Twenty-four hour ambulatory blood pressure monitoring pattern of resistant hypertension

OBJECTIVE: Ambulatory blood pressure monitoring (ABPM) is a tool to diagnose resistant hypertension (RH). The objective of this study is to describe the pattern of 24-h ABPM in patients using at least three anti hypertensive drugs without blood pressure (BP) control, classifying them as true RH or white-coat RH. METHODS: A cross-sectional study involving resistant hypertensives that were submitted to clinical, laboratory and 2D-echocardiographic evaluation. Ambulatory blood pressure monitoring was used to diagnose true or white-coat RH. The chi-squared test was used for comparisons among categorical variables and Kruskall-Wallis test for continuous ones. RESULTS: Of the 286 patients, 161 (56.3%) were classified as true RH and 125 (43.7%) as white-coat RH. Sex, age, office BP and the cardiovascular risk factors for both groups were similar. True resistant hypertensives had more target organ damage then white-coat resistant hypertensives; nephropathy (40.1 versus 23.9%, P=0.007) and left ventricular hypertrophy (83.3 versus 76.3%, P=0.05). In ABPM, the true RH group had a smaller nocturnal systolic and diastolic BP reduction (6.4+/-8.8 versus 9.8+/-7.5 mmHg, P=0.0004; 10.4+/-9.6 versus 13.6+/-9.2 mmHg, P=0.001) and 68.7% of them were non-dippers versus 49.6% in the white-coat RH group (P=0.001). True RH also had a larger 24 h pulse pressure (65.8+/-13.7 versus 51.5+/-10.0 mmHg, P < 0.0001). CONCLUSIONS: Ambulatory blood pressure monitoring is a fundamental tool to diagnose RH, and to check treatment efficacy. The presence of a greater pulse pressure and a lower nocturnal blood pressure reduction in true RH patients may be responsible for this increased cardiovascular risk profile.     

Twenty-four hour ambulatory blood pressure in the population

Objectives. To establish a population-based 24-h ambulatory blood pressure (ABP) reference material with day/night mean BP calculated by standardized and true bedtimes.
Design. A cross-sectional study of 200 randomly selected subjects (20 men and 20 women in each 10-year age interval 20–70 years) in Linköping, Sweden.
Setting. University Hospital of Linköping, Sweden.
Results. Participation rate was 67%. Mean supine clinic BP (CBP) and 24-h-ABP values for the whole material were 123±13/79±8 mmHg and 120± 10/73±7 mmHg, respectively. White coat BP phenomenon increased with age (systolic CBP/ABP ratio versus age, r =0.35, P <0.0001). Seventeen participants had a night/day mean arterial blood pressure ratio >0.9 (non-dipper) when calculated from their own time-notations. If standardized day (06.00–23.00) and night (23.00–06.00) limits were used, 24 subjects were non-dippers. Of these, only eight were 'true'. 'True' non-dippers had a similar day-time mean arterial ABP as 'true' dippers (92.4±11 mmHg versus 91.9±13 mmHg, P = 0.92) while night-time BP was higher (89.9± 13 mmHg versus 74.1±7 mmHg, P <0.0001).
Conclusion. Population-based ABP reference values have been defined. We found 9% non-dippers and that standardized day/night-time limits may lead to misclassification. This could be due to gender- and age-differences in sleeping habits, which was also shown in this study. The frequency of white coat BP phenomenon increases with age.     

Twenty-four hour ambulatory blood pressure in therapeutically resistant hypertensive patients

Circadian blood pressure and heart rate rhythms were determined in essential and renal hypertensive patients who failed to respond to drug therapy. Indirect ambulatory blood pressure and heart rate recordings were measured in 31 subjects for 24 hours. Essential hypertensive patients exhibit 'white coat hypertension', are normotensive outside the clinic and have a higher awake than sleep blood pressure. Blood pressure and heart rate of renal hypertensive patients do not increase in the presence of a physician and there is no difference between awake and sleep values. In contrast to patients with essential hypertension, the circadian fluctuations of blood pressure were depressed in renal hypertensive patients. We conclude that essential hypertensive patients who appear clinically uncontrolled are in fact well controlled in their domestic environment, whereas renal hypertensive patients are consistently uncontrolled. Ambulatory monitoring may help in differentiating the various types of patient and in the evaluation of antihypertensive therapy.     

