SEARCH · PubMed Health

Results for “PRESSURE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 757 records · Page 42Linked to original sources

PubMed1998

[Analysis of arterial pressure variability among individuals with white coat hypertension and essential arterial hypertension using blood pressure ambulatory monitoring].

OBJECTIVES: To compare patients with "white coat" hypertension (WCH) and essential hypertension for variability in blood pressure (BP) taken in the clinic. DESIGN: Crossover study. SETTING: La Orden Health Centre, Huelva. PATIENTS: 126 people with light-to-moderate hypertension, de novo or not, being monitored but not treated by drugs. Two groups were formed: WCH defined by mean daily systolic and distolic pressures below 135 and 85 mmHg, and hypertension when the BP was over 140 and/or 90 mmHg. MEASUREMENTS AND MAIN RESULTS: BP was taken in the clinic in two periods: by day (7 a.m. to midnight) and at night (00.01 to 06.59), with readings every 15 and 30 minutes, respectively. Variability was compared by analysing: a) variability indices (VI), and b) coefficients of variation (CV) in BP. A regression test and multiple correlation was used. Both groups (hypertension and WCH) contained 63 people (average age: 53.4 +/- 10 and 50 +/- 10). No significant differences between the two groups in the VI were observed, except greater variability in the VI of the nocturnal systolic pressure of the hypertension group. The CV was higher in the WCH group for all pressures, with differences for 24-hour and day-time systolic pressure. The VI of systolic pressure correlated significantly with its overall clinical systolic pressure in the 24-hour period, with the day and night-time readings and with age in the day-time period. CONCLUSIONS: Variability in the blood pressure of people with essential hypertension and WCH does not differ. Variability in systolic pressure shows positive correlation with clinical systolic pressure and, to a lesser extent, with age.

Blood Pressure Monitoring, Ambulatory↗

PubMed1976

[Volume and pressure changes due to nitrousoxide diffusion in costumary and in low-pressure cuffs of endotracheal tubes (author's transl)].

Changes of volume and pressure due to N2O-diffusion into PVC and Latex cuffs of endotracheal tubes were measured. Endotracheal tubes with a small-volume cuff (Magill and Portex) and one type of a large-volume, low-pressure cuff (Lanz) were examined. Within 48 h significant changes of volume and pressure were registered at different starting volumes and different N2O-concentrations. In the small-volume cuffs of the Portex and Magill tubes very high pressures were always noted; increases of volume were always seen, which were accompanied by increases, in some cases also by decreases of pressure. In the large-volume cuffs of the Lanz tube there were increases of volume and pressure; the measured pressures where however, in a clinical unimportant range. These changes are caused by N2O-diffusion into the cuff, slowed N2-diffusion out of the cuff, prestretching of the cuff membrane by the starting volume and further stretching by N2O diffusing into the cuff. These measurements are of practical clinical significance: This high-pressures due to starting volume and N2O-diffusion in small-volume cuffs explains the higher rate of trauma to the trachea, even after short term intubation, in contrast to the extremely low pressures in large-volume, low-pressure cuffs.

Diffusion↗

PubMed1992

Does the shunt opening pressure influence the effect of shunt surgery in normal pressure hydrocephalus?

Thirteen patients with normal pressure hydrocephalus were operated upon with an externally maneuverable shunt system (Sophy SU8) in order to investigate its influence on clinical outcome, intracranial pressure and cranial CT parameters. The opening pressure was set at high at surgery and lowered stepwise at intervals of three months to medium and low. The clinical condition, intracranial pressure and cranial CT parameters were examined at the end of the 3 months interval on each pressure level. The patients improved within the first 3 months inspite of an unchanged mean intracranial pressure and remained in a stable clinical condition during the rest of the study period. The intracranial pressure was significantly reduced at 9 months. The ventricular index, Evans index, temporal horn and third ventricle width were reduced 3 months post-operatively and did not change significantly during the rest of the study. The pre-operative third ventricle width was correlated to high psychometric test results after shunt surgery. Reduction in ventricular index, Evans index and third ventricle width after surgery correlated to improvement in psychometric scoring. The clinical improvement after shunt surgery for normal pressure hydrocephalus is seen within 3 months and is independent of the adjusted valve pressure.

