Cuff and ambulatory blood pressure in subjects with essential hypertension

Relationship of stress testing blood pressure with electrocardiographic and fundoscopy indices of hypertensive end-organ damage

In our study we tested firstly, whether BP changes induced by laboratory stress testing could be better related than resting blood pressure (BP) to hypertensive target-organ damage (TOD) and secondly, whether an exaggerated reactivity to stress testing might be associated with an increased prevalence of TOD. In 49 untreated essential hypertensives, BP measured at sitting rest and during a variety of stressful situations was related to the presence of TOD, assessed by electrocardiography (ECG) and fundoscopy examination. The degree of TOD was significantly correlated to resting SBP; neither SBP at peak of isometric or dynamic exercise, nor SBP during mental test showed a greater correlation with TOD than resting SBP (NS). A large variability of individual's level of BP reactivity across the different laboratory tests was observed. Patients were arbitrarily dichotomised into groups according to a hyperreactive or normoreactive response to each stress testing; patients classified as hyperreactive (SBP increase greater than upper 95% confidence limit) did not disclose a greater rate of cardiac and ocular damage than normoreactors (NS). In conclusion, stress BP does not increase the strength of relationship with TOD compared to resting BP. Cardiovascular reactivity differs according to the laboratory stimulus employed and an exaggerated BP rise during stress testing is not associated with an increased rate of TOD.

The treatment of hypertension: new lamps for old?

Meta-analysis of clinical trials does not help the clinician to treat individual patients. A general conclusion that the reduction of high blood pressure is beneficial has to be matched by specific information about the level of blood pressure that is acceptable and about the effect of particular doses of specific drugs. Results obtained from trials of "old-fashioned" antihypertensive drugs cannot confidently be extrapolated to "modern" agents. Sufficient data do not exist to encourage universal drug treatment for patients with "mild" hypertension.

Effect of regular exercise on 24-hour arterial pressure in older hypertensive humans

The experimental goals were to determine if regular low-intensity aerobic exercise reduces 24-hour arterial blood pressure in middle-aged and older (aged 50 years or older) humans with mild diastolic (90-105 mm Hg) essential hypertension and, if so, whether this is accurately reflected by changes in casual recordings made at rest. Fourteen subjects walked 3-4 days/wk for 6 months, with 10 exercising an additional 6 months; 12 other subjects served as nonexercising controls. In the exercising subjects, maximal oxygen consumption increased 7-14% (p less than 0.05) with little or no change in body weight or fat. Conventional casual readings of systolic, mean, and diastolic arterial pressure at rest were lower (5-10 mm Hg, p less than 0.05) in all body positions after 6 months of exercise and changed little thereafter. Casual recordings made during additional circulatory measurements showed 6-month decreases of only half this magnitude and were specific to a particular blood pressure phase and body position; however, all changes were significant after 12 months of exercise. The reductions in arterial pressure at rest were associated with decreases in heart rate (p less than 0.05) and cardiac output (p less than 0.05). Ambulatory-determined 24-hour arterial pressure was unchanged after 6 months of exercise, but mean levels were slightly lower (4 mm Hg, p less than 0.05) after 12 months due to reductions in daytime (7 mm Hg, p less than 0.05) and nighttime (4 mm Hg, NS) systolic pressure; diastolic pressure was unchanged throughout the year of training. In the controls, conventionally recorded casual blood pressure levels were lower after 6 months (p less than 0.05), but no other changes were observed in any other variable over the 12 months of study. We conclude 1) regular low-intensity aerobic exercise at best produces only small reductions in 24-hour levels of arterial pressure in middle-aged and older humans with mild (diastolic) essential hypertension and 2) training-associated changes in casually determined blood pressure at rest are dependent on the measurement conditions and, most importantly, do not necessarily reflect the magnitude or even the direction of changes in arterial pressure throughout an entire day.

Accuracy of ambulatory blood pressure determination: a comparative study

This study was designed to discriminate, according to their accuracy, between three ambulatory pressurometers (Diasys 200R, Novacor; P IV, Del Mar Avionics; SpaceLab 90202, SpaceLab). The evaluation was performed against invasive arterial reference measurements. Accuracy was assessed by calculating the error on pressure (EOP) as the difference between invasive and non-invasive measurement of arterial blood pressure. For the systolic values, accuracy (mean of EOP differences) and uncertainty (SD of these differences) were -0.9 +/- 9.7, -4.3 +/- 10.1 and -16.7 +/- 10.1 mmHg for, respectively, Diasys, PIV and SpaceLab. For diastolic values, they were, respectively, 5.9 +/- 6.7, 6.8 +/- 8.5 and 9.1 +/- 6.6 mmHg. EOP was then separated in two different types of errors: (i) the error of dispersion appreciated by the index of homogeneity calculated by a Lehmann analysis and leading to a statistical classification (ii) the error due to the drift of EOP with the reference value, this last error being easier to correct. Two different behaviours were observed for the EOP: (i) the drift of EOP of systolic values was significantly larger for the oscillometric (SpaceLab) than for the auscultatory (Diasys and P IV) method, with no difference between Diasys and P IV (ii) the homogeneity index was not statistically different among these three devices. These data suggest that, in case the correction of the drift of EOP is carried out, there is no statistical significant difference in accuracy between these three pressurometers. However, in our experimental conditions, the two ambulatory pressurometers recording the Korotkoff sounds have a better accuracy than the one using the oscillometric approach.

Twenty-four hour arterial pressure and heart rate as predictors of left-ventricular hypertrophy

Hypertrophy of the left ventricle occurs in some but not all hypertensive patients. The present study was designed to examine the office and the 24-hour arterial pressure (AP) and heart rate (HR) recordings, and the AP response to physical stress in two age- and sex-matched hypertensive groups who differed in their left-ventricular mass (LVM). In addition, we tried to determine whether AP and HR measured at rest, under stress, or with 24-hour AP monitoring correlate with LVM. Ten hypertensive subjects with left-ventricular hypertrophy (LVH) made up the study group and 10 hypertensive subjects without LVH made up the control group. Antihypertensive medication was withdrawn at least four weeks prior to evaluation. The mean office AP measured during the washout period was 157 +/- 13/100 +/- 11 mm Hg in the study group and 157 +/- 17/104 +/- 7 mm Hg in the control group. However, 24-hour AP monitoring disclosed that the study group had significantly higher AP than the control group during both day and night. The control group had a significantly faster HR in the clinic and at night. The HR response to bicycle exercise was less in the control group than in the LVH group. The maximal AP and the rise in AP during bicycle exercise did not differ between groups. The LVM index did not correlate with the office AP or with maximal AP during effort, but did correlate negatively with the office HR and with the HR prior to the exercise test.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure during sleep: antihypertensive medication

