Blood Pressure Measurement Technique Research Articles

Systolic blood pressure measurement by detecting the photoplethysmographic pulses and electronic Korotkoff-sounds during cuff deflation

Objective:The commonly used noninvasive techniques for blood pressure measurement, auscultatory Korotkoff-based sphygmomanometry and oscillometry, both have limitations in their clinical use. The former is relatively accurate but is limited to use in a physician’s office because its automatic variant is subject to noise artifacts. Automatic oscillometers can be used at home, but their accuracy is low. In the current study, we present two electronic techniques for systolic blood pressure (SBP) measurement that are more accurate than the available techniques, and can be automated.Approach:The cuff-based electronic techniques for SBP measurement used in this study utilize a finger photoplethysmographic (PPG) signal or electronically recorded Korotkoff sounds, and detection of the first appearance of PPG or Korotkoff-based pulses during cuff deflation. Most noise artefacts were eliminated by means of a time-reference signal—a PPG signal measured in the free hand.Main results:The two electronic techniques showed good agreement. Both techniques were found to be more accurate than the auscultatory Korotkoff-based technique, the gold-reference, in those examinations where large discrepancies were found between them, since the PPG and Korotkoff-based electronic pulses appeared before Korotkoff sounds were heard. The PPG signal in the free hand, that served as a time-reference signal, enabled both electronic techniques to eliminate artefacts—noise pulses that appeared outside the time intervals in which a blood-pressure-related pulses should appear.Significance:The two electronic techniques provide accurate systolic blood pressure measurements and can be implemented automatically, as was shown in a previous study on blood pressure measurement by PPG.Trial registration number of the institutional ethical committee of Shaare-Zedek Medical Center, Jerusalem is 0154-16-SZMC.

Comparison of Various Blood Pressure Measurement Techniques with Standard Office Based Blood Pressure Mesurement

Comparison of Various Blood Pressure Measurement Techniques with Standard Office Based Blood Pressure Mesurement

Accuracy of fully automated oscillometric central aortic blood pressure measurement techniques.

Central aortic blood pressure (cBP) is a valuable predictor of cardiovascular risk. The lack of fully automated measurement devices impeded an implementation in daily clinical practice so far. The present study compares two novel automated oscillometric devices with invasively measured cBP. From March 2017 to March 2018, we enrolled consecutive patients undergoing elective coronary angiography to this cross-sectional study. Noninvasive assessment of cBP was performed by the SphygmoCor XCEL device and the Mobil-O-Graph NG device simultaneously to invasive measurement. Our study included 502 patients (228 women, 274 men) with a mean age of 67.9 ± 11.6 years. The noninvasive measurement of cBP was successful in 498 patients (99%) with SphygmoCor XCEL device and in 441 patients (88%) with Mobil-O-Graph NG device (P = 0.451). Measurements of both devices revealed a high correlation to invasively measured systolic (SphygmoCor R 0.864, P < 0.001; Mobil-O-Graph R 0.763, P < 0.001) and diastolic (SphygmoCor R 0.772, P < 0.001; Mobil-O-Graph R 0.618, P < 0.001) cBP. Both devices slightly underestimated systolic and overestimated diastolic central blood pressure: biases were -5.0 ± 7.7/0.5 ± 6.2 mmHg with SphygmoCor XCEL and -6.0 ± 10.4/3.6 ± 8.3 mmHg with Mobil-O-Graph NG device. Correlations (R) were higher and biases were lower with the SphygmoCor device (P < 0.001 each). The present study is the largest validation study of noninvasive cBP measurement techniques so far and shows that two current automated oscillometric monitors are able to assess cBP with acceptable accuracy. Automated oscillometric devices may facilitate the implementation of cBP in daily clinical practice.

Approaches for the Management of Resistant Hypertension in 2020.

