The Relationship between Arterial Blood Pressure and Pulse Transit Time During Dynamic and Static Exercise

The relationships between arterial systolic and diastolic blood pressure (SBP and DBP), interbeat interval (IBI), and various pulse transit times were investigated in 5 young, healthy males during physical exercise and at rest. Transit times monitored were radial, brachial and dorsalis pedis RPIs (ECG R-wave to pulse intervals), and brachial-radial and radial-dorsalis pedis PPIs (pulse to pulse intervals). Experimental sessions consisted of three periods: two involving mild dynamic exercise plus rests, and one involving static exercise (handgrips) plus rests. Correlation and regression analyses within period and subject were performed on individual beat data. Radial RPI was highly correlated with SBP (during dynamic periods, range ?.57 to ?.89, median r?.81; during static periods, range ?.80 to ?.88, median r=?.87) and moderately correlated with DBP (during dynamic periods, range ?.10 to ?.63, median r?.52; during static periods, range ?.17 to ?.77, median r?.66). Median correlations of radial RPI with SBP and DBP during exercise and rest separately were ?.75 and ?.40 (dynamic), ?.79 and ?.57 (static), and ?.74 and ?.26 (rest). The IBI X radial RPI product was very highly correlated with the rate-pressure product (heart rate X SBP), an index of myocardial oxygen consumption (median r=?.96). The only PPI which reliably indexed SBP or DBP change was brachial-radial PPI during the static exercise period (median r=?.86 and ?.83).     

Effect of satisfaction with social support on blood pressure in normotensive and borderline hypertensive men and women

The relation between blood pressure (BP) and two aspects of social support, perceived satisfaction and structural social support network characteristics, were examined in adults classified as having normal BP or borderline hypertension. Casual BP_s were taken by a trained technician on 3 separate visits, each approximately 1 week apart. Participants were categorized as borderline hypertensive if screening systolic blood pressure (SBP) fell in the range 130-160 mmHg and/ordiastolic blood pressure (DBP) fell in the range 85-100 mmHg; BP_s below these ranges were considered normotensive. Participants underwent ambulatory BP monitoring, Individuals classified as normotensive reported significantly greater support satisfaction than individuals with borderline hypertension. Social network characteristics were not associated with BP. During 24 hr of ambulatory BP monitoring, high perceived support satisfaction was associated with lower SBP and DBP at work, home, and during sleep. These data suggest that perceived satisfaction with social support is associated with lower BP. The presence of social support also may reduce BP levels during daily life. This study was supported by National Institutes of Health (NIH) Grants HL49427, HL49572. HL53724, and MOI-RR-30, National Center far Research Resources, Clinical Research Centers Program, National Institutes of Health.     

The Covariation of Blood Pressure and Pulse Transit Time in Hypertensive Patients

To examine the relationship between blood pressure (BP) and pulse transit time (PTT) as measured by the time between the ECG R-wave and an associated peripheral pulse, BP was recorded via a radial artery catheter in 3 hvpertensive subjects who underwent a variety of conditions to alter BP. Overall. 70% of the data was usable. Absolute levels of systolic blood pressure (SBP) but not diastolic blood pressure (DBP) were found to correlate appreciably with PTT. There were significant associations between PTT and both SBP and mean BP but not DBP for direction of BP change. With large SBP changes (> 4 mmHg) an increase in the strength of association occurred in 14 of the 21 conditions across subjects. Overall, PTT did not accurately predict actual BP. PTT and SBP covaried more appreciably in these hypertensives than has been reported for normotensives.     

Posture, Place, and Mood Effects on Ambulatory Blood Pressure

Ambulatory blood pressure was studied as a function of posture, place, and mood in 131 subjects classified according to race, gender, and hypertensive status. The effect of posture was significant and explained a substantial proportion of within-subject variability. After controlling for posture, significant place and mood effects were observed when subjects were sitting but not when they were standing. Home vs. work differences in both systolic and diastolic blood pressure were significantly greater in Whites than in Blacks. Similar differences in systolic blood pressure were greater in mild hypertensive than in normotensive subjects. The results of this study underscore the need to control for effects of posture when interpreting ambulatory blood pressure readings.     

