Assessment of repeatability and correlates of arterial compliance

OBJECTIVES: The aim of these studies was to assess repeatability of large (C1) and small (C2) arterial elasticity indices over various time intervals using the HDI/Pulsewave CR-2000 Research CardioVascular Profiling System (Hypertension Diagnostics, Inc., Eagan, Minnesota, USA). Non-invasive hemodynamic parameters using this device were compared to invasive measurements. METHODS: After a 5-min period of rest, 31 healthy hospital employees underwent cardiovascular profiling on two occasions within 1 h apart. Another 59 healthy hospital employees underwent cardiovascular profiling on two occasions, an average 52 days apart. An additional group of 23 patients underwent right and left heart catheterizations for routine clinical indications and hemodynamic assessment was performed invasively and non-invasively. RESULTS: For short-term repeatability, the mean difference of C1 was +0.25 +/- 2.83 ml/mmHg x 10 (P = NS) and C2 was -0.14 +/- 1.86 ml/mmHg x 100 (P = NS). For intermediate test repeatability, the mean difference of C1 was -0.415 +/- 2.97 ml/mmHg x 10 (P = NS) and C2 was -0.19 +/- 2.67 ml/mmHg x 100 (P = NS). In the invasive protocol, both aortic diastolic blood pressure (-4.74 +/- 9.7 mmHg) and systemic vascular resistance (-194 +/- 264 dyne x s x cm(-5)) were significantly lower invasively. CONCLUSIONS: Measurements with the HDI/Pulsewave CR-2000 Research CardioVascular Profiling System are repeatable over both a short and intermediate period of observation. Furthermore, non-invasive hemodynamic parameters reasonably agree with invasive measurements.     

Performance of the UA-787 oscillometric blood pressure monitor according to the European Society of Hypertension protocol

OBJECTIVE: To determine the accuracy of the UA-787 oscillometric blood pressure monitor developed by the A&D Company. DESIGN: Evaluation of the UA-787 was performed using the new protocol of the European Society of Hypertension. The performance of the monitor was assessed in relation to the subjects' gender, age, skinfold thickness, arm circumference, body mass index and elasticity index of large (C1) and small (C2) arteries. METHODS: The UA-787 monitor was assessed according to European Society of Hypertension requirements, which are based on four zones of accuracy differing from the mercury standard by 5, 10, 15 mmHg, or more. In all subjects (n=33), indices of large-artery elasticity (C1) and small-artery elasticity (C2) were measured with the HDI/Pulsewave CR-2000 Research Cardiovascular Profiling System. RESULTS: The UA-787 passed all three phases of the protocol for both systolic and diastolic blood pressure. The mean blood pressure difference between device and the observers was 1.0+/-5.3 mmHg for systolic pressure, and 0.7+/-5.3 mmHg for diastolic pressure. In univariate analysis, the discrepancy between device and the observers was related to forearm circumference (P=0.02) for systolic pressure. For diastolic blood pressure, a significant relationship was found only for heart rate (P<0.01). However, in a multivariable regression analysis no clinical variable was an independent predictor of device-observer discrepancy. In particular, the performance of the UA-787 appeared to be uniform across the whole range of C1 and C2. CONCLUSIONS: These data show that the A&D UA-787 device satisfies the new recommended European Society of Hypertension accuracy levels for both systolic and diastolic pressure. Its performance is uniform across sub-groups of subjects with different clinical characteristics.     

