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Aims: To understand the accuracy of non-invasively obtained blood pressure gradients (cuff vs Doppler gradient) with an invasively measured pressure gradient. Study Design: Retrospective study. Place and Duration of Study: Department of Pediatrics, Section of Pediatric Cardiology, King Faisal Specialist Hospital & Research Center, Jeddah, Saudi Arabia, between Jan, 2010 till Jan, 2020. Methodology: A retrospective study of patients with CoA who underwent cardiac catheterization between Jan, 2010 till Jan, 2020 was performed. Cuff BP gradients and Doppler echocardiography were measured prior to cardiac catheterization and afterwards, when an intervention was performed. Student t test and Bland-Altman analysis were performed. Results: 55 patients with aortic coarctation underwent 92 cardiac catheterizations. Among them 75 needed interventions. This resulted in a total of 162 cardiac catheterizations (cath), from them 67 pressure gradients included in the analysis. There was no statistically significant difference between mean Doppler measurements and invasively derived catheter gradients (p=0.12). In contrast peak Doppler measurement (p < 0.00001) and cuff blood pressure gradients (p=0.03) showed significant differences to the cath gradient. We found that cuff blood pressure gradients accurately reflected cath measurement in native COA (p=0.40) and in those who weigh less than 10 kg (p=0.67). Mean Doppler measurements had a small tendency for underestimation. Peak Doppler gradient and cuff pressure gradient usually overestimated cath measurement. Conclusion: The mean Doppler echocardiography seems to be the most accurate among the other noninvasive methods in use to estimate severity of aortic coarctation. It provided reasonable agreement with the invasively obtained aortic coarctation gradient.

Purpose: to evaluate the left ventricular (LV) echocardiographic indices of myocardial work using the LV pressure-strain loops method in healthy individuals.Material and methods. The study included 50 healthy subjects (28 men, mean age: 44 ± 14 years). The inclusion criteria were the absence of any cardiovascular diseases and diabetes mellitus. After calculating global longitudinal strain (GLS) from speckle-tracking Echo and inserting values of brachial artery cuff blood pressure (BP), the vendor-specific module constructed non-invasive LV pressure-strain loops. The following parameters were calculated: global myocardial work index (GWI), global constructive work (GCW), global wasted work (GWW), global work efficiency (GWE).Results. The lowest values of GWI in men and women were 1382 mmHg% and 1821 mmHg%, the highest values were 2875 mmHg% and 2589 mmHg%, mean values were 2056 ± 326 mmHg% and 2109 ± 200 mmHg%, respectively. Mean values of GCW were 2292 ± 329 mmHg% in men and 2304 ± 211 mmHg% in women. The median and the highest value of GWW were 66 mmHg% and 313 mmHg% in men and 79,5 mmHg% and 172 mmHg% in women, respectively. The lowest value of GWE were 89% in men and 91% in women. GWI was significantly and naturally correlated only with systolic BP (r = 0,30, р = 0,03) and GLS (r = -0,72, р < 0,001). GCW was significantly correlated with systolic BP (r = 0,36, р = 0,01) and GLS (r = -0,72, р < 0,001) too, however, the negative relationship with the age of the patients was found (r = -0,27, р = 0,04). LV myocardial work indices did not significantly differ between men and women. Coefficients of variation for GWI, GCW and GWE did not exceed 10%, which is typical for good reproducible indices.Conclusion. The study presents values of the echocardiographic LV myocardial work indices, obtained with help of the LV pressure-strain loops method in healthy individuals. The natural correlation of LV myocardial work indices with strain and blood pressure was demonstrated, as well as a dependence on the age of the subjects and good reproducibility.

While Doppler and cuff blood pressure techniques are prevalent methods of assessing blood pressure in patients with continuous flow left ventricular assist devices, the impact of pulsatility on measurement is not well established. Retrospective chart analysis of clinical variables including pulse perception, blood pressure (Doppler and standard cuff), and aortic valve opening on echo at clinic visit were abstracted. Stable outpatients on continuous flow left ventricular assist devices support with concomitant portable echo assessment were included. Mean average difference was calculated and Pearson’s correlation performed for all those patients who had both Doppler and cuff pressure obtained. In all, 74 Heartmate-II patients with a median time from implant of 380 days were analyzed. A pulse was perceived in 82% of patients with persistent aortic valve opening on portable echo and also in 30% of those who had a persistently closed aortic valve. The mean average difference between the Doppler and systolic cuff pressure was ~13 mmHg ( r = 0.5, p = 0.004) when a pulse was present and ~11 mmHg when aortic valve was open ( r = 0.68, p

