Showing papers on "Ambulatory blood pressure published in 1985"

What is the role of ambulatory blood pressure monitoring in the management of hypertensive patients

Abstract: Noninvasive ambulatory blood pressure (BP) recording is now clinically available for the evaluation of hypertensive patients. It is well known that pressures measured in the office or clinic are unreliable and that repeated measurements are better at predicting outcome than are single measurements. Several studies have compared the correlation between target organ damage and different measures of BP, and in every instance ambulatory BP measurements have given better correlations than clinic readings. In one prospective study the ambulatory BP readings were more predictive of BP-related morbidity than were clinic readings. Data are now being obtained that will establish normal ranges of BP during ambulatory monitoring, against which values from patients being evaluated for hypertension can be compared. It is concluded that ambulatory BP monitoring is of clinical value for the evaluation of patients with mild hypertension.

The standardized mental stress test protocol: test-retest reliability and comparison with ambulatory blood pressure monitoring.

Abstract: The mental stress test protocol is used extensively in research, but different laboratories often employ different stress tasks, utilize different dependent variables to index the stress response, and perform different transformations on the gathered data. The present study determined the test-retest reliability of 11 cardiovascular dependent variables during a resting baseline and three common stress tasks: playing a video game, performing a choice reaction-time test, and performing a cold-pressor test. Sixty healthy, middle-aged males underwent testing twice, approximately three months apart. Instructions were delivered via videotape and data were gathered on-line by computer to ensure a standard laboratory environment. Each task elicited significant increases in blood pressure, vascular rigidity, LVET, heart rate, and stroke volume. In addition, the cold-pressor test led to increases in total systemic resistance and mean systolic ejection rate. The absolute levels of the 11 dependent variables were correlated across tasks (partial r, baseline removed, = .06 to .69, 32 of 33 comparisons significant at p<.05), indicating that reactivity to stress generalizes across alternate test forms. The absolute levels also showed significant test-retest reliability (r= .32 to .82; 40 of 44 comparisons significant at p<.05). In addition, for 19 of 33 comparisons, absolute levels showed greater test-retest reliability than change scores derived by subtracting the initial resting baseline value from the stress-task value. Finally, blood pressures taken during the stress tests were more highly correlated with the average blood pressures measured via ambulatory monitoring than casual office pressures, suggesting that such stress values may more accurately reflect average blood pressure.

Lack of alerting reactions to intermittent cuff inflations during noninvasive blood pressure monitoring

Abstract: Intermittent noninvasive blood pressure monitoring is becoming increasingly popular because of the belief that a daytime blood pressure profile can provide a better clinical evaluation of hypertension than that provided by casual blood pressure measurements. This approach has potential limitations, however, one of which is that the cuff inflations permitting blood pressure to be repeatedly measured may induce an alerting reaction and a pressor response in the patients and lead to an overestimation of their daytime blood pressure. Blood pressure in 22 subjects was invasively recorded for 24 hours by the Oxford method. During the day of the recording blood pressure was also measured by a noninvasive device (Vita-Stat 901), which had its cuff applied to the opposite arm from which the intra-arterial signal was derived. For 2 hours the device provided automatic cuff inflations at 10-minutes intervals. For another 2 hours it was programmed to provide cuff inflations only following patients' commands, also at 10-minute intervals. Analysis of the intra-arterial blood pressure trace during the periods preceding and following the automatically or semiautomatically induced cuff inflations showed that these procedures caused no increment in systolic and diastolic blood pressure. This finding applied not only to the mean data but also to each individual measurement considered separately, including the initial one. Our results indicate that automatic and semiautomatic blood pressure monitorings do not induce an alarm reaction and a blood pressure rise and thus do not overestimate daytime blood pressure values.

Does self-measurement of blood pressure improve patient compliance in hypertension?

Abstract: Compliance with antihypertensive therapy was measured before and after distribution of non-automatic blood pressure devices. After 2 weeks of placebo treatment, 37 patients were treated with an antihypertensive combination drug containing triamterene. Adherence to therapy was assessed over 8 months by measuring urine fluorescence due to triamterene at intervals of 2-4 weeks, unknown to the patients. After 3 months of therapy, all patients, not just those with poor compliance, were given blood pressure devices and were carefully instructed in their use. The results showed that self-recording of blood pressure increased the compliance rate in the total group from 65% at the beginning of the study to 81% at the end. In those who initially showed poor compliance, there was an increase in compliance from 0 to 70% after self-measuring of blood pressure was introduced. We conclude that self-recording of blood pressure may be of value in patients with unsatisfactory blood pressure responses in whom poor compliance is suspected.