Assessment of sequential same arm agreement of blood pressure measurements by a CVProfilor DO-2020 versus a Baumanometer mercury sphygmomanometer

OBJECTIVE: The aim of this study was to assess the accuracy of sequential same arm blood pressure measurement by the mercury sphygmomanometer with the oscillometric blood pressure measurements from a device that also determines arterial elasticity. METHODS: A prospective, multicentre, clinical study evaluated sequential same arm blood pressure measurements, using a mercury sphygmomanometer (Baumanometer, W. A. Baum Co., Inc., Copiague, New York, USA) and an oscillometric non-invasive device that calculates arterial elasticity (CVProfilor DO-2020 Cardiovascular Profiling System, Hypertension Diagnostics, Inc., Eagan, Minnesota, USA). Blood pressure was measured supine in triplicate, 3 min apart in a randomized sequence after a period of rest. RESULTS: The study population of 230 normotensive and hypertensive subjects included 57% females, 51% Caucasians, and 33% African Americans. The mean difference between test methods of systolic blood pressure, diastolic blood pressure, and heart rate was -3.2 +/- 6.9 mmHg, +0.8 +/- 5.9 mmHg, and +1.0 +/- 5.7 beats/minute. For systolic and diastolic blood pressure, 60.9 and 70.4% of sequential measurements by each method were within +/- 5 mmHg. Few or no points fell beyond the mean +/- 2 standard deviations lines for each cuff bladder size. CONCLUSION: Sequential same arm measurements of the CVProfilor DO-2020 Cardiovascular Profiling System measures blood pressure by an oscillometric method (dynamic linear deflation) with reasonable agreement with a mercury sphygmomanometer.     

Wrist blood pressure overestimates blood pressure measured at the upper arm

OBJECTIVE: Whether blood pressure (BP) measured at the wrist differs from blood pressure measured at the arm is not well known. The aim of this study was to compare the BP readings obtained at the arm with those obtained at the forearm and to assess whether the wrist-arm discrepancies were related to subjects' clinical characteristics. METHODS: We measured blood pressure at the forearm and at the upper arm in 85 subjects using conventional sphygmomanometry. Wrist-arm blood pressure discrepancies were assessed in relation to gender, age, body mass index, skin-fold thickness, arm size, blood pressure level, and arterial compliance measured with the HDI/Pulsewave CR-2000. RESULTS: Blood pressure measured at the wrist consistently overestimated blood pressure taken at the arm with a mean (+/-SD) discrepancy of 8.2 +/- 9.7/9.2 +/- 6.4 mmHg. The systolic blood pressure differences were greater in men than in women (p=0.006) and, among the men, varied according to arm adiposity (positive association, p=0.01). In men, diastolic blood pressure differences correlated with diastolic blood pressure level (negative association, p=0.01). Among the women, only age (p=0.04) was a significant positive independent predictor of the wrist-arm diastolic BP differences. CONCLUSIONS: These results indicate that forearm blood pressure measurement markedly overestimates upper arm blood pressure and that the between-site difference may vary from subject to subject. Wrist blood pressure measurement is not a valid alternative to traditional measurement at the arm and its use should be discouraged.     

Relationship between glycosylated hemoglobin and arterial elasticity

Arterial elasticity is decreased in diabetes, but it is unclear whether there is a relationship between glycosylated hemoglobin (HbA1c) and arterial elasticity. To evaluate this question, 111 subjects with diabetes mellitus had HbA1c and arterial elasticity determined in an academic outpatient setting. Three measurements of arterial elasticity indices were obtained supine using the HDI/PulseWave CR-2000 Research CardioVascular Profiling System (Hypertension Diagnostics Inc., Eagan, MN). The study population was 49% black and 51% women. Population characteristics included age, 49.2 years; duration of diabetes, 12.1 years; HbA1c, 8.9%; large artery elasticity, 11.8 mL/mm Hg x 10; and small artery elasticity, 4.7 mL/mm Hg x 100. Age correlated with diminished large artery elasticity. Women had a lower large artery elasticity than men (10.6 vs. 13.3 mL/mm Hg x 10; p = 0.0002). Decreasing small artery elasticity was associated with increasing age (p = 0.0001), HbA1c (p = 0.0184), and African-American ethnicity (p = 0.0306). Women had less small artery elasticity than men (3.8 vs. 5.8 mL/mm Hg x 100; p = 0.0001). Black diabetic patients had a reduced arterial elasticity compared with whites. Increasing HbA1c is associated with decreasing small artery elasticity, but not large artery elasticity. In diabetic patients, small artery elasticity is reduced to a greater extent in women than men and in blacks than whites.     