Resistant hypertension is diagnosed if the blood pressure (BP) is not controlled despite optimum doses of 3 first-line classes of antihypertensive drugs including a thiazide diuretic or if adequate BP control needs 4 or more antihypertensive drugs from different classes. Pseudohypertension and white coat hypertension must be excluded. Poor patient compliance, inadequate doses of antihypertensive drugs, poor office BP measurement technique, and having to pay for costs of drugs are factors associated with pseudoresistant hypertension. Secondary hypertension must be excluded and treated. Therapy of resistant hypertension includes improving compliance with use of medication, detection, and treatment of secondary hypertension, use of lifestyle measures, and treatment of obesity and other comorbidities. Switching the patient from hydrochlorothiazide to a longer acting thiazide-type diuretic such as chlorthalidone may improve BP control. The beneficial effects of thiazide diuretics are reduced when the glomerular filtration rate is reduced to less than 40mL/min/1.73m2. These patients should be treated with a loop diuretic such as furosemide every 12h. If a fourth antihypertensive drug is needed to control blood pressure in persons treated with adequate doses of antihypertensive drugs from different classes including a thiazide-type diuretic, a mineralocorticoid receptor antagonist should be added to the therapeutic regimen. Further research is needed on investigational drugs and device therapy for treating resistant hypertension. Clinical trials are indicated for the treatment of resistant hypertension by sacubitril/valsartan and also by firibastat.

Blood Pressure Measurement: A KDOQI Perspective

The majority of patients with chronic kidney disease (CKD) have elevated blood pressure (BP). In patients with CKD, hypertension is associated with increased risk for cardiovascular disease, progression of CKD, and all-cause mortality. New guidelines from the American College of Cardiology/American Heart Association (ACC/AHA) recommend new thresholds and targets for the diagnosis and treatment of hypertension in patients with and without CKD. A new aspect of the guidelines is the recommendation for measurement of out-of-office BP to confirm the diagnosis of hypertension and guide therapy. In this KDOQI (Kidney Disease Outcomes Quality Initiative) perspective, we review the recommendations for accurate BP measurement in the office, at home, and with ambulatory BP monitoring. Regardless of location, validated devices and appropriate cuff sizes should be used. In the clinic and at home, proper patient preparation and positioning are critical. Patients should receive information about the importance of BP measurement techniques and be encouraged to advocate for adherence to guideline recommendations. Implementing appropriate BP measurement in routine practice is feasible and should be incorporated in system-wide efforts to improve the care of patients with hypertension. Hypertension is the number 1 chronic disease risk factor in the world; BP measurements in the office, at home, and with ambulatory BP monitoring should adhere to recommendations from the AHA.

Repurposing of Iloperidone: Antihypertensive and ocular hypotensive activity in animals

PurposeIloperidone, second generation antipsychotic drug, reported in clinical trial to produce orthostatic hypotension as side effect. It was claimed to be antagonistic at alpha adrenergic receptor in central nervous system. We evaluated effect of Iloperidone on peripheral alpha 1 adrenoreceptor by in silico and in vitro methods while in vivo hypotensive, antihypertensive and ocular hypotensive activity was evaluated in animals. MethodsPharmacological activity prediction of Iloperidone was done using PASSOnline and SwissTargetPrediction softwares and molecular docking with Alpha 1A adrenoreceptor using AutoDock Vina. Hypotensive activity in normotensive and antihypertensive activity against DOCA-salt induced hypertension in rats were evaluated at doses 0.03 mg/Kg and 0.1 mg/Kg, i.p of Iloperidone. Blood pressure was measured by invasive blood pressure measurement technique using PowerLab 4/30 and intraocular pressure was measured using digital tonometer. ResultsIloperidone (0.1 mg/Kg) showed significant decrease in blood pressure (38.96 ± 1.1%) in normotensive rats, while in DOCA salt induced hypertensive rats, systolic blood pressure was found to be decreased by 29.04 ± 1.45% and 31.43 ± 1.21% in 0.03 mg/Kg and 0.1 mg/Kg treated rats respectively. Iloperidone prevented rise in systolic BP with adrenaline. Intraocular pressure was found to be decreased by 36.66 ± 3.15% in rabbits after 1 h of instillation of 0.1% Iloperidone. ConclusionIloperidone exerted hypotensive and/or anti-hypertensive activity in rats and ocular hypotensive activity in rabbits.