Evaluation of hypertension and related target organ damage by average day-time blood pressure.

Abstract: Aim of the present study was to verify whether average blood pressure continuously recorded throughout the day correlates with the degree of target organ damage more closely than casual pressure in hypertensive patients. The study was conducted in 102 subjects with borderline, moderate and severe hypertension. Our results confirm a closer relationship between cardiovascular complications and recorder blood pressure than casual pressure possibly because the latter less perfectly reflects the patients usual pressures which are generally lower. However our results further demonstrate that blood pressure variability also contributes to the degree of target organ damage since for equal average day-time pressures a greater severity of cardiovascular complications was observed in patients with the highest blood pressure variability and the highest peaks of pressure. These findings should be carefully considered when evaluating the effect of antihypertensive drugs.

Body-sodium and blood volume in a patient with licorice-induced hypertension.

Abstract: A 68-year-old man a nine-year history of licorice ingestion had moderate hypertension and low plasma potassium. Exchangeable sodium and blood volume were increased to 128 and 111%, respectively of the expected values; plasma renin and aldosterone levels were suppressed. Plasma norepinephrine concentration was distinctly elevated but the pressor response to infused norepinephrine was normal. After licorice withdrawal, blood pressure, plasma potassium and blood volume reverted to normal levels within three weeks, exchangeable sodium and plasma renin within four months. Exchangeable sodium in our patient with licorice-induced hypertension was increased to a comparable extent as in primary hyperaldosteronism. Moreover, blood pressure in relation to body sodium or plasma potassium did not differ between the exogenous or the endogenous types of mineralocorticoid excess. This observation does not support the possibility that in primary hyperaldosteronism excess aldosterone secretion per se could play an important pressor role independently from sodium retention.

Validity and usefulness of non-invasive ambulatory blood pressure monitoring.

Abstract: In the past few years non-invasive blood pressure monitoring has become increasingly popular in the belief that this approach: can provide accurate mean blood pressure values over a 24-h period or through the day and these values may define better than the casual values the severity of hypertension and its related risk of developing cardiovascular morbidity and mortality. In this paper a number of problems concerning non-invasive ambulatory blood pressure monitoring in hypertension will be reviewed. First, evidence will be shown that blood pressure measurements at intervals up to 30 min can provide a 24-h blood pressure mean similar to that obtained by continuous analysis of the blood pressure tracing, which demonstrates that intermittent readings do not represent a limitation of automatic blood pressure monitoring. Then, it will be shown that the periodical cuff inflations of automatic or semi-automatic blood pressure monitoring may not trigger an alarm reaction or disturb patients' sleep. However, these advantages must be balanced against other still unverified aspects of these new techniques: the inability of intermittent blood pressure readings to evaluate accurately blood pressure variability, which may be a determinant of the overall risk profile, the error inherent in non-invasive measurements of blood pressure and the limited prospective evidence that average 24-h or daytime blood pressure values indeed correlate with the development of target organ damage better than casual blood pressure values do.

Effects of chronic nitrendipine on casual (office) and 24-hour ambulatory blood pressure.

Abstract: To assess the clinical efficacy of chronic nitrendipine therapy in mild to moderate essential hypertension, we studied blood pressure (BP) and heart rate responses in 22 subjects receiving maintenance nitrendipine therapy. Ten subjects (45%) whose hypertension was controlled with chronic monotherapy had an 11/12 mm Hg decrease in supine BP (P < 0.05) with a mean (± SD) dose of 71 ± 15 mg/day. The 12 (55%) subjects whose hypertension was not controlled with monotherapy had a comparatively higher baseline BP than the other 10 (156/105 ± 10/6 compared with 150/98 ± 15/4 mm Hg; P < 0.05). Eight of the 10 subjects demonstrating office BP control with chronic nitrendipine monotherapy who also had full-time employment underwent continuous ambulatory BP monitoring before and after maintenance monotherapy. Nitrendipine induced a reduction in the mean 24-hour BP and mean BP at home, but did not reduce the BP during work or while asleep. These data suggest that nitrendipine lowers BP when assessed by casual office methods. The ambulatory BP monitor data demonstrate that the hypotensive response to chronic nitrendipine is modified during work periods, which are generally associated with increased adrenergic activity. Ambulatory BP monitoring may be superior to office (casual) monitoring in the assessment of the overall efficacy of antihypertensive drugs. Clinical Pharmacology and Therapeutics (1985) 38, 60–64; doi:10.1038/clpt.1985.135

Ambulatory blood pressure monitoring does not interfere with the haemodynamic effects of sleep.