Twenty-four hour automatic monitoring of blood pressure and heart rate at work and at home

It proved feasible and practical to automatically record indirect blood pressure at 15 minute intervals with a 4 pound portable device throughout a 24 hour period in five subjects at work and at home, awake and asleep. Of the subjects, two were apparently healthy and three had coronary artery disease, mild essential hypertension, and emphysema, respectively. Most striking was the hypotension accompanying sleep, which was greatest in the hypertensive subject and least in the subject with emphysema. Activity, while mainly walking, resulted in only modest changes in pressure. There was a tendency toward slight pressure rises associated with eating and modest tachycardia while driving a car. There was a tendency in all five subjects to exhibit somewhat higher pressures during the first 4 to 5 hours after awakening.     

Twenty-four hour ambulatory blood pressure for the management of antihypertensive treatment: a randomized controlled trial

The aim of this study was to assess whether the use of 24-h blood pressure (BP) measurement in the management of antihypertensive therapy improves BP in patients with sustained hypertension. Patients with sustained hypertension (office BP > or =140/90 mm Hg, and 24-h systolic BP > or =130/80 mm Hg) were randomly assigned to a strategy using 24-h BP to manage antihypertensive treatment (target <130/80 mm Hg) or to a standard strategy using office BP (target <140/90 mm Hg). The primary end point was change in 24-h systolic BP at 1 year of follow-up. We included 136 patients in the primary analysis. After 1 year of follow-up, the change in 24-h systolic BP was significantly greater in the ambulatory BP group compared with the office BP group (mean difference (95% confidence interval) -3.6 (-7.0, -0.3), P=0.03). Intention-to-treat analysis revealed essentially unchanged results. The mean number of antihypertensive drugs per participant at 1 year of follow-up was 1.76+/-1.1 and 1.95+/-0.9 in the ambulatory and office BP group, respectively (P=0.049). The benefit of ambulatory BP monitoring was mainly seen in patients with previously known hypertension (mean difference -7.2 (-11.6, -2.8), P=0.002), but not in those with newly detected hypertension (mean difference 0.2 (-4.9, 5.4), P=0.93). In conclusion, using 24-h BP for the management of antihypertensive therapy in patients with sustained hypertension leads to a greater BP reduction compared with a standard treatment strategy using office BP, although fewer antihypertensive drugs were used in the ambulatory BP group.     

Twenty-four hour systolic blood pressure predicts long-term mortality following acute stroke.

OBJECTIVE: To assess the effects of acute blood pressure (BP) on long-term mortality following stroke. DESIGN: Prospective observational study. SETTING: Leicester Teaching Hospitals. PATIENTS: Two hundred and nineteen consecutive patients were recruited within 24 h of acute stroke. INTERVENTIONS: Clinic and 24 h BP levels were measured. Other risk factors previously associated with stroke mortality were recorded within 24 h of admission. No specific pharmacological interventions;were made. MAIN OUTCOME MEASURES: The primary outcome measure was death over a median follow-up period of over 2.5 years. The hazards ratios associated with predefined variables were assessed using Cox's proportional hazards modelling, and Kaplan-Meier survival plots were also calculated. RESULTS: On multiple variable analysis, 24 h systolic BP (> or = 160 mmHg) was associated with an increased hazards ratio of 2.41 (95% confidence intervals: 1.24-4.67) for death, compared to the reference group (140-159 mmHg). The addition of 24 h heart rate was significant, with increasing heart rate (> 83 bpm) associated with an increased mortality (P = 0.006), although this effect was not constant over time. Increasing age (> 80 years) at presentation was also associated with an increased hazards ratio of 2.53 (1.14-5.62) compared to age < or = 66 years. CONCLUSIONS: This study provides evidence that elevated 24 h systolic BP in the acute stroke period is associated with increased long-term mortality. This may have implications in the therapeutic management of BP following stroke, though further research is required to determine the timing, nature and effect of such an intervention.     

