat hypertension and masked hypertension in 107 individuals not taking antihypertensive medication was 25.4-26.8% and 30.6-33.3% based on ausAOBP, daytime ABP, and average HBP, respectively. The prevalence of white-coat uncontrolled hypertension and masked uncontrolled hypertension in 76 of those taking antihypertensive medication was 31.7-34.1% and 17.1-37.1%, respectively.ConclusionThis study showed a large disparity between office BP and out-of-office BP which became more pronounced when office BP by auscultation increased, suggesting that various BP measurement methods should be used to more accurately assess BP status.
Project description:Blood pressure (BP) is critical in diagnosing certain cardiovascular diseases such as hypertension. Some previous studies have proved that BP can be estimated by pulse transit time (PTT) calculated by a pair of photoplethysmography (PPG) signals at two body sites. Currently, contact PPG (cPPG) and imaging PPG (iPPG) are two feasible ways to obtain PPG signals. In this study, we proposed a hybrid system (called the ICPPG system) employing both methods that can be implemented on a wearable device, facilitating the measurement of BP in an inconspicuous way. The feasibility of the ICPPG system was validated on a dataset with 29 subjects. It has been proved that the ICPPG system is able to estimate PTT values. Moreover, the PTT measured by the new system shows a correlation on average with BP variations for most subjects, which could facilitate a new generation of BP measurement using wearable and mobile devices.
Project description:ObjectiveTo compare blood pressure (BP) in tonometric radial artery recordings during passive head-up tilt with ambulatory recordings and evaluate possible laboratory cutoff values for hypertension.MethodsLaboratory BP and ambulatory BP were recorded in normotensive (n = 69), unmedicated hypertensive (n = 190), and medicated hypertensive (n = 151) subjects.ResultsMean age was 50.2 years, BMI 27.7 kg/m 2 , ambulatory daytime BP 139/87 mmHg, and 276 were male (65%). As supine-to-upright changes in SBP ranged from -52 to +30 mmHg, and in DBP from -21 to +32 mmHg, the mean values of BP supine and upright measurements were compared with ambulatory BP. The mean(supine+upright) systolic laboratory BP was corresponding to ambulatory level (difference +1 mmHg), while mean(supine+upright) DBP was 4 mmHg lower ( P < 0.05) than ambulatory value. Correlograms indicated that laboratory 136/82 mmHg corresponded to ambulatory 135/85 mmHg. When compared with ambulatory 135/85 mmHg, the sensitivity and specificity of laboratory 136/82 mmHg to define hypertension were 71.5% and 77.3% for SBP, and 71.7% and 72.8%, for DBP, respectively. The laboratory cutoff 136/82 mmHg classified 311/410 subjects similarly to ambulatory BP as normotensive or hypertensive, 68 were hypertensive only in ambulatory, while 31 were hypertensive only in laboratory measurements.ConclusionBP responses to upright posture were variable. When compared with ambulatory BP, mean(supine+upright) laboratory cutoff 136/82 mmHg classified 76% of subjects similarly as normotensive or hypertensive. In the remaining 24% the discordant results may be attributed to white-coat or masked hypertension, or higher physical activity during out-of-office recordings.
Project description:The Veterans Affairs (VA) medical centers provide care for millions of Veterans at high risk of cardiovascular disease and accurate BP measurement in this population is vital for optimal BP control. Few studies have examined terminal digit preference (TDP), a marker of BP measurement bias, clinician perceptions of BP measurement, and BP control in VA medical centers. This mixed methods study examined BP measurements from Veterans aged 18 to 85 years with hypertension and a primary care visit within 8 VA medical centers. TDP for all clinic BP measurements was examined using a goodness of fit test assuming 10% frequency for each digit. Interviews were also conducted with clinicians from 3 VA medical centers to assess perceptions of BP measurement. The mean age of the 98,433 Veterans (93% male) was 68.5 years (SD 12.7). BP was controlled (<140/90 mmHg) in 76.5% and control rates ranged from 72.2% to 81.0% across the 8 VA medical centers. Frequency of terminal digits 0 through 9 differed significantly from 10% for both SBP and DBP within each center (P < .001) but level of TDP differed by center. The highest BP control rates were noted in centers with highest TDP for digits 0 and 8 for both SBP and DBP. Clinicians reported use of semi-automated oscillometric devices for clinic BP measurement, but elevated BP readings were often confirmed by auscultatory methods. Significant TDP exists for BP measurement in VA medical centers, which reflects continued use of auscultatory methods.