Aged↗

PubMed2000

The relationship of electronically monitored physical activity to blood pressure, heart rate, and the circadian blood pressure profile.

We studied how closely changes in electronically monitored physical activity are reflected in changes in blood pressure and heart rate in a group of untreated hypertensive subjects. Thirty-nine hypertensive patients (office blood pressure > 140/ 90 mm Hg) of mean age 57 +/- 10 years (mean +/-SD) wore an ambulatory blood pressure monitor and a wrist actigraph simultaneously. Both average and peak activity for 5 min before each valid blood pressure reading were determined, as was average activity for awake and sleep periods, determined by patient kept diaries. For the overall group, awake and 24-h activities were inversely correlated to age (n = 39, r = -0.42; P = 0.01 and n = 39, r = -0.38; P = 0.01, respectively). No correlation was found between group awake activity and group-average blood pressure or heart rate. For individual patients, there was marked variation in the degree of correlation between awake activity measures (both peak and average) and blood pressure and heart rate. The strongest positive correlation was between activity levels and the heart rate-pressure product. Nondipper profile hypertensives had higher sleep activity than dipper hypertensives (44 +/- 28 units/min v 25 +/- 20 units/min, df = 37, t = 2.12; P = 0.04), but awake activity levels were similar. The higher sleep activity remained after adjustment for age. These findings indicate that the relationship between actigraphic activity and hemodynamic parameters is highly variable and that the rate-pressure product is the strongest correlate of short-term activity. Furthermore, hypertensives with the nondipper profile have higher sleep activity than dipper hypertensives. These findings stress the need for further study into the role of day-to-day activity in determining ambulatory blood pressure and heart rate variability.

Activities of Daily Living↗

PubMed2002

Independence of changes in right atrial pressure and central venous pressure.

Dynamics of changes in right-atrial pressure and venous pressure measured in the inferior and superior vena cava at their orifices (central venous pressure) after bolus injection of 20 ml physiological saline or epinephrine (5.0 mg/kg) was studied in acute experiments on cats. The initial pressure in the right atrium was equal to that in caval veins. Pressor stimuli either increased or decreased the right atrial pressure, but always increased blood pressure in the caval veins. Moreover, right atrial pressure returned to the initial level more rapidly compared to that in caval veins. Our results suggest that the dynamics of the right-atrial pressure does not reflect the shifts in the central venous pressure.

Animals↗

PubMed1981

The effects of high-frequency positive-pressure ventilation on intracranial pressure and brain surface movement in cats.

Compared to traditional, low-frequency ventilation (LFV), mechanical ventilation at high frequencies (60-200 breaths/min) and low tidal volumes (HFV) is known to: 1) eliminate respiratory-synchronous variations in blood pressure; 2) minimize ventilatory effects on the cardiovascular system; 3) reduce peak airway pressures; and 4) suppress spontaneous respiratory efforts. Since these and other properties may make HFV useful in patients with acute intracranial pathology, we studied the effects of HFV on intracranial pressure (ICP) in cats. Compared with LFV (rate 11/min, tidal volume equals 15 ml/kg), HFV (rate 100/min, VT equals 3.3 ml/kg) had little effect on mean arterial pressure, heart rate, right atrial pressure, mean ICP or mean cerebral perfusion pressures, even if baseline ICP was raised using an epidural balloon. However, HFV effectively eliminated ventilator-linked fluctuations in both blood pressure and ICP, and at all levels of mean ICP studied (4.8, 15, and 30 torr), significantly reduced the peak ICP seen during a single respiratory cycle. The reduction in ICP fluctuation and peak pressure was more pronounced as intracranial complicance fell. However, the physiologic significance of such a change in the ICP pressure waveform is unknown. Because of the observed influence of HFV on ICP fluctuations, we also examined its effects on the physical movement of the exposed brain, using a non-contact, inductive displacement measuring device. During LFV, the cortical surface moved "in and out" by 0.36 plus or minus 0.1 (plus or minus SD) mm, a distance sufficient to make microscopic focusing difficult. Changing to HFV reduced surface movement to 0.05 plus or minus 0.01 mm, producing a very stable surface. These results suggested that HFV may play a very important role in the intraoperative management oif patients undergoing certain neurosurgical procedures, particularly those requiring microsurgical techniques where reduced brain movement may facilitate surgery.