Twenty-four hour ambulatory blood pressure in a population of elderly men

OBJECTIVES: The principal aim was to study ambulatory and office blood pressure in a population of elderly men. We also wanted to describe the prevalence of hypertension and investigate the blood pressure control in treated elderly hypertensives. DESIGN: A cross-sectional study of a population of elderly men, conducted between 1991 and 1995. SUBJECTS: Seventy-year-old men (n = 1060), participants of a cohort study that began in 1970. MAIN OUTCOME MEASURES: Office and 24 h ambulatory blood pressure. RESULTS: Average 24 h blood pressure in the population was 133 +/- 16/75 +/- 8 mmHg, and daytime blood pressure 140 +/- 16/80 +/- 9 mmHg. Corresponding values in untreated subjects (n = 685) were 131 +/- 16/74 +/- 7 and 139 +/- 16/79 +/- 8, respectively. An office recording of 140/90 mmHg corresponded to an ambulatory pressure of 130/78 (24 h) and 137/83 mmHg (daytime) in untreated subjects. In subjects identified as normotensives according to office blood pressure (n = 270), the 95th percentiles of average 24 h and daytime blood pressures were 142/80 and 153/85 mmHg, respectively. The prevalence of hypertension, defined as office blood pressure greater than or = 140/90 mmHg, was 66%. Despite treatment, treated hypertensives (n = 285) showed higher office (157/89 vs. 127/76 mmHg) and 24 h ambulatory (138/78 vs. 122/71 mmHg) pressures than normotensives (P < 0.05). Fourteen per cent of the treated hypertensives had an office blood pressure < 140/90 mmHg. CONCLUSIONS: Our results provide a basis for 24 h ambulatory blood pressure reference values in elderly men. The study confirms previous findings of a high prevalence of hypertension at older age. It also indicates that blood pressure is inadequately controlled in elderly treated hypertensives.     

Twenty-four hour blood pressure after exercise in patients with coronary artery disease

The objective was to assess the influence of a cardiac rehabilitation training session on blood pressure measured shortly after exercise and during the subsequent 24 h in patients with stable coronary artery disease. Blood pressure was measured conventionally and by use of 24-h ambulatory blood pressure monitoring in seven men, mean age 53+/-8 (s.d.) years, after participation in a cardiac rehabilitation session and, in randomised order, on a non-exercise control day. Conventional blood pressure averaged 112+/-7/77+/-5 mm Hg in the sitting position on the control day and was not different at the same time of the day shortly after the patients had participated in a cardiac rehabilitation training session. Standing systolic pressure was lower by 7.8+/-4.3 mm Hg (P < 0.005) after exercise compared to the control situation, but this was not associated with orthostatic symptoms. However, ambulatory monitoring showed no differences in blood pressure with the non-exercise day during the subsequent 24-h period. In conclusion, standing but not sitting blood pressure was slightly lower shortly after a cardiac rehabilitation session, but the postexercise orthostatic hypotension was not sustained during normal activities of daily living.     

Twenty-four hour ambulatory blood pressure in the Hypertension Optimal Treatment (HOT) study

BACKGROUND AND AIMS: The Hypertension Optimal Treatment (HOT) study showed that when antihypertensive treatment reduces diastolic blood pressure well below 90 mmHg, there can be a further reduction of cardiovascular events, particularly myocardial infarction, with no evidence of a J-shaped curve at lower pressures. Office measurement, however, gives no information about blood pressure outside the office. This paper describes a HOT substudy in which patients underwent both office measurement and 24 h ambulatory blood pressure monitoring. METHODS: The mean age of the substudy population was 62 +/- 7 years. Substudy patients were treated for a median period of 2 years. All received the dihydropyridine calcium antagonist felodipine, while some also received an ACE-inhibitor, a beta-blocker or a diuretic. Average 24 h, day and night ambulatory blood pressure values were computed at baseline (n = 277) and during treatment (n = 347): 112 patients had been randomized to a target office diastolic blood pressure 相似文献   

