BP as a determinant of cardiac left ventricular muscle mass

The relationship between casual BPs and measures of cardiac hypertrophy, derived from the ECG, has been described as fairly weak. In this study, ECG and echocardiographic measurements of left ventricular muscle mass were related to various measures of BP obtained during circadian ambulatory BP monitoring in 12 patients with hypertension. Casual BP did not correlate substantially with ECG voltages or with echocardiographic measurements of muscle mass. The correlations between whole-day, daytime, or nighttime BP averages and ECG voltages were not significant. However, echocardiographic left ventricular muscle mass correlated significantly with the averages of whole-day, daytime, and nighttime, and two-hour morning systolic pressures. The correlations between diastolic BP and left ventricular muscle mass were not significant. Therefore, serial BP measurements are required to evaluate the relationship between BP and left ventricular muscle mass as measured by the M-mode echocardiogram. The ECG is of little value in this relationship.     

Effect of ambulatory blood pressure monitoring on the diagnosis and cost of treatment for mild hypertension

Detection of mild hypertension by a small number of casual blood pressures may be inaccurate for the determination of average blood pressure. Nonetheless, casual pressures remain the basis for the diagnosis and treatment of hypertensive patients. We compared casual and noninvasive ambulatory blood pressure monitoring in a consecutive series of 60 subjects evaluated for possible mild hypertension on the basis of casual pressures. Ambulatory blood pressure monitoring was performed on days of usual activity. Correlations between casual systolic and average ambulatory systolic pressures or casual diastolic and average ambulatory diastolic pressures were not significant. Nearly half of the subjects had average ambulatory systolic pressures less than 130 mm Hg. Sixty percent had average ambulatory diastolic pressures less than 85 mm Hg. Nearly 40% had both systolic and diastolic pressures less than those limits. A preliminary analysis of the effects of these results on the short-term cost of antihypertensive treatment was made, assuming that treatment could be withheld from those with average ambulatory pressures less than 130/85 mm Hg. This approach suggests that ambulatory blood pressure monitoring need not increase overall cost, if the results of this evaluation are used in the decision to treat.     

Primary arterial hypertension. 24-hour recording or casual blood pressure measurement?]

In 134 patients with essential hypertension 24-hour blood pressure ambulatory monitoring (ABPM) as well as traditional blood pressure measurements (casual BP) were performed. Maximal and mean whole-day systolic and diastolic blood pressure values in ABPM were compared with casual BP (using test t). The casual BP was also compared with mean systolic and diastolic blood pressure values calculated separately in three eight-hours periods of day. Maximal BP values in ABPM were significantly higher and mean significantly lower than casual BP values. Blood pressure registered during work hours was closest to casual BP values. Blood pressure in the evening was similar to whole-day blood pressure mean. The results indicate, that automatic blood pressure monitoring performed in this period of day has the greatest diagnostic value because it could be free from "white coat hypertension" syndrome.     

Circadian blood pressure patterns in ambulatory hypertensive patients: Effects of age

Circadian blood pressure monitoring was performed in 50 untreated ambulatory hypertensive patients to study the effects of age on the pattern and variability of Mood pressure and heart rate. Casual blood pressure, measured in the morning, was greater than the average of the blood pressures measured at 7.5 minute intervals for 24 hours (148 ± 2/95 ± 2 and 137 ± 2/88 ± 2 mm Hg, p < 0.001). The correlation between casual systolic pressure and the 24 hour average was stronger (p < 0.05) in younger (less than 55 years of age) patients (r = 0.69, n = 24, p < 0.001) than in older patients (r = 0.42, n = 26, p < 0.1). Similarly, diastolic pressures correlated more strongly (p < 0.05) in younger patients (r = 0.71, p < 0.001) than in older patients (r = 0.43, p < 0.05). Variability of systolic pressure, defined as the standard deviation of all readings obtained during 24 hours, was greater than that of diastolic pressure (16.7 and 13.1 mm Hg, respectively, p < 0.001). Moreover, the variability of systolic pressure was greater in older than in younger patients (18.1 and 15.2 mm Hg, respectively, p < 0.01). The variability of diastolic pressure was slightly but not significantly greater in older patients (13.7 and 12.5 mm Hg, not significant). The Circadian pattern of blood pressure, expressed as averages of readings obtained during consecutive 2 hour intervals, was similar in the two age groups. However, the level of systolic pressure was consistently higher (p < 0.01) and that of both diastolic pressure and heart rate consistently tower (p < 0.01) in older patients. Thus, ambulatory circadian blood pressure monitoring reveals significant changes in blood pressure levels and its variability with age; the casual blood pressure does not accurately reflect these changes. Longer periods of Mood pressure monitoring are required for accurate assessment of the characteristics of hypertension in the aged.     