Increased ambulatory arterial stiffness index and blood pressure load in normotensive obese patients

ObjectivesIt has been shown that blood pressure (BP) values measured in obese subjects are higher than the individuals with normal weight, even in normotensive limits. However, data concerning the Ambulatory Arterial Stiffness Index (AASI) and blood pressure load in normotensive obese subjects is lacking. This study was aimed to compare the ambulatory arterial stiffness index and blood pressure load in normotensive obese and healthy controls.MethodsOne hundred normotensive obese and one hundred normal weight subjects were included in this study. All subjects underwent 24-hour ambulatory blood pressure monitoring. Ambulatory arterial stiffness index was calculated from 24-hour ambulatory blood pressure monitoring records. Ambulatory arterial stiffness index was defined as one minus the regression slope of unedited 24-h diastolic on systolic blood pressures. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) load values were calculated from 24-hour ambulatory blood pressure monitoring analysis.ResultsAmbulatory arterial stiffness index of the obese subjects was significantly higher than the healthy controls (0.48±0.2 vs. 0.33±0.11, p<0.001). 24-hours systolic blood pressure and diastolic blood pressure loads were significantly higher in obese subjects. Logistic regression analysis revealed that body mass index (BMI) was an independent predictor for an abnormal ambulatory arterial stiffness ındex (≥0.50) (OR: 1.137, 95% CI: 0.915-1.001, p=0.004).ConclusionBlood pressure load and ambulatory arterial stiffness index are increased in normotensive obese patients. Moreover, body mass index is an independent predictor for an abnormal ambulatory arterial stiffness index. Our results indicate that obese subjects are at higher risk for future cardiovascular events despite normal office BP levels.     

Cardiovascular Responses to Stress: I. Measures of Myocardial Response and Relationship to High Resting Systolic Pressure and Parental Hypertension

A comparison of pre-ejection period (PEP), heart rate (HR), and systolic (SBP) and diastolk (DBP) blood pressure responses to the cold pressor test and a pseudo-shock avoidance reaction time task was performed in 183 young men. These tasks differ in the extent to which they evoke enhanced myocardial and vascular adrenergic activity. Decreases in PEP were more pronounced during the reaction time task, while DBP increased more during the cold pressor test. MR and SBP responses did not differentiate the two tasks. PEP decreases occurred in the absence of any apparent increase in cardiac preload or decrease in afterload. Parental hypertension as determined by physician reports was associated with higher SBP across all conditions. A subgroup of individuals (15%) showed SBP levels >140 mm Hg when typical clinical stethoscopic determinations were made, but less than half as many showed such elevations during a more extended resting baseline using remotely operated devices. High stethoscopic SBP was associated with greater cardiovascular responses to the stressors, while high SBP during the extended baseline was not.     

How Many Blood Pressure Measurements are Enough?: An Application of Generalizability Theory to the Study of Blood Pressure Reliability

Generalizability theory was applied to blood pressure measurements collected under various designs in order to determine the number of readings needed to attain reliable estimates. The designs assessed variation within the same day in the laboratory, home, and work; variation across days in the laboratory; and variation across measuring devices. Two samples of normotensive (n=40 and n=79) subjects participated in the study. Blood pressure was measured using either a mercury sphygmomanometer, a Dinamap Adult/Pediatric monitor, or a Spacelabs Ambulatory monitor. The results showed that only one reading is necessary whenever generalizations are restricted to the same day in the laboratory. At least six readings of systolic blood pressure are needed at home and at work, and 6 to 10 diastolic blood pressure readings may be required from work and home, respectively. To generalize across days, one or two readings from each of two days for systolic blood pressure and from more than three days for diastolic blood pressure may be required. At least one replication with each of two instruments is necessary in order to generalize across instruments in the laboratory.     

Aortic-Radial Pulse Transit Time and ECG Q-Wave to Radial Pulse Wave Interval as Indices of Beat-By-Beat Blood Pressure Change

This study examined beat-by-beat relationships between blood pressure, the time interval from the ECG Q-wave to the radial pulse wave (QRPI), and its two components, the cardiac pre-ejection period (PEP) and aortic-radial arterial pulse transit time (AR-PTT). In 8 subjects, intra-arterial systolic (SBP) and diastolic (DBP) blood pressure, QRPI, PEP, and AR-PTT were measured during rest, mental arithmetic, cold pressor, and inhalation of amyl nitrite. Both PEP and AR-PTT varied widely during each experimental condition indicating that QRPI change reflected both PEP and AR-PTT change. AR-PTT varied inversely with SBP and DBP; PEP sometimes varied directly and sometimes inversely with both SBP and DBP. QRPI varied inversely with both SBP and DBP with the magnitude of the correlation in a particular instance depending on the relationships for that instance between blood pressure and both PEP and AR-PTT. Implications of the results for the use of either QRPI or AR-PTT as indices of blood pressure change are discussed.     

