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American Journal of Hypertension May 2023There are six different formulae for estimating mean arterial pressure (MAP) from systolic and diastolic pressure readings. This study is to determine the optimum...
BACKGROUND
There are six different formulae for estimating mean arterial pressure (MAP) from systolic and diastolic pressure readings. This study is to determine the optimum formula for calculating MAP when compared to the gold standard approach, which is the area under the curve of an invasively measured pulse waveform divided by the cardiac cycle duration.
METHODS
Eight live pigs were used as the experimental model for the invasive measurement of femoral artery pressure (AP) by a fluid filled catheter connected with a pressure transducer. In addition, intraocular pressure (IOP) and jugular vein pressure (JVP) were also recorded. The mean pressure (MP) was calculated from digital waveforms sampled at 1,000 points per second with the six formulae and area method for AP, IOP and JVP.
RESULTS
The absolute mean difference between the area MAP and each formula's MAP ranged from 0.98 to 3.23 mm Hg. Our study also found that even under physiological conditions, area MAP can vary between successive pulses by up to 5 mm Hg. For mean IOP and JVP, the mean difference between a formula's MP and the area method's was less than 1 mm Hg for most formulae. With the pooled data, there was excellent agreement amongst all formulae for MAP with the intra-class correlation coefficient (ICC) ranging from 0.97 to 0.99, while the ICC of most formulae for IOP and JVP was 1.0.
CONCLUSIONS
Our study suggests that all current formulae are adequate for estimating MAP, though some formulae are not suitable for mean IOP and JVP.
Topics: Swine; Animals; Blood Pressure; Intraocular Pressure; Arterial Pressure; Heart; Heart Rate
PubMed: 36945835
DOI: 10.1093/ajh/hpad026 -
American Journal of Physiology.... Oct 2023Peripheral artery disease (PAD) refers to obstructed blood flow in peripheral arteries typically due to atherosclerotic plaques. How PAD alters aortic blood pressure and...
Peripheral artery disease (PAD) refers to obstructed blood flow in peripheral arteries typically due to atherosclerotic plaques. How PAD alters aortic blood pressure and pressure wave propagation during exercise is unclear. Thus, this study examined central blood pressure responses to plantar flexion exercise by investigating aortic pulse wave properties in PAD. Thirteen subjects with PAD and 13 healthy [age-, sex-, body mass index (BMI) matched] subjects performed rhythmic plantar flexion for 14 min or until fatigue (20 contractions/min; started at 2 kg with 1 kg/min increment up to 12 kg). Brachial (oscillometric cuff) and radial (SphygmoCor) blood pressure and derived-aortic waveforms were analyzed during supine rest and plantar flexion exercise. At rest, baseline augmentation index ( = 0.0263) and cardiac wasted energy ( = 0.0321) were greater in PAD due to earlier arrival of the reflected wave ( = 0.0289). During exercise, aortic blood pressure (aMAP) and aortic pulse pressure showed significant interaction effects ( = 0.0041 and = 0.0109, respectively). In particular, PAD had a greater aMAP increase at peak exercise ( = 0.0147). Moreover, the tension time index was greater during exercise in PAD ( = 0.0173), especially at peak exercise ( = 0.0173), whereas the diastolic time index ( = 0.0685) was not different between the two groups. Hence, during exercise, the subendocardial viability ratio was lower in PAD ( = 0.0164), especially at peak exercise ( = 0.0164). The results suggest that in PAD, the aortic blood pressure responses and myocardial oxygen demand during exercise are increased compared with healthy controls.