Clinical management of hypertension and hypotension has been hindered by current cuff blood pressure (BP) measurement devices, which are not always readily available or continuous and can be disruptive to the user. Photoplethysmography (PPG) is a simple yet effective tool for tracking pulsatile arterial blood volume changes that can improve BP measurement. Volume clamping via finger cuff-PPG devices is a proven continuous method, whereas oscillometry via PPG-force sensor units, pulse transit time detected via PPG waveform(s), and PPG waveform feature extraction are potential cuff-less methods. The objective of this chapter is to facilitate the advancement of PPG-based BP monitoring. First, the clinical BP measurement methods and their limitations are explained. Then, the PPG principle and available sensors are reviewed. Next, the four PPG-based BP measurement methods are described including principles, embodiments, and empirical evidence. Finally, these methods are compared, future research directions are pinpointed, and a brief outlook on the approach is provided.

Background. Cuff blood pressure (BP) measurement has been the standard method for taking BP in routine daily practice for more than a century. However, some concerns were raised about the accuracy of this method which could lead to misclassification of BP in many situations. We aimed primarily to confirm a recent major discovery that distinct BP phenotypes based on central-to-peripheral systolic blood pressure (SBP) amplification do exist, and whether application of a validated cuff BP method (e.g. oscillometric) could accurately discriminate these differences. Material and methods. Among 106 participants (mean age 62 ± 11; 58% males) undergoing coronary angiography, intra-arterial BP was measured at 3 points (ascending aorta, brachial and radial arteries). Central-to-peripheral SBP amplification (SBPamp) was defined as ≥ 5 mm Hg SBP increased from aorta-to-brachial and/or from brachial-to-radial arteries. A validated cuff BP device (oscillometric) was used to measure BP at 4 different time points. Results. Four different BP phenotypes were confirmed based on the magnitude of SBPamp; phenotype-I, both aortic-to brachial and brachial-to radial SBPamp; phenotype-II, only aortic-to-brachial SBPamp; phenotype-III, only brachial-to-radial SBPamp; and phenotype-IV, no SBPamp at all. Aortic SBP was significantly higher in phenotypes-III and IV compared to phenotypes-I and II (p = 0.001). This was not discriminated using a validated cuff BP device measurement (p = 0.996). Results for the pulse pressure (PP) followed the same pattern. Conclusion. Distinct BP phenotypes do exist based on SBPamp. A validated cuff BP method failed to discriminate this. Improving quality of BP measurements in daily practice is a priority.

To present the evidence that describes what is being measured by upper-arm cuff blood pressure (BP) and the level of accuracy compared with invasive central aortic and brachial BP. Potential causes of inaccuracy and emerging methods are also discussed. On average cuff systolic BP systematically underestimates invasive brachial systolic BP, although in a given individual it may substantially under- or over-estimate central aortic systolic BP. Such errors may affect individual health management outcomes and distort population level data on hypertension prevalence and control. Oscillometric cuff BP is particularly susceptible to inaccuracy in people with high arterial stiffness and with pathophysiological BP waveform shapes. Emerging cuff-less BP methods will be susceptible to inaccuracy if oscillometric cuff BP is used for calibration. The original purpose of cuff BP was to estimate central aortic BP. Recent evidence has shown substantial inaccuracy of oscillometric cuff BP exists for the measurement of invasive central aortic and brachial BP. Thus, development of more accurate BP methods, through better understanding of oscillometric and BP waveform morphology, is needed to improve health outcomes related to high BP.