Optimizing cuff width for noninvasive measurement of blood pressure

BACKGROUND: It is well established that indirect measurements of blood pressure made with a standard 13cm-wide cuff are erroneously high for large arms and low for small arms. To correct for this error, the American Heart Association recommends adjusting cuff width to 40% of the arm's circumference. OBJECTIVE: To test the validity of this method of correction. DESIGN: This study was a prospective, nonblinded, paired Student's t-test analysis. METHODS: Blood pressures in 50 subjects were measured directly by using a radial artery line and indirectly by the Korotkov method. For each subject multiple indirect measurements of blood pressure were made with the cuff width:arm circumference ratio varied from 30-55% in 5% increments. Error was defined as indirect blood pressure minus direct blood pressure. RESULTS: A ratio of 40% resulted in overestimation of blood pressure for most arms and with particularly high errors for small arms. The ratio producing zero mean error for the pooled study group was 46.4+/-0.7% (mean+/-SEM). Using this ratio of 46.4%, the error varied inversely with arm circumference (P<0.02), resulting in overestimation of systolic blood pressure for small arms and underestimation of systolic blood pressure for large arms. This error is comparable in magnitude, but opposite in sign, to that which occurs with a standard 13cm-wide cuff for all arms. The optimum ratio was found to be closely approximated by the relationship, cuff width=9.34 log(10) arm circumference. Using this relationship, error in systolic blood pressure was insensitive to arm circumference (r=0.04, P>0.05) and near zero. CONCLUSION: The optimum cuff width for the indirect measurement of blood pressure is not directly proportional to arm circumference, but is proportional to the logarithm of the arm's circumference.     

Reactive rise in blood pressure upon cuff inflation: cuff inflation at the arm causes a greater rise in pressure than at the wrist in hypertensive patients

OBJECTIVE: Cuff inflation at the arm is known to cause an instantaneous rise in blood pressure, which might be due to the discomfort of the procedure and might interfere with the precision of the blood pressure measurement. In this study, we compared the reactive rise in blood pressure induced by cuff inflation when the cuff was placed at the upper arm level and at the wrist. PARTICIPANTS AND METHODS: The reactive rise in systolic and diastolic blood pressure to cuff inflation was measured in 34 normotensive participants and 34 hypertensive patients. Each participant was equipped with two cuffs, one around the right upper arm (OMRON HEM-CR19, 22-32 cm) and one around the right wrist (OMRON HEM-CS 19, 17-22 cm; Omron Health Care Europe BV, Hoofddorp, The Netherlands). The cuffs were inflated in a double random order (maximal cuff pressure and position of the cuff) with two maximal cuff pressures: 180 and 240 mmHg. The cuffs were linked to an oscillometric device (OMRON HEM 907; Omron Health Care). Simultaneously, blood pressure was measured continuously at the middle finger of the left hand using photoplethysmography. Three measurements were made at each level of blood pressure at the arm and at the wrist, and the sequence of measurements was randomized. RESULTS: In normotensive participants, no significant difference was observed in the reactive rise in blood pressure when the cuff was inflated either at the arm or at the wrist irrespective of the level of cuff inflation.Inflating a cuff at the arm, however, induced a significantly greater rise in blood pressure than inflating it at the wrist in hypertensive participants for both systolic and diastolic pressures (P<0.01), and at both levels of cuff inflation. The blood pressure response to cuff inflation was independent of baseline blood pressure. CONCLUSIONS: The results show that in hypertensive patients, cuff inflation at the wrist produces a smaller reactive rise in blood pressure. The difference between the arm and the wrist is independent of the patient's level of blood pressure.     