Project description:Purpose of reviewAutomated office blood pressure (AOBP) measurements may provide more accurate estimation of blood pressure (BP) than manual office blood pressure (MOBP) measurements. This systematic review investigated the diagnostic performance of AOBP and MOBP using ambulatory blood pressure measurement (ABPM) as reference. Several databases including MEDLINE, Embase, Scopus, and China Academic Journals were searched. Data were extracted, double-checked by two investigators, and were analysed using a random effects model.Recent findingsA total of 26 observational studies were included. The mean systolic/diastolic BP obtained by AOBP was not significantly different from that obtained by ABPM. The sensitivity and specificity of AOBP to detect elevated BP were approximately 70%. Fewer participants had white-coat hypertension on AOBP measurement than on MOBP measurement (7% versus 14%); however, about 13% had masked hypertension on AOBP measurement. The width of the limit of agreement comparing (i) AOBP and ABPM and (ii) MOBP and ABPM was comparable. AOBP may reduce the rate of the observed white-coat effect but undermine masked hypertension. The current recommendation, however, is limited by the absence of high-quality studies and the high heterogeneity of our results. More high-quality studies using different AOBP machines and in different population are therefore needed.
Project description:Ambulatory blood pressure (BP) monitoring (ABPM) may cause sleep disturbances. Some home BP monitoring (HBPM) devices obtain a limited number of BP readings during sleep and may be preferred to ABPM. It is unclear how closely a few BP readings approximate a full night of ABPM. We used data from the Jackson Heart (N = 621) and Coronary Artery Risk Development in Young Adults (N = 458) studies to evaluate 74 sampling approaches to estimate BP during sleep. We sampled two to four BP measurements at specific times from a full night of ABPM and computed chance-corrected agreement (i.e., kappa) of nocturnal hypertension (i.e., mean asleep systolic BP ≥ 120 mmHg or diastolic BP ≥ 70 mmHg) defined using the full night of ABPM and subsets of BP readings. Measuring BP at 2, 3, and 4 h after falling asleep, an approach applied by some HBPM devices obtained a kappa of 0.81 (95% confidence interval [CI]: 0.78, 0.85). The highest kappa was obtained by measuring BP at 1, 2, 4, and 5 h after falling asleep: 0.84 (95% CI: 0.81, 0.87). In conclusion, measuring BP three or four times during sleep may have high agreement with nocturnal hypertension status based on a full night of ABPM.
Project description:This study was performed to investigate the association between four BP measurements (systolic blood pressure [SBP], diastolic blood pressure [DBP], mean arterial pressure [MAP], and pulse pressure [PP]) and four TOD parameters (left ventricular mass index [LVMI], E/e', estimated glomerular filtration rate [eGFR], and obstructive coronary artery disease [CAD]). Data were obtained from a nation-wide registry, composed of 652 patients (471 women, 58.4 ± 10.5 years) with suspected CAD who underwent elective invasive coronary angiography (CAG). A total of 217 patients (33.2%) had obstructive CAD (≥50%). In multivariable analyses, E/e' was associated with SBP, MAP and PP, and CAD was associated with SBP and PP (P < 0.05 for each). All four BP measurements were not associated with LVMI and eGFR (P > 0.05 for each). In patients undergoing elective invasive CAG, SBP, and PP had stronger relationships with E/e' and CAD than DBP and MAP.