Abstract: Automatic or semi-automatic blood pressure (BP) monitoring is a widely used method for assessing 24-h BP profile. However, the ability to achieve this goal depends on several factors that have not yet been controlled. The present study examined the possibility that cuff inflations disturb the sleep of patients and prevent the nocturnal fall in BP. This issue was investigated in 10 hospitalized subjects in whom BP was recorded intra-arterially for 48 h using the Oxford method. During the first or the second 24 h BP was also monitored non-invasively (Squibb ICR portable device), the cuff inflations being performed at 15 min intervals during the day and at 30 min intervals during the night. The computer analysis of the two different 24-h intra-arterial tracings showed that the addition of automatic BP monitoring had not caused any alteration in the day and night intra-arterial BP and heart rate profiles. Thus, disturbances of the haemodynamic effects of sleep do not characterize 24-h automatic BP recording, at least when made with the device employed in the present study. This removes an important objection against the ability of this approach to evaluate the patients' BP profiles properly.

Devices used for self-measurement of blood pressure: revised statement of the national high blood pressure education program

Abstract: Several factors have necessitated an update of the 1980 report of the National High Blood Pressure Education Program on blood pressure measurement devices used by consumers.1First, new information relating to the use and accuracy of blood pressure measurement devices has become available.2Second, due to heightened awareness and improved technology, sales and use of self-measurement equipment (including home blood pressure devices and automated machines) have increased.3Last, and of equal importance, is the increasing interest in ambulatory blood pressure monitoring systems among health professionals, leading to questions concerning the appropriateness of their use in the control of high blood pressure.4,5 The statement that follows addresses the use and accuracy of three types of blood pressure measurement equipment: portable home devices, stationary automated machines, and noninvasive ambulatory monitors. Benefits and concerns relating to each type of equipment are discussed. Recommendations regarding the use of devices for

Ambulatory blood pressure versus casual pressure for the evaluation of target organ damage in hypertension: complications of hypertension.

Abstract: In 122 patients aged between 14 and 58 years with different degrees of hypertension, mean 24-h ambulatory blood pressure (BP) and casual BP were measured to evaluate the relationship with hypertensive target organ damage. The following results were obtained: (1) In agreement with previous reports, this study found a better relationship between target organ damage and mean ambulatory BP than with causal BP, although the correlation coefficients were similar for both. (2) A higher degree of cardiovascular complications occurred in patients with higher variability in BP. These data emphasize the superiority of BP monitoring over causal BP for the study of hypertension and its complications.

Whole-day BP monitoring in ambulatory normotensive men.

Abstract: • Noninvasive automated ambulatory BP monitoring techniques were used to evaluate BP patterns in 34 healthy normotensive men. Daytime BPs (128±12/80±7 mm Hg) were significantly higher and nighttime BP averages (109±11/67±9 mm Hg) were significantly lower than the casual BPs (119±13/76±9 mm Hg) of the subjects studied. On the average, 15.6% of the readings in each tracing showed systolic BPs above 140 mm Hg, and more than 25% of these elevated readings were found in six of the 34 subjects. The average incidence of elevated diastolic BPs (>90 mm Hg) observed during each monitoring period was 14.4%, but six subjects had incidences of more than 25%. The incidence of elevated BP readings was not age related. However, subjects with a family history of hypertension generally had more elevated systolic BPs than those with no family history of hypertension (24% v 9%). ( Arch Intern Med 1985;145:271-274)

Blood pressure response to antihypertensive therapy: ambulatory versus office blood pressure readings.

