Automatic Blood Pressure Recorder Research Articles

Arrhythmias and diabetes: atrial fibrillation

Arrhythmias and diabetes: atrial fibrillation

Hemodynamic Effects of Local Anesthesia and its Possible Correlation with Chromogranin A

Aim: To study the effects of local anesthesia on blood pressure in patients undergo extraction of maxillary teeth under infiltration local anesthesia and to compare the level of salivary chromogranin A before and after administration of local anesthesia and its possible correlation with hemodynamic effects of local anesthesia. Materials and Methods: A total of 26 patients (18 female, 8 male) who need tooth extraction under infiltration local anesthesia were examined in two situations (pre and post local anesthetic administration). For each patient salivary sample was collected by salivette to estimate the level of chromogranin A using ELISA Kits. For all patients, the blood pressure and pulse rate were measured before and after administration of local anesthesia using automatic blood pressure recorder. Results: the results showed significant differences between salivary chromogranin A for patients before the administration of local anesthesia (580.33 ± 130.42) ng/ml and after the administration of local anesthesia (674.51+ 130.93) ng/ml with p 0.05) with pre –local anesthetic value. The pulse rate was increase in it is value after local anesthetic administration with a significant differences (p 0.05) while it caused increase in pulse rate with a significant effect (p < 0.05). Administration of infiltration local anesthesia caused significant effects on salivary chromogranin A levels, also this study showed that there was significant inverse correlation between systolic blood pressure and chromogranin A levels(p < 0.05) after administration of infiltrations local anesthesia during dental treatments (tooth extraction).

A Prospective Randomized Study of Automated versus Mercury Blood Pressure Recordings in Hypertensive Pregnancy (PRAM Study)

Background. Mercury sphygmomanometry is being replaced with automated blood pressure (BP) recording. We tested the potential impact of this change on the outcomes of pregnant women with hypertension. Methods. Following routine detection of hypertension by mercury sphygmomanometry, 220 pregnant women with hypertension were randomized to have all subsequent BPs recorded with either mercury sphygmomanometry or an automated BP device (Omron HEM-705CP) for the remainder of their pregnancy. We used a prospective randomized open study with blinded end points design. Main Outcome Measures. The primary maternal outcome measure was the number of women having any episode of severe hypertension (BP 170/110 mmHg). The primary fetal outcome measure was small for gestational age baby. Results. Both groups were similar in age, weight, parity, race, use of assisted reproductive technology before this pregnancy, diabetes prevalence, smoking, mercury BP in the first trimester, use of antihypertensives at the time of study entry, and type of hypertension (essential, gestational or preeclampsia) at study entry. Severe hypertension occurred in 39% of women using mercury sphygmomanometry and 44% using the automated device (p = 0.5). Small for gestational age rates were 12 and 17%, respectively (p = 0.3). About 47% of women had preeclampsia at delivery. Birth weight and perinatal mortality were similar between groups. Conclusions. Using this automated BP recording device in hypertensive pregnant women is associated with similar maternal and fetal outcomes as in women whose BP is measured by sphygmomanometry, despite intra-individual BP differences between the two methods of recording BP.

Can We Use the Omron T9P Automated Blood Pressure Monitor in Pregnancy?

Background. Recent events in our hospital, combined with international recommendations, catalyzed the need to move from mercury sphygmomanometry to automated blood pressure (BP) recording in pregnancy. Aim. To test the accuracy of the Omron T9P automated BP recorder in pregnant women, using mercury sphygmomanometry as the gold standard. Setting. Antenatal clinics and obstetric day assessment unit, St George Hospital, Sydney. Participants. Eighty-five pregnant women, 11% of whom were receiving antihypertensives. Methods. Differences in both systolic and diastolic BP between the T9P Omron device and mercury sphygmomanometer were obtained for each woman, using sequential automated and mercury BP recordings, as required by a modified British Hypertension Society (BHS) protocol. The accuracy of the device was graded according to the BHS and the Association for the Advancement of Medical Instrumentation (AAMI) standards. Results. The Omron T9P device received an A/A grade according to this modified BHS and AAMI testing process, though the range of the 255 differences was 1–13 for systolic BP and 1–10 for diastolic BP. Conclusions. The Omron T9P device is an accurate device for use predominantly in an outpatient antenatal clinical setting. Further studies are required solely within hypertensive pregnant women before its use can be recommended with certainty in this group.