Which out-of-office measurement technique should be used for diagnosing hypertension in prehypertensives?

Hypertension (HT) is diagnosed with high office blood pressure (BP), although confirmation with the addition of out-of-office measurements is currently recommended. However, insufficient data are available concerning the use of out-of-office BP measurement techniques for the diagnosis of HT in the prehypertensive population. The aim of the present study was to determine which out-of-office measurements yielded earlier and more frequent detection of development of HT in prehypertensive patients. Two hundred seven prehypertensive patients under monitoring in the Cappadocia cohort were included in the study. Office BP was measured five times at 1-min intervals, followed by 24-h ambulatory BP monitoring (24-h ABPM). Home BP measurement (HBPM) was performed five times, at the same times in the morning and evening, at 1-min intervals for 1 week. The same procedure was carried out at 4–6-month intervals for ~2 years. HT was diagnosed in 25.6% of subjects, masked HT in 11.1%, and white coat HT in 2.9%, while 23.7% remained prehypertensive and 36.7% became normotensive. Briefly, 56.6% of the patients with HT were diagnosed with office plus 24-h ABPM, 13.2% with office plus HBPM, and 30.2% with office plus HBPM and 24-h ABPM. Office with 24-h ABPM yielded statistically significantly more diagnoses (p < 0.001). In conclusion, our prospective observational study evaluated the usefulness of out-of-office BP measurements in confirming diagnosis of HT in prehypertensive patients. The findings show that 24-h ABPM detected HT earlier and more frequently in this high-risk population.

To what extent can the chosen blood pressure measurement technique affect the outcomes of an observational survey?

Aim: We analyzed to what extent measurement protocol influenced individual blood pressure (BP) and achievement of treatment target in patients with coronary heart disease. Methods: In a subsample of Czech EUROASPIRE III-V survey participants (n=913), we compared the per-protocol BP measurement (by automated oscillometric device OMRON at the beginning of survey procedure) with control auscultatory measurement (by physician during interview). Results: Per-protocol approach produced significantly (p<0.0001) higher BP values (by 9/6mmHg in median) than auscultatory measurements and led to markedly higher proportion of patients over target BP (less than 140/90mmHg; 59.3 vs 34.9% [p<0.0001], per-protocol vs auscultatory technique, respectively). Conclusion: Per-protocol oscillometric technique was not equivalent to conventional auscultatory measurement and seriously over-rated the real nonachievement of BP target in observational surveys.

COMPARISON OF AUTOMATED OFFICE BLOOD PRESSURE WITH OFFICE AND OUT-OF-OFFICE MEASUREMENT TECHNIQUES

Objective:Automated office blood pressure (AOBP), a fully automated unattended BP measurement technique represents an attractive alternative or integrative option to assess patient's blood pressure (BP) status. However, the lack of strong evidences to establish a threshold value for hypertension dia

Comparisons between different blood pressure measurement techniques in patients with chronic kidney disease.

BackgroundAutomated office blood pressure (AOBP) machines measure blood pressure (BP) multiple times over a brief period. We aimed to compare the results of manual office blood pressure (MOBP) and AOBP methods with ambulatory BP monitoring (ABPM) in patients with chronic kidney disease (CKD).MethodsThis study was performed on 64 patients with CKD (stages 3–4). A nurse manually measured the BP on both arms using a mercury sphygmomanometer, followed by AOBP of the arm with the higher BP and then ABPM. Mean BP readings were compared by paired t test and Bland–Altman graphs.ResultsThe mean ± standard deviation (SD) age of participants was 59.3 ± 13.6. The mean ± SD awake systolic BP obtained by ABPM was 140.2 ± 19.0 mmHg, which was lower than the MOBP and AOBP methods (156.6 ± 17.8 and 148.8 ± 18.6 mmHg, respectively; P < 0.001). The mean ± SD awake diastolic BP was 78.6 ± 13.2 mmHg by ABPM which was lower than the MOBP and AOBP methods (88.9 ± 13.2 and 84.1 ± 14.0 mmHg, respectively; P < 0.001). Using Bland–Altman graphs, MOBP systolic BP readings showed a bias of 16.4 mmHg, while AOBP measurements indicated a bias of 8.6 mmHg compared with ABPM.ConclusionAOBP methods may be more reliable than MOBP methods for determining BP in patients with CKD. However, the significantly higher mean BPs recorded by AOBP method suggested that AOBPs may not be as accurate as ABPM in patients with CKD.