Introduction: Isolated systolic hypertension (ISH) is the most common form of hypertension in older people. However, accurate identification of ISH may be hindered because cuff blood pressure (BP) underestimates systolic BP (SBP) and overestimates diastolic BP (DBP). This study aimed to determine the influence of cuff BP accuracy on the identification of ISH. Methods: Cuff BP and invasive aortic BP were measured simultaneous (or near-simultaneously) in 1737 subjects (63 ± 12 years, 68% male) during coronary angiography. Data was derived from 32 studies, using 20 different cuff BP devices, from the Invasive Blood Pressure Consortium (INSPECT). ISH was defined as ≥140/

Background: Cuff blood pressure (BP) is intended to approximate central aortic BP and accuracy is paramount. Sex differences in BP physiology could influence the accuracy of cuff BP as an estimate of invasive aortic BP, but this has not been explored in-depth and was the aim of this study. Methods: Cuff and invasive aortic BP were measured in 1701 subjects (31.9% female, aged 63 ± 12) during coronary angiography from the INvaSive blood PressurE ConsorTium (INSPECT) database. Cuff accuracy was defined as cuff–invasive BP. In a sub-sample (n = 376, 27% female, aged 63 ± 11), invasive brachial BP was recorded to assess systolic (SBP) amplification (invasive brachial–aortic SBP). Results: Invasive aortic SBP was higher in females compared with males (mean [95% CI]: 141.8 mmHg [137.1, 146.3] versus 132.9 mmHg [129.4, 136.4], p < 0.001). Cuff SBP significantly underestimated invasive aortic SBP in females compared with males (−3.1 mmHg [−5.9, −0.2] versus 1.4 mmHg [−1.1, 4.0], p < 0.001 for difference). Sex differences remained after adjustment for age and height. In the sub-sample, aortic-to-brachial SBP-amplification was lower in females (7.1 mmHg [3.3, 10.8] versus 10.2 mmHg [5.1, 15.4], p = 0.0070). Sex, SBP-amplification, height and age were associated with cuff BP inaccuracy, but only SBP-amplification and age remained associated in multivariable analysis (p < 0.05). Conclusion: Females have greater propensity towards cuff BP inaccuracy through underestimation of aortic SBP. Both age and the magnitude of aortic-to-brachial SBP-amplification are related to cuff BP inaccuracy, which provide greater understanding of sex differences in BP physiology and may help improve the accuracy of cuff BP methods.

Introduction The wideband external pulse (WEP) recorded during blood pressure measurement reveals three components (K1, K2, K3). K1 is recorded with cuff pressure (CP) above systolic (SP). Aim To assess whether the K1 pattern contains information about the functional and structural properties of the cardiovascular system. Methods WEP analysis, echocardiography, carotid artery (CA) ultrasonography and applanation tonometry were conducted on 178 hypertensives. K1R, a feature of K1, was defined to provide a measure between the arterial incident and backward reflective waves. Results K1R was strongly correlated to vascular functional and structural parameters compatible with vascular effects of aging and hypertension. ANOVA analysis (K1R 0) showed that K1R 0 (Nagelkerke R2 = 0.77). Conclusions K1R is related to vascular functional properties, with suggestive evidence that K1R is also related to vascular structural properties and perhaps subsequent cardiovascular risk.

Shortcomings of single cuff blood pressure devices have led to research of devices with more than one cuff for improved accuracy. We assessed two devices that use two cuffs and one device that uses three cuffs. The devices with two cuffs use one occluding arm cuff and one cuff that detects pulses that pass past the occluding cuff. The device with three cuffs uses pulse delay time. The advantages and the shortcomings of the devices are discussed in this paper.

Introduction: Higher blood pressure variability (BPV) is associated with worse outcome after stroke. Accurate quantification of BPV requires frequent measurements, which is not practical with arm cuff sphygmomanometry. Hypothesis: 15 minutes of beat-to-beat BPV (bBPV) will accurately predict arm cuff BPV (aBPV) for acute ischemic stroke patients' entire hospitalization. Methods: To measure aBPV, we used all arm cuff blood pressures during hospitalization. We measured bBPV with a finger photo-plethysmographer (Figure 1) for 15 minutes. We report Pearson’s correlation coefficient for 5 different statistical estimations of variability. Results: We enrolled 30 patients with acute ischemic stroke. Mean age was 60.9 years, NIHSS was 5.4, and 19/30 were male. The mean days from stroke onset to bBPV measurement was 2, and the mean length of hospitalization was 5 days. The mean number of arm cuff and beat-to-beat blood pressure measurements was 62 and 1,830. Correlation between aBPV and bBPV was moderate to excellent (Table 1 and Figure 2). Conclusion: This pilot study demonstrates the feasibility of predicting long-term BPV with 15 minutes of finger photo-plethysmography. As opposed to deriving BPV from arm cuff measurements, which takes days, our approach allows early and rapid identification of patients who will subsequently have high BPV and may benefit from therapeutic intervention.