Orthostatic Hypotension and Risk of Cardiovascular Disease in Elderly People: The Rotterdam Study

To determine the prognostic role of orthostatic hypotension for cardiovascular disease (CVD) and all-cause mortality in elderly people. Prospective study. Community based. Five thousand sixty-four subjects from the Rotterdam study aged 55 and older. Orthostatic hypotension was measured using a Dinamap automatic blood pressure recorder. Orthostatic hypotension is defined as a decline in systolic blood pressure of 20 mmHg or more or a decline in diastolic blood pressure of 10 mmHg or more from supine to standing position at any of three measurements taken 1, 2, and 3 minutes after standing. At baseline, 901 subjects had orthostatic hypotension. During follow-up, 668 subjects had coronary heart disease (CHD) (mean follow-up 6.0 +/- 3.5 years), and 1,835 subjects died (mean follow-up period 7.8 +/- 3.8 years). Orthostatic hypotension increased the risk of CHD (hazard ratio (HR)=1.31, 95% confidence interval (CI)=1.08-1.57) and all-cause mortality (HR=1.22, 95% CI=1.09-1.36), in models adjusted for age and sex. The risk was slightly lower after additional adjustment for cardiovascular risk factors. In analyses stratified for age, the HRs for all-cause mortality were 1.80 (95% CI 1.25-2.60), 1.13 (0.89-1.42), and 1.27 (95% CI=1.11-1.44), in the first, second, and third tertile of age, respectively. Orthostatic hypotension increases the risk of CHD and all-cause mortality in elderly people. The risk of CVD and mortality is strongest in younger and very old subjects.

Comparison Between an Automated and Manual Sphygmomanometer in a Population Survey

An automated sphygmomanometer, the BpTRU, was used in a blood pressure (BP) survey of 2,551 residents in the province of Ontario. Automated BP readings were compared with measurements taken by a mercury sphygmomanometer under standardized conditions in a random 10% sample. BP was recorded in 238 individuals in random order using both a standard mercury device and an automated BP recorder, the BpTRU. All subjects rested for 5 min prior to the first BP reading, which was then discarded. The mean of the next three readings was obtained using the mercury device whereas the BpTRU was set to record a mean of five readings taken at 1 min intervals with subjects resting alone in a quiet room. The mean s.d. BP with the automated device was 115 +/- 16/71 +/- 10 mm Hg compared to 118 +/- 16/74 +/- 10 mm Hg for the manual BP (P < 0.001). A systolic BP > or = 140 mm Hg was present for 16 automated and 19 manual readings. Similarly, the diastolic BP was > or = 90 mm Hg for 9 automated and 14 manual readings. Linear regression analysis showed that automated BP was a significant (P < 0.001) predictor of both manual systolic and diastolic BP. Conventional manual BP readings can be replaced by readings taken using a validated, automated BP recorder in population surveys. The slightly lower readings obtained with the BpTRU device (in the context of reduced observer-subject interaction) may be a more accurate estimate of BP status.

Studies of autonomic response patterns: Rationale and methods

This report briefly summarizes the results of eighteen years of research on the measurement of autonomic functions in human subjects during rest, and presents a discussion of hypotheses and methodology for the study of autonomic response patterns. Most of the report is devoted to a discussion of instrumentation and methods of measurement employed in current investigations. The following variables are measured: electrical resistance of palmar skin; respiration rate; finger, face, and axillary temperatures; heart rate, potentials and rhythms; changes in finger and leg blood volume; systolic and diastolic blood pressures; stroke volume of the heart; pupillary diameter; stomach and lower bowel motility; salivary output; and selected muscle action potentials. Most responses are amplified and recorded continuously and simultaneously by means of chopper type Offner amplifiers. Pupillary diameter and systolic and diastolic blood pressure are time sampled; the former by means of a Bolex motion picture camera, the latter by means of a Gilson automatic blood pressure recorder. Stomach motility is recorded continuously by means of a new method—a magnetometer which remotely detects the movements of a small ingested magnet. Lower bowel motility is recorded by a bipolar electrode.