The position of the arm during blood pressure measurement in sitting position

OBJECTIVE: Determining the influence of the position of the arm on blood pressure measurement in the sitting position. METHODS: Blood pressure of 128 individuals (the majority being treated hypertensive patients) visiting the outpatient clinic was measured simultaneously on both arms with arms in two different positions. First, both arms were placed at the chair support level and blood pressure was measured three times on both arms after 10 min of rest. Subsequently, while still remaining in the same sitting position, five blood pressure measurements were made simultaneously at both arms with one arm placed on the desk and one arm placed and supported at heart level (mid-sternal). The arm placed at heart level served as the reference arm. The choice of which arm was placed at desk level and which arm was placed at heart level was randomized. RESULTS: Both at desk level and at chair support level, mean (+/-SD) systolic and diastolic blood pressures were higher than blood pressure at heart level by 6.1/5.7+/-4.6/3.1 and 9.3/9.4+/-5.4/3.4 mmHg, respectively. The effect of the height differences between the arm positions on the blood pressure readings was smaller than predicted (0.49 mmHg/cm systolic and 0.47 mmHg/cm diastolic). No significant correlation was found between blood pressure difference in the different arm positions (desk and heart level) and age, sex, weight or baseline blood pressure. CONCLUSIONS: Different arm positions below heart level have significant effects on blood pressure readings. The leading guidelines about arm position during blood pressure measurement are not in accordance with the arm position used in the Framingham study, the most frequently used study for risk estimations.     

Loose Cuff Hypertension

In this study, an analysis of the effects of cuff looseness on mean blood pressure readings was performed. Using a standard adult blood pressure cuff, pressure readings were taken on each arm at a cuff looseness of 0, 2, 4, and 6 cm beyond patient arm circumference. The cuff was then switched to the opposite arm and the procedure repeated. Blood pressure readings taken from the left arm with the cuff at an appropriately snug fit served as the reference. Increasing cuff looseness simulates the possibly incorrect blood pressure cuff placement by health care workers in the clinical setting. Data from 24 subjects support the claims that mean blood pressure increases with respect to increasing cuff looseness. It was shown that measurements taken on left and right arms will result in significantly different blood pressure readings (p < 0.001). It is therefore crucial to properly place the cuff at a snug fit on the patient’s arm for each measurement procedure, to prevent false readings. Lack of consistent cuff size and snugness procedures can lead to misdiagnosis of hypertension, acute patient discomfort, and inconvenient costs to the patient and health care provider.     

Blood pressure measurement in obese patients: comparison between upper arm and forearm measurements

BACKGROUND: It is well known that blood pressure measurement with a standard 12-13 cm wide cuff is erroneous for large arms. OBJECTIVE: To compare arm blood pressure measurements with an appropriate cuff and forearm blood pressure measurements (BPM) with a standard cuff, and both measurements by the Photopletismography (Finapres) method. METHODS: One hundred and twenty-nine obese patients were studied (body mass index=40+/-7 kg/m2). The patients had three arm BPM taken by an automatic oscillometric device using an appropriate cuff and three forearm BPM with a standard cuff in the sitting position after a five-minute rest. Data were analysed by the analysis of variance. The correction values were obtained by the linear regression test. RESULTS: Systolic and diastolic arm BPM with an appropriate cuff were significantly lower (p<0.05) than forearm BPM with a standard cuff. The measurements obtained by Finapres were significantly lower (p<0.05) than those found for forearm systolic and diastolic blood pressures and upper arm diastolic blood pressure. The equation to correct BPM in forearm in obese patients with arm circumference between 32-44 cm was: systolic BPM=33.2+/-0.68 x systolic forearm BPM, and diastolic BPM=25.2+0.59 x forearm diastolic BPM. CONCLUSION: This study showed that forearm blood pressure measurement overestimates the values of arm blood pressure measurement. In addition, it is possible to correct forearm BPM with an equation.     