Objectives: Accurate blood pressure (BP) measurement is critical for appropriate hypertension diagnosis and management. Aortic BP represents pressure loading on vital organs and this can be approximated using upper arm cuff BP. With advancing age, cuff systolic BP (SBP) increases and diastolic BP (DBP) decreases (widening pulse pressure [PP]), but whether age may influence cuff BP compared with invasive BP is unknown and was the aim of this study. Methods: Cuff BP was measured simultaneously, or near-simultaneously, with invasive aortic BP during catheterization in 1696 individuals within the INSPECT consortium (an international collaboration comprising data from 31 studies and 19 different cuff BP devices [17 oscillometric, 2 mercury sphygmomanometry]). Differences in cuff and invasive BP were assessed using mixed models. Results: Subjects were aged 63.3 ± 10.6 years and 32% female. Cuff SBP overestimated invasive aortic SBP in those aged 40–49, but with increasing age there was a progressive increase in the underestimation of aortic SBP (Table). Conversely, cuff DBP systematically overestimated aortic DBP, increasingly with age. Thus, there was a progressively higher error (underestimation) in cuff PP with older age. Adjusting models for sex, mean arterial pressure, heart rate and catheter type did not alter the findings, and no interactions between these parameters and age were found. Conclusion: Cuff BP is progressively more biased with increasing age, exposing older people to greater chance for misdiagnosis of risk related to BP. The findings highlight the need to improve cuff BP methods to ensure all people receive appropriate diagnosis and management of hypertension.

Pressure data acquired from a blood pressure cuff during a blood pressure test are the starting point of noninvasive, single cuff blood pressure determination. Most blood pressure devices on the market use the single cuff method. This paper describes acquisition, analog and digital processing, and storage of raw data from a blood pressure cuff during gradual cuff deflation. Raw data from 30 arm cuff tests and 20 wrist cuff tests were organized to form a database of text files. Separate annotation documents were also created. The database was uploaded to the Google Drive. The database can be downloaded by any interested party. The data can be used for the development of algorithms for blood pressure determination and for the assessment of some cardiovascular variables.

Arterial stiffness may influence the contour of the peripheral pulse, suggesting that contour analysis of the digital volume pulse (DVP) might be used to estimate peripheral blood pressure and a stiffness index (SI). The objective is to establish a transfer function that estimates the peripheral blood pressure using the PPG pulse, calibrated with a brachial pressure cuff, and then to deduce a stiffness index using the established parameters. We positioned the photodiode sensor on the finger. Brachial blood pressure measurement was performed with a cuff adapted to the arm circumference and an oscillometric device (Omron M10 -IT). Pulse wave velocity (PWV) measurements were performed with the pOpmètre® system. DVP waveforms were recorded over a 10 s period and ensemble-averaged to obtain a single waveform from which DT (DVP) was determined as the time between the first systolic peak and the early diastolic peak/inflection point in the waveform. The SI is the ratio of the subject’s height to the DT (DVP). 69 subjects were included: 24 healthy subjects and 45 patients with essential hypertension. The correlation between the estimated peripheral diastolic pressure and the brachial one was good and significant (r2 = 0.51; p < 0.001). A better correlation was found in terms of peripheral systolic pressure (r2 = 0.56; p < 0.001). The correlation between the SI and the ft-PWV was significant (r = 0.5; p < 0.001) classifying the estimation as good agreement. The estimation of the peripheral blood pressure and a stiffness index with the PPG signal qualifies as good agreement with the reference technique.

Background The ventricular-vascular coupling ratio (Ea/Ees) is defined as the ratio of arterial elastance (Ea) to left ventricular elastance (Ees) and is a key determinant of cardiac performance. Ventricular-vascular coupling has not been examined in populations with coronary artery disease (CAD) and its association with heart failure (HF) in this population is unknown. Methods We measured baseline ventricular-vascular coupling at rest and after exercise using echocardiography and cuff blood pressure in 815 patients with stable CAD enrolled in the Heart and Soul Study. Patients were prospectively followed for the endpoint of HF hospitalization. We used Cox proportional hazard models, adjusted for baseline demographics and medical comorbidities, to evaluate the association between ventricular-vascular coupling and HF hospitalizations. Results Ea and Ees increased with exercise, while the Ea/Ees ratio decreased modestly. After a median of 8.9 years, 144 (18%) patients were hospitalized for HF. After multivariable adjustment, patients in the highest tertile of resting Ees (HR 0.24, CI 0.13 to 0.43, P Conclusions The Ea/Ees ratio, at rest and after exercise, is strongly associated with future HF hospitalizations in patients with stable CAD and low rates of baseline HF. The association is driven primarily by Ees, while Ea has little prognostic significance.

