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Objective: Optimal medication use obscures the impact of physical activity on traditional cardiometabolic risk factors. We evaluated the relationship between step counts and carotid-femoral pulse wave velocity (cfPWV), a summative risk indicator, in patients with type 2 diabetes and/or hypertension. Research design and methods: Three hundred and sixty-nine participants were recruited (outpatient clinics; Montreal, Quebec; 2011–2015). Physical activity (pedometer/accelerometer), cfPWV (applanation tonometry), and risk factors (A1C, Homeostatic Model Assessment–Insulin Resistance, blood pressure, lipid profiles) were evaluated. Linear regression models were constructed to quantify the relationship of steps/day with cfPWV. Results: The study population comprised 191 patients with type 2 diabetes and hypertension, 39 with type 2 diabetes, and 139 with hypertension (mean ± SD: age 59.6 ± 11.2 years; BMI 31.3 ± 4.8 kg/m2; 54.2% women). Blood pressure (125/77 ± 15/9 mmHg), A1C (diabetes: 7.7 ± 1.3%; 61 mmol/mol), and low-density lipoprotein cholesterol (diabetes: 2.19 ± 0.8 mmol/l; without diabetes: 3.13 ± 1.1mmol/l) were close to target. Participants averaged 5125 ± 2722 steps/day. Mean cfPWV was 9.8 ± 2.2 m/s. Steps correlated with cfPWV, but not with other risk factors. A 1000 steps/day increment was associated with a 0.1 m/s cfPWV decrement across adjusted models and in subgroup analysis by diabetes status. In a model adjusted for age, sex, BMI, ethnicity, immigrant status, employment, education, diabetes, hypertension, medication classes, the mean cfPWV decrement was 0.11 m/s (95% confidence interval −0.2, −0.02). Conclusions: cfPWV is responsive to step counts in patients who are well controlled on cardioprotective medications. This ability to capture the ‘added value’ of physical activity supports the emerging role of cfPWV in arterial health monitoring.

OBJECTIVES Central pulse pressure (PP) has been suggested a better predictor of cardiovascular risk than brachial PP, and its routine noninvasive assessment can be useful for risk stratification. The present study evaluated the capability of a radiofrequency-based carotid wall tracking to estimate central PP from distension curves, comparing the values of carotid PP as obtained by wall tracking with those provided by applanation tonometry. Furthermore, the associations of carotid PP with intermediate markers of cardiovascular risk, like carotid intima-media thickness (IMT) and left ventricular mass (LVM), were assessed. METHODS Carotid PP was measured by wall tracking and applanation tonometry during the same session in 346 individuals (healthy controls, patients with hypertension and diabetes). IMT was measured in all individuals and LVM was measured in 253. RESULTS Carotid PP values as measured by wall tracking and applanation tonometry were highly correlated [r = 0.87; slope 0.90 (0.85-0.95); P

BACKGROUND Vascular phenotype by assessing carotid-femoral pulse wave velocity (cf-PWV) and central SBP (cSP) in the young could be used as an intermediate cardiovascular outcome measure. Tonometry is considered the gold-standard technique, but its use is challenging in clinical practice, especially when used in children. The purpose of this study was to validate cf-PWV and cSP assessment with novel oscillometric device (SphygmoCor XCEL) in children and adolescents. METHODS cf-PWV and cSP were measured in 72 children and adolescents aged 6-20 years. Measurements were performed by applanation tonometry and by the SphygmoCor XCEL device at the same visit under standardized conditions. Regression analysis and Bland-Altman plots were used for comparison of the tonometer-based with oscillometric-based method. RESULTS Mean cf-PWV measured by applanation tonometry was 4.85 ± 0.81 m/s and measured by SpygmoCor XCEL was 4.75 ± 0.81 m/s. The mean difference between the two devices was 0.09 ± 0.47 m/s (P = NS). cSP measured by SpygmoCor XCEL was strongly correlated with cSP measured by applanation tonometry (R = 0.87, P

Objective:Subendocardial viability ratio (SEVR), also known as the Buckberg index, has been proposed as a surrogate measure of myocardial perfusion, as it correlates with the ratio of subendocardial to subepicardial blood flow. SEVR can be non-invasively estimated by applanation tonometry with lower