Relation between Nocturnal Arterial Oxygen Desaturation and Morning Blood Pressure

Objective. Arterial oxygen saturation (SpO2) in volunteers had been previously investigated, and the possibility that a decrease in SpO2 leads to an increase in blood pressure (BP) in airline passengers experiencing oxygen desaturation at high altitudes was reported. It was also shown that mean nocturnal SpO2 was lower in subjects with high-normal BP or mild hypertension than in those with normal BP. The present study investigated nocturnal SpO2, evening BP, and morning BP of volunteers during daily life and examined the relation between nocturnal SpO2 and change in BP (morning BP minus evening BP) to determine the influence of SpO2 on BP. Methods. Sixty-two volunteers (31 men and 31 women) aged 40–87 years (mean: 55.9 ± 12 [SD] years) underwent measurement of SpO2 and heart rate with a ring-shaped pulse oximeter during sleep at home. Evening BP and morning BP were measured by automatic BP recorder. Subjects that were classified as having high SpO2 (mean nocturnal SpO2 ≥ 95%; n = 23, 10 men and 13 women; mean age: 53.2 ± 12 years) or low SpO2 (mean nocturnal SpO2 < 94%; n = 21, 12 men and 9 women; mean age: 58.7 ± 13 years) were compared. The relation between mean nocturnal SpO2 and morning BP and the relation between mean nocturnal SpO2 and change in BP were investigated. Results. There was a significant negative correlation between mean nocturnal SpO2 and morning systolic BP (SBP; r = −0.50, p < 0.01) and between mean nocturnal SpO2 and morning diastolic BP (DBP; r = −0.37, p < 0.01). A significant negative correlation between mean nocturnal SpO2 and change in SBP was observed (r = −0.57, p < 0.01). Morning BP was significantly higher in the low nocturnal SpO2 group than in the high nocturnal SpO2 group (p < 0.001). Conclusion. The increase in morning BP from evening BP was significantly greater in subjects with a low nocturnal SpO2. The decrease in SpO2 during sleep may affect morning BP rise.

Automated blood pressure measurement in routine clinical practice

To compare blood pressure measurements taken in routine clinical practice using an automated recorder, the BpTRU (VSM MedTech Ltd, Coquitlam, Canada), with readings taken by a conventional mercury sphygmomanometer. Fifty consecutive patients [28 women, 22 men; mean (+/-SD) age 62+/-16 years] referred to a specialist for management of hypertension had blood pressure taken on the first visit in random order using both a mercury sphygmomanometer and an automated device. The mean initial automated reading (mmHg) taken with the observer present (162+/-27/85+/-12) was similar to the mean manual blood pressure taken in duplicate (163+/-23/86+12). Both values were higher (P<0.001) than the mean of the next five readings taken with the automated recorder when the patient was resting quietly alone (142+/-21/80+/-12). Women exhibited a greater fall in blood pressure with the automated device than men. Use of an automated blood pressure recorder can eliminate some of the white-coat effect associated with readings taken by a mercury sphygmomanometer.

Automated self-initiated blood pressure or 24-hour ambulatory blood pressure monitoring in pregnancy?