Topics: Humans; Arterial Pressure; Blood Pressure; Peripheral Arterial Disease; Heart Rate; Exercise; Pulse Wave Analysis
PubMed: 37486070
DOI: 10.1152/ajpregu.00303.2022 -
Reviews in Cardiovascular Medicine Jan 2022Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting 0.5%-1% of people worldwide. Hemodynamic changes due to stiffening of the arteries may cause... (Review)
Review
Atrial fibrillation (AF) is the most common cardiac arrhythmia, affecting 0.5%-1% of people worldwide. Hemodynamic changes due to stiffening of the arteries may cause cardiac structural and electrical remodeling that induces AF.Pulse wave velocity (PWV) is a direct non-invasive method to measure arterial stiffness (AS). Central pulse pressure (PPc) describes oscillations around the mean arterial pressure and is increased in more rigid arteries. These two central variables can be considered markers of AF. Sympathetic activity has been reported to be directly relatedto PWV even in patients without comorbidities. Therefore, in patients with more rigid arteries, sudden changes in pressure could affect the activation of arterial baroreceptors, leading to an acute imbalance between the sympathetic and parasympathetic responses in the heart. The coexistence of AF and AS is common. This critical review aims to bring information about the role of AS in the pathophysiology of AF and discuss results of clinical studies on this topic. Althuogh discussed in the literature, further studies are needed to confirm the predictive role of these variables in AF, and their use in clinical practice.
Topics: Arterial Pressure; Atrial Fibrillation; Blood Pressure; Humans; Pulse Wave Analysis; Vascular Stiffness
PubMed: 35092224
DOI: 10.31083/j.rcm2301032 -
American Journal of Hypertension May 2022Heart failure (HF) is frequent in patients with diabetes mellitus (DM), and early detection improves prognosis. We investigated whether analysis of brachial blood...
BACKGROUND
Heart failure (HF) is frequent in patients with diabetes mellitus (DM), and early detection improves prognosis. We investigated whether analysis of brachial blood pressure (BP) in daily practice can identify patients with DM and high risk for subsequent HF, as defined by brain natriuretic peptide (BNP) >50 pg/ml.
METHODS
3,367 outpatients with DM without a history of cardiovascular disease were enrolled in a prospective study.
RESULTS
Age (mean ± SD) was 56 ± 14 years, 57% were male, 78% had type 2 DM, and HbA1C was 7.4 ± 1.4%. A history of hypertension was recorded in 43% of patients and uncontrolled BP was observed in 13%. BNP concentration (mean ± SD) was 21 ± 21 ng/l and 9% of patients had high risk of incident HF. Brachial pulse pressure (PP) was the best BP parameter associated with high risk of incident HF compared with diastolic, systolic, or mean BP (area under the receiver operating characteristic curve: 0.70, 0.65, 0.57, and 0.57, respectively). A multivariate analysis demonstrated that elevated PP was independently associated with high risk of incident HF (odds ratio [95% confidence interval, CI]: 2.1 [1.5-2.8] for PP ≥65 mm Hg). Study of central aortic BP and pulse wave velocity on 117 patients demonstrated that high risk of incident HF was associated with increased arterial stiffness and subendocardial ischemia. After a mean follow-up of 811 days, elevated PP was associated with increased all-cause mortality (hazard ratio [95% CI]: 1.7 [1.1-2.8]).
CONCLUSIONS
Brachial PP is powerful and independent "easy to record" BP parameter associated with high risk of incident HF in diabetic patients.
Topics: Adult; Aged; Blood Pressure; Diabetes Mellitus; Female; Heart Failure; Humans; Hypertension; Male; Middle Aged; Natriuretic Peptide, Brain; Prospective Studies; Pulse Wave Analysis
PubMed: 34969077
DOI: 10.1093/ajh/hpab179 -
Stroke Apr 2022Increased cerebral arterial pulsatility is associated with cerebral small vessel disease, recurrent stroke, and dementia despite the best medical treatment. However, no...
BACKGROUND
Increased cerebral arterial pulsatility is associated with cerebral small vessel disease, recurrent stroke, and dementia despite the best medical treatment. However, no study has identified the rates and determinants of progression of arterial stiffness and pulsatility.