To investigate whether excessive reduction of blood pressure (BP) by antihypertensive medications correlates with myocardial infarction, especially during sleep in elderly patients, we used telemetry and cuvette dye-dilution methods to assess the direct BP and the hemodynamics of 68 inpatients with essential hypertension during wakefulness and sleep. There were 25 patients greater than or equal to 60 years old (OH-group) and 43 were less than or equal to 59 years old (YH-group). Of the OH-group, 36% showed high BP during the day, with marked decreases (minimum BP less than 110/70 mm Hg) during sleep. Average cardiac index (CI) of the OH-group was low during wakefulness and extremely low during slow-wave sleep. Changes of mean BP in the OH-group correlated with changes in total peripheral vascular resistance index (TPRI) during sleep, but this correlation was not observed in the YH-group. The antihypertensive effects on nocturnal BP of the various medications was: central adrenergic inhibitors less than or equal to beta blockers with intrinsic sympathomimetic activity less than or equal to alpha (alpha beta) blockers less than or equal to angiotensin-converting enzyme inhibitors less than or equal to calcium antagonists. Because BP and CI were found to be very low and TPRI seems to play an important role in BP regulation in sleeping elderly patients, excessive antihypertensive medication may be harmful to this subgroup. However, because the effects on nocturnal BP differ among various antihypertensive treatments, further research is required on the relation between antihypertensive medication and the hemodynamics of sleeping elderly hypertensive patients.

Prognostic significance of exercise versus resting blood pressure in hypertensive men

The outcome of 143 male hypertensive patients, investigated in the period 1972-1982, was ascertained in 1989 to determine if brachial artery pressure measured during a progressive graded exercise test on the bicycle ergometer is a better predictor of mortality and cardiovascular events than pressure at rest. During the total follow-up time of 1,573 patient years, 27 patients suffered at least one fatal or nonfatal cardiovascular event and 13 patients died. Using the Cox regression model, the age-adjusted relative hazard rates of systolic pressure at supine rest, at 50 W, at peak work load, and at 50% of peak exercise capacity were significant for total mortality (p less than or equal to 0.01) and for cardiovascular events (p less than or equal to 0.03). Pressure during exercise, however, did not significantly (p = 0.11-0.97) predict the outcome of the patients when age and pressure at rest were taken into account. The results were similar for diastolic pressure. In conclusion, intra-arterial pressures at rest and during submaximal and peak exercise significantly predict mortality and the incidence of cardiovascular events in hypertensive men, independent of age. However, there is no additional prognostic precision of the exercise pressures when age and the rest pressure are taken into account.

Cardiac and blood pressure responses to mental stress in reactive hypertensives

To study the haemodynamic response to a standardized mental stress, we measured ascending aorta velocity using Doppler ultrasonography in 20 reactive ("white-coat") hypertensives and 20 age and sex matched normal controls (NC) familiar with the hospital setting. Reactive hypertensives (RH) had 3 office diastolic BP recordings between 90-110 mmHg and ambulatory BP less than 140/90 mmHg. The cardiac response to mental arithmetic was greater in RH than NC (minute distance, RH: +36.7 +/- 40.2% vs NC: +10.3 +/- 19%, p less than 0.05; peak velocity, RH: +8.4 +/- 16.5% vs NC: -1.4 +/- 11.9%, p less than 0.05), and there was a different peripheral resistance response (RH: -12.2 +/- 24.2% vs NC: +6.5 +/- 22%, p less than 0.05). We suggest that subjects with reactive hypertension have a strong cardiac response to mental stress and this could be a characteristic of this condition.

Ambulatory blood pressure in young subjects with familial history of hypertension

Office blood pressure (BP), ambulatory blood pressure, (one determination every 15 min, over an entire 24 h span), were measured in 206 young male subjects, including 96 individuals having first degree familial history of hypertension (the F group) and 110 control subjects, matched for age, having no familial history of hypertension (the C group). In both groups, age ranged from 19 to 25 y. After a complete clinical and laboratory examination, all subjects were diagnosed as in good health. In particular, none had cardiac, renal or neurologic involvement. No subject received medication. Over the whole sample, 126 subjects had normal office BP and 80 had borderline office BP. No difference was found in office diastolic BP between the C and F groups. Office systolic BP was somewhat higher in the F group, when compared to the C group, but the difference was in the limit of statistical significance (0.05 less than p less than 0.10). In contrast, ambulatory systolic BP was significantly higher in the F group, when compared to the C group, the difference (0.05 less than p less than 0.001) occurred in daytime and at night. The above difference was more significant (p less than 0.02 to p less than 0.005) and persisted over larger time-spans when only subjects with normal office BP in the C and F groups are compared. In contrast, when restricted to the borderlines only, office and ambulatory BP was the same in subjects with and without familial history of hypertension.

Silent cerebrovascular disease in the elderly. Correlation with ambulatory pressure

Does the average daily blood pressure correlate with hypertensive cerebrovascular disease better than the casual pressure, as has been reported in other target organ involvement? We investigated the associations of two abnormal findings on brain magnetic resonance imaging suggestive of a vascular etiology, low intense foci (lacunae), and periventricular hyperintense lesions on T1- and T2-weighted images, with both office and average daily blood pressure values in a population of 73 healthy normotensive and hypertensive elderly individuals (70 +/- 6 years old). Lacunae were detected in 34 subjects (47%); the number per subject ranged from 0 to 19 and was significantly correlated with advancing age. Furthermore, these changes were supposedly related to the average of noninvasive ambulatory (24-hour and during awake and asleep periods) pressure recordings but not to office pressures. The grade of periventricular hyperintensity was also significantly associated with advancing age and the average of ambulatory systolic pressure recordings, particularly during sleep, but not with office blood pressure. In comparisons of normotensive, "office hypertensive," and hypertensive subgroups, abnormalities on magnetic resonance imaging were appropriate to the level of the 24-hour blood pressure measurements but not to that of clinic pressure. In hypertensive patients, the presence of electrocardiographic evidence of left ventricular hypertrophy was also associated with greater abnormalities on magnetic resonance imaging. We conclude that ambulatory blood pressure monitoring is superior to casual pressure measurements in predicting latent cerebrovascular disease, which is unexpectedly common in apparently healthy elderly subjects.