Animals↗

PubMed1994

Inferior vena caval pressure reliably predicts right atrial pressure in pediatric cardiac surgical patients.

OBJECTIVE: To compare "central venous pressure" in pediatric patients in a clinical setting as measured from catheters in the infrahepatic inferior vena cava and the right atrium. DESIGN: Prospective, unblinded study. SETTING: Cardiothoracic intensive care unit of a tertiary care university hospital. PATIENTS: Thirty-three pediatric cardiac surgical patients, 2 days to 92 months of age (mean 24 +/- 4 months). INTERVENTIONS: All patients had intraoperative placement of an 8-cm, double-lumen, femoral venous catheter and a transthoracic right atrial catheter. Patients were studied for 0 to 2 days after surgery. MEASUREMENTS AND MAIN RESULTS: Measurements were obtained during mechanical and spontaneous ventilation. Although not statistically identical, measurements of "central" venous pressure in the inferior vena cava and right atrium correlated well (r2 = .87 for mechanical ventilation; r2 = .83 for spontaneous ventilation). Of 31 data pairs in mechanically ventilated patients, the absolute difference in pressures was as large as 3 mm Hg in three patients and <3 mm Hg in all the rest. In 15 spontaneously breathing patients, there were only three data measurements where the difference in pressure was 2 mm Hg and none of the differences was greater. In spontaneously breathing patients, the phasic changes due to respiratory variations in venous pressure were in phase in both the intrathoracic and intra-abdominal catheter positions. CONCLUSIONS: We conclude that while "central" venous pressures measured in the inferior vena cava and in the right atrium are not statistically identical, any differences are well within clinically important limits. Placement of central venous pressure catheters in the inferior vena cava by the femoral venous approach is a reliable alternative to cannulating the superior vena cava in pediatric patients without clinically important intra-abdominal pathology and with anatomic continuity of the inferior vena cava with the right atrium. Relatively short femoral vein catheters allow adequate measurement of central venous pressure without concern for exact catheter tip position and without the risk of right atrial perforation, intracardiac arrhythmias, and inadvertent puncture of carotid and intrathoracic structures. Unlike previously reported results in neonates, we found that the phasic changes of venous pressure with the respiratory cycle were similar in both intrathoracic and intra-abdominal recordings, making this an inappropriate clinical indicator of venous catheter tip position.

Atrial Function, Right↗

PubMed2002

Comparison of Portapres non-invasive blood pressure measurement in the finger with intra-aortic pressure measurement during incremental bicycle exercise.

BACKGROUND AND DESIGN: In order to evaluate the accuracy of continuous, non-invasive blood pressure measurements in the finger during stress, blood pressure was measured in six patients with a Portapres Model 2 during increasing levels of bicycle exercise, using simultaneously registered intra-aortic (aortic arch) pressure as a reference. METHODS: Blood pressure was measured continuously and non-invasively in the left middle finger using the Portapres Model 2 device, at the same time invasively using a pigtail catheter situated in the aortic arch at rest and during and after standardized bicycle exercise. At the end of each stress level, in accordance with the protocol of the Association for the Advancement of Medical Instrumentation, systolic and diastolic blood pressure and pulse values were determined from the non-invasive (Portapres Model 2) and invasive measurements for 15 s each, and the mean values and standard deviations were calculated. RESULTS: Compared with simultaneous invasive blood pressure measurement in the aortic arch, the difference in measured blood pressure value (the value determined by the device minus the value determined invasively) at rest fell within the authorized normal range for German and European blood pressure measurement devices: systolic +1.7 +/- 1.8 mmHg and diastolic -3.7 +/- 6.2 mmHg. The difference in measured value increased with the stress level. CONCLUSION: Blood pressure and pulse can be determined reliably and accurately using the Portapres Model 2, non-invasively, both at rest and at low-to-moderate levels of stress.