Abstract: Blood pressure readings obtained by the physician in his office and ambulatory blood pressures recorded with the semi-automatic Remler device, were compared during a controlled antihypertensive drug trial. Either timolol or methyldopa was administered in in double-blind fashion to 30 patients with uncomplicated essential hypertension. All exhibited a diastolic office blood pressure greater than 95 mmHg at the end of a four-week placebo period. All patients then received a combination of hydrochlorothiazide (25 mg/day) and amiloride (2.5 mg/day). After four weeks of diuretic therapy, timolol (10 mg/day, n = 14) or methyldopa (250 mg/day, n = 16) were added randomly for six weeks. The dose of all antihypertensive agents was doubled after two weeks of therapy with diuretics combined with timolol (n = 7) or methyldopa (n = 16) because of the persistence of diastolic blood pressure levels greater than 90 mmHg at the office. When assessed in the office, the antihypertensive effect of timolol and methyldopa was similar. During ambulatory blood pressure monitoring, however, pressure levels were lower in the patients given timolol (P less than 0.05 for the diastolic). With both regimens, the blood pressure response measured outside the clinic during usual daily activities could not be predicted from that observed with office blood pressure readings. Furthermore the magnitude of the drug induced blood pressure decrease was more reproducible in time when determined outside the clinic. These data suggest that ambulatory blood pressure monitoring is more precise in evaluating the efficacy of antihypertensive therapy than office blood pressure measurement.

Definition of normalcy in whole-day ambulatory blood pressure monitoring.

Abstract: In this study we have performed 24-hour ambulatory blood pressure monitorings in age-matched normotensive and hypertensive male subjects. The data have been analyzed in an attempt to define standards for the clinical use of ambulatory blood pressure monitoring in the diagnosis of hypertension. The data were analyzed with respect to possible differences in the averages of the whole-day, daytime and nighttime blood pressures, and differences in the prevalence of abnormal blood pressures between the two groups. A considerable overlap was found between the two groups with respect to the various blood pressure averages. The overlap in blood pressures occurred in fewer patients for diastolic than for systolic blood pressure, and less often when nighttime pressures were considered. Hypertensive men showed on average a greater incidence of abnormal blood pressures than normotensive subjects. However, nine of the normotensive control subjects showed more than 25 percent of abnormal readings of systolic or diastoli...

The Rumpel-Leede Sign Associated With a Noninvasive Ambulatory Blood Pressure Monitor

Abstract: To the Editor.— The ambulatory blood pressure recorder is a recently developed device useful in the evaluation of the blood pressure and heart rate in those patients demonstrating lability in the physician's office or clinic.1The technique of ambulatory monitoring has also become popular in the evaluation of the efficacy of antihypertensive drugs.2In the past few years, a number of noninvasive blood pressure-monitoring units that utilize a standard sphygmomanometer attached to a programmable portable motor-driven pump have become available.3,4I would like to describe a previously unreported complication of ambulatory blood pressure monitoring. Report of a Case.— A 65-year-old diabetic woman with a history of marked fluctuation in blood pressure levels in her physician's office was referred for ambulatory blood pressure monitoring. Her usual medications were timolol maleate, hydrochlorothiazide, nifedipine, and NPH insulin. There had been no previous history of easy bruisability, skin lesions, bleeding episodes,

Blood pressure monitoring over short day and night times cannot predict 24-hour average blood pressure.

Abstract: Evidence has been produced that average 24-h or day-time blood pressure (BP) values provide a better diagnosis of hypertension and a better prediction of its risk than BP values provided by one or few isolated measurements. This has led to a number of attempts to simplify the time-consuming procedur

Effects of physical training on blood pressure in hypertension.

Abstract: Although initial studies did not allow conclusions on the effects of physical training on blood pressure in hypertension because the groups studied were too small, and because of a mixture of hypertension types, body weight changes and lack of controls, recent studies are not rendered difficult to interpret by such deficiencies. Such studies seem now to allow the conclusion that physical training lowers blood pressure in borderline hypertension by decreasing heart rate and cardiac output, but not peripheral resistance. It is noteworthy that increases of heart rate and cardiac output, as well as a number of other symptoms of increased activity of the central sympathetic nervous system, are characteristic of a large group of subjects with borderline hypertension, and it seems that these subjects are particularly good responders to physical training. Recent studies suggest that physical activity, as well as electric nerve stimulation and acupuncture, sends specific afferent nerve signals to the central nervous system resulting afterwards in increased pain threshold, and lower activity in the central sympathetic nervous system, resulting in lower heart rate and blood pressure. These effects seem to be mediated via endorphin release in the central nervous system because they can be mimicked by local administration of these substances and inhibited by naloxone. It seems an interesting possibility that physical training lowers blood pressure and other expressions of increased sympathetic nervous system activity via such a mechanism. Further studies along this line may be rewarding from different aspects.

Adrenergic and vagal influences on blood pressure variability.