Optimal size of cuff bladder for indirect measurement of arterial pressure in adults

This study tested the hypothesis that a sphygmomanometer cuff bladder long enough to encircle the arm in most adults ('obese cuff') would provide a more accurate and precise estimate of intra-arterial pressure than the usual 'standard' cuff bladder. In 53 patients undergoing diagnostic coronary angiography (35 males, 18 females, aged 36-79 years), indirect blood pressure, measured in the left arm with a random-zero sphygmomanometer, was compared with simultaneously measured femoral intra-arterial pressure. Duplicate indirect measurements were made with each of two cuffs containing bladders measuring 39 x 15 cm ('obese') and 23 x 12 cm ('standard'). The obese cuff bladder encircled 80% or more of the arm circumference in all subjects, whereas the standard cuff bladder met this requirement in only 19% of the subjects. For both systolic and diastolic pressure there was marked interindividual variability in the differences between indirect and direct measurements with both cuffs. With the obese cuff there was no systematic error in the diastolic blood pressure measurement. The standard cuff consistently overestimated diastolic pressure by 7.7 +/- 8.3 mmHg (mean +/- s.d.). For both cuffs, the difference between indirect and direct diastolic pressure increased with arm size (P less than 0.05). Both cuffs underestimated systolic blood pressure, the obese cuff by 15.5 +/- 11.7 mmHg and the standard cuff by 7.6 +/- 12.1 mmHg. These systolic blood pressure underestimates were greater at higher blood pressures (P less than 0.01) and with smaller arms (P less than 0.05). Age was not related to measurement error with either cuff.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of standard cuff on blood pressure readings in patients with obese arms. How frequent are arms of a 'large circumference'?

OBJECTIVE: To measure the effect on blood pressure readings when a standard cuff is used on patients with arms of a large circumference, and to determine the frequency of arms of a large circumference. SUBJECTS: Blood pressures were taken in 120 subjects with an arm circumference greater than 33 cm. Also, the arm circumference was determined in 244 patients from a family health unit, and in 216 patients from a hypertension clinic. METHOD: A mercury sphygmomanometer and two different cuff sizes were used in a random sequence; therefore, 60 patients' blood pressure were first measured with a large cuff, followed by a standard cuff; the opposite sequence was then applied for another 60 patients. With the obtained values and using a regression analysis, the difference in blood pressure overestimation was calculated. Arm circumference measurement percentages were used to determine the frequency of arms of a large circumference. RESULTS: Both systolic and diastolic blood pressures were significantly greater when the standard cuff was used. For every 5 cm increase in arm circumference, starting at 35 cm, a 2-5 mmHg increase in systolic blood pressure, and a 1-3 mmHg increase in diastolic blood pressure was observed. The prevalence of arms with a large circumference in the family medicine unit and hypertension clinic was 42% and 41.8%, respectively. CONCLUSIONS: There is an overestimation of blood pressure when a standard cuff is used in obese subjects. The high prevalence of these individuals in our environment, both in the hypertensive and normotensive population, makes it necessary to have on hand different sizes of cuffs for taking blood pressure in order to avoid incorrect decisions.     

The elevation of forearm arterial blood pressureduring Riva-Rocci-Korotkoff measurements

OBJECTIVE: To investigate why the forearm pressure rises above the systemic blood pressure upon the release of occluding cuff pressure during Riva-Rocci-Korotkoff blood pressure measurements and whether this overshoot could, as has been suggested, be used to predict the accuracy of Riva-Rocci-Korotkoff measurements in a certain patient. DESIGN AND METHODS: Finger arterial pressure was measured during Riva-Rocci-Korotkoff measurements on the same arm. Riva-Rocci-Korotkoff measurements were performed with different cuff deflation rates and after elevation of the arm, to study the nature of the overshoot reaction. Intra-arterial blood pressure was measured contralaterally. Vascular rigidity was measured by impedance plethysmography. RESULTS: Both diastolic and systolic blood pressure overshoots increased with increasing blood pressure, filling of the forearm circulation, pulse pressure, age and vascular rigidityh. They increased when lower, and decreased when higher, cuff deflation rates were used or when the arm was elevated before and during cuff inflation. Riva-Rocci-Korotkoff measurements were accurate, but finger pressures tended to underestimate the intra-arterial blood pressure in patients with high blood pressure overshoots. CONCLUSION: These findings are consistent with the hypothesis that the diastolic blood pressure overshoot results from increased filling of the forearm vasculature during Riva-Rocci-Korotkoff measurements. The systolic blood pressure overshoot probably results from pulse wave amplification in the partially occluded artery underneath the upper arm cuff. The overshoot phenomenon was not related to Riva-Rocci-Korotkoff errors.     