Twenty-four hour blood pressure rhythm in patients with hypertension and ischemic heart disease

AIM: To elucidate relationship between presence of ischemic heart disease and 24-hour blood pressure (BP) profile. MATERIAL AND METHODS: Twenty four hour BP index characterizing degree of nocturnal blood pressure fall was measured in patients with hypertension without coronary heart disease (n=65, group 1), with hypertension and effort angina (n=35, group 2), with effort angina and normal BP (n=25, group 3). RESULTS: Values of 24-hour BP systolic and diastolic index were in group 1 12.7+/-1.3 and 16.0+/-1.1%, respectively, in group 2 5.8+/-2.4 and 7.4+/-3.6%, respectively, in group 3, 6.0+/-2.2 and 6.0+/-3.0%, respectively (p<0.05, groups 2 and 3 vs group 1). CONCLUSION: Decreased nocturnal BP lowering could be a compensatory reaction aimed at maintenance of adequate blood flow through stenosed coronary vessels.     

Conventional and ambulatory blood pressure measurement in older patients with isolated systolic hypertension:second progress report on the ambulatory blood pressure monitoring project in the Syst-Eur trial

OBJECTIVES: To compare clinic and ambulatory blood pressure measurement and the reproducibility of these measurements in older patients with isolated systolic hypertension.PATIENTS: A total of 477 patients aged >/= 60 years with isolated systolic hypertension on clinic measurement were monitored during the placebo run-in phase of the Syst-Eur trial. METHODS: The time-weighted 24 h blood pressure, clock time day and night blood pressure, the cumulative sum-derived crest and trough blood pressure and the high and low blood pressure levels of the square-wave model were computed. The daily alteration between the high and low blood pressure spans was quantified using the clock time day-night difference, the cumulative sum-derived circadian alteration magnitude, the Fourier amplitude and the difference between the high and low blood pressure levels of the square-wave model. RESULTS: The daytime ambulatory systolic blood pressure was, on average, 21 mmHg lower than the clinic blood pressure, whereasthe diastolic blood pressure was, on average, similar with both techniques of measurement. In the 132 patients who underwent repeat measurements, clinic blood pressure levels and the parameters describing the difference betgween the daily high and low blood pressure spans were equally reproducible. However, both were less reproducible than the ambulatory blood pressure levels. The repeatability coefficients, expressed as percentages of near maximum variation, were 50 and 51% for the clinic systolic and diastolic blood pressures, 30 and 33% for the mean 24 h systolic and diastolic blood pressures and between 44 and 54% for the parameters describing the daily alteration between the high and low blood pressure spans. CONCLUSION: In older patients with isolated systolic hypertension, clinic and ambulatory systolic blood pressure may differ greatly; the prognostic significance of this difference remains to be elucidated. Furthermore, the level of blood pressure in these patients is more reproducible by ambulatory measurement than it is by clinic measurement.     

Twenty-four hour automatic recording of blood pressure and cardiac rhythm in patients with borderline hypertension