[The significance of 24-hour blood pressure monitoring in the diagnosis and therapy of arterial hypertension]

The use of ABPM allows an improved assessment of blood pressure (BP) and therefore of the individual cardiovascular risk. It is able to identify patients who truly need therapy more exactly. Mostly patients with white coat hypertension who don't need therapy are identified. Furthermore, ABPM correlates more closely to target organ damage and to cardiovascular morbidity and mortality. This may be helpful to treat especially those patients who truly need therapy. BP exhibits a typical circadian rhythm with the highest values during the early morning hours and a decline during the night. A change of the day/night rhythm during shift work leads to an adaptation of BP rhythm. The early morning rise of BP and heart rate is accompanied by hemodynamic, rheological and biochemical alterations, which together may contribute to the increased frequency of vascular complications during the morning hours. The nightly decline of BP is often absent in patients with secondary hypertension and cardiac or renal organ damage. A lack of the nocturnal BP decline should therefore lead to further patients' evaluation. Elevated nocturnal BP seems to worsen the prognosis. ABPM offers better individual control of BP in patients on treatment and therefore is helpful to optimize the treatment. A more exact individual BP control during the awakening and sleeping period is possible as well as an avoidance of overtreatment. Patients could be protected both from prescription of too many drugs and from lowering BP too much. A further advantage lies in an improved control of patients with nocturnal hypertension.

Physiological, psychological, and behavioral factors and white coat hypertension

Patients with hypertension in the clinic but not during daily activities ("white coat" hypertension) may be at lower risk of hypertensive morbidity and mortality than patients with hypertension in both settings ("persistent" hypertension). We hypothesized that the white coat phenomenon was due to greater blood pressure reactivity to the stress of a clinic visit and that, as a consequence, white coat hypertensive patients would display greater blood pressure reactivity to exercise and mental stress, as well as increased emotional reactivity and higher levels of anger, anxiety, or depression. We studied 89 patients with essential hypertension between 29 and 59 years old with ambulatory blood pressure monitoring, treadmill exercise testing with oxygen consumption measurement, mental stress testing (including mental arithmetic, public speaking, and video game tasks), and psychological testing (State-Trait Anxiety Scale, Cook-Medley Hostility Scale, Center for Epidemiologic Studies Depression Scale, emotional reactivity scale). We defined white coat hypertension as a mean ambulatory systolic blood pressure of 135 mm Hg or less and diastolic 85 mm Hg or less and persistent hypertension as a mean ambulatory systolic blood pressure of 140 mm Hg or more or diastolic 90 mm Hg or more. Forty-nine patients were classified as persistent hypertensives and 20 as white coat hypertensives. No significant differences were seen in demographic or clinical characteristics, fitness level, blood pressure response to exercise or mental stress, or psychological characteristics, except that white coat hypertensive patients had lower systolic blood pressures in the clinic and during exercise and greater variability of clinic diastolic blood pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood pressure measurement in adults: large cuffs for all?

STUDY OBJECTIVE

The aim of the study was to determine whether a single size of cuff for adult blood pressure measurements is appropriate for general clinical practice.

DESIGN

The study was a prospective survey of a sample of adult blood pressure measurements using two cuffs with different bladder sizes (12 X 23 cm and 15 X 33 cm) in a randomised design using a random zero sphygmomanometer.

SETTING

Blood pressures were measured in a general practice and in a hospital outpatient clinic.

PARTICIPANTS

The participants were 35-60 year old men and women invited to attend a blood pressure screening programme in the general practice (n = 170), and 35-74 year old patients attending a general medical outpatients (n = 72).

MEASUREMENTS AND MAIN RESULTS

The small cuff gave higher readings of systolic blood pressure than the large cuff (mean difference 4.4 mm Hg). The difference increased as systolic pressure increased but did not show a clear association with arm circumference. The small cuff also gave higher diastolic pressure readings (mean difference 3.0 mm Hg), but only when arm circumference exceeded 30 cm. The variability of the differences between readings from the two cuffs was wide, little affected by arm circumference, and was similar to the variability between measurements using the same cuff size.

CONCLUSIONS

In terms of precision there is no basis for using two different cuff sizes unless it is physically difficult to obtain a reading with one or the other. Since readings with large cuffs are closer to intraarterial pressures in large arms, and the large cuff used here did not underestimate diastolic pressure in small arms, the large cuff alone could be recommended for general use.

Isolated systolic hypertension: does it really exist on ambulatory blood pressure monitoring?

1. The diagnosis of isolated systolic hypertension, diastolic hypertension and normotension in elderly subjects, as defined by casual office blood pressure measurement, was compared with 24 h ambulatory blood pressure monitoring using an Accutracker II. 2. Mean day-time ambulatory blood pressure monitoring underestimated the casual systolic blood pressure in all three clinical groups. Diastolic pressure was not underestimated to the same extent. 3. Ambulatory blood pressure monitoring best reflected casual blood pressure determination for normotensive subjects. In subjects with isolated systolic hypertension ambulatory blood pressures were only consistent with that diagnosis for 8% of the day time period. For 34% of the day time, their ambulatory blood pressures were consistent with diastolic/mixed hypertension. 4. It is concluded that isolated systolic hypertension may not be a sustained condition, but rather an isolated response to office measurement of blood pressure.

Magnitude, reproducibility, and components of the pressor response to the clinic

We investigated the magnitude of the pressor response to the clinic with ambulatory monitors by comparing blood pressure readings related to the medical visit with all clinic-unrelated readings during the day. One hundred studies were conducted on 51 hypertensive patients who were placed either on placebo (67) or on monotherapy with hydrochlorothiazide, atenolol, or the converting enzyme inhibitors captopril or zofenopril. On placebo, clinic-related systolic (162 +/- 2), diastolic (101 +/- 1), and pulse (61 +/- 2) pressures (mm Hg) were significantly higher than the respective clinic-unrelated values (149 +/- 2, 93 +/- 1, and 56 +/- 1 mm Hg). Heart rates were not different. Despite significant reductions of blood pressure, the same pattern was found during treatment. After initiating the monitoring and while in transit to job or home (initial component of the clinic-related readings), systolic (166 +/- 2 mm Hg) and pulse (64 +/- 2 mm Hg) pressures were higher than those during return to the office the next day (final component, 158 +/- 3 and 58 +/- 2 mm Hg). Blood pressures of both components, however, were significantly higher than the clinic-unrelated ones. In 19 repeat studies carried out 2-24 months apart on placebo, the average pressor response did not change from the first (13 +/- 3/11 +/- 2) to the second (13 +/- 4/11 +/- 2 mm Hg) procedure. No correlation, however, was found between the first and second study responses of individual patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive ambulatory blood pressure monitoring during clinic visit in elderly hypertensive patients