Accuracy of the Microlife large-extra large-sized cuff (32-52 cm) coupled to an automatic oscillometric device

To determine the accuracy of the large-extra large-sized (L-XL) cuff (32-52 cm) coupled to a Microlife WatchBP Office ABI blood pressure measuring device tested according to the requirements of the International Protocol of the European Society of Hypertension. The L-XL cuff tested in this study is designed to provide accurate blood pressure measurements in patients with large arms (arm circumference≥32 cm) over a wide range of arm circumferences using a single 145±1×320±1 mm bladder. The evaluation was made in 33 patients with a mean±standard deviation age of 53±17 years (range: 30-96 years). Their systolic blood pressure (SBP) was 142±21 mmHg (range: 110-180 mmHg), diastolic blood pressure (DBP) was 87±14 mmHg (range: 62-106 mmHg) and arm circumference was 36±5 cm (range: 32-50 cm). Blood pressure measurements were made in the sitting position. The L-XL cuff coupled to the WatchBP Office ABI passed all three phases of the European Society of Hypertension protocol for SBP and DBP. Mean blood pressure differences between device and observer were -1.3±5.1 mmHg for SBP and -1.8±5.8 mmHg for DBP. Similar device-observer differences were observed in patients divided into two subgroups according to whether their arm circumference was above or below the median in the group. These results indicate that the L-XL cuff coupled to the WatchBP Office ABI monitor provides accurate blood pressure readings in patients with large arms over a wide range of arm circumferences.     

The influence of obesity on arterial compliance in adult men and women

The objective of this study was to determine whether differences in large and small arterial compliance existed among normal weight, overweight, and obese older men and women, and whether large and small arterial compliance were associated with abdominal, hip, and subcutaneous fat distribution. A total of 134 individuals who were 40 years of age and older (age = 62 +/- 11 years; mean +/- SD) were grouped into normal weight (BMI: 18.5-24.9 kg/m2; n = 33), overweight (BMI: 25.0-29.9 kg/m2; n = 48), or obese (BMI: > or =30.0 kg/m2; n = 53) categories. The hemodynamic and arterial compliance measurements were obtained using the HDI/PulseWave CR-2000 CardioVascular Profiling System (Hypertension Diagnostics, Inc). Body mass index, nine-site sum of skinfolds, and circumference measures around the hip and waist were used for analysis. Large and small arterial compliance was lower (p < 0.001) in the obese group (12.4 +/- 4.8 ml/mmHg x 10 vs 4.6 +/- 2.5 ml/mmHg x 100, respectively) than the normal weight (16.2 +/- 4.9 ml/mmHg x 10 vs 5.5 +/- 2.7 ml/mmHg x 100) and overweight (15.2 +/- 4.3 ml/mmHg x 10 vs 5.0 +/- 2.2 ml/mmHg x 100) groups. This difference remained (p < 0.001) after adjusting for body surface area, sex, hyperlipidemia, and hypertension. Additionally, large arterial compliance correlated (p < 0.05) with sum of skinfolds (r = - 0.209), while small arterial compliance correlated with hip circumference (r = - 0.189). Arterial compliance measures were not related (p > 0.05) to waist circumference or waist-to-hip ratio. In conclusion, obesity was associated with a decrease in large and small arterial compliance independent of conventional risk factors. Additionally, subcutaneous fat and fat around the hips were inversely related to arterial compliance.     