AIMS We determined the extent to which relationships between nurse-derived blood pressures (BPs) and cardiovascular damage may be attributed to isolated increases in in-office SBP independent of ambulatory BP. METHODS In 750 participants from a community sample, nurse-derived office BP, ambulatory BP, carotid-femoral pulse wave velocity (PWV; applanation tonometry and SphygmoCor software; n=662), and left ventricular mass indexed to height (LVMI; echocardiography; n=463) were determined. RESULTS Nurse-derived office BP was associated with organ changes independent of 24-h BP (LVMI; partial r=0.15, P

Objectives: The Vicorder is a new brachial cuff-based device that estimates central blood pressure (cBP) using a brachial-to-aortic transfer function. The aim of this study was to evaluate cBP estimated by the Vicorder. Methods: During cardiac angiography, cBP estimated by the Vicorder and the SphygmoCor was evaluated against simultaneous invasive cBP in 50 patients. The two devices were also compared noninvasively in a separate group of 90 healthy individuals. Results: Central SBP (cSBP) obtained with each device satisfied the American Association for the Advancement of Medical Instrumentation accuracy criteria when peripheral waveforms were calibrated to invasive mean arterial

BACKGROUND Noninvasive applanation tonometry studies of the brachial and radial artery pressure waves show that the arterial pulse is substantially amplified between the brachial and radial sites. Brachial tonometry waveforms have also been used to calibrate carotid tonometry waves as a measure of central pressure in major clinical trials. These trials assume identity of mean and of DBP in calculation of central (carotid) SBP. None of these trials showed superiority of central over brachial pressure in predicting outcome, but all showed equivalence of SBP and pulse pressure at brachial and carotid sites! METHOD We tested this method by measuring pressure waves at brachial, radial and carotid sites by applanation tonometry in 100 patients, with attention to any subtle difference between brachial and radial waveforms, and with both calibrated to cuff SBP and DBP. RESULTS The results confirmed no proximal and strong distal amplification in the arm. However, this was accompanied by blunting of the brachial compared with radial waveform with brachial pressure 2.7 mmHg higher during most of the cardiac cycle. Form factor of the ensemble-averaged brachial wave [39.1 standard deviation (SD) 4.9%] was similar to the carotid (40.2 SD 4.1%) but different to the radial wave (34.8 SD 3.7%; P < 0.01). CONCLUSIONS All findings were explained by inability to applanate the brachial artery, and resulting systematic error in generating brachial waveforms. In estimation of central pressure with applanation tonometry, the radial pressure wave, which can be accurately applanated, should be used, and calibrated to the brachial cuff. (No funders listed)

Objectives As the impact of mild smoking on blood pressure (BP) is uncertain, we assessed the relationship between predominantly mild current smoking and out-of-office BP and the effect of angiotensin-converting enzyme (ACE) genotype on this relationship in a community sample of black African ancestry. Methods In 689 participants randomly recruited from an urban, developing community of black African descent, we assessed smoking habits, out-of-office (24-h), and in-office conventional and central (applanation tonometry) BP, and ACE insertion (I)/deletion (D) variant genotype. Results A total of 14.5% (n = 100) were current smokers, the majority being mild (72%, 7.4 ± 4.6 cigarettes/day). Despite current smokers having only modest increases in in-office (P

Reconstruction of the central aortic pressure wave from the noninvasive recording of the radial pulse with applanation tonometry has become a standard tool in the field of hypertension. It is not presently known whether recording the radial pulse on the dominant or the nondominant side has any effect on such reconstruction.We carried out radial applanation tonometry on both forearms in young, healthy, male volunteers, who were either sedentary (n = 11) or high-level tennis players (n = 10). The purpose of including tennis players was to investigate individuals with extreme asymmetry between the dominant and nondominant upper limb.In the sedentary individuals, forearm circumference and handgrip strength were slightly larger on the dominant (mean +/- SD respectively 27.9 +/- 1.5 cm and 53.8 +/- 10 kg) than on nondominant side (27.3 +/- 1.6 cm, P0.001 vs. dominant, and 52.1 +/- 11 kg, P = NS). In the tennis players, differences between sides were more conspicuous (forearm circumference: dominant 28.0 +/- 1.7 cm nondominant 26.4 +/- 1.5 cm, P0.001; handgrip strength 61.4 +/- 10.8 vs. 53.4 +/- 9.7 kg, P0.001). We found that in both sedentary individuals and tennis players, the radial pulse had identical shape on both sides and, consequently, the reconstructed central aortic pressure waveforms, as well as derived indices of central pulsatility, were not dependent on the side where applanation tonometry was carried out.Evidence from individuals with maximal asymmetry of dominant vs. nondominant upper limb indicates that laterality of measurement is not a methodological issue for central pulse wave analysis carried out with radial applanation tonometry.