Abstract: The present paper reviews our recent studies set up to define the role of sympathetic and vagal nervous influences on blood pressure variability. Blood pressure and its variability was measured in men by Arteriosonde or by Portometer (the latter recording 12 hours ambulatory blood pressure) and in the dog by intraarterial recordings. It was shown that sympathetic nerves do not influence variability as no change was seen with drugs acting on either beta (atenolol, metoprolol, propranolol) or alpha adrenergic receptors (prazosin, phentolamine, guanfacine). Also no correlation was found with plasma catecholamines or sympathetic function tests. By contrast, clear inhibition was demonstrated with atropine indicating an important role of vagal nerves on variability. However, in men, inhibition was not complete with atropine; thus, also other mechanisms play a role but these are, at present, largely unknown.

Diabetic autonomic dysfunction, blood pressure, and sleep

Abstract: We measured serially the blood pressure of 7 normal controls and 11 Type I insulin-dependent and 6 Type II non-insulin-dependent diabetic patients during sleep. All subjects underwent 2 or 3 nights of monitoring during which blood pressure was measured with an arteriosonde, a Doppler-type system with a cuff that automatically inflates every 15 minutes. All 7 normal controls, 3 of 11 Type I, and all 6 Type II diabetic patients had normal results from bedside tests of autonomic function. The Type I patients had abnormal systolic blood pressure measurements throughout the night. Unlike normal controls and Type II diabetics, their blood pressure did not rise progressively in the early morning hours. During rapid eye movement (REM) sleep, their blood pressure measurements were significantly higher and lower than values measured during non-REM sleep, in sharp contrast to those in the other two groups, whose REM sleep-related blood pressure values were slightly above the preceding non-REM sleep measurements.

Blood pressure recording in the ambulatory patient and evaluation of cardiovascular risk.

Abstract: Many large epidemiological studies, such as the one going on in Framingham [1], have clearly established that hypertension is one of the major risk factors for cardiovascular diseases. Well controlled intervention trials have also clearly demonstrated that antihypertensive therapy can significantly reduce the incidence of complications such as stroke, congestive heart failure and possibly myocardial infarction [2-4]. There exists no doubt about the important causal relationship between elevated blood pressure and cardiovascular complications. The measurement of blood pressure has thus become one of the most frequent procedures carried out by any practising physician. Notwithstanding, some doubt has been expressed whether all patients with a slightly elevated blood pressure at the physician9s office are indeed prone to suffer a heart attack or a stroke and need lifelong antihypertensive therapy [5, 6]. Does the casual blood pressure measurement at the physician9s office accurately assess the risk of each individual patient of suffering a heart attack in the future?

The role of home and ambulatory blood pressure recording in the management of hypertension.

Abstract: A review of the literature shows that doctor-recorded measurement (DRM) of blood pressure is higher than patient-recorded measurement (PRM) by either home-recording or ambulatory measurement. The role of home-recording and ambulatory measurement as a means of supplementing doctor-recorded measurement is discussed. The results of two studies comparing home-recording with clinic and ambulatory blood pressure showed that home-recording of blood pressure did not lower blood pressure.

Phlebitis associated with noninvasive 24-hour ambulatory blood pressure monitor.

Abstract: To the Editor.— The ambulatory blood pressure monitor is a recently developed device used in diagnosis and treatment of hypertension. Previous reports have suggested that there have been no adverse effects while using noninvasive 24-hour blood pressure monitors.1Recently, development of the Rumpel-Leede sign in association with use of a noninvasive ambulatory blood pressure monitor has been reported inJAMA, demonstrating that complications can occur with this device.2 We have used 24-hour ambulatory blood pressure monitoring for the past 18 months in both research investigations and in a wide range of clinical circumstances. The blood pressure cuff is applied in the usual fashion and attached to a microprocessor-controlled, battery-powered compressor and worn like a Holter monitor. Cuff inflation causes recurrent, intermittent obstruction to veins, which might lead to the development of thrombophlebitis. This letter reports a malfunction of this device associated with clinical thrombophlebitis occurring in alternate arms

Nadolol in essential hypertension: effect on ambulatory blood pressure, renal haemodynamics and cardiac function.