A Non-Invasive Continuous Blood Pressure Estimation Approach Based on Machine Learning.

Considering the existing issues of traditional blood pressure (BP) measurement methods and non-invasive continuous BP measurement techniques, this study aims to establish the systolic BP and diastolic BP estimation models based on machine learning using pulse transit time and characteristics of pulse waveform. In the process of model construction, the mean impact value method was introduced to investigate the impact of each feature on the models and the genetic algorithm was introduced to implement parameter optimization. The experimental results showed that the proposed models could effectively describe the nonlinear relationship between the features and BP and had higher accuracy than the traditional methods with the error of 3.27 ± 5.52 mmHg for systolic BP and 1.16 ± 1.97 mmHg for diastolic BP. Moreover, the estimation errors met the requirements of the Advancement of Medical Instrumentation and British Hypertension Society criteria. In conclusion, this study was helpful in promoting the practical application of methods for non-invasive continuous BP estimation models.

Blood pressure measurement in pregnancy and in hypertensive disorders of pregnancy: devices, techniques and challenges.

Measurement of blood pressure is essential for clinical management of patients. To obtain an accurate blood pressure reading, the use of a validated device and an appropriate technique are required. This is of particular importance in pregnancy where the physiological changes affect vessel wall compliance. Moreover, currently it is difficult to predict in early pregnancy (prior to 20 weeks of gestation) which women would develop hypertension or pre-eclampsia. For this reason, blood pressure devices require validation in pregnancy and in hypertensive disorders of pregnancy to ensure that accurate readings are obtained and utilised for clinical decisions, otherwise the safety of the mother or the foetus/neonate or both may be compromised. The authors provide a narrative review on devices and techniques for blood pressure measurement in pregnancy and hypertensive disorders of pregnancy as well as the associated challenges.

The Management of Hypertension in 2018: What Should the Targets Be?

To provide an overview of the different guidelines for hypertension management from around the world. The guidelines discussed include those from the United States (US), Europe, Canada, and Latin America. All guidelines except the US define hypertension as >140/90mmHg, and the US defines it as >130/80mmHg. In general, all guidelines except those from the US emphasize lifestyle modification as the cornerstone of initial therapy given blood pressure levels <140/90mmHg. The US emphasizes lifestyle modification at all BP levels starting at 130/80mmHg. Additionally, all guidelines emphasize the need to assess cardiovascular risk with the Canadian guidelines indicating that a high cardiovascular risk person should have a goal of <130/80mmHg. All agree on the proper method of blood pressure measurement techniques and importance of home blood pressure. All support use combination therapy with the European guideline emphasizing initial therapy should be a combination pill. All guidelines stress the importance of patient adherence to maintain blood pressure control. All guidelines emphasize lifestyle modification, need for home blood pressure measurement, as well as use of proper techniques to measure blood pressure. The fundamental difference between US and all other guidelines is the definition of hypertension, >130/80mmHg in US and > 140/90mmHg in the rest of the world.