METHODS
In consecutive patients within 6 weeks of transient ischemic attack or nondisabling stroke (OXVASC [Oxford Vascular Study]), arterial stiffness (pulse wave velocity [PWV]) and aortic systolic, aortic diastolic, and aortic pulse pressures (aoPP) were measured by applanation tonometry (Sphygmocor), while middle cerebral artery (MCA) peak (MCA-PSV) and trough (MCA-EDV) flow velocity and Gosling pulsatility index (PI; MCA-PI) were measured by transcranial ultrasound (transcranial Doppler, DWL Doppler Box). Repeat assessments were performed at the 5-year follow-up visit after intensive medical treatment and agreement determined by intraclass correlation coefficients. Rates of progression and their determinants, stratified by age and sex, were determined by mixed-effects linear models, adjusted for age, sex, and cardiovascular risk factors.
RESULTS
In 188 surviving, eligible patients with repeat assessments after a median of 5.8 years. PWV, aoPP, and MCA-PI were highly reproducible (intraclass correlation coefficients, 0.71, 0.59, and 0.65, respectively), with progression of PWV (2.4%; <0.0001) and aoPP (3.5%; <0.0001) but not significantly for MCA-PI overall (0.93; =0.22). However, PWV increased at a faster rate with increasing age (0.009 m/s per y/y; <0.0001), while aoPP and MCA-PI increased significantly above the age of 55 years (aoPP, <0.0001; MCA-PI, =0.009). Higher aortic systolic blood pressure and diastolic blood pressure predicted a greater rate of progression of PWV and aoPP, but not MCA-PI, although current MCA-PI was particularly strongly associated with concurrent aoPP (<0.001).
CONCLUSIONS
Arterial pulsatility and aortic stiffness progressed significantly after 55 years of age despite the best medical treatment. Progression of stiffness and aoPP was determined by high blood pressure, but MCA-PI predominantly reflected current aoPP. Treatments targetting cerebral pulsatility may need to principally target aortic stiffness and pulse pressure to have the potential to prevent cerebral small vessel disease.
Topics: Animals; Blood Pressure; Geese; Humans; Middle Aged; Middle Cerebral Artery; Pulse Wave Analysis; Vascular Stiffness
PubMed: 34852644
DOI: 10.1161/STROKEAHA.121.035560 -
Hypertension (Dallas, Tex. : 1979) Feb 2023An association between blood pressure and aortic stiffness is well known, but ambiguity remains as to whether one precedes the other. This study aimed to investigate the...
BACKGROUND
An association between blood pressure and aortic stiffness is well known, but ambiguity remains as to whether one precedes the other. This study aimed to investigate the association of aortic stiffness with contemporaneous versus historic blood pressure and direction of causality between aortic stiffening and hypertension in female twins.
METHODS
Aortic stiffness, measured by carotid-femoral pulse wave velocity (PWV), and mean arterial pressure (MAP) was recorded in 2037 female TwinsUK participants (mean age: 62.4±9.7 years) at a single time point. A subset of 947 participants had repeat PWV and MAP measures (mean interval 5.5±1.7 years) with additional historic MAP (mean interval 6.6±3.3 years before baseline).
RESULTS
Cross-sectional multivariable linear regression analysis confirmed PWV significantly associated with age and MAP. In longitudinal analysis, annual progression of PWV was not associated with historic MAP (standardized beta coefficient [β]=-0.02, =0.698), weakly associated with baseline MAP (β=0.09, =0.049) but strongly associated with progression (from baseline to most recent measurement) of MAP (β= 0.26, <0.001). Progression of MAP associated with both baseline and progression of PWV (β=0.13, =0.003 and β=0.24, <0.001, respectively).
CONCLUSIONS
Progression of aortic stiffness associates more strongly with contemporaneous MAP compared with historic MAP. In contrast, progression of MAP is associated with prior arterial stiffness. These findings suggest a bidirectional relationship between arterial stiffness and blood pressure, and that lowering blood pressure may prevent a cycle of arterial stiffening and hypertension.
Topics: Humans; Female; Middle Aged; Aged; Blood Pressure; Pulse Wave Analysis; Cross-Sectional Studies; Arterial Pressure; Hypertension; Vascular Stiffness
PubMed: 36408690
DOI: 10.1161/HYPERTENSIONAHA.122.19311 -
Journal of Hypertension Sep 2023The aim was to study if children following preeclampsia (PE) develop alterations in blood pressure (BP) and arterial stiffness already early in life, and how this is... (Clinical Trial)
Clinical Trial
OBJECTIVES
The aim was to study if children following preeclampsia (PE) develop alterations in blood pressure (BP) and arterial stiffness already early in life, and how this is associated with gestational, perinatal and child cardiovascular risk profiles.