The pressor response to blood pressure measurements in a routine outpatient clinic setting has not been adequately characterized. Blood pressure was monitored in 104 hypertensive patients, mean age of 62 years, by noninvasive automatic ambulatory monitoring device at 5 minutes interval throughout the time of their visits to our outpatient clinic. The average rise in systolic and diastolic blood pressures upon patients' visit to doctor's room was 17 and 7 mm Hg respectively. There was concomitant tachycardia (average rise 3 beats/minute). The rise in blood pressure and heart rate was significantly related to the value in the doctor's room, but was not related to either age, the value in the waiting room or treatment. The rise in systolic blood pressure was more prominent in female patients than in males. Blood pressure and heart rate returned to the baseline level by approximately 40 minutes after leaving the doctor's room. These results illustrate a transient rise in blood pressure during measurement by a doctor in an outpatient clinic. Noninvasive ambulatory blood pressure monitoring during clinic visit in hypertensive patients may be a potentially useful and convenient method for the better diagnosis of hypertension by abolishing the alerting reaction.

Blood pressure decrease prior to initiating pharmacological therapy in nonemergent hypertension

In order to characterize the decrease in blood pressure that occurs in the emergency department (ED) setting in cases of nonemergent hypertension before beginning pharmacological therapy, 94 consecutive cases of hypertension seen at the University of Illinois Hospital were reviewed. Each patient in the analysis had a triage blood pressure recorded by the nursing staff and second blood pressure reading taken between 10 minutes and 2 hours after the triage pressure before pharmacological therapy was begun. Patients with diastolic pressures less than 90 mm Hg were excluded, as were patients with acute end-organ pathology secondary to hypertension. In the remaining 54 cases, the mean arterial pressure fell by 6% (P less than .003), the systolic pressure fell by 6% (P less than .022), and the diastolic pressure fell by 6.4% (P less than .003), suggesting that in nonemergent hypertension, a significant decrease in blood pressure occurs in the ED before pharmacological therapy is begun. The blood pressure decrease was not statistically different when sex and age were considered, but when patients were grouped into those with diastolic pressures between 90 mm Hg and 114 mm Hg and those with diastolic pressures greater than or equal to 115 mm Hg, there was a statistically significant decrease in systolic, diastolic, and mean arterial pressures only in patients with diastolic pressures greater than or equal to 115 mm Hg. Our findings suggest that patients with nonemergent hypertension do not always require immediate and aggressive pharmacological intervention in the ED setting and are best observed for a short period and then reassessed before beginning pharmacological therapy.

Clinical use of home and ambulatory blood pressure monitoring

Blood pressure measurements made in the physician's office with a mercury-column sphygmomanometer traditionally have been the standard for diagnosis of hypertension and determination of the efficacy of antihypertensive agents. The utility of this measurement is limited, however, by the characteristic variability of blood pressure; office blood pressure readings are not always reliable indicators of pressures occurring throughout the course of the day. Therefore, blood pressure measurements performed by patients or family members at home and automatic ambulatory blood pressure monitoring are two supplementary methods used in the clinical management of hypertension. In this article, the role of these methods in the diagnosis of hypertension and other cardiovascular disorders as well as in the evaluation of the efficacy of antihypertensive therapy is addressed.

Effort blood pressure control in the course of antihypertensive treatment

In 30 patients with mild hypertension (diastolic blood pressure, 95 to 105 mmHg), the antihypertensive effect of rilmenidine 1 mg was compared in a double-blind study, with the effect of hydrochlorothiazide 25 mg. Patients not satisfactorily controlled received a combined therapy on the same doses of the two drugs used. Rilmenidine and hydrochlorothiazide induced a significant reduction (p = 0.01) of supine and erect systolic/diastolic blood pressure 23 hours after drug intake with no change in heart rate. This effect was due to a reduction in cardiac output (bioimpedance method) significant (p = 0.05) only for rilmenidine. Both drugs controlled the increase of effort systolic blood pressure in comparison with placebo on systemic vascular resistance treadmill exercise testing. Effort cardiac output was increased by each treatment in comparison with baseline values. Both at rest and on exertion, there was no effect on systemic vascular resistance induced by the two drugs. In a second group of 10 patients with moderate hypertension (diastolic blood pressure, 105 to 115 mmHg), rilmenidine 1 mg was administered in order to evaluate its efficacy and hemodynamic effects (bioimpedance and radionuclide ventriculography), at rest and during a lying cycloergometer effort test. The drug induced a significant decrease in blood pressure at rest and on exertion four hours after drug intake. This effect was due to a reduction (p = 0.05) in systemic vascular resistance, whereas cardiac output and heart rate remained unchanged. Our results show that the reduction in systolic/diastolic blood pressure induced by rilmenidine 1 mg is comparable with that induced by the well-known antihypertensive drug hydrochlorothiazide in mild hypertension. In moderate hypertension, the 1-mg dose appears to be insufficient in controlling the blood pressure in all patients. The drug exerts its antihypertensive effect through the normalization of the altered hemodynamic parameters of hypertension (high cardiac output and/or increased systemic vascular resistance). Rilmenidine also respects the physiologic increase in blood pressure and cardiac output on exertion.