To determine whether self-initiated and recorded automated blood pressure measurement can provide an accurate estimate of ambulatory blood pressure in pregnant women suspected of having 'white coat hypertension'. A prospective observational study. Women's and Children's Health Unit, St George Hospital, a teaching hospital of the University of New South Wales. Pregnant women being assessed for possible 'white-coat hypertension'. Sixty-six pregnant women who were undergoing 24 hour ambulatory blood pressure monitoring (ABPM) in their home or work environment also measured their blood pressure six times during this interval using a self-initiated automated blood pressure recorder (Omron HEM 705CP). Agreement between awake ABPM and Omron recorded blood pressures was tested by Bland-Altman analysis. Limits of agreement between blood pressures measured by each device. Average blood pressures obtained by the two devices were identical (125/77 mmHg) but limits of agreement were wide, -20 to +23 mmHg for systolic blood pressure and -9 to +15 mmHg for diastolic blood pressure. The Omron HEM 705CP is a useful device for measuring group average blood pressures in pregnant women suspected of having white coat hypertension but cannot reliably replace ABPM for clinical management of individual pregnant women.

Use of an automated blood pressurerecording device, the BpTRU, to reduce the“white coat effect” in routine practice

Background Patients often exhibit higher blood pressure (BP) readings in the doctor’s office, a phenomenon known as the white coat effect. This study examines the presence of a physician in the examining room as a possible factor in provoking a white coat effect. Methods Blood pressure measurements taken by an automated BP recording device, the BpTRU (VSM MedTech Ltd., Vancouver, BC, Canada) with the patient alone in the examining room, were compared with the following: 1) BP taken by the patient’s family physician; 2) BP taken on the first visit to a hypertension specialist; 3) BP measured by a trained research technician and 4) the mean awake ambulatory BP (ABP). The BpTRU and trained research technician readings were taken outside of the office (treatment) setting in an ABP research unit. Results Blood pressure readings (mm Hg, mean ± SEM) taken by the BpTRU (155 ± 5/88 ± 2) tended to be lower than for the family physician (166 ± 4/89 ± 3) and the hypertension specialist (174 ± 5/92 ± 2; P < .001). However, BP taken by the trained research technician (158 ± 4/90 ± 2) was similar to the value obtained by the BpTRU. The mean awake ABP was lower ( P < 0.01) than the other four BP values. Conclusions Use of an automated BP recording device outside of the office (treatment) setting can partly eliminate the white coat effect. A similar finding was observed with readings taken by a trained research technician under similar conditions. Referral of patients to nonoffice settings for automated BP recordings may provide a more accurate estimate of a patient’s BP status, with partial elimination of the white coat effect associated with readings taken by a physician.

A fermented milk high in bioactive peptides has a blood pressure–lowering effect in hypertensive subjects

Angiotensin-converting enzyme (ACE; EC 3.4.15.1) plays a dual role in the regulation of hypertension: it catalyzes the production of the vasoconstrictor angiotensin II and it inactivates the vasodilator bradykinin. By inhibiting these processes, ACE inhibitors have antihypertensive effects. Peptides derived from milk proteins can have ACE-inhibiting properties and may thus be used as antihypertensive components. We evaluated the long-term blood pressure-lowering effect of milk fermented by Lactobacillus helveticus LBK-16H in hypertensive subjects. In a randomized placebo-controlled study, 39 hypertensive patients received 150 mL/d of either L. helveticus LBK-16H fermented milk or a control product for 21 wk after a 2-wk run-in period. During the run-in period, the average baseline diastolic and systolic blood pressure values were 155 and 97 mm Hg, respectively, in the test product group and 152 and 96 mm Hg, respectively, in the control group. After the run-in period, blood pressure was measured at home on the same day every week with the use of an automatic blood pressure recorder. There was a mean difference of 6.7 +/- 3.0 mm Hg in systolic blood pressure (P = 0.030) and of 3.6 +/- 1.9 mm Hg (P = 0.059) in diastolic blood pressure between the test product and control groups. Demographic factors had no significant effect on the responses. L. helveticus LBK-16H fermented milk containing bioactive peptides in normal daily use has a blood pressure-lowering effect in hypertensive subjects.