Tetra-amelia syndrome is a congenital disorder associated with near or complete absence of all 4 limbs. Noninvasive hemodynamic monitoring may be difficult or impossible in such patients. We describe the use of a finger cuff blood pressure system for continuous noninvasive blood pressure monitoring in an infant with near-complete tetra-amelia undergoing laparoscopic gastrostomy tube placement. This case suggests the potential use of such a blood pressure monitoring system for other patients with comparable deformities.

Early and accurate diagnosis of pulmonary vascular disease is important given the high mortality of untreated pulmonary hypertension. The development of cardiopulmonary exercise testing (CPET) has allowed an early diagnosis of PAH in “at risk” patients or those with suggestive clinical findings. CPET can quantify the degree of exercise impairment, and rule out a pulmonary mechanical limit to exercise. It can also be used to monitor disease progression and response to treatment. CPET generally consists of an incremental symptom-limited cycling or treadmill exercise test with measurements of ventilation and pulmonary gas exchange. Noninvasive testing is done with continuous 12-lead ECG, cuff blood pressure monitoring and pulse oximetry. Invasive CPET adds arterial and pulmonary artery catheters for blood gas, pH and pressure measurements. CPET when used in the context of a diagnostic algorithm, can confirm the diagnosis of exercise-induced PH, distinguish between pulmonary arterial and venous hypertension, and rule out confounders such as impaired systemic O2 extraction. CPET may be used alone or combined with other modalities, such as transthoracic cardiac Doppler echo and MRI. Recent expert consensus statements suggest CPET is useful in the diagnosis, management and risk stratification of PH. This chapter provides an overview of the history of CPET, describes how measurements are obtained and interpreted, and discusses its use in diagnosis and monitoring of pulmonary hypertensive diseases including exercise-induced pulmonary hypertension and pulmonary hypertension associated heart and lung disease.

A simple, convenient to use apparatus suitable for patient self-monitoring is described and illustrated with graphs of mean arterial pressure determinants which provide clinically useful hemodynamic details unobtainable with cuff blood pressure measurements. A bathroom scale and a forearm cuff blood pressure system completes the home monitoring apparatus.

Blood pressure monitoring during anesthesia is an American Society of Anesthesiology standard. However, the anesthesia provider sometimes fails to engage the patient monitor to make periodic (generally every 3-5 min) measurements of Non-Invasive Blood Pressure (NIBP), which can lead to extended periods (5 min) when blood pressure is not monitored. We describe a system to automatically detect such gaps in NIBP measurement and notify clinicians in real-time to initiate measurement. We applied a decision support system called the Smart Anesthesia Messenger (SAM) to notify the anesthesia provider if NIBP measurements have not been made in the last 7 min. Notification messages were generated only if direct arterial blood pressure was not being monitored. NIBP gaps were analyzed for 9 months before and after SAM notification was initiated (12,000 cases for each period). SAM notification was able to reduce the occurrence of extended NIBP gaps15 min from 15.7 ± 4.5 to 6.7 ± 2.0 instances per 1,000 cases (p0.001). In addition, for extended gaps (15 min) the mean gap duration declined from 23.1 ± 2.0 to 18.6 ± 1.1 min after SAM notification was initiated (p0.001). However, for 7-15 min gaps, SAM notification was not effective in reducing the occurrence. The maximum gap encountered before SAM was 64 min, while it was 27 min with SAM notification. Real-time notification using SAM is an effective way to reduce both the number of instances and the duration of inadvertent, extended (15 min) gaps in blood pressure measurements in the operating room. However, the frequency of gaps15 min could not be reduced using the current configuration of SAM.