Adult↗

PubMed1997

Estimation of central aortic pressure waveform by mathematical transformation of radial tonometry pressure. Validation of generalized transfer function.

BACKGROUND: Central aortic pressures and waveform convey important information about cardiovascular status, but direct measurements are invasive. Peripheral pressures can be measured noninvasively, and although they often differ substantially from central pressures, they may be mathematically transformed to approximate the latter. We tested this approach, examining intersubject and intrasubject variability and the validity of using a single averaged transformation, which would enhance its applicability. METHODS AND RESULTS: Invasive central aortic pressure by micromanometer and radial pressure by automated tonometry were measured in 20 patients at steady state and during hemodynamic transients (Valsalva maneuver, abdominal compression, nitroglycerin, or vena caval obstruction). For each patient, transfer functions (TFs) between aortic and radial pressures were calculated by parametric model and results averaged to yield individual TFs. A generalized TF was the average of individual functions. TFs varied among patients, with coefficients of variation for peak amplitude and frequency at peak amplitude of 24.9% and 16.9%, respectively. Intrapatient TF variance with altered loading (> 20% variation in peak amplitude) was observed in 28.5% of patients. Despite this, the generalized TF estimated central arterial pressures to < or = 0.2 +/- 3.8 mm Hg error, arterial compliance to 6 +/- 7% accuracy, and augmentation index to within -7% points (30 +/- 45% accuracy). Individual TFs were only marginally superior to the generalized TF for reconstructing central pressures. CONCLUSIONS: Central aortic pressures can be accurately estimated from radial tonometry with the use of a generalized TF. The reconstructed waveform can provide arterial compliance estimates but may underestimate the augmentation index because the latter requires greater fidelity reproduction of the wave contour.

Abdomen↗

PubMed2002

Prediction of pulmonary arterial wedge pressure from arterial pressure or pulse oximetry plethysmographic waveform.

OBJECTIVE: To assess the possibility of using arterial pressure waveform or pulse oximetry plethysmographic waveform variation to estimate the pulmonary arterial wedge pressure (PAWP). METHODS: Fourteen American Society of Anesthesiologists grade I - II patients aged 33 - 69 years and weighing 62.0 +/- 9.5 kg scheduled for elective abdominal tumor surgery were studied. Their hemoglobin exceeded 120 g/L and hematocrit exceeded 35 percent. Pre-operative acute hypervolemic hemodilution was applied immediately after general anesthestic induction and tracheal intubation. PAWP, systolic pressure variation (SPV), delta down (dDown), SPV(plet), dDown(plet) and other hemodynamic parameters were measured and recorded when total fluid volume (crystalloid and colloid) infused reached 10 ml/kg and 20 ml/kg and again at the end of the operation. Central venous pressure was maintained at 10 - 12 mm Hg during operation. Systolic blood pressure at the end of Valsalva maneuver (airway pressure was kept at 22 mm Hg) and the systolic pressure before the Valsalva manoeuvre during apnea were used to calculate arterial pressure ratio (APR). RESULTS: APR, SPV, dDown, SPV(plet) and dDown(plet) all correlated well with PAWP (r = 0.717, -0.695, -0.680, -0.522 and -0.624 respectively, P < 0.01). There was a closer linear correlation between APR and PAWP than between the other parameters. The regression equation was PAWP (mm Hg) = 0.207 x APR (%) - 0.382. CONCLUSION: During positive pressure mechanical ventilation, APR, SPV, dDown, SPV(plet) and dDown(plet) can be used to estimate PAWP effectively.

Adult↗

PubMed1991

Age-related characteristics of ambulatory blood pressure load and mean blood pressure in normotensive subjects.