The aim of the study was to evaluate the usefulness of 24-hour automatic recording of blood pressure and cardiac rhythm in patients with borderline hypertension. The study was performed in 50 patients aged 38.8 +/- 13.1 using the Del Mar Avionics device. Mean time of recordings was 21.3 hours, and the mean number of blood pressure measurements per one patient was 52.4. Great fluctuations of systolic blood pressure (from 92.1 +/- 12.6 to 191 +/- 37.0 mm Hg) and diastolic one (from 57.3 +/- 11.4 to 118.9 +/- 13.8 mm Hg) were observed. Mean systolic blood pressure (125.6 +/- 10.6 mm Hg) was significantly lower than the mean value of last three ambulatory measurements (141.9 +/- 9.8; p less than 0.001). Also mean diastolic pressure was lower than that obtained in the out patient clinic (84.7 +/- 9.7 vs 91.9 +/- 3.2 mm Hg; p less than 0.001). Mean heart rate during the day was 86.2 +/- 10.7 and at night 69.7 +/- 10.5 beats per minute. Ventricular and/or supraventricular cardiac arrhythmias were observed in 14 (28%) of examined patients. Results of the study indicate, that 24-hour automatic blood pressure recording is the valuable method, affording possibilities for more precise estimation of blood pressure and its 24-hour fluctuations in patients with borderline hypertension.     

Twenty-four hour ambulatory blood pressure profile of a new,sustained-release preparation of nicardipine

Summary The 24-hour blood pressure (BP) profile of a new sustained-release preparation of nicardipine was assessed in 16 patients with essential hypertension (supine cuff diastolic BP>95 mmHg). Twenty-four hour ambulatory intraarterial BP monitoring (Oxford system) before treatment revealed a mean (SD) daytime BP of 174 (19) mmHg systolic and 105 (8) mmHg diastolic, and a mean nighttime BP of 142 (26) mmHg systolic and 83 (12) mmHg diastolic. Sustained release nicardipine (60 mg) was administered twice daily for 4–6 weeks and the ambulatory BP monitoring repeated. No significant change in heart rate occurred throughout the 24-hour period. However, there was a significant reduction (p<0.0001) in the mean daytime BP of 21 (13) mmHg systolic and 12 (9) mmHg diastolic and of mean nighttime BP of 21 (15) mmHg systolic and 13 (11) mmHg diastolic. A similar reduction in hourly mean BP occurred throughout the whole 24-hour period, including the steep early morning rise in BP. Although vasodilatory-type side effects occurred, they were generally mild to moderate and transient. This preparation produces a significant reduction in BP throughout the 24-hour period without reflex tachycardia.     

Twenty-four hour, ambulatory blood pressure responses following acute exercise: impact of exercise intensity

OBJECTIVES: Mild to moderate acute, endurance exercise has generally been shown to reduce blood pressure (BP) in hypertensive (HT) individuals. Whether a slightly more strenuous bout of exercise can elicit a greater and more prolonged BP reduction is unknown. Therefore, the purpose of this study was to examine the effects of two, 30-min exercise bouts, conducted at 50% and 75% of maximal oxygen uptake (VO2max), on the quantity and quality of BP reduction over a 24-h period. METHODS: Sixteen, Stage 1 and 2 non-medicated, HT (8 men/8 women) subjects were matched with normotensive (NT) men and women (n = 16). All subjects were evaluated for VO2max with a symptom-limited treadmill test and then completed a 30-min exercise bout at 50% and 75% of VO2max as well as a control (no exercise) session in random fashion on separate days. Twenty-four hour ambulatory BPs were measured after both the exercise and control settings. Data was assessed at 1, 3, 6, 12, and 24 h post-exercise and control session. RESULTS: A repeated-measures ANOVA showed non-significant differences between HT men and women and that both exercise intensities, relative to the control session, significantly (P<0.05) reduced systolic (S) and diastolic (D) BPs. NT subjects showed non-significant reductions following both intensities. The reductions in the HT men and women averaged 4 and 9 mm Hg (SBP)/5 and 7 mm Hg (DBP) for 50% and 75%, respectively. On average, the HT subjects (men and women combined) maintained significant SBP reductions for 13 h after the 75% bout compared to 4 h after the 50% intensity. Likewise, DBP was reduced for an average of 11 h following the 75% bout compared to 4 h after the 50% intensity. CONCLUSIONS: These results suggest that an exercise bout conducted between 50-75% VO2max significantly decreases SBP and DBP in HT subjects and that a greater and longer-lasting absolute reduction is evident following a 75% of maximum bout of exercise.