Comparison of the automated Dinamap blood pressure monitor with the mercury sphygmomanometer for detecting hypertension in the day case pre-assessment clinic

Patients will be rejected from surgery by nurse-led pre-assessment clinics and will need to be assessed by their general practitioners if their blood pressure is higher than a pre-determined value. We have assessed the accuracy of the Dinamap automatic blood pressure recorder compared with manual mercury sphygmomanometry for detecting pre-operative hypertension in the day case pre-assessment clinic under everyday conditions. Two hundred consecutive patients attending for day case surgery pre-assessment had their blood pressure measured using the automated and the manual methods. We found that the Dinamap over-read systolic blood pressure by a mean of 8.38 mmHg and under-read diastolic pressure by a mean of 1.68 mmHg when compared with manual readings. Of the patients 6.5% would have been inappropriately diagnosed as hypertensive using the Dinamap and thus potentially rejected from day surgery and inappropriately referred to their general practitioner.

Effect of elapsed time after standing up on orthostatic blood pressure change in the elderly

The effect of time elapsed after standing on the orthostatic change in blood pressure was investigated. The study subjects were recruited from 237 community-dwelling elderly residents free from any history of cardiovascular disease and not on medication. Basal blood pressure was determined by averaging two determinations of supine blood pressure measured with an automatic oscillometric blood pressure recorder after resting for more than 10 minutes. Orthostatic change in systolic blood pressure (SBP) was determined as more than a 10% increase or decrease in SBP after standing. In the total population, maximum change in SBP was observed at 1 minute after standing-up. However, 8.4% and 7.2% of subjects showed abnormal increase or decrease in SBP only after 3 minutes. These results suggests that orthostatic dysregulation of blood pressure could be evaluated by measuring at 1 minute after standing up. However, if abnormal variation of blood pressure was not observed at 1 minute after standing up, repeated measurement at 3 minutes would be necessary.

Is local anaesthesia hazardous to hearts?

In Brief Objectives This investigation was designed to study the haemodynamic effects of two different local anaesthetic solutions during restorative dental treatment in children. Design A randomised, single-blind, split-mouth cross-over design was employed using children undergoing bilaterally similar restorative treatments over two visits. Setting The study was performed in a dental hospital paediatric dentistry department. Methods Ten children participated. At one visit the local anaesthetic was 2% lidocaine (lignocaine) with 1:80,000 epinephrine (adrenaline); at the other the anaesthetic was 3% prilocaine with 0.03IU/ml felypressin. Local anaesthetic was administered at a dose of 0.5 ml/10 kg body weight. Blood pressure and heart rate were measured before and during treatment with an automatic blood pressure recorder. Data were analysed by ANOVA and Student's paired t test. Results Significant differences between treatments in diastolic blood pressure (F = 2.37; P = 0.05) and heart rate (F = 2.98; P < 0.02) were noted. The heart rate increased ten minutes following the injection of the epinephrine-containing solution. The diastolic blood pressure fell 20 minutes after injection of lidocaine with epinephrine. Conclusion The choice of local anaesthetic solution influences the haemodynamic response during restorative treatment in children.

Criteria of normal blood pressure and hypertension in Japanese preschool children.

The blood pressure (BP) of 5332 Japanese preschool children from 2 to 6 years of age was measured using an automated BP recorder (Dinamap Model 8104). The third reading of the consecutive measurement of BP was used for analysis. This study adopted a definition of hypertension developed by The Task Force conducted in the United States in 1987, which showed the 95th percentiles of systolic and diastolic BP for age and sex. Stepwise regression analysis revealed that body height, weight and heart rate had significant effects on both systolic and diastolic BP, whereas age had an effect on diastolic BP only, while sex and area where the subjects lived did not affect either BP. The 95th percentiles of systolic/diastolic BP at 2, 3, 4, 5, and 6 years of age were 115/69, 113/68, 114/65, 118/67 and 116/69 mm Hg in boys, and 121/70, 114/69, 115/67, 118/68 and 120/69 mm Hg in girls, respectively. The BP of Japanese preschool children can be evaluated using the data shown in this study.