Ambulatory blood pressure monitoring has become increasingly popular for diagnosing and treating hypertension. However, data from normotensive subjects are needed for interpretation of hypertensive readings. Ambulatory blood pressure was monitored in 126 normotensive subjects (age range, 20 to 84 years). Mean systolic and diastolic blood pressure and blood pressure loads (percentage of systolic readings greater than 140 mm Hg and diastolic readings greater than 90 mm Hg) were obtained and interpreted. Mean awake systolic and diastolic pressures ranged from 125 +/- 10 to 137 +/- 17 mm Hg and 70 +/- 8 to 71 +/- 9 mm Hg, respectively. The systolic and diastolic trends of subjects' blood pressures taken during office visits and the 24-hour measurements were similar. Ranges for systolic and diastolic blood pressure loads from youngest to oldest ages were 9% +/- 14% to 25% +/- 20% and 3% +/- 7% to 4% +/- 7%, respectively. A comparison of blood pressure means from our sample that were taken during office visits and blood pressure means from a 2122-patient community survey demonstrated that our sample was reflective of an unselected population.

Adult↗

PubMed1982

[Intracranial pressure pulse waveform: considerations about its origin and methods of estimating intracranial pressure dynamics].

Epidural pulse waveform is important as an indicator of intracranial pressure (ICP) dynamics. In this study, the origin of epidural pulse and the clinical implication of its waveform were investigated, using anesthetized artificially ventilated dogs. For this purpose, a cortical artery and a vein were cannulated, and the pressures were recorded simultaneously with epidural pressure (EDP), epidural pulse waveform (EDP-WF), systemic arterial pressure measured in a carotid artery (SAP), central venous pressure (CVP) and electrocardiogram. EDP-WF is composed of several initial peaks and a small delayed peak on the descending limb. The former peaks were slightly delayed from the SAP pulse and were synchronous with the cortical arterial pulse. The latter peak was synchronous with the atrial "a" wave on CVP, but not with the cortical venous pulse. Moreover, the cortical venous pulse was quite similar to EDP-WF. These findings indicate that the pulsation of the brain may be generated by the pulsatile arterial blood flow into the brain, which also affected the pulsation of the cortical vein. The latter peak which was considered to be of venous origin may reflect the dynamics of venules in the brain, not of the cortical vein. Increase of ICP by constant inflation of the epidural balloon or inhalation of CO2 cause EDP-WF monotonous. It is possible that the transmission of arterial pulse into the brain was augmented because of the tightness of the brain or decrease of cerebral vascular tone, although the cortical arterial pressure was not significantly changed or was even slightly decreased. Using a bolus injection technique, the change of EDP-WF in cats was compared with volume-pressure response (VPR) and pulse pressure (PP) which are reported to be good indicators for ICP dynamics. At about 30mmHg, EDP-WF became monotonous while VPR or PP showed only linear relationships with EDP up to 50 to 60 mmHg. Therefore EDP-WF may provide useful information about ICP dynamics in a relatively lower pressure range which could not be detected by VPR or PP study.

Animals↗

PubMed1990

Succinylcholine-induced increases in CSF pressure are not affected by PaCO2 or mean arterial pressure in dogs.

The effects of PaCO2 and mean arterial pressure (MAP) on succinylcholine-induced changes in cerebrospinal fluid (CSF) pressure were examined in 31 dogs anesthetized with halothane (0.7% end-expired) and nitrous oxide (66% inspired) in oxygen. Group 1 (n = 9) received succinylcholine (1.5 mg/kg i.v.) without control of PaCO2 or MAP. Group 2 (n = 12) received succinylcholine with CO2 maintained at control, and no regulation of MAP. Group 3 (n = 10) received succinylcholine without regulation of PaCO2 and maintenance of MAP at control values with trimethaphan. Succinylcholine produced an increase in CSF pressure of 1.7 +/- 1.7-3.9 +/- 3.6 cm H2O (mean +/- SD). There were no differences in CSF pressure increase between groups. The increase in CSF pressure was compared to the variation in the uncontrolled physiological parameter (i.e., CSF pressure was compared to PaCO2 and MAP in group 1, MAP in group 2, and PaCO2 in group 3). The CSF pressure increase over time did not strictly parallel changes in PaCO2 and/or MAP, and the magnitude of increase of CSF pressure did not correlate significantly with PaCO2 and/or MAP. It is concluded that, in anesthetized dogs, succinylcholine produces relatively small increases in CSF pressure whether or not PaCO2 or MAP is controlled. These results do not support the hypothesis that a succinylcholine-induced increase in CSF pressure is due chiefly to an increase in PaCO2 and/or MAP and can be abolished by preventing those changes.