An evaluation of self-measured blood pressure in a study with a calcium-channel antagonist versus a beta-blocker.

In recent years self-measurement of blood pressure at home has gained increasing importance but there have been only a few studies comparing casual, ambulatory, and self-measured blood pressure determinations during a single clinical trial. We therefore compared treatment-induced blood pressure-reductions in a double-blind, placebo-controlled, parallel study design with a single morning dose of either 10 mg bisoprolol (n = 26) or 20 mg nitrendipine (n = 27) with casual blood pressure readings in the morning before the dose, ambulatory 24-h monitoring, and self-recorded measurements in the morning before the dose and in the evening. Mean reductions for systolic and diastolic blood pressure after 4 weeks of therapy were significantly greater for bisoprolol than for nitrendipine. The treatment-induced blood pressure reductions were most pronounced as assessed by casual readings but showed good agreement between casual, ambulatory, and self-measured blood pressure for group comparisons. In some patients, however, marked individual differences between the three methods were observed. Correlation coefficients between ambulatory and self-measured blood pressure were 0.4 for systolic blood pressure (P less than .05) and 0.6 for diastolic blood pressure (P less than .0005). Under the conditions of this parallel study design and the usual statistical risks, a difference of 5 mm Hg in diastolic blood pressure can be detected in 118 patients at the clinic, in 70 patients if ambulatory blood pressure is used, or in 56 patients if self-measured blood pressure is used. In conclusion, bisoprolol was more effective over 24 h than nitrendipine at the doses studied.(ABSTRACT TRUNCATED AT 250 WORDS)     

比索洛尔、拉西地平和赖诺普利对高血压病患者24小时血压的影响

目的比较比索洛尔、拉西地平和赖诺普利对２９例高血压病患者的降压疗效。方法采用随机、单盲和交叉的方法，运用２４小时动态血压监测。结果三药均能显著降低血压，彼此间降低偶测血压的幅度无显著差异。比索洛尔和拉西地平降低２４小时平均和白天平均血压的幅度大于赖诺普利。三药均能有效控制清晨血压高峰期的血压，它们的降压谷／峰比值都超过６５％。结论比索洛尔、拉西地平和赖诺普利均可每日服用１次，前二药控制２４小时血压及清晨醒后的高峰期血压较后者为佳。     

24小时动态观察纳多洛尔的降压疗效

作者通过24小时动态血压监测,观察纳多洛尔(萘羟心安)对高血压病患者的降压效果及两种不同剂量对血压和心率的影响。结果表明:纳多洛尔的降压疗效确切,增加剂量效果更加明显。并指出动态血压计具有重复性好,病人易接受,观察药物疗效更准确、更科学等优点。     

Assessing duration of antihypertensive effects with whole-day blood pressure monitoring