Covariation of mood and blood pressure during daily activities

The relationship between blood pressure (BP) and self-reported mood states was examined for 49 subjects in their natural environment. Subjects performed their usual activities during a 2-day period and recorded their BP using a semiautomated BP monitor at predetermined intervals. Adjective checklists describing mood states and perceptions of the environment as stressful were completed concurrent with each BP measurement. A correlational analysis of average BP and average mood state ratings was performed along with a paired t-test analysis of mood states associated with high versus low BP. The results show that holding anger in correlated positively with average SBP and negatively with average HR. Neither anger arousal nor the expression of anger arousal was able to distinguish between high and low BP readings. The Type A adjective cluster discriminated between high and low SBP as well as between high and low HR readings. The cluster of negative moods also discriminated between high and low SBP. Perceptions of the environment as hostile and demanding discriminated high versus low SBP and high versus low DBP. The discussion focuses upon the value of repeated-measures designs in examining mood/BP relationships as individuals ambulate in their natural environment.This article is based on the first author's dissertation, which was supervised by the second author and submitted to Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the doctoral degree.Portions of this article were presented at the 8th Annual Meeting of the Society of Behavioral Medicine, Washington, D.C., 1987.     

Physical Symptoms Associated with Blood Pressure

Two experiments employed within-subject designs to assess the degree to which selected physical symptoms correlated with systolic blood pressure (SBP) fluctuations. In the first study, 30 normotensive undergraduates (15 male and 15 female) participated in a series of 20 tasks and 20 baseline sessions, each lasting 1–2 min. Following each task or baseline, readings of systolic and diastolic blood pressure, heart rate, skin resistance, and finger pulse volume were taken. Immediately before the physiological measurements, subjects rated the degree to which they were experiencing each of 7 symptoms (e.g., sweaty hands, pounding heart). For each subject, simple correlations were computed between each of the symptoms and SBP across the 40 measurement periods. Forty-four percent of the subjects had at least one symptom-SBP correlation of + .70 or greater. Seventy-seven percent had at least one statistically significant symptom-SBP correlation. Between-subject analyses yielded no symptom-SBP relationships. The within-subjects correlation patterns varied from subject to subject, were internally consistent, and were related to sex and SBP variability. A second naturalistic experiment corroborated the findings. Theoretical and practical implications of the results are discussed.     

Target Blood Pressure in Patients with Diabetes: Asian Perspective

Recently, the Action to Control Cardiovascular Risk in Diabetes (ACCORD) blood pressure (BP) trial enrolled 4733 participants with type 2 diabetes and randomized them to a target systolic blood pressure (SBP) of less than 120 mm Hg or 140 mm Hg. Despite the significant difference in the achieved SBP, there was no significant difference in the incidence of primary outcomes. Based on this evidence, the target SBP for diabetics has been revised in the majority of major guidelines. However, there is a steeper association between SBP and stroke in Asians than other ethnicities, with stroke being the leading cause of cardiovascular mortality. This suggests that target BP in the Asian region should be tailored towards prevention of stroke. In the ACCORD study, the intensive BP treatment was associated with significant reductions in both total stroke and non-fatal stroke. The results from the ACCORD study are supported by a subgroup analysis from the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) study, which showed that, in diabetic patients, the risk of stroke continues to decrease to a SBP value of 115 mm Hg with no evidence of J curve. As diabetes is highly associated with underlying coronary artery disease, there is a justified concern for adverse effects resulting from too much lowering of BP. In a post hoc analysis of 6400 diabetic subjects enrolled in the International Verapamil SR-Trandolapril (INVEST) study, subjects with SBP of less than 110 mm Hg were associated with a significant increase in all-cause mortality. In the ONTARGET study, at any levels of achieved SBP, diastolic blood pressure (DBP) below 67 mm Hg was associated with increased risk for cardiovascular outcomes. As such, a prudent approach would be to target a SBP of 130–140 mm Hg and DBP of above 60 mm Hg in diabetics with coronary artery disease. In conclusion, hypertension, in association with diabetes, has been found to be significantly correlated with an elevated risk for cardiovascular events. As the association between stroke and BP is stronger in Asians, compared to other ethnicities, consideration should be given for a target BP of 130/80 mm Hg in Asians.     