METHODS
One hundred eighty-two PE (46 early-onset with diagnosis before 34 gestational weeks, and 136 late-onset) and 85 non-PE children were assessed 8-12 years from delivery. Office and 24-h ambulatory BP, body composition, anthropometrics, lipids, glucose, inflammatory markers, and tonometry-derived pulse wave velocity (PWV) and central BPs were assessed.
RESULTS
Office BP, central BPs, 24-h systolic BP (SBP) and pulse pressure (PP) were higher in PE compared with non-PE. Early-onset PE children had the highest SBP, SBP-loads, and PP. SBP nondipping during night-time was common among PE. The higher child 24-h mean SBP among PE was explained by maternal SBP at first antenatal visit and prematurity (birth weight or gestational weeks), but child 24-h mean PP remained related with PE and child adiposity after adjustments. Central and peripheral PWVs were elevated in late-onset PE subgroup only and attributed to child age and anthropometrics, child and maternal office SBP at follow-up, but relations with maternal antenatal SBPs and prematurity were not found. There were no differences in body anthropometrics, composition, or blood parameters.
CONCLUSIONS
PE children develop an adverse BP profile and arterial stiffness early in life. PE-related BP is related with maternal gestational BP and prematurity, whereas arterial stiffness is determined by child characteristics at follow-up. The alterations in BP are pronounced in early-onset PE.Clinical Trial Registration information: https://clinicaltrials.gov/ct2/show/NCT04676295ClinicalTrials.gov Identifier: NCT04676295.
Topics: Child; Female; Humans; Pregnancy; Arterial Pressure; Blood Pressure; Blood Pressure Monitoring, Ambulatory; Cardiovascular Diseases; Heart Disease Risk Factors; Hypertension; Pre-Eclampsia; Pulse Wave Analysis; Risk Factors; Vascular Stiffness
PubMed: 37337860
DOI: 10.1097/HJH.0000000000003485 -
Biomedizinische Technik. Biomedical... Jun 2021Arterial blood pressure is one of the most often measured vital parameters in clinical practice. State-of-the-art noninvasive ABP measurement technologies have... (Review)
Review
Arterial blood pressure is one of the most often measured vital parameters in clinical practice. State-of-the-art noninvasive ABP measurement technologies have noticeable limitations and are mainly based on uncomfortable techniques of complete or partial arterial occlusion by cuffs. Most commonplace devices provide only intermittent measurements, and continuous systems are bulky and difficult to apply correctly for nonprofessionals. Continuous cuffless ABP measurements are still an unmet clinical need and a topic of ongoing research, with only few commercially available devices. This paper discusses surrogate-based noninvasive blood pressure measurement techniques. It covers measurement methods of continuously and noninvasively inferring BP from surrogate signals without applying external pressures, except for reference or initialization purposes. The BP is estimated by processing signal features, so called surrogates, which are modulated by variations of BP. Discussed techniques include well-known approaches such as pulse transit time and pulse arrival time techniques, pulse wave analysis or combinations thereof. Despite a long research history, these methods have not found widespread use in clinical and ambulatory practice, in part due to technical limitations and the lack of a standardized regulatory framework. This work summarizes findings from an invited workshop of experts in the fields covering clinical expertise, engineering aspects, commercialization and standardization issues. The goal is to provide an application driven outlook, starting with clinical needs, and extending to technical actuality. It provides an outline of recommended research directions and includes a detailed overview of clinical use case scenarios for these technologies, opportunities, and limitations.
Topics: Blood Pressure; Blood Pressure Determination; Humans; Pulse Wave Analysis; Signal Processing, Computer-Assisted
PubMed: 33565285
DOI: 10.1515/bmt-2020-0209 -
Blood Pressure Dec 2024Carotid-femoral pulse wave velocity (cfPWV) and central pulse pressure (PP) are recognised as significant indicators of vascular health and predictors of cardiovascular...