Combined consumption of olive oil and wine is common in the Mediterranean diet, but there are no data concerning their synergistic haemodynamic response. We sought to determine the combined postprandial effects of wine and olive oil on wave reflections and central haemodynamics.Fifteen healthy subjects consumed four standard meals on different days, containing 50 g of olive oil and 250 ml of wine, in a randomized cross-over study design. Two types of wine [red (R) and white (W)] and two types of olive oil [green (G) and refined (O) (rich and poor in antioxidants, respectively)] were used in all possible combinations (RO, RG, WO and WG). Applanation tonometry and aortic pulse wave analysis were performed when fasting and 1, 2 and 3 h postprandially. A second group of 15 healthy individuals matched for age, gender and body mass index served as the control group.All meals decreased AIx (RO and RG, P0.001; WO, P = 0.007; and WG, P = 0.039). The AIx reduction after RG, RO, WO and WG was significantly different from the respective AIx response of the control group. No difference was observed in the reduction of AIx between sessions, but a significantly earlier peak decrease in AIx, as well as a more prolonged decreasing effect, was observed after RG and RO consumption compared to WO and WG. Central systolic and diastolic pressures were diminished after all four combinations of wine and olive oil (P0.05).Combined consumption of wine and olive oil provided beneficial postprandial effects on haemodynamics. These findings reveal an additional favourable effect of components of the Mediterranean diet on haemodynamics in the postprandial state.

Continuing reports in the literature regarding the potential of central pulse wave analysis in clinical practice and a recent consensus statement demonstrate the increasing interest in the clinical application of arterial transfer functions. A number of misconceptions, however, persist regarding their use. In spite of ongoing controversy, there are considerable published data that would permit users to assess the validity and accuracy of the technique. We provide a comprehensive review of available data, all of which appear to be clear and consistent. The technique does not permit accurate reconstruction of central waveforms from entirely non-invasively acquired data. We should move on from the misconception that what is being studied is central aortic data when transfer functions are applied non-invasively, and accept that it is radial waveform data that have been passed through a single mathematical transformation. We have a readily applicable, non-invasive and reproducible technique for acquiring radial waveform data, with or without the application of a generalized arterial transfer function. We must explore the potential of this technique in an analytical manner, and without untenable preconceptions, if we are to learn the secrets that it may yet reveal.

Wave reflections are implicated increasingly in clinical research.The purpose of the present study was to investigate whether wave reflection indices are reproducible when measured repeatedly (more than twice) at longer time intervals, namely hour-to-hour and week-to-week, in healthy subjects; something that has not yet been examined.Bland-Altman plots, the interclass correlation coefficients (ICC) and coefficient of variation were used for this purpose. Two series, with measurements repeated in triplicate, were performed in 22 healthy subjects: the first at intervals of 1 h and the second at 1-week time intervals. Augmentation index (AIx), heart rate-corrected AIx (AI@75) and arrival time of reflected waves at the central aorta (tr) were calculated by aortic pulse wave analysis.AIx and AI@75 presented very good to excellent reproducibility (ICC = 0.86) for hour-to-hour repeated measurements, while tr was also highly reproducible (ICC = 0.79). AIx, AI@75 and tr were substantially reproducible when measured repeatedly with 1-week intervals, providing ICCs greater than 0.70. Bland-Altman plots confirmed these results, indicating that more than 90% of AIx, AI@75 and tr measurements fell within two standard deviations of the mean difference.Wave reflections are substantially reproducible even when measurements repeated in triplicate are performed at longer time intervals (hours and weeks). A quantifiable amount of variation was reported, which should be taken carefully into consideration in interventional studies with repeated measurements and in observational studies investigating differences or correlations of these indices.