Twenty-four-hour ambulatory blood pressure in shift workers

Blood pressure and heart rate of 15 male shift workers were measured every 15 minutes for 24 hours during three work shifts: morning, 4:00 AM to noon; afternoon, noon to 8:00 PM; and night, 8:00 PM to 4:00 AM. For each shift, 24-hour systolic and diastolic blood pressure showed a large "trough" (the low pressure span) and a continuous range of elevated pressure (the high pressure span). Fourier series were used to model the 24-hour blood pressure profiles. A careful examination of the residuals (measured minus predicted pressures) showed that four harmonics were necessary to describe the data accurately. The model enabled localization in each blood pressure profile of the high and low pressure spans that did not coincide with the subject's work and rest periods. The time and slope of blood pressure entering and leaving these spans could also be individually determined. Mean blood pressure during the high pressure span was the same for the three shifts, but mean blood pressure during the low pressure span was lower when the subject worked in the afternoon. During that shift, the systolic blood pressure slopes entering and leaving the low pressure span were steeper than during the two other shifts. The high pressure span was longest during the night shift and shortest during the afternoon shift. Therefore, a change in the working time profoundly perturbed the 24-hour blood pressure profile.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory pressure monitoring in the assessment of antihypertensive therapy

A low-cost, ambulatory blood-pressure monitor has been calibrated and validated against a random zero sphygmomanometer. The repeatability of ambulatory pressure recordings after a placebo month in 44 mild to moderate untreated hypertensives was assessed. Systolic blood pressure showed a mean difference over 1 month of 2.0 mmHg, with a standard deviation of differences of 9.3 mmHg. The diastolic blood pressure mean difference was 0.1 mmHg (SD = 6.3 mmHg). This variability was much less than for clinic readings (SD = 17.3 mmHg) or for single home pressure readings (SD = 19.7 mmHg). Using ambulatory monitoring to detect a drop in pressure of 8/5 mmHg with a power of 0.9, the number of subjects needed in a parallel group trial is reduced from 360 to 68, and in a crossover study from 88 to 16 subjects. The usefulness of ambulatory pressure monitoring is demonstrated in a placebo-controlled comparison of atenolol, nifedipine retard, or their combination in random order. Eleven subjects, 21-60 years, with initial average blood pressures of 166.5/104.7 mmHg, showed a reduction in pressure with atenolol 50 mg a day of 15.1/10.0 mmHg, with nifedipine retard 20 mg b.i.d. of 21.0/11.6 mmHg, and with atenolol 50 mg and nifedipine retard 20 mg once a day of 26.2/16.8 mmHg. Ambulatory monitoring of pressure improved the accuracy of the trial and demonstrated a reduction in the alerting response with atenolol.

Efficacy of four antihypertensive drugs (clonidine, enalapril, nitrendipine, oxprenolol) on stress blood pressure

The impact of 4 antihypertensive drug regimens on blood pressure (BP) during everyday life stress and on BP during experimental stress in the laboratory was examined in an open clinical study. Sixty middle-aged men with mild-to-moderate essential hypertension never previously treated were treated either with low-dose clonidine (n = 10), oxprenolol (n = 20), nitrendipine (n = 20) or enalapril (n = 10). Before therapy, all 4 groups did not differ in age, weight, degree of obesity, BP at work site and casual BP measured in the outpatient clinic. After 6 months of effective therapy (casual BP within the normotensive range), casual diastolic BP was identical among the 4 groups, whereas systolic BP was lower in patients treated with clonidine or oxprenolol than in those who received enalapril. A disparate pattern of antihypertensive efficacy among the 4 groups emerged when stress BP was compared, with average ambulatory BP higher in patients receiving clonidine or enalapril than in those who had oxprenolol or nitrendipine. During ambulatory BP monitoring, patients treated with oxprenolol had the lowest level at each level of physical activity and self-reported emotional arousal. During bicycle exercise, patients receiving clonidine had the highest increase in systolic BP and those administered oxprenolol the lowest, whereas the BP response during mental stress was similar among all 4 therapeutic groups. The analysis of the hemodynamic response pattern during mental stress unmasked further disparities. Oxprenolol provoked an abnormal hemodynamic response during mental stress tests (increase in total peripheral resistance), whereas nitrendipine and enalapril preserved the physiological hemodynamic profile (decrease of total peripheral resistance).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the efficacy and acceptability of nicardipine and propranolol, alone and in combination, in mild to moderate hypertension

1. We evaluated the relative efficacies and tolerability of various low-dose combinations of nicardipine and propranolol in patients with mild-moderate essential hypertension (DBP Phase V of greater than 90-125 mmHg; WHO Grades I and II) in order to select the best one. 2. Sixty patients completed the double-blind, balanced, randomised three-way cross-over protocol, with each phase lasting 4 weeks, and in which twice daily nicardipine 40 mg or propranolol 80 mg was compared with four twice daily combinations of nicardipine (20 or 30 mg) plus propranolol (40 or 80 mg). 3. At 'peak' effect time (i.e., 2 h post-dosing) all four treatment combinations were significantly more effective than propranolol, with effects ranging from 9-23 mmHg (systolic) and 5-15 mmHg (diastolic). Only the two 30 mg nicardipine combinations with propranolol were more effective than nicardipine monotherapy, further reducing BP by 8-13 mmHg (systolic) and 5-7 mmHg (diastolic); there were no significant differences between them. 4. 'Trough' diastolic pressures were not different between treatments and 'trough' BP control was sub-optimal on all treatments. 5. 70% of patients on nicardipine monotherapy, 33% of those on propranolol monotherapy and 30% of patients during the placebo run-in complained of symptoms. In terms of complaint rates, there was little to choose between the four combinations (27-33%). Serum potassium and creatinine levels were elevated following propranolol monotherapy by 0.19 mmol 1-1 and 6.5 mumol 1-1 respectively (P less than 0.01 for both) and following the nicardipine 30 mg/propranolol 80 mg combination. Nicardipine monotherapy elevated serum T4 levels by an average of 0.57 ng dl-1 (P less than 0.05). 6. The twice daily combination of nicardipine 30 mg plus propranolol 40 mg was therefore the optimum one in terms of its efficacy and tolerability. Further studies need to be performed to test the hypothesis that a higher dose of propranolol might ameliorate troublesome vasodilator side effects. However, none of the treatments studied was ideal for clinical use in the twice daily dosage used in this study.

New insights and new approaches for the treatment of essential hypertension: selection of therapy based on coronary heart disease risk factor analysis, hemodynamic profiles, quality of life, and subsets of hypertension

The pharmacologic therapy of mild primary hypertension (diastolic blood pressure less than 105 mm Hg) has effectively reduced hypertensive arteriolar end organ disease such as cerebrovascular accidents, congestive heart failure, and nephropathy, but there has been no convincing evidence that coronary heart disease (CHD) or its complications, acute myocardial infarction or angina, have been reduced. The risks of therapy with certain antihypertensive drugs may outweigh their treatment benefits as it relates to CHD. The optimal treatment strategy should be to reduce all CHD risk factors, reverse the hemodynamic abnormalities present by lowering the systemic vascular resistance (SVR), preserving cardiac output (CO) and perfusion, and to select the best antihypertensive drug for concomitant medical diseases or problems while maintaining a good quality of life. Antihypertensive drugs that have favorable or neutral effects on CHD risk factors include alpha blockers, calcium channel blockers, central alpha agonists, and angiotensin-converting enzyme inhibitors. On the other hand, diuretics and beta blockers without intrinsic sympathomimetic activity have unfavorable effects on many CHD risk factors. Baseline and serial evaluation of the effects of these drugs on serum lipids, lipid subfractions, glucose, uric acid, electrolytes, exercise tolerance, left ventricular hypertrophy, blood pressure, SVR, CO, perfusion, concomitant diseases, and side effects is necessary to evaluate overall cardiovascular risk.