Journal Article↗

PubMedDate not supplied

Monitoring middle ear pressure by tympanometry. A study of middle ear pressure variation through seven hours.

The aim of this investigation was to monitor fluctuations in middle ear pressure, to study tympanometric signs of Eustachian tube functioning and to assess the validity of the tympanometric readings. In 20 patients with a low initial middle ear pressure (-150 daPa or lower) and 5 normals, impedance tympanometry was performed every 3 min through 7 h. Median pressure for the patients was -150 daPa (range 100 to -400 daPa) and for the normals 0 daPa (range 50 to -50 daPa). A remarkable pressure increase was seen after changing the body position to the supine. The patients were arranged into three groups according to the lowest middle ear pressure registered. Median pressures for the groups were running at a rather constant level. However, the individual pressure fluctuations in many patients were so great that a single tympanometric reading has to be considered unreliable when selecting patients for insertion of ventilation tubes. Thirteen patients never equalized their negative middle ear pressure, indicating that their Eustachian tube did not open during the test period. In spite of this the pressure did not decrease to lower values, indicating that maintaining a relative constant middle ear pressure is independent of opening of the Eustachian tube.

Acoustic Impedance Tests↗

PubMed1996

Effects of three methods of analysis on ambulatory blood pressure indices and the early morning rise in blood pressure.

OBJECTIVE: To study the effects of actigraphic, diary and fixed-time methods of analysis on ambulatory blood pressure, the day (awake)-night (asleep) difference and early morning blood pressure. METHODS: We analyzed 50 ambulatory blood pressure studies of patients who also underwent actigraphic activity studies. We divided each study into awake and sleeping intervals by three methods: a patient diary of sleep hours, actigraphically determined sleep hours and a fixed schedule of estimated sleep (2200-0700 h). We then calculated the overall ambulatory blood pressure averages, the awake-asleep differences and the average blood pressure for 4 h after awakening. RESULTS: We found that actigraphic division of the data and patient-kept diaries provided similar ambulatory blood pressure averages whereas fixed-time analysis (2200-0700 h as the sleeping period) was less similar to that using the diary method. The nocturnal decline in diastolic blood pressure calculated by the diary method tended to be higher than that obtained by the fixed time method (16+/-6 versus 14+/-7%, P = 0.037). The limits of agreement for the early morning blood pressure rise for diary and fixed-time analyses were wider than those for diary and actigraphic analyses (-9.5 to +10.0/-6.6 to +7.0) versus (-4.4 to +4.7/-4.1 to +4.0 mmHg). CONCLUSION: Actigraphic division of the ambulatory blood pressure data is more similar to the diary than it is to the fixed-time method studied here. Researchers studying the early morning rise in blood pressure should consider using either actigraphy or diary rather than fixed-time methods of analysis to identify times of awakening.

Journal Article↗

PubMed1988

An improved pressure-sensitive capsule for endoscopic measurement of esophageal variceal pressure.

A new small noninvasive pressure-sensitive capsule for the endoscopic measurement of esophageal varix pressure was evaluated and compared to an initial Yale-designed capsule to test the hypothesis that the diameter of the capsule measuring surface is a limiting factor for the accuracy and variability of capsule pressure measurements. Capsule pressures obtained with each capsule, using rabbit mesenteric vessels comparable in size to human esophageal varices, were correlated with direct intraluminal pressure measurements. There was an excellent correlation between capsule pressure measurements obtained with the small capsule and intraluminal pressure (r2 = 0.97) which was significantly greater than the correlation obtained when the initial capsule was studied (r2 = 0.89, P less than 0.01). The variability of capsule pressure measurements obtained with the small capsule was less than that observed when measurements were obtained with the initial capsule (P less than 0.01). Therefore, this new small capsule should provide the most accurate and reproducible noninvasive measurements of variceal pressure.