Can an electronic device with a single cuff be accurate in a wide range of arm size? Validation of the Visomat Comfort 20/40 device for home blood pressure monitoring

An appropriate cuff according to the individual's arm circumference is recommended with all blood pressure (BP) monitors. An electronic device for home monitoring has been developed (Visomat Comfort 20/40) that estimates the individual's arm circumference by measuring the cuff filing volume and makes an adjustment of measured BP taking into account the estimated arm circumference. Thus the manufacturer recommends the use of a single cuff for arm circumference 23-43 cm. The device accuracy was assessed using the European Society of Hypertension International Protocol. Simultaneous BP measurements were obtained in 33 adults by two observers (connected mercury sphygmomanometers) four times, sequentially with three measurements taken using the tested device. Absolute device-observer BP differences were classified into < or =5, < or =10 and < or =15 mm Hg zones. For each participant the number of measurements with a difference < or =5 mm Hg was calculated. The device produced 60/89/97 measurements within 5/10/15 mm Hg respectively for systolic BP, and 72/97/98 for diastolic. Twenty-three subjects had at least two of their systolic BP differences < or =5 mm Hg and three had no differences < or =5 mm Hg (for diastolic 27 and 1, respectively). Mean device-observer BP difference (systolic/diastolic) was 3.7 +/- 5.6/-1.5 +/- 4.7 mm Hg (4.7 +/- 4.9/ - 1.7 +/- 4.3 in arm circumference 23-29 cm [39 readings] and 3.1 +/- 5.9/-1.4 +/- 5.0 in arm 30-34 cm [60 readings], P=NS). In conclusion, the device fulfils the International Protocol requirements and can be recommended for clinical use. Interestingly, the device was accurate using a single cuff in a wide range of arm circumference (23-34 cm). This study provides no information about the device accuracy in larger arms.     

The reliability of auscultatory measurement of arterial blood pressure. A comparison of the standard and a new methodology

In 48 individuals with a wide range of arm circumferences blood pressure measured indirectly with two different cuffs was compared to direct intraarterial measurements. The two cuffs were a standard size cuff (12 X 35 cm) and a newly developed cuff, containing three rubber bags of different sizes, which automatically selects the appropriately sized bag in relation to arm circumference (Tricuff, Pressure Group AB, Sweden). The Tricuff correctly placed 42 of the 43 patients in the "normotensive" range, ie, diastolic blood pressure less than 90 mm Hg, whereas the standard cuff put only 33 of 44 patients in this range (P less than .005). The discrepancy was not only due to the expected better performance in patients with obese arms, but also in the subgroup of patients with arms in the range 22 to 31 cm, in which group both cuffs would measure blood pressure with a 12 cm wide rubber bag. The number of correctly identified "normotensive" patients was noticeably higher with the Tricuff than with the standard cuff (30/31 v 25/32, P = .053). The better specificity of the new cuff thus offers an improvement over the standard cuff. There are several potential clinical advantages of this, mainly that the risk of erroneously labelling normotensive individuals as hypertensive is reduced.     

Arterial elasticity among normotensive subjects and treated and untreated hypertensive subjects

OBJECTIVE: The aim of this study was to determine arterial elasticity in normotensive and hypertensive individuals. BACKGROUND: In addition to blood pressure, other parameters serve as markers for vascular disease. Arterial elasticity is one parameter that can be determined by a modified Windkessel model of the circulation. This model estimates, from a computerized pulse contour analysis, the proximal (capacitive) elasticity of the large arteries and the distal (reflective) elasticity of the small arteries. METHODS: A prospective, multi-center, controlled clinical study evaluated large-artery and small-artery elasticity indices in four groups: (1) normotensives without a family history of hypertension; (2) normotensives with a family history of hypertension; (3) treated and controlled hypertensives; and (4) untreated and uncontrolled hypertensives. Blood pressure, using a mercury manometer, and arterial elasticity, using a CVProfilor DO-2020 CardioVascular Profiling System (Hypertension Diagnostics, Inc., Eagan, MN, USA), were measured supine in triplicate 3 min apart in a randomized sequence. RESULTS: There were 212 evaluable subjects of mean age 46 years; 57% were women, 51% Caucasian and 33% African-American. Comparing normotensives without a family history and untreated hypertensives, both large-artery and small-artery elasticity indices were significantly different (P < 0.0001). After controlling for age and body surface area, a significant linear trend (P = 0.0001) across the four groups was detected for both large- and small-artery elasticity indices. CONCLUSION: As the hypertension status worsened, large- and small-artery elasticity indices decreased, suggesting a potential for the diagnostic use of arterial elasticity determinations.     