The relationship between casual and ambulatory blood pressure in essential hypertension: the influence of work, duration of hypertension and antihypertensive treatment

Casual blood pressure (BP) and ambulatory BP (mean 24-h BP) were determined in 23 untreated patients with essential hypertension and in 11 normotensive healthy control subjects. Mean 24-h BP was significantly lower than casual BP in patients with essential hypertension, but not in control subjects. This was demonstrated in the patients who did not work during the ambulatory BP monitoring and in the patients with newly recognized hypertension, whereas no differences were revealed either in the patients who went to work or had a known duration of hypertension longer than 6 months. The size of the difference between casual BP and mean 24-h BP was unaffected by antihypertensive therapy with metoprolol and also individually reproducible. An accordance between casual and ambulatory BP measurements in evaluation of the efficacy of antihypertensive treatment was found in 75% of the patients. Casual BP and mean 24-h BP were weakly correlated both before and during antihypertensive treatment. It is concluded that the higher casual BP than ambulatory BP in essential hypertension may be a specific characteristic of the disease. Both work and known duration of hypertension longer than 6 months eliminate the difference between casual ambulatory BP in essential hypertension. Ambulatory BP monitoring seems to be superior to casual BP measurements in the evaluation of antihypertensive treatment.

Differentiation and investigation of primary versus secondary hypertension (Cushing reflex)

Hypertensive encephalopathy is a rare complication of severe or malignant hypertension. When treated promptly it is potentially reversible without leaving long-term neurologic damage. It can be difficult to differentiate from cerebrovascular accidents or uremia. Acute elevations of intracranial pressure cause acute elevations of blood pressure--the Cushing reflex. This association is less clear for chronic elevations of intracranial pressure, which could occur with tumors. In patients with hypertensive encephalopathy, there are usually diffuse neurologic signs, evidence of visual upset, variable alterations in conscious level, and often a history of rather gradual onset and more systemic symptoms beforehand. The optic fundi show the characteristic hemorrhages, exudates and papilledema, while the urine usually contains protein red cells and casts. Early treatment is mandatory but need not be by the parenteral route, and any blood pressure reduction should be gradual. Vigorous antihypertensive therapy under such circumstances can lead to problems with relative hypotension and underperfusion of vital organs such as the brain, the heart and the kidneys.

Increased sympathetic nerve activity at home in young subjects with hypertension

Plasma and urine norepinephrine, epinephrine, plasma renin activity and aldosterone were measured in 11 young men (mean age, 21 years) with a high blood pressure in the clinic who maintained a high home blood pressure and 12 men with an elevated clinic blood pressure who had a normal home blood pressure. Plasma samples were drawn following 30 min rest in the clinic, and 24-hour urine samples were collected at home. The two groups of hypertensives could not be distinguished on the basis of clinic blood pressure, plasma norepinephrine, epinephrine, renin activity or aldosterone. Patients with a high home blood pressure were characterized by a high urinary norepinephrine excretion. These results suggest that the patients whose blood pressure remained elevated at home had an increased sympathetic nerve activity at home.

Lack of correlation between clinic and 24 hour ambulatory blood pressure in subjects participating in a therapeutic drug trial

Although previous studies document that blood pressure measured in the clinic may differ significantly from blood pressure recorded over 24 hours, the impact of these differences on patient selection for therapeutic drug trials is unknown. A placebo controlled double-blind evaluation of an experimental antihypertensive agent was conducted. Of 30 patients entered, 21 were admitted to the active drug phase of the protocol on the basis of a clinic supine diastolic blood pressure greater than or equal to 95 mmHg; 9 subjects with lower levels of diastolic blood pressure were dropped. Noninvasive ambulatory blood pressure monitoring was performed during the placebo period. Comparison of the two subgroups demonstrated similar levels of 24 hour blood pressure (142 +/- 13/86 +/- 7 vs 137 +/- 10/82 +/- 10). Analysis of individual patient data showed that 24 hour mean diastolic blood pressure was apparently normal (less than or equal to 80 mmHg) in 5/21 (24%) "admitted" and 3/9 (33%) "dropped" subjects. Circadian blood pressure pattern were similar in the two subgroups. A statistically large difference was noted between clinic and 24 hour blood pressures in the "admitted" subgroup (20 +/- 18/13 +/- 7 vs 7 +/- 12/4 +/- 6, p less than 0.08/p less than 0.001), suggesting that patients exhibiting a marked blood pressure rise in the clinic setting were preferentially selected.

Value of echocardiographic and ambulatory blood pressure monitoring in hypertension

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.

Effects of prolonged administration of the angiotensin converting enzyme inhibitor CGS 16617 in normotensive volunteers

A new, orally active angiotensin converting enzyme (ACE) inhibitor, CGS 16617, has been evaluated in normotensive subjects during acute and prolonged administration. Single ascending doses of CGS 16617 20 to 100 mg were given to 9 normotensive volunteers at one week intervals and the changes in blood pressure, plasma ACE and renin activity were examined up to 72 h after drug intake. Also, CGS 16617 50 mg/day or placebo were given for 30 days to 8 and 6 normotensive subjects, respectively, maintained on an unrestricted salt diet. Blood pressure was measured daily in the office and ambulatory blood pressure profiles were also obtained before, during and after therapy, using the Remler M 2000 blood pressure recording system. CGS 16617 was an effective and long lasting ACE inhibitor. It did not induce a consistent change in blood pressure, but, the individual responses were very variable and several subjects experienced a clear decrease in the average of the blood pressures recorded during the daytime.