Abstract P171: Effect of Intensive and Standard Clinic-Based Hypertension Management on the Concordance Between Clinic and Ambulatory Blood Pressure and Blood Pressure Variability: Systolic Blood Pressure Intervention Trial (SPRINT)

Blood pressure (BP) varies over time within individual patients and across different BP measurement techniques. The effect of different BP targets on the concordance between BP measurements is unknown. The goal of this analysis was to evaluate concordance in: 1) clinic BP and ambulatory BP, 2) clinic visit-to-visit variability and ambulatory BP variability and 3) initial and repeat ambulatory BP. We also sought to evaluate whether treatment assignment of intensive vs standard BP target affected these relationships. The Systolic Blood Pressure Intervention Trial (SPRINT) ambulatory blood pressure monitoring ancillary study obtained ambulatory BP readings in 897 SPRINT participants at the 27 month follow up visit and 203 consecutive repeat ambulatory BP readings taken an average of 9.8 months later. There was poor agreement between clinic systolic BP and daytime ambulatory systolic BP (limits of agreement in Bland-Altman plots of -21 to 34 mm Hg in the intensive treatment group and -26 to 32 mm Hg in the standard treatment group). There was poor agreement between clinic visit-to-visit variability (coefficient of variation) and ambulatory BP variability (coefficient of variation of a 24 hr ambulatory BP) with correlation coefficients for systolic BP &lt;0.16. While there was a high correlation between ambulatory BP at 27 months and repeat ambulatory BP (r ~0.56), there was significant variability between repeat ambulatory BP assessments (limits of agreement of -27 to 21 mm Hg in the intensive group and -23 to 20 mm Hg in the standard group). In conclusion, irrespective of treatment target, we found low concordance in BP and BP variability between clinic BP and ambulatory BP, and additionally between repeat ambulatory BP assessments. These results reinforce the need for multiple guideline adherent BP measurements prior to clinical decision making.

Ambulatory Blood Pressure Monitoring: Profiles in Chronic Kidney Disease Patients and Utility in Management.

Optimal control of blood pressure (BP) may reduce the risk of progression of CKD. Misclassification of hypertension (HTN) and status of control may result in suboptimal management. Clinic or home BP may overestimate or underestimate status of control compared with ambulatory BP monitoring (ABPM), which is considered the gold standard. The latter relates not only to the superiority of ABPM concerning outcome prognosis but also to its ability to accurately diagnose white coat and masked HTN, which is critical in assuring adequate BP control. However, ABPM has not gained widespread use in practice because of limited third-party reimbursement and a paucity of high quality randomized controlled intervention studies evaluating its use. Herein, we review HTN phenotypes that have been identified in patients with CKD, and the potential value of ABPM in this high-risk population.

Resistant Hypertension: Diagnosis and Management.

Resistant hypertension is defined as high blood pressure requiring 3 or more medications for adequate control or controlled blood pressure requiring 4 or more medications. Considering the growing prevalence of hypertension and the strong link with cardiovascular disease, it is vital to understand the causes and treatment of resistant hypertension. This review article starts with an overview of the prevalence and little-known pathophysiology of resistant hypertension. Afterward, we discuss the evaluation and management of suspected secondary resistant hypertension in 2 broad categories: pseudoresistant hypertension and true resistant hypertension. Strategies for the identification and management of pseudoresistant hypertension are addressed. In addition, causes of true resistant hypertension, such as obstructive sleep apnea, primary aldosteronism, and renal artery stenosis, are examined along with their respective treatments. Finally, treatment of resistant hypertension is reviewed including pharmacologic treatments and novel procedural interventions for resistant hypertension. Overall, the review hopes to provide practitioners with a cohesive approach for the diagnosis and treatment of resistant hypertension.

Assessment of Blood Pressure: Techniques and Implications From Clinical Trials.

Hypertension is a global health problem and without adequate diagnosis and treatment is a risk factor for morbidity and mortality. Proper assessment of blood pressure is key to diagnosis and management of hypertension. Different methods of measurement are available for use and varying techniques are applied to patient care. Understanding the proper methods of blood pressure measurement both in and out of the physician's office is crucial for providing appropriate care to an individual patient. In addition, understanding the techniques used in research, on which current guidelines are based, is critical for proper application to daily practice. In this article, we review the types of blood pressure measurement techniques, discuss the benefits and limitations to each, explore future technological advances in measurement devices, and provide insight into research techniques, which ultimately guide our practice.