Pulse Transit Time and Blood Pressure: An Intensive Analysis

Relationships between pulse transit time (PTT) and intra-arterial systolic (SBP), diastolic (DBP), and mean arterial blood pressure (MAP) were examined in 4 subjects under three conditions: rest, paced respiration, and mental arithmetic. PTT was measured from the EKG R-wave to two peripheral pulses (brachial and radial) and from one pulse to the other. Three points on each pulse wave were used (peak, foot, slope) in the measurements, yielding nine different measures of PTT. The nine PTT measures were not consistently intercorrelated. PTTs initiated by the R-wave were moderately correlated with SBP, but not with DBP or MAP. Brachial to radial PTTs were not correlated with any measures of BP. Relationships between PTT and BP also varied from subject to subject. The limited magnitude of the correlations and their inconsistency suggest caution in the simple substitution of PTT for beat-to-beat measures of BP.     

Trait Anger, Anger Expression, and Ambulatory Blood Pressure: A Meta-Analytic Review

A meta-analysis of 15 studies was conducted to investigate the relationship between trait anger and ambulatory blood pressure. Overall, the experience of anger was significantly and positively associated with systolic blood pressure (r ₊ = 0.049), but not reliably associated with diastolic blood pressure (r ₊ = 0.028). After removing an outlier, the expression of anger was found to have a reliable inverse relationship with diastolic blood pressure (r ₊ = –0.072). No reliable relationship between expression of anger and systolic blood pressure (r ₊ = –0.041) was found. These results continue to support the modest role of self-reported trait anger and anger expression in blood pressure levels. Several suggestions for future research are discussed, including increasing the focus on the complexity and synergism of these effects.     

老年高血压的动态血压监测

对60例老年高血压病患者(Ⅰ期24例,Ⅱ期21例、Ⅲ期15例)、30例健康老年人、30例健康中青年分别进行动态血压监测和比较。结果老年对照组动态血压监测各参数值均明显高于中青年对照组;高血压Ⅰ、Ⅱ、Ⅲ期各组与老年对照组比较各参数值也明显增高。如以老年对照组各项参数的(?)±2s为正常高限,则高血压Ⅰ、Ⅱ、Ⅲ期各组分别有9、13、15项数值超过正常。其中以24小时平均收缩压和舒张压日间平均收缩压和舒张压、夜间平均收缩压和舒张压及血压负荷值等为诊断动态高血压的重要指标。     

Blood pressure levels and variance assessed by ambulatory monitoring: Optimal parameters

We obtained multiple ambulatory blood pressure monitoring (ABPM) records over five years from two trained, normotensive subjects experienced in wearing the apparatus. The resulting time series data on systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were used to suggest optimal parameters for monitoring by two instruments (Colin Medical Instruments ABPM-630 and Del Mar Avionics Pressurometer) and to compare two indirect methods (auscultatory and oscillometric). A 10-min sampling interval day and night provided sufficient density of data to support spectral analysis for ultradian rhythms in the frequency range of one cycle per hour to one cycle per 9 h on a 24-h record. Rhythms with major periods of approximately 3, 6, and 9 h were variously found in 94 normotensive subjects, aged 20 to 95 years, including the two trained subjects. When the monitoring period was extended to 72 h, the circadian (∼24 h) rhythm could be more sharply defined, as well as a 12-h harmonic. In some studies the two trained subjects wore two monitors, one on each arm, set to read simultaneously. From the simultaneous measurements on both arms, it was shown that averaging across three points (30 min of record) reduced the coefficient of variation between the two simultaneous records to 6% or less. Auscultatory and oscillometric methods were equally reliable. Echocardiographic data were obtained in five normotensive subjects and compared to their ABPM data. The ABPM records provided additional information about cardiovascular function not merely duplicating that obtained by acute stress tests, such as exercise or cold pressor responses, or echocardiography. Standards for ABPM are suggested.     

Caffeine, extended stress, and blood pressure in borderline hypertensive men

Caffeine increases blood pressure (BP), and its pressor effects are larger in borderline hypertensive (BH) men than in controls. This article extends findings of larger caffeine effects on BP at rest and to brief mental stress in BH to a new analysis of caffeine and prolonged mental stress in BH. In a double-blind, crossover study, 24 male BH (140/90 mmHg < BP < 160/95 mmHg) and 23 normotensive controls who were habitual caffeine consumers (NT; BP < 135/85 mmHg; negative parental history) worked on alternating mental stressors for 35 min after placebo or caffeine (3.3 mg/kg). Caffeine raised systolic blood pressure (SBP) and diastolic blood pressure (DBP) alone and during the extended tasks (all ps < .00001/.00001). BH had larger SBP and DBP increases over all postcaffeine periods (ps < .04/04) and larger DBP rises to the extended tasks after caffeine (p = .007). These combined effects led to undesirably high BPs (> 140/82 mmHg) relative to controls (< 130/75) during the 100 min after caffeine intake. Caffeine taken by BH at times of extended behavioral stress may elevate BP to a clinically meaningful degree. This research was supported by the Medical Research Service of the Department of Veterans Affairs and the National Heart Lung and Blood Institute of the National Institutes of Health, grant numbers HL32050 and HL07640. We thank Barbara McKey and Judith Silverstein for their efforts in data collection and Terrie Thomas for her valuable comments on an earlier version of this article.     