Antihypertensive treatment, myocardial infarction, and nocturnal myocardial ischaemia

Patients with critical coronary stenoses or hypertrophied ventricles have impaired coronary vasodilator reserve and are at greatest risk of myocardial ischaemia or infarction if subendocardial perfusion pressure falls below the lower threshold of bloodflow autoregulation. During sleep, antihypertensive treatment may cause coronary artery perfusion pressure to fall below these limits in such patients. Unrecognised nocturnal hypotension may be one reason why treatment has not diminished the risk of myocardial infarction in patients with hypertension.

Experience with 24-hour ambulatory blood pressure monitoring in hypertension

Traditional sphygmomanometric blood pressure measurements may lead to errors in the diagnosis of arterial hypertension due to a number of factors, among which are the alerting reaction and pressor response induced in patients by the doctor's visit. This phenomenon, as quantified in our laboratory by continuous intraarterial recordings, is responsible for an average rise in systolic and diastolic blood pressure of 27/15 mm Hg, a rise that does not seem to be reduced by simply desensitizing the patient by means of more frequent physician visits. Twenty-four hour ambulatory blood pressure monitoring may theoretically improve the diagnostic approach to hypertensive patients by overcoming some limitations of isolated cuff measurements. In recording intraarterial blood pressure in 108 ambulant hypertensive subjects, we have found that 24-hour blood pressure values are able to discriminate among patients with different degrees of target organ damage better than isolated sphygmomanometric readings. Moreover, these studies have indicated that 24-hour blood pressure variability may be as important as blood pressure mean values in the assessment of cardiovascular complications. In clinical practice, however, intraarterial blood pressure monitoring is not feasible, and only noninvasive recorders can be used. Use of these devices does not induce any alerting reaction in the patients and does not interfere with day-night blood pressure changes. Although it is characterized by intermittent readings, this approach is not incompatible with a precise estimate of 24-hour blood pressure mean values.(ABSTRACT TRUNCATED AT 250 WORDS)

Ambulatory blood pressure monitoring: practical considerations

Ambulatory blood pressure monitoring (ABPM) allows one to evaluate the blood pressure (BP) profile over a 24-hour period in the patient's natural environment. Casual pressure measurements in the physician's office can be affected by alarm reactions, thus causing "white coat" hypertension. ABPM allows one to evaluate these reactions and determine the average pressure and variability of BP along with the effects of physical activity and emotional arousal on BP patterns while at work, at home, and during sleep. Average pressures determined by ABPM are more predictive of target organ involvement and cardiovascular complications of hypertension than casual monitoring of BP in the clinic. The absence of physiologic decline in arterial pressure during sleep is associated with increased prevalence of atherosclerotic complications and left ventricular hypertrophy as well as impairment of the autonomic nervous system. Although further prospective studies are needed to confirm the benefits of home pressure readings and ABPM, ABPM can be helpful in the diagnosis and determination of prognosis and therapeutic responses in a select group of patients.

Point of view: why hypertension is overdiagnosed and overtreated in 1987

1. The decision whether arterial blood pressure (BP) is elevated or normal is usually based on inadequate data: few readings in the presence of great variability of BP; levels higher in the presence of the doctor; and diastolic BP often higher sitting and standing than lying. 2. Assessments of response and of the need for increases in drug dosage are also based on insufficient data. 3. Increased morbidity and mortality from stroke and heart attack, and incomplete correction with treatment have been interpreted as suggesting further benefit from aggressive reduction of BP to 'normal' in all patients. 4. The emergence of powerful drugs with few side-effects, and the promise of lowering office BP to 'normal' as monotherapy, has removed the hesitation to treat 'mild' hypertension. 5. Attempts to lower sitting office diastolic BP to 'normal' have led to increasing drug dosage, dose-related, drug-specific side-effects, and lethargy due to hypotension. 6. Newer self-measurement BP units can be used easily by most patients, cost less than five visits to the doctor and provide a cheap method of obtaining sufficient data on which to base informed management decisions. Supported by normal echocardiographic left ventricular mass, normal 'home BP' (including lying diastolic) permits many mild hypertensives to remain off medications. 7. Non-drug therapy avoids or reduces long-term drug therapy, with its side-effects.

Blood pressure monitoring outside the office for the evaluation of patients with resistant hypertension

Although severe hypertension is associated with a poor prognosis, there exists a substantial number of patients who have persistently elevated blood pressures, but no signs of target organ damage, and nearly normal life expectancy. In such cases, measurement of blood pressure outside the clinic may give readings that are as much as 30 mm Hg lower than the clinic readings. The first step recommended in the identification of such patients is to use home blood pressure monitoring. If home blood pressures are low, 24-hour ambulatory blood pressure recording is indicated. If this also gives low readings, it is appropriate to treat patients according to their level of home blood pressure. Because of the unreliability of clinic pressures, ambulatory and home blood pressure monitoring may also be of value in assessing the response to treatment.

Factors influencing blood pressure and heart rate variability in hypertensive humans

We examined the influence of baroreceptor reflex sensitivity (the increase in pulse interval in response to a phenylephrine-induced increase in blood pressure), age, blood pressure, and beta-adrenergic receptor blockade on the variability of blood pressure and heart rate in essential hypertension. Fifty-six subjects were studied before treatment; intra-arterial blood pressure was recorded outside the hospital for 24 hours. Variability was defined (from all beats occurring while subjects were awake) as the standard deviation about the average waking value for mean arterial pressure (MAP) or pulse interval. The correlation (r) between baroreceptor reflex sensitivity and blood pressure variability was -0.47 (p less than 0.0002). Baroreceptor reflex sensitivity was the only independent determinant of blood pressure variability on multiple regression analysis. Thirty subjects were restudied after 5 months of beta-adrenergic receptor blockade. Ambulatory blood pressure was lower during treatment, whereas pulse interval, its variability, and baroreceptor reflex sensitivity were higher. Blood pressure variability was unchanged. The variability of MAP was inversely correlated with baroreceptor reflex sensitivity before (r = -0.42, p less than 0.02) and during (r = -0.45, p less than 0.02) treatment, but it was unrelated to the average ambulatory MAP or to the variability of pulse interval either before or during beta-blockade. Sixteen subjects whose average waking ambulatory blood pressure was 140/90 mm Hg or less were not treated. This group of borderline hypertensive subjects had less variable MAP than did the remaining 40 subjects (12.4 +/- 2.3 [SD] vs 14.5 +/- 2.5 mm Hg; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the antihypertensive effect of celiprolol by ambulatory blood pressure monitoring