Principales conclusiones del Consenso Argentino de Hipertensión Arterial

A summary is presented in this article of the principal concepts of the Argentine Consensus on Arterial Hypertension, which has been carried out for the first time jointly by the three main scientific societies associated with the diagnosis and treatment of arterial hypertension in Argentina (Argentine Society of Arterial Hypertension, Argentine Society of Cardiology and Argentine Federation of Cardiology).Among its main points, is emphasised the need to improve the diagnosis and control of high blood pressure, the use of ambulatory blood pressure measurement techniques, the importance of the risk stratification of the hypertensive patient, and the early use of pharmacological combinations in the treatment as a means to quickly achieve control. Finally, it lists the main recommendations for the management of hypertension in special populations, such as pregnant women, elderly people, diabetics, resistant patients, as well as patients with chronic kidney disease.

Pulse transit time technique for cuffless unobtrusive blood pressure measurement: from theory to algorithm.

Cuffless technique holds great promise to measure blood pressure (BP) in an unobtrusive way, improving diagnostics and monitoring of hypertension and its related cardiovascular diseases, and maximizing the independence and participation of individual. Pulse transit time (PTT) has been the most commonly employed techniques for cuffless BP estimation. Many studies have been conducted to explore its feasibility and validate its performance in the clinical settings. However, there is still issues and challenges ahead before its wide application. This review will investigate the understanding and development of the PTT technique in depth, with a focus on the physiological regulation of arterial BP, the relationship between PTT and BP, and the summaries of the PTT-based models for BP estimation.

Blood Pressure Estimation Using Photoplethysmography Only: Comparison between Different Machine Learning Approaches.

Introduction Blood pressure (BP) has been a potential risk factor for cardiovascular diseases. BP measurement is one of the most useful parameters for early diagnosis, prevention, and treatment of cardiovascular diseases. At present, BP measurement mainly relies on cuff-based techniques that cause inconvenience and discomfort to users. Although some of the present prototype cuffless BP measurement techniques are able to reach overall acceptable accuracies, they require an electrocardiogram (ECG) and a photoplethysmograph (PPG) that make them unsuitable for true wearable applications. Therefore, developing a single PPG-based cuffless BP estimation algorithm with enough accuracy would be clinically and practically useful. Methods The University of Queensland vital sign dataset (online database) was accessed to extract raw PPG signals and its corresponding reference BPs (systolic BP and diastolic BP). The online database consisted of PPG waveforms of 32 cases from whom 8133 (good quality) signal segments (5 s for each) were extracted, preprocessed, and normalised in both width and amplitude. Three most significant pulse features (pulse area, pulse rising time, and width 25%) with their corresponding reference BPs were used to train and test three machine learning algorithms (regression tree, multiple linear regression (MLR), and support vector machine (SVM)). A 10-fold cross-validation was applied to obtain overall BP estimation accuracy, separately for the three machine learning algorithms. Their estimation accuracies were further analysed separately for three clinical BP categories (normotensive, hypertensive, and hypotensive). Finally, they were compared with the ISO standard for noninvasive BP device validation (average difference no greater than 5 mmHg and SD no greater than 8 mmHg). Results In terms of overall estimation accuracy, the regression tree achieved the best overall accuracy for SBP (mean and SD of difference: −0.1 ± 6.5 mmHg) and DBP (mean and SD of difference: −0.6 ± 5.2 mmHg). MLR and SVM achieved the overall mean difference less than 5 mmHg for both SBP and DBP, but their SD of difference was >8 mmHg. Regarding the estimation accuracy in each BP categories, only the regression tree achieved acceptable ISO standard for SBP (−1.1 ± 5.7 mmHg) and DBP (−0.03 ± 5.6 mmHg) in the normotensive category. MLR and SVM did not achieve acceptable accuracies in any BP categories. Conclusion This study developed and compared three machine learning algorithms to estimate BPs using PPG only and revealed that the regression tree algorithm was the best approach with overall acceptable accuracy to ISO standard for BP device validation. Furthermore, this study demonstrated that the regression tree algorithm achieved acceptable measurement accuracy only in the normotensive category, suggesting that future algorithm development for BP estimation should be more specific for different BP categories.