Predicting Home and Work Blood Pressure Measurements from Resting Baselines and Laboratory Reactivity in Black and White Americans

The relationship between blood pressure in the laboratory (both at rest and in response to laboratory tasks) and ambulatory blood pressure at home and at work was evaluated. One hundred nineteen normotensive and unmedicated mild-moderate hypertensive black and white females and males participated in laboratory blood pressure monitoring at rest and during four challenging tasks (structured interview, video game, bicycle exercise, and cold pressor test) as well as ambulatory blood pressure monitoring while at home and at work. Baseline blood pressure taken while subjects were at rest was the strongest predictor of ambulatory systolic blood pressure (r = .64) and diastolic blood pressure (r = .77) at work. Among reactivity tasks the strongest predictors of ambulatory blood pressure in the total population were the structured interview and the video game (both psychological tasks) followed by the cold pressor test. Racial comparisons, however, determined that the cold pressor test predicted diastolic blood pressure significantly better for blacks (r = .73) than for whites (r = .40), suggesting a possible difference in blood pressure regulation.     

Blood pressure effects of long-term stimulant use in disorders of hypersomnolence

Untoward cardiovascular effects have been implicated as a deterrent to long-term central nervous system (CNS) stimulant use in disorders of hypersomnolence. In this study, we reviewed the relationship between blood pressure and long-term stimulant use. Medical records of 54 patients with narcolepsy and idiopathic CNS hyper- somnolence (ICH) were reviewed. The overall mean number of months of follow-up for the entire group was 45.6 (95% CI: 42–49). Both simple linear regression and multiple regression utilizing generalized estimating equations were used to show relationships between blood pressure (BP), time and other covariates. In the simple linear regression model, the average slope of the line of systolic BP (SBP) on time for the entire group was 0.06 (95% CI: -0.09, 0.13) and the line of diastolic BP (DBP) on time was 0.01 (95% CI: -0.05, 0.07). Two multiple regression equations were fitted for the continuous response variables SBP and DBP. Covariates in the model included: time, hypertension, weight at baseline, weight, SBP baseline (SBPBL), DBP baseline (DBPBL), high vs. low dose stimulant therapy and age at starting treatment. For SBP, the covariates weight at baseline, weight and SBPBL were significant (P< 0.05) predictors. For DBP, covariates reaching statistical significance (P< 0.05) included weight and DBPBL. There was no significant change in SBP or DBP over time in either model. Two different statistical models support the conclusion that there was no significant change in SBP or DBP over time in this population.     

Cardiac vagal control mediates the relation between past depression and blood pressure several years later among young adults

Depression has been associated with high blood pressure (BP). However, the mechanisms of the relation between depression and high BP are unclear. We therefore examined whether impaired cardiac vagal control, indexed as low levels of resting respiratory sinus arrhythmia (RSA), serves as a route from depression to high BP. The sample included 125 subjects with histories of depression (probands), 123 never depressed siblings of probands (high-risk siblings), and 156 controls. Resting RSA was assessed at Time 1 (T1) along with BP when subjects were adolescents (M_age = 16.3 years); systolic and diastolic BP (SBP and DBP) were measured again at Time 2 (T2) when subjects were young adults (M_age = 22.3 years). Linear mixed-effects models were used to examine the group differences in resting RSA and T2 BP outcomes and to test for RSA mediation of the relation between depression (history or being at high risk) and BP. Resting RSA was lower among probands than controls but was similar among high-risk siblings and controls, while the subject groups did not differ in T2 SBP or DBP. Controlling for T1 BP, depression history indirectly affected T2 DBP (but not SBP) through resting RSA. The findings suggest that, although the direct detrimental effects of depression on BP are not yet evident in young adulthood, among those with depression histories, impaired cardiac vagal control appears to serve as a mechanism of elevated DBP.