The use of ambulatory blood pressure monitoring has gained popularity because it is not subject to those limitations associated with traditional sphygmomanometry (inaccuracy of blood pressure readings, low number of readings, and failure to represent daytime blood pressure readings). In the present study, we provide evidence that the 24-hour mean blood pressure obtained through intraarterial blood pressure measurements in ambulatory patients provides a more accurate diagnosis (and perhaps a prognosis) of hypertension than that provided by cuff-obtained casual blood pressure measurement. Furthermore, despite a reduction in the amount and in the accuracy of the information obtained, blood pressure data provided by noninvasive blood pressure monitoring are also more accurate diagnostically than cuff-obtained casual blood pressure measurements. In 15 essential hypertensive patients in whom celiprolol, 400 mg once daily, was compared with placebo in a randomized double-blind crossover study, the use of noninvasive 24-hour automatic blood pressure monitoring showed that in responsive patients, celiprolol induced a sustained reduction in systolic and diastolic blood pressure throughout the 24 hours. The blood pressure reduction was also apparent during the night, despite the concomitant occurrence of a slight tachycardia. These findings demonstrate that once-daily administration of celiprolol provides an effective lowering of the 24-hour blood pressure profile. This dosing schedule can therefore be regarded as appropriate for antihypertensive therapy.

Statistical criteria for using short-term measurements as an index of 24-hour mean arterial pressure in unanesthetized unrestrained dogs

This study assessed the statistical validity of short time-interval measurements as estimators of true 24 hour mean arterial pressure in unanesthetized, unrestrained dogs. 24 hour intra-arterial pressure recordings were obtained using a stable FM telemetry system. The 24 hour pressure measurements approximated a normal distribution whose variance was inversely related to the selected averaging interval. Given the variance of a normal distribution one can calculate the 95% confidence interval for any single random measurement. Conversely the number of random samples necessary to be within a prescribed confidence interval can be determined. In this study, the 95% confidence interval for a single, random 30 minute arterial pressure average was calculated to be 11.2 mmHg. Only 4.8 +/- 1.4% of 480 individual 30 minute arterial pressure measurements fell beyond this confidence interval. These outlying values were distributed throughout the 24 hour period. The data suggest that randomly chosen short time-interval measurements may be a valid index of true 24 hour mean pressure if the average variance of a population is known and confidence intervals are defined.

Are some hypertensive patients overtreated? A prospective study of ambulatory blood pressure recording

Ambulatory blood pressure (BP) was recorded in hypertensive patients whose physicians had been asked to reduce diastolic pressure measured in the office to 90 mm Hg or less. 34 hypertensive patients with a diastolic pressure measured by their physician of 95 mm Hg or more despite antihypertensive therapy had their treatment changed with the aim of achieving this pre-set goal within 3 months. At the beginning and the end of the study, ambulatory BP was monitored during the daytime with a portable non-invasive recorder. The results of the ambulatory recordings were not made available to the physicians until completion of the study. In half the patients the ambulatory diastolic pressure was already 90 mm Hg or less at the start. In these patients, treatment adjustment did not further decrease ambulatory BP. In contrast, patients who initially had an ambulatory diastolic pressure above 90 mm Hg had a significantly decreased ambulatory BP at the end of the study. Intensifying the therapy of hypertensive patients who have a normal ambulatory BP may result in overtreatment without any real gain in BP control.

Placebo does not lower ambulatory blood pressure

The effects of 4 weeks of placebo on clinic and on ambulatory blood pressure, measured non-invasively using the Remler M 2000 portometer, were studied in 46 hypertensive patients who were included in three consecutive double-blind randomized placebo-controlled trials with antihypertensive drugs. Placebo significantly reduced clinic blood pressure, but had no significant effect on ambulatory blood pressure.

Alerting reaction and rise in blood pressure during measurement by physician and nurse

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.

A finger volume-oscillometric device for monitoring ambulatory blood pressure: laboratory and clinical evaluations

A new portable device for the indirect measurement of ambulatory blood pressure in the finger was successfully applied to normotensive and hypertensive subjects in and outside a ward setting. The device uses the volume-oscillometric technique and, equipped with a microprocessor, permits long-term ambulatory monitoring of indirect systolic and mean blood pressure at desired intervals (once every 1-10 min). Systolic and mean blood pressures obtained by this method were well correlated with those measured by the direct (Oxford) and arm-cuff methods. Systolic and diastolic blood pressure obtained by the volume-oscillometric device were almost identical with those recorded by an arm-cuff. Systolic blood pressure obtained by the volume oscillometric method was, however, significantly lower than that measured by the direct method. The new device has also been used to measure blood pressure during treadmill exercise and ice-water immersion. Mean values of blood pressure and the SD of these averaged for 24 hours, or for every hour, were reproducible when the measurements were repeated under the same condition. The present device is portable, causes minimal noise, can detect rapid change in blood pressure and causes less discomfort when compared to the conventional arm-cuff method. Regular measurements can be made with minimal sleep disturbance. This fully automatic volume-oscillometric device allows reliable 24-hour monitoring of ambulatory blood pressure not only in but also outside a ward setting, and as such is useful for studies of hypertension.

Improved left ventricular filling accompanies reduced left ventricular mass during therapy of essential hypertension

Abnormal left ventricular diastolic performance, an early manifestation of hypertension in the heart, may precede the development of left ventricular hypertrophy. To assess effects of antihypertensive therapy on the heart, left ventricular mass (determined by echocardiography) and rapid left ventricular filling rate (determined by radionuclide ventriculography) were compared before and after 6 months of treatment of 16 patients. Nitrendipine (a dihydropyridine calcium channel blocker) was given alone or in combination with either propranolol or hydrochlorothiazide, or both, and significantly reduced blood pressure (156/103 +/- 12/7 to 137/89 +/- 10/6 mm Hg). In 6 of the 16 patients, left ventricular mass decreased by more than 10% (270 +/- 95 to 193 +/- 47 g, p less than 0.01); in the same patients, left ventricular filling rate increased (2.03 +/- 0.35 to 2.30 +/- 0.45 end-diastolic counts/s [EDC/s], p less than 0.01). In the one patient whose left ventricular mass increased (137 to 195 g), left ventricular filling rate decreased from 2.01 to 1.78 EDC/s. In the remaining nine patients who had no change in left ventricular mass, there was no significant changes in left ventricular filling. The changes in ventricular mass and filling could not be related to the extent of change in blood pressure or heart rate. These data suggest that regression of left ventricular mass during antihypertensive therapy with nitrendipine is accompanied by improved diastolic function.