The whole-day blood pressure response to once-daily and twice-daily administration of a combination of captopril and hydrochlorothiazide was measured in a study of elderly patients (aged 59 to 78 years) with mild to moderate hypertension. Whole-day automated ambulatory blood pressure profiles were obtained at baseline, after 8 weeks of therapy with a combination of 25 mg of captopril and 15 mg of hydrochlorothiazide twice daily, and again after 8 weeks of once-daily therapy with 50 mg of captopril and 25 mg of hydrochlorothiazide. Average systolic and diastolic whole-day blood pressures significantly decreased from baseline during both twice-daily treatment (mean +/- SEM change, 18 [+/- 3]/10 [+/- 2] mm Hg) and once-daily treatment (11 [+/- 2]/9 [+/- 1] mm Hg). While the decrease in systolic blood pressure during once-daily therapy was less than that during twice-daily therapy for the group as a whole, 16 of 19 patients achieved normal systolic (less than 140 mm Hg) and diastolic (less than 90 mm Hg) blood pressures throughout the day during the once-daily regimen. During once-daily therapy, the blood pressure reductions were sustained throughout the 24-hour period, and were not attenuated during the final 2 to 4 hours before the next dose. A subgroup of 5 patients were identified who appeared unresponsive to both twice-daily and once-daily antihypertensive treatment. Despite hypertensive office-measured blood pressures at entry to the study, 4 of these 5 patients actually had normotensive whole-day blood pressure averages at baseline (mean, 131 [+/- 7]/81 [+/- 4] mm Hg). Thus, whole-day ambulatory blood pressure monitoring is a valuable tool for testing treatment responses. It demonstrated that once-daily treatment with low doses of captopril and hydrochlorothiazide was as effective as twice-daily administration in decreasing diastolic pressures throughout the day, but was slightly less effective in decreasing systolic pressures. Additionally, the monitoring identified apparently normotensive patients in whom treatment may not be indicated.     

Tracking of 24-hour and casual blood pressure: a 1-year follow-up study in adolescents

OBJECTIVE: Tracking of blood pressure begins in childhood but the relationship between casual blood pressure in childhood and adult levels is not strong enough to predict adult hypertension. The variability of blood pressure in children might suggest that 24 recordings would have less consistency than casual readings when repeated even a relatively short time later. This study compares the short-term tracking ability of casual versus 24-h blood pressure. DESIGN: An ambulatory blood pressure device was placed on 50 teenagers. Readings were taken at rest and the device was then worn for approximately 24 h, which included the schoolday. The protocol was repeated 1 year later. RESULTS: The correlation coefficient for systolic readings taken 1 year later were: 0.4 for casual, 0.6 for school, 0.6 for home, 0.5 for night-time and 0.8 for 24-h mean systolic blood pressures. When divided into upper and lower tertiles of systolic blood pressure the relationship between tertile ranking 1 year later was stronger for 24-h blood pressure than the casual readings. Casual diastolic pressure was more consistent than the 24-h mean diastolic measurement. CONCLUSIONS: In adolescents, in whom tracking of casual blood pressure has been shown to be poor, 24-h mean systolic blood pressure tracks better than any other time period and significantly better than the casual systolic readings. This study needs to be extended and the ability of 24-h blood pressure to track from childhood to adult life investigated.     

Ambulatory blood pressure monitoring: technique and application in the study of cardiac dysfunction and congestive heart failure

Ambulatory blood pressure monitoring has become a widely used method of blood pressure and heart rate evaluation in the free-living subject. Recently, ambulatory monitoring has become covered by Medicare for the evaluation of "white-coat" hypertension. Although the technique provides only intermittent readings throughout the 24-hour period, average blood pressures obtained in this way correlate well with a variety of hypertensive disease processes and are also a better prognostic marker for future cardiovascular events than office blood pressure. Ambulatory blood pressure averages also correlate well with indices of diastolic dysfunction. In patients with congestive cardiac failure and systolic dysfunction, ambulatory monitoring suggests an impaired circadian blood pressure profile with high nocturnal blood pressure. Further research is needed on the relationship between ambulatory blood pressure and cardiac dysfunction, as well as the impact of observed circadian blood pressure changes on outcome. (c)2001 CHF, Inc.     

Ambulatory blood pressure monitoring in diabetic males: A method for detecting blood pressure elevations undisclosed by conventional methods

Twenty-one diabetic males, ages 20 to 61 years (mean 48.4±10.5) and 14 healthy males, 22 to 59 years (mean 42.5±10.4) consented to participate in a study during which 24-h recordings of systolic and diastolic blood pressures, heart rates, and rhythm were obtained. The diabetic subjects were considered nor-motensive except for two patients, who had been observed to have rare insignificant elevations in blood pressure and were untreated. Diabetic subjects had a higher mean maximal systolic blood pressure (160.7±49.8 mmHg) than the normal controls (132.4±12.1 mmHg) (p<0.05). They also had a higher frequency (15.1%) of systolic blood pressure readings ≥ 150 mmHg compared to normal men (0.2%) (p<0.01). The frequency of diastolic blood pressure readings ≥90 mmHg was 22.1% in the former and 9.2% in the latter group (p<0.01). Of 21 diabetic males, 14 (66.7%) had systolic pressures ≥ 150 mmHg, diastolic pressures ≥100 mmHg, or both. In the normal men, 3 (21.4%) of the 14 had such pressures. Twenty-four hour monitoring of ambulatory blood pressures revealed elevations not detected by routine casual readings in patients with diabetes.     