S everal clinical epidemiological studies have suggested the relevance of the assessment of central blood pressure by means of noninvasive methods for a better evaluation of cardiovascular risk [1–3]. In particular, attention has been focused on the phenomenon of pulse pressure amplification in the clinical evaluation of cardiovascular patients [4–6]. Applanation tonometry is currently considered the reference method for noninvasive evaluation of central blood pressure and central pulse wave analysis [7,8]. Even if transcutaneous arterial tonometry is not yet considered to be one of the diagnostic tests recommended for routine arterial hypertension management, all the same, it represents a useful tool for more in-depth investigation of vascular changes in a number of clinical conditions characterizing daily practice. In particular, it is useful in conditions in which an accurate central pulse wave analysis is required, for an indirect estimate of myocardial function or cardiac work. Therefore, it is necessary that central blood pressure values recorded with this method are reliable and that parameters describing central arterial pressure waveform faithfully reflect the corresponding ones invasively recorded in the ascending aorta. The study by Hirata et al. [9], published in this issue of the Journal of Hypertension, focuses on a particular aspect concerning the position of the patient during acquisition of the central arterial pressure waveform, which appears to be an important requirement to optimize standardization of applanation tonometry in clinical practice. As a matter of fact, some tonometric devices are used with the patient in sitting position, whereas other instruments require the patient to lie down in a supine position during arterial pressure waveform recording.

The Sphygmocor system purports to be able to assess ascending aortic blood pressure using a transfer function. It has been shown to be accurate when data obtained invasively are used, but has not been tested prospectively using data obtained non-invasively.To investigate the accuracy of this equipment when measurements are obtained non-invasively, as would normally be the case in the clinic setting.The study was observational. Ascending aortic pressure measurements were taken simultaneously with radial artery pressure wave recordings for estimation of ascending aortic blood pressure, in 28 patients undergoing diagnostic cardiac catheterization.The transfer function in the Sphygmocor system significantly underestimated invasively measured systolic blood pressure [mean -7.23 +/- 10.07 mmHg; 95% confidence interval (CI) -3.3 to -11.14 mmHg, P = 0.001] and significantly overestimated invasively measured diastolic blood pressure (mean 12.20 +/- 7.14 mmHg; 95% CI 9.43 to 14.97 mmHg, P0.001). Oscillometrically measured brachial systolic blood pressure was not significantly different from that measured invasively in the ascending aorta (mean 3.36 +/- 10.47 mmHg; 95% CI -0.69 to 7.43 mmHg, P = 0.1), but oscillometric measurement of brachial diastolic blood pressure gave a significant overestimation of that measured invasively (mean 11.70 +/- 7.18 mmHg; 95% CI 8.91 to 14.49 mmHg, P0.001). CONCLUSIONS The transfer function in the Sphygmocor system is no better at estimating ascending aortic blood pressure than are standard peripheral blood pressure measurements. It may be necessary to derive a new transfer system that is based on data that are acquired entirely non-invasively.

The study of the pulse using the technique of applanation tonometry is undergoing a resurgence with the development of new computerized equipment. We aim here to present a critical review of the uses, potential uses, strengths and weaknesses of the technique of applanation tonometry for the assessment of augmentation index and pulse wave velocity. We will review the technique of applanation tonometry, the physiological factors affecting pulse wave velocity and pulse wave analysis, the changes in pulse wave velocity and pulse wave analysis with pharmacological interventions, and the use of the technique of applanation tonometry as a prognostic tool. We conclude that, although the technique of applanation tonometry initially seems promising, several pertinent issues need to be addressed before it can be used reliably as a clinical or research tool. Importantly, use of the technique of applanation tonometry to derive the central waveform from non-invasively acquired peripheral data needs to be validated prospectively.

AIMS To determine whether SBP or DBP is best associated with different components of left ventricular diastolic dysfunction. METHODS In 241 randomly selected participants, echocardiographic left ventricular diastolic function was assessed from early-to-atrial (E/A) transmitral velocity and E/e' where e' represents myocardial tissue lengthening velocity in early diastole as measured at the mitral annulus. Relationships between diastolic function and blood pressure (BP) were assessed from brachial and central aortic (radial applanation tonometry and SphygmoCor software) measurements. RESULTS Independent of confounders, brachial DBP (partial r = -0.21, P