BACKGROUND
Carotid-femoral pulse wave velocity (cfPWV) and central pulse pressure (PP) are recognised as significant indicators of vascular health and predictors of cardiovascular outcomes. In this study, associations between central hemodynamics and left ventricular (LV) echocardiographic parameters were investigated in subjects with heart failure with reduced ejection fraction (HFrEF), comparing the results to healthy individuals.
METHODS AND RESULTS
This cross-sectional prospective controlled study included 50 subjects with HFrEF [mean LV ejection fraction (EF) 26 ± 6.5%] and 30 healthy controls (mean LVEF 65.9 ± 5.3%). Pulse wave analysis (PWA) and carotid-femoral pulse wave velocity (cfPWV) were used to measure central hemodynamics and arterial stiffness. The HFrEF group displayed higher cfPWV (8.2 vs. 7.2 m/s, = 0.007) and lower central (111.3 vs. 121.7 mmHg, = 0.001) and peripheral (120.1 vs. 131.5 mmHg, = 0.002) systolic blood pressure. Central pulse pressure (PP) was comparable between the two groups (37.6 vs. 40.4 mmHg, = 0.169). In the HFrEF group, cfPWV significantly correlated with left ventricular end-diastolic volume (LVEDV) index (mL/m) and LVEF, with LVEDV index being a significant independent predictor of cfPWV (R = 0.42, = 0.003). Central PP was significantly associated with heart rate, LVEF and LVEDV index, with the latter being a significant independent predictor of central PP (R = 0.41, < 0.001). These correlations were not observed in healthy controls.
CONCLUSIONS
Significant associations between central hemodynamic measures and LV echocardiographic parameters were identified, suggesting the potential to use PWA and cfPWV as possible tools for managing HFrEF.
Topics: Humans; Heart Failure; Male; Female; Cross-Sectional Studies; Middle Aged; Pulse Wave Analysis; Blood Pressure; Stroke Volume; Prospective Studies; Vascular Stiffness; Aged; Echocardiography
PubMed: 38819846
DOI: 10.1080/08037051.2024.2359932 -
Current Hypertension Reviews 2021The relationship between the increases in pulse pressure (PP) and arterial stiffness determined by aging or systemic hypertension has been widely reported. These...
BACKGROUND
The relationship between the increases in pulse pressure (PP) and arterial stiffness determined by aging or systemic hypertension has been widely reported. These findings are supported by large-cohort analyzes conducted in well-known populations, such as Framingham Study. However, there is evidence that an age-PP curvilinear relationship may exist in hypertensive subjects. This study aimed to evaluate the age-related change in pulse pressure and arterial stiffness in a population-based study.
METHODS
Carotid-femoral Pulse Wave Velocity (cfPWV) were obtained in 2075 subjects.
RESULTS
Age-related changes of PP showed a curvilinear relationship (R=0.39, p<0.0001) in normotensive subjects, with a nadir at around 50 years of age. On the other hand, the age-cfPWV relationship showed a linear and positive correlation (R=0.72, p<0.0001). PP also showed a curvilinear relationship with age (R=0.36, p<0.0001) in hypertensive subjects, with a nadir around 50 years of age. The age-cfPWV relationship showed a linear and positive correlation (R=0.55, p<0.0001). Similar results were observed in the adult population (age≥16 years). Multivariate analysis showed that age, sex, cfPWV, and mean arterial pressure are determinants of PP values in the entire population; however, this result was not uniform when different subgroups were analyzed.
CONCLUSION
In conclusion, age-related changes in PP showed a curvilinear relationship and no parallelism with the age-cfPWV relationship for both normotensive and hypertensive subjects. The determinants of PP impact it differently depending on age and the pathological condition of the subject.
Topics: Adult; Arterial Pressure; Blood Pressure; Humans; Hypertension; Middle Aged; Pulse Wave Analysis; Vascular Stiffness
PubMed: 33305707
DOI: 10.2174/1573402116999201210195123