Abstract: Chronic administration of nadolol has been reported to reduce blood pressure either without or with a concomitant fall of renal blood flow. We therefore studied the effects of nadolol 80 mg once daily on ambulatory blood pressure, renal and systemic haemodynamics in patients with mild to moderate essential hypertension. Ten patients took part in this randomized, double-blind, placebo-controlled, crossover study, each phase of which lasted 4 weeks. Nadolol significantly reduced ambulatory blood pressure and heart rate, but had no effect on blood pressure variability. Cardiac output was significantly reduced by nadolol and total peripheral resistance increased but without reaching statistical significance. Despite the fall in blood pressure and cardiac output, renal blood flow and glomerular filtration rate remained unchanged. The fraction of cardiac output reaching the kidneys rose significantly and renal vascular resistance was significantly reduced. Body weight, urinary sodium excretion and urine flow rate remained unchanged. We conclude that nadolol 80 mg once daily lowers ambulatory blood pressure in patients with mild to moderate hypertension without impairment of renal blood flow, indicating a redistribution of cardiac output to the kidneys. The mechanism of the renal vasodilator effect of nadolol remains to be determined.

The influence of monotherapy with oxprenolol and nitrendipine on ambulatory blood pressure in hypertensives.

Abstract: We investigated whether beta-blockers or calcium-antagonists might be preferred in baseline antihypertensive therapy. In middle-aged male patients with essential BP readings did not differ between patients on Oxpranolol or on Nitrendipine (average BP: 123 12/81 14 vs. 129 17/80 10 mmHg), when clinical casual BP was within the normotensive range. Average BP at work was lower than clinical casual BP taken at the same day (125 14/80 12 vs. 133 12/87 13 mmHg). A linear dependency between SBP at work and level of self reported physical activity (F(3,413) = 7.6; p 0.001) and arousal was found (F(3, 374) = 5.2; p 0.02). Patients on Oxprenolol consistently had lower SBP at a particular level of physical activity and at lower levels of arousal than patients on Nitrendipine. We conclude that both regimen were equally effective as baseline antihypertensive monotherapy.

Ambulatory versus casual blood pressure in the diagnosis of hypertensive patients.

Abstract: Recent advances in medical technology have enabled the development of fully automatic portable noninvasive blood pressure recorders which can reliably monitor changes of blood pressure over periods of 24 hour or more. The commercial availability of such recorders raises the question of their relevance to the practical management of hypertensive patients.The rationale for the use of Ambulatory Blood Pressure monitoring (ABPM) is the enormous variability of blood pressure. This has been amply demonstrated with both invasive and noninvasive ABPM, and is not a matter of dispute (1,2). Since the adverse effects of blood pressure on the circulation are thought to depend either on the average level of pressure over time or possibly also on the peak levels of pressure, there is a sound theoretical reason for thinking that multiple measurementspage missing 258-258

Rumpel-Leede Sign Associated With a Noninvasive Ambulatory Blood Pressure Monitor

Abstract: To the Editor.— In a letter reporting a petechial rash as a complication of ambulatory blood pressure monitoring, Dr White 1 noted that the 65-year-old patient had diabetes but no apparent peripheral vascular disease or bleeding or clotting disorder. He felt that the patient may have had increased capillary fragility as a result of age and possibly also due to the diabetes, which could increase the risk of capillary hemorrhages from the blood pressure cuff. In a study of capillary fragility in diabetes, 2 we found that 68% of 72 diabetic patients had a positive Rumpel-Leede phenomenon but this occurred in only 35% of age- and sex-matched nondiabetic controls. The presence of abnormal capillary fragility correlated with duration of diabetes and presence of diabetic retinopathy, neuropathy, and nephropathy. The incidence of positive tourniquet test results was 100% after 20 years of diabetes. Since prolonged application of a sphygmomanometer cuff can

Blood Pressure Variability and Hemodynamic Response to Stress in Patients with Paroxysmal Elevation of Blood Pressure

Abstract: Blood pressure variability during 24 hours and hemodynamic response to stress were studied in essential hypertensive patients, displaying paroxysmal hypertension and pheochromocytoma-type symptoms (PH). Hemodynamics at rest, in response to mental arithmetic, bicycle ergometer exercise or the cold together with baroreflex sensitivity were not different between these patients and other essential hypertensives (EH). Average waking systolic blood pressure was lower but variabilities of both systolic and diastolic blood pressure were greater in PH than in EH. During sleep, these differences disappeared. Thus, the greater variability in blood pressure seen only in waking PH patients cannot be estimated from the hemodynamic patterns at rest and is not likely to be related to an excessive response to stress or impaired baroreflex.