AIMS We sought to determine whether within normal/high-normal blood pressure (BP) ranges (120-139/80-89 mmHg), aortic BP may further refine BP-related cardiovascular risk assessment, as determined from target organ changes. METHODS In 1169 participants from a community sample of African ancestry, 319 (27%) of whom had a normal/high-normal BP, aortic BP was determined using radial applanation tonometry and SphygmoCor software, and target organ changes assessed from carotid-femoral pulse wave velocity (PWV) (n = 1025), estimated glomerular filtration rate (eGFR) (n = 944), and left ventricular mass indexed to height (LVMI) (n = 690). RESULTS Normal versus high-normal BP categories failed to differentiate between those participants with a BP above optimal values with versus without multivariate-adjusted target organ changes. However, in those with a normal/high-normal BP with aortic SBP values that were less than 95% confidence interval of healthy participants with optimal BP values (45% of those with a normal/high-normal BP), no unadjusted or multivariate adjusted target organ changes were noted. In contrast, those with a normal/high-normal BP with aortic SBP values that exceeded optimal thresholds, demonstrated unadjusted and multivariate adjusted increases in PWV and LVMI and decreases in eGFR (P

BACKGROUND A semi-automated devise for oscillometric measurement (Vicorder) of carotid-femoral pulse wave velocity (cfPWV) has been considered to be especially suited for multicenter studies in children and adolescents. METHODS Within a healthy pediatric population (156 boys/158 girls; mean age 10.8 years, range 5.0-19.6 years), the transit time of the pulse wave was measured oscillometrically (Vicorder) between a carotid and femoral cuff. For calculation of cfPWV, the traveled path length was set to 80% of the direct distance between both sites of measurement. Reference tables were generated using the maximum-likelihood curve-fitting technique and SD scores were calculated. Normalizing the same set of data with reference values specific for applanation tonometry yielded Z(at)values. Effects of sex, age, height, weight, BMI, blood pressure (BP), and heart rate on cfPWV as well as the correlation between sex-specific age-related and height-related Z(osci) and Z(at)were investigated. RESULTS Sex-specific reference values and curves for cfPWV as a function of age and height are presented. cfPWV correlated positively with age, height, weight, SBP, mean arterial BP, and sex (each P < 0.005). Multiple regression analysis identified age, sex, and mean arterial pressure as significant independent predictors of cfPWV explaining 42% of the overall variability. Strong linear relationships between Z(osci) and Z(at) were noted and per sex a set of age and height-related equation for conversion was derived: Z(at),age = -0.22 + 0.68 × Z(osci),age; r = 0.98 and Z(at),height = -0.33 + 0.66 × Z(osci),height; r = 0.99 in boys and Z(at),age = -0.61 + 0.81 × Z(osci),age; r = 0.98 and Z(at),height = -0.73 + 0.72 × Z(osci),height; r = 0.97 in girls (each P

Central arterial pressure is a better predictor of adverse cardiovascular outcomes than brachial blood pressure, but noninvasive measurement by applanation tonometry is technically demanding.Pulsecor R6.5 is a novel device adapted from a standard sphygmomanometer which estimates the central aortic pressure from analysis of low-frequency suprasystolic waveforms at the occluded brachial artery. A physics-based model, which simulates the arterial system using elastic, thin-walled tube elements and Navier-Stokes equations, is used to calculate arterial pressure and flow propagation. To determine the reliability of the device, we compared 94 central systolic pressures estimated by Pulsecor to the simultaneous directly measured central aortic pressures at the time of coronary angiography in 37 individuals.There was good correlation in central SBP between catheter measurements and Pulsecor estimates by either invasive or noninvasive calibration methods (r = 0.99, P 0.0001 and r = 0.95, P 0.0001, respectively). The mean difference in central systolic pressure was 2.78 (SD 3.90) mmHg and coefficient of variation was 0.03 when the invasive calibration method was used.When the noninvasive calibration method was used, the mean difference in central systolic pressure was 0.25 (SD 6.31) mmHg and coefficient of variation was 0.05.We concluded that Pulsecor R6.5 provides a simple and easy method to noninvasively estimate central SBP, which has highly acceptable accuracy.