Animals↗

PubMed1989

Alcohol and blood pressure: results from the Luebeck Blood Pressure Study.

Data from the Luebeck Blood Pressure Study, a cross-sectional study on a random sample (n = 3,100) of the 30- to 69-year-old population of Luebeck, were analyzed with regard to alcohol consumption and blood pressure. Putative confounders such as obesity, smoking, physical activity, and educational attainment were controlled for by multiple regression analyses. Luebeck men who consumed more than 40 g of alcohol per day revealed 5-6 mm Hg higher mean systolic and 4-5 mm Hg higher mean diastolic blood pressure values. A J-shaped relationship between alcohol consumption and systolic blood pressure was seen in Luebeck men. According to our calculations, about 7% of hypertension among Luebeck men is due to alcohol consumption of greater than or equal to 40 g/day. Among women, strong interactions between age and alcohol consumption were found, therefore two age groups, 30-44 and 45-69 years, were analyzed separately. In the younger age group the alcohol-blood pressure relationship was not pronounced. In the older age group a strong interaction between alcohol consumption and smoking was found. For female smokers steep increases in the adjusted mean diastolic (5.2 mm Hg) and systolic (9.6 mm Hg) blood pressure values were seen for the alcohol consumption category greater than or equal to 20 g/day. For female nonsmokers a flat curve was seen with regard to mean diastolic and systolic blood pressure values. The data from the Munich Blood Pressure Study show a very similar relationship between alcohol consumption and mean systolic and diastolic blood pressure values.

Adult↗

PubMed2005

Carotid tonometry versus synthesized aorta pressure waves for the estimation of central systolic blood pressure and augmentation index.

OBJECTIVE: To assess the interchangeability of carotid tonometry and synthesized aorta pressure waveforms for estimating central systolic blood pressure (SBP) and augmentation index (AIx). METHODS: Tonometry waveforms were acquired with a custom built hardware and software platform in 276 subjects (179 men/97 women; aged 45.5 +/- 5.7 years; mean +/- standard deviation) at the radial (P(wf,ra)), brachial (P(wf,ba)), and carotid artery (P(wf,ca)). The P(wf,ba) was calibrated using systolic (SBP(ba)) and diastolic (DBP(ba)) sphygmomanometer pressure. The DBP(ba) and calculated mean (MAP(ba)) brachial pressure were subsequently used for calibration of P(wf,ra) and P(wf,ca). A central pressure waveform (P(wf,sao)) was synthesized from P(wf,ra) using a generalized pressure transfer function (TFF). The AIx and SBP were measured on P(wf,ra), P(wf,ca), and P(wf,sao). RESULTS: The SBP(ra), SBP(ca), and SBP(sao) were 138.5 +/- 16.8, 130.0 +/- 16.2, and 131.1 +/- 16.6 mm Hg, respectively. The SBP(ra) correlated well with the SBP(ca) (r = 0.93) and the SBP(sao) (r = 0.94), as did the SBP(ca) and the SBP(sao) (r = 0.97) with a mean bias of 1.35 +/- 3.90 mm Hg. The AIx derived from P(wf,ra), P(wf,ca), and P(wf,sao) were -20.8% +/- 14.5%, 12.4% +/- 13.9%, and 20.0% +/- 11.7%, respectively. The correlation between radial and carotid, and radial and central AIx was 0.72 and 0.94, respectively. The correlation between AIx derived from P(wf,ca) and P(wf,sao) was 0.75 with a bias of 11.0% +/- 14% (all correlations P < .001). CONCLUSIONS: The use of a generalized TFF in combination with well-calibrated radial pressure curves yields estimates of SBP in good agreement with carotid tonometry. Although AIx derived from a measured radial pressure curve correlates surprisingly closely with AIx measured on a synthesized aortic pressure curve, the correlation with a directly measured AIx on carotid signals is relatively poor.

Adult↗