Impact of type 1 diabetes and body weight status on cardiovascular risk factors in adolescent children

Type 1 diabetes (T1D) is a risk factor for cardiovascular disease. However, it is unclear whether increased body weight amplifies that risk in T1D patients. This is a cross-sectional study examining the presence of cardiovascular risk factors in normal and overweight children, both with and without T1D. Sixty-six children (aged 16±2.2 years) were included in one of the following groups: (T1D and normal weight, T1D and overweight, healthy and normal weight, and healthy and overweight). A fasting blood sample was analyzed for lipid profile (triglyceride, cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol), apolipoprotein B (apoB), and apolipoprotein C-III (apoC-III) levels. Body composition was determined by dual energy x-ray absorptiometry and vascular elasticity by HDI/Pulsewave CR-2000 (Hypertension Diagnostics, Eagan, MN). Statistical analyses examined the effect of T1D and body weight status and their interactions on cardiovascular risk parameters. In this study, the authors were unable to demonstrate an additive effect of body weight status and T1D on cardiovascular risk profile. However, subgroup analysis of patients with T1D revealed higher apoC-III levels in overweight patients with T1D (P=.0453) compared with normal-weight diabetic children. Most notably, there was a direct relationship of small artery elasticity to body weight status. This seemingly paradoxical observation supports recent data and warrants further investigation.     

Inter-arm differences in blood pressure: when are they clinically significant?

OBJECTIVE : To determine whether there is significant disparity in blood pressure between the two arms. DESIGN : Prospective, observational study. SETTING : One general hospital in Birmingham, England. PARTICIPANTS : Four hundred participants [age 56.3 +/- 19.7 years (mean +/- SD), 50% male] were recruited from staff and patients. Simultaneous bilateral blood pressure measurements were obtained using Omron HEM-705CP automated oscillatory devices; with two measurements taken in each arm. MAIN OUTCOME MEASURES : Mean inter-arm blood pressure differences and frequency of clinically important disparities. RESULTS : Mean +/- SD inter-arm differences in systolic and diastolic blood pressure were 1.81 +/- 8.6 mmHg and -0.23 +/- 8.3 mmHg, respectively. The analogous figures for mean +/- SD absolute differences were 6.32 +/- 6.12 mmHg and 5.06 +/- 6.57 mmHg, respectively. Significant differences were present between the mean right and left arm systolic blood pressure [t(399) = 4.20, P < 0.0001], and the mean absolute difference for both systolic [t(399) = 20.65; P < 0.0001] and diastolic [t(399) = 15.39; P < 0.0001] blood pressure. The variation in mean inter-arm blood pressure was unrelated to age, sex, ethnicity, arm circumference, handedness, being hypertensive, diabetic, or previous history of cardiovascular disease. Clinically significant inter-arm differences in systolic blood pressure of > 10 and > 20 mmHg were found in 20 and 3.5%, respectively; diastolic differences of > 10 and > 20 mmHg were present in 11 and 3.5%, respectively. Age was the only significant predictor of clinically significant variations in inter-arm blood pressures and mean absolute blood pressure differences. CONCLUSIONS : Significant differences in mean inter-arm systolic blood pressure, and mean absolute inter-arm systolic and diastolic blood pressure are present. This emphasizes the importance of measuring blood pressure in both arms initially to prevent this misdiagnosis of hypertension, due to normal differences in blood pressure between the arms.