Background The carotid-femoral pulse wave velocity (PWVcf) is used as an indicator of arterial stiffness. It is often measured using applanation tonometry, for instance with the SphygmoCor. In young children, this method is difficult to perform. Therefore, techniques are needed that are less dependent on patient compliance. The Vicorder device uses the oscillometric technique to measure the PWVcf and is thought to be less time consuming and less dependent on operator skills. Objective To compare the PWVcf measured by an extensively used device (SphygmoCor) and the Vicorder in adults initially. Methods Thirty-eight healthy volunteers (20 men, mean age 48 +/- 13.1 years) participated in this cross-sectional study. The PWVcf was assessed twice using the SphygmoCor and the Vicorder by a single investigator during one visit. Intra-rater reproducibility of each instrument and comparison between the two instruments were assessed by the Bland-Altman method. Results The mean difference (95% confidence interval) between repeated measurements was 0.09 (-0.20 to 0.38) m/s and 0.24 (-0.55 to 1.03) m/s, for the SphygmoCor and Vicorder, respectively. The Limits of Agreement (LoA) were -1.53 to 1.71 m/s and -4.24 to 4.72 m/s, for the SphygmoCor and Vicorder, respectively. The mean PWVcf measured by the Vicorder was 0.58 (-0.20 to 1.35) m/s higher than the PWVcf measured by the SphygmoCor. The LoA between the two instruments were -3.50 to 4.66 m/s. Conclusion The LoA of both instruments exceed a value of 1.5 m/s. The LoA of the Vicorder PWVcf measurements are considered too wide for using this technique reliably in adults or in children. J Hypertens 28: 1687-1691 (c) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins

Increased aortic and carotid arterial augmentation index (AI) has been directly linked with cardiovascular disease risk, mortality and morbidity. The aim of this study was to examine whether AI obtained directly from radial artery pressure waveforms (radial AI) can provide information comparable with carotid arterial AI measurements.In a cross-sectional study of 204 apparently healthy subjects (88 men and 116 women) aged 19-76 years (51 +/- 15 years, mean +/- SD), carotid AI [(second peak carotid systolic pressure - first peak carotid systolic pressure)/carotid pulse pressure*100] and radial AI [(second peak radial systolic pressure - diastolic pressure)/(first peak radial systolic pressure - diastolic pressure)*100] were measured using applanation tonometry.Radial AI was strongly correlated with carotid AI (r = 0.86, P0.0001, SD of difference 10.0%), although radial AI was consistently approximately 66% higher than carotid AI. In 16 apparently healthy young adults (11 men and five women, aged 23 +/- 3 years) handgrip exercise was immediately followed by post-exercise muscle ischaemia (PEMI) to compare changes in carotid and radial AI during increased sympathetic nervous activity. PEMI caused parallel increases in carotid and radial AI (26 and 19%). Accordingly, changes in radial AI with PEMI were strongly correlated with corresponding changes in carotid AI (r = 0.86, P0.0001, SD of difference 7.3%).These results suggest that AI obtained directly from radial arterial pressure waveforms could provide equivalent information to carotid arterial AI, and has potential as a surrogate marker of cardiovascular disease.

Pulse pressure is not constant throughout the arterial tree. Use of pulse pressure at one arterial site as surrogate for pulse pressure at another arterial site may be erroneous. The present study compares three non-invasive techniques to measure local pulse pressure: (i) internally calibrated readings from applanation tonometry, (ii) alternative calibration of pressure waves obtained with applanation tonometry and (iii) alternative calibration of arterial distension waves obtained with echo-tracking. Alternative calibration assumes mean and diastolic blood pressure constant throughout the large artery tree.Study 1 used invasive measurements in the ascending aorta as a reference method and internally calibrated tonometer readings and alternatively calibrated pressure waves at the common carotid artery as test methods. Study 2 used alternatively calibrated pressure waves as a reference method and alternatively calibrated distension waves and internally calibrated applanation tonometer readings as test methods.In study 1, pulse pressure from internally calibrated tonometer readings was 10.2+/-14.3 mmHg lower and pulse pressure from alternatively calibrated pressure waves was 1.8+/-5.2 mmHg higher than invasive pulse pressure. Pulse pressure from calibrated distension waves was 3.4+/-6.9 mmHg lower than pulse pressure from alternatively calibrated pressure waves. According to British Hypertension Society criteria, pulse pressure from the internally calibrated tonometer achieved grade D and pulse pressure from alternatively calibrated pressure waves achieved grade A. Pulse pressure from calibrated distension waves achieved grade B when alternatively calibrated pressure waves were used as a reference method.Pulse pressure obtained from alternatively calibrated tonometer-derived pressure waves and echo-tracking-derived distension waves demonstrates good accuracy. Accuracy of pulse pressure from internally calibrated applanation tonometer readings at the carotid artery is poor.