Urinary kallikrein activity is increased during the first few weeks of exercise training in essential hypertension

To determine whether the renal kallikrein-kinin and dopamine systems participate in lowering blood pressure during mild exercise in hypertensives. After a general clinical observation period of 4 weeks, 27 essential hypertensives were divided into two groups. The exercise group underwent blood lactate threshold exercise, using a cycle ergometer for 60 min three times a week for 10 weeks. The non-exercise group was observed at the outpatient clinic. Blood pressure and humoral parameters were measured at weeks 0, 1, 2, 4 and 10 in both groups. Blood pressure was measured indirectly with an automatic blood pressure recorder. Twenty-four-hour urinary kallikrein activity (by kininogenase assay), total or free dopamine and total noradrenaline (by high-performance liquid chromatography) were also measured. In the non-exercise group blood pressure and humoral parameters did not change. In the exercise group the change in resting blood pressure between weeks 0 and 10 was statistically significant. The change in 24-h urinary kallikrein activity of the exercise group was significantly greater than that of the non-exercise group between weeks 0 and 1 and weeks 0 and 2. Moreover, the change in systolic blood pressure (SBP) between weeks 0 and 2 was negatively correlated with the change in urinary kallikrein activity between weeks 0 and 2, the change in total dopamine between weeks 0 and 2 was negatively correlated with the change in diastolic blood pressure in the same period, and the change in SBP between weeks 0 and 10 was positively correlated with the change in total noradrenaline in the same period in the exercise group. Subjects with a relatively high baseline urinary kallikrein activity had a significantly greater change in SBP between weeks 0 and 10 than subjects with a relatively low baseline activity. The renal kallikrein-kinin and dopamine systems may participate in lowering blood pressure during the first few weeks of exercise training. The subsequent reduction of sympathetic activity may be involved in maintaining the lowered blood pressure. Mild exercise is more effective in reducing blood pressure in hypertensives who have a relatively high basal renal kallikrein-kinin system activity.

Validation of automated blood pressure recording in pregnancy

Validation of automated blood pressure recording in pregnancy

Assessing hypertension management: the role of 24-hour blood pressure monitoring.

The first fully automatic portable invasive blood pressure recorder was developed 30 years ago. Today, portable noninvasive ambulatory blood pressure devices are capable of measuring blood pressure intermittently for periods of 24 to 48 hours. To discuss the utility of automatic ambulatory blood pressure recording in assessing antihypertensive therapy. Ambulatory blood pressure monitoring is helpful in assessing the pharmacodynamics and the clinical efficacy of antihypertensive drugs. It is superior to office blood pressure measurement in predicting hypertensive end-organ disease. In clinical trials, ambulatory blood pressure monitoring permits a more varied population to enter a study, the number of subjects required is often reduced, and a placebo control group may be unnecessary. The various methods of analyzing ambulatory blood pressure data should be used in a complementary fashion to evaluate antihypertensive drug therapy. We believe that this technique will soon become much more commonly used for hypertension management.

Nocturnal variations in peripheral blood flow, systemic blood pressure, and heart rate in humans

Subcutaneous adipose tissue blood flow rate, together with systemic arterial blood pressure and heart rate under ambulatory conditions, was measured in the lower legs of 15 normal human subjects for 12-20 h. The 133Xe-washout technique, portable CdTe(Cl) detectors, and a portable data storage unit were used for measurement of blood flow rates. An automatic portable blood pressure recorder and processor unit was used for measurement of systolic blood pressure, diastolic blood pressure, and heart rate every 15 min. The change from upright to supine position at the beginning of the night period was associated with a 30-40% increase in blood flow rate and a highly significant decrease in mean arterial blood pressure and heart rate (P less than 0.001 for all). Approximately 100 min after the subjects went to sleep an additional blood flow rate increment (mean 56%) and a simultaneous significant decrease in mean arterial blood pressure (P less than 0.001) were observed. The duration of this hyperemic phase was 116 min. A highly significant reduction of the subcutaneous vascular resistance (50%) was demonstrated during the hyperemic blood flow rate phase compared with the surrounding phases (P less than 0.0001). The synchronism of the nocturnal subcutaneous hyperemia and the decrease in systemic mean arterial blood pressure point to a common, possibly central nervous or humoral, eliciting mechanism.