Aim of the study was to assess the relative susceptibility to the development of nitroglycerin tolerance in the arterial and venous circulation in man and to evaluate the interactions between nitroglycerin and N-acetyl-cysteine. Twenty patients with coronary artery disease underwent a continuous 24-h nitroglycerin infusion followed by a bolus administration of N-acetylcysteine. Forearm blood flow (ml/lOOml/min) and venous volume (ml/l00 ml) were measured by strain gauge plethysmography under control conditions, at the end of nitroglycerin titration, after 24 h of infusion and after N-acetylcysteine; vascular resistance was calculated as mean cuff blood pressure/flow. After 24 h of nitroglycerin infusion, the initial increase in venous volume was reduced by 48 % (p

We thank Rossen and Hansen (1) for their interest in our article (2). The participants represented a consecutive series of patients fulfilling the exclusion/inclusion criteria who were recruited from those referred to the hospital for evaluation by ambulatory blood pressure monitoring (ABPM) mainly to confirm or reject the diagnosis of hypertension inferred by clinic cuff blood pressure measurement. Diagnosis of hypertension in our trial was based on accepted ABPM criteria, i.e., an awake systolic blood pressure (SBP)/diastolic blood pressure (DBP) mean ≥135/85 mmHg and/or an asleep SBP/DBP mean ≥120/70 mmHg (3). Despite a recommended target goal for clinic SBP/DBP in diabetes of 130/80 mmHg, current guidelines do not provide separate ABPM threshold values for patients with and without diabetes (3). Patients with diabetes in our trial …

—Alan H. Jobe, MD, PhD Preterm infants often develop late onset sepsis in the NICU, which is associated with significant mortality. In older children or adults with sepsis, intensive cardiovascular monitoring, often with intravascular catheters, is common. The preterm infant with late onset sepsis is usually only monitored with oxygen saturation, heart rate, and cuff blood pressure monitors, which provide minimal information about the cardiovascular response to sepsis or its treatment. In this issue of The Journal, de Waal and Evans evaluated the cardiovascular status of 20 infants with a mean gestational age of 27 weeks who developed late onset sepsis. After initial volume infusion, the infants had relatively high left and right cardiac outputs, low systemic vascular resistances, and normal blood pressures. The 5 infants who did not survive had lower initial blood pressures and cardiac outputs that fell on subsequent measurements. Survivors maintained the low systemic vascular resistances. This information is helpful for decisions about which drugs might be beneficial for the infants with sepsis and a poor prognosis. Article page 918 <

SUMMARY 1. Finger cuff blood pressure monitors that provide continuous presentation of arterial pressure at the finger are available. 2. The operation of such instruments is based on ‘clamping’ arterial volume under a pressurized encircling cuff applied to a digit. Blood volume is detected by measuring infra-red transmission across the finger. 3. The compressed veins adopt cuff pressure and combine with the resistance of the peripheral vascular bed at the finger tip to control the blood flow. This results in waterfall behaviour in the veins under the cuff. 4. With the cuff set just 5 mmHg below the undisturbed arterial pressure, adequate flow to the distal finger is maintained. 5. Two potential sources of error affect the finger cuff blood pressure method. These are related to the increase in systolic pressure associated with moving peripherally and the variable value of occluding transmural pressure, both of which depend on muscular tone.

This paper describes the alerting reaction and blood pressure rise induced in the patient when blood pressure measurement is taken by the doctor, emphasizing that this may be responsible for important errors in estimating the real untreated or treated blood pressure in hypertension. It then examines the advantages offered by ambulatory blood pressure monitoring. It is shown that when performed intra-arterially this approach may be useful in the diagnosis of pheochromocytoma. However, its wider use as a means to better discriminate between normotensive and borderline or mild hypertensive subjects should not yet be advocated because information on normalcy of ambulatory blood pressure values is limited. Furthermore, although target organ damage of hypertension correlates more closely with 24-hour or day-time blood pressure mean than with sphygmomanometric values, there is insufficient prospective evidence that ambulatory blood pressure is prognostically superior to cuff blood pressure. Finally, noninvasive ambulatory blood pressure monitoring (ie, the only approach suitable for clinical practice) is not accurate because of the relatively large number of artifactual readings and their limited correspondence to intra-arterial values.

This paper reviews the advantages and disadvantages of two new examinations to be employed in hypertension, i.e. echocardiography and ambulatory blood pressure monitoring. It will be emphasized that echocardiography can detect left ventricular hypertrophy in a much more sensitive fashion than electrocardiography thereby allowing a better estimate of the patient's risk of cardiovascular complications. However, this advantage should be considered in the face of the greater cost of this procedure and the inability to obtain reliable echocardiograms in a number of patients. Caution should also be applied in clinical use of ambulatory blood pressure monitoring because of the insufficient data-base on normal ambulatory blood pressure values, the lack of prognostic validation of 24 hour or day-time blood pressure means and the inaccuracy of the automatic blood pressure measuring devices currently available. However, values derived from ambulatory blood pressure monitoring show a better correlation with the target organ damage of hypertension than cuff blood pressure taken in the doctor's office. This justifies the interest in this approach and makes further research on its clinical value worthy.

The cardiovascular effects of a new antiarrhythmic Class I agent, pirmenol, were assessed noninvasively in 10 patients without heart failure. Infusion of 100 mg pirmenol was given over 30 min following baseline M-mode echocardiography, cuff blood pressure and systolic time interval measurements. The measurements were repeated after the infusion, and 15 and 60 min later. Heart rate increased by 14.7% (P less than 0.01). Significant increases were also noted in afterload parameters, mean arterial pressure (+10.1%; P less than 0.001) and mid-systolic left ventricular wall stress (+8.0%; P less than 0.05). Concomitantly a slight increase was observed in preload, reflected in lengthening of left ventricular end-diastolic diameter (+4.8%; P less than 0.05). A decrease in fractional shortening (-6.5%; P less than 0.05) and an increase in pre-ejection period/left ventricular ejection time ratio (+16.2%; P less than 0.01) suggested a negative inotropic effect. The increased afterload and heart rate may have contributed to changes in these indices, and therefore myocardial depression may appear more pronounced than it actually was. The main effects of intravenous administration of pirmenol are elevations in heart rate and blood pressure. The induced decrease in myocardial contractility is slight.

Cuff blood pressure measurement has changed very little since the beginning of this century and has provided an immense amount of valuable data on outcome and risk. Restrictions of the technique make it of limited value in sleep, exercise or at work, although there are now devices which inflate and deflate automatically. Perhaps the biggest problem is the alerting or defence reaction which is engendered by the observer or even by the cuff inflation with automatic devices. For this reason there have been many attempts to develop systems which track blood pressure non invasively. We have used the measurement of pulse wave velocity to follow beat to beat changes in pressure (1). This and similar systems have not so far proved adequate for ambulatory use, and all indirect systems have severe problems with calibration and validation.

Thirty-two patients with mildly elevated blood pressure (BP), but without target organ damage, attended a BP measuring clinic where duplicate BP measurements were made on 12 visits. During visits 1-3, BP showed a systematic decrease which varied from patient to patient. During visits 4-12, no further systematic changes in BP were observed. During the latter period, between-visit variation in BP was substantial, the standard deviation of the difference in BP from one visit to another being 10.4 mmHg for systolic, 6.8 mmHg for diastolic (phase IV) and 7.0 mmHg for diastolic (phase V). These values were used to determine the chance that the BP estimated after a number of visits differed from the average stable BP. After visit 4, the chance of a difference of 5 mmHg or more was 0.50 systolic blood pressure (SBP) and 0.32 diastolic blood pressure (DBP; phase V). Increasing the number of visits to six or more reduced the chance of error. Before initiating lifelong treatment in mild hypertensives free of target organ damage, BP should be recorded in duplicate on a minimum of six visits.

Blood pressure was monitored by a continuous intra-arterial recording in 46 subjects to investigate whether the alarm reaction and the blood pressure and heart rate increases that occur during cuff blood pressure measurement made by a physician 1) attenuate when the physician's visit is repeated several times and 2) are less pronounced if a nurse measures the blood pressure. In 16 subjects the peak mean blood pressure and heart rate rises that occurred in the early part of the physician's first visit (22.6 +/- 1.8 mm Hg and 17.7 +/- 1.7 beats/min) were virtually identical to those occurring during three subsequent visits by the same physician throughout a 2-day intra-arterial blood pressure monitoring. The less pronounced pressor and tachycardic responses observed in the last part of the physician's visit also were virtually identical among the four visits. In contrast, in 30 other subjects the blood pressure and heart rate rises that occurred during the nurse's visit were 46.7% and 42.1% less (p less than 0.01) than those occurring during the physician's visit. The late and less pronounced pressor and tachycardic responses to the visit were also significantly less (p less than 0.01) in the former than in the latter condition. These results indicate that the error of overestimation of blood pressure inherent in cuff blood pressure measurement by a physician cannot be avoided by repeated visits by the physician over a short time span. It clearly can be reduced, however, if blood pressure measurements are performed by a nurse.