Noninvasive ambulatory blood pressure monitoring in patients with recently detected systemic hypertension

Noninvasive ambulatory blood pressure monitoring and Doppler echocardiography were used in a recent study evaluating persons aged 18 to 50 years who were initially found to have mild hypertension by casual blood pressure determination. Ambulatory blood pressure recordings were performed on a day of usual activity in 54 subjects; a subgroup of 24 patients had evaluation of left ventricular dimensions and diastolic filling patterns by Doppler echocardiography. Average ambulatory systolic pressures of 42% of subjects were greater than or equal to 130 mm Hg. Only 35% had average diastolic pressures greater than or equal to 85 mm Hg, and 57% had either systolic or diastolic pressures greater than or equal to 130/85 mm Hg. Correlation between casual and ambulatory pressures was not significant. No subject had left ventricular hypertrophy determined by echocardiography. Abnormal left ventricular diastolic filling was noted in 38% of those patients with average ambulatory pressures greater than or equal to 130/85 mm Hg, but in no patients with average pressures less than 130/85 mm Hg (p less than 0.05). These results suggest that ambulatory blood pressure monitoring may be a specific method for detecting those patients with mild hypertension who may have early and potentially reversible cardiac abnormalities.     

Ambulatory blood pressure monitoring of chronically dialyzed pediatric patients.

BACKGROUND: Background Ambulatory blood pressure monitoring (ABPM) has been shown to be more representative of blood pressure levels in adult patients than are casual measurements of blood pressure. OBJECTIVE: To evaluate, by means of ABPM, the behavior of blood pressure in children with chronic renal failure submitted to continuous ambulatory peritoneal dialysis and compare the results with casual blood pressure monitoring measurements. DESIGN: Evaluation of blood pressures in chronically dialyzed pediatric patients by ABPM. METHODS: Ten pediatric patients, treated by continuous ambulatory peritoneal dialysis were evaluated by ABPM using the oscillometric SpaceLabs 90207 monitor, every 10 min during the day and every 15 min during the night, for 24h. RESULTS: Six of 10 patients were found normotensive by office measurement of blood pressure; four of 10 patients were found hypertensive by casual measurements of blood pressure. With ABPM we obtained a mean success rate of 92.5%, confirmed hypertension in all the patients classified hypertensive in terms of office readings and reclassified six of six patients from normotensive to hypertensive. The mean systolic and diastolic physiologic falls in blood pressure at night were respectively by 10 and 15%. At the time of the ABPM study end-organ damage was present in two patients judged to be normotensive in terms of office blood pressures. CONCLUSION: Casual recordings of blood pressure are not representative of average blood pressure in dialyzed pediatric patients. ABPM seems to be a useful diagnostic aid for assessing treatment of hypertension in children with end-stage renal disease.     

Reproducibility of Blood Pressure Values in Normotensive Subjects

The reproducibility of whole-day blood pressure (BP) averages was evaluated in 56 normal volunteers. Blood pressure was monitored using a non-invasive automatic device that measured BP at 7.5 minute intervals for a 24h period. The whole-day systolic BP averages were closely similar on the two study days, 119 10 (S.D) and 117 11 mm Hg. A difference between the two whole-day averages of systolic blood pressure of greater than 10 mm Hg was found in 10 subjects. Values for the diastolic BP averages were 75 7 and 73 8 mm Hg with differences of greater than 5 mm Hg found in 15 subjects. Strong consistency of BP averages during the separate study days was also found for shorter monitoring periods: the 2h period (8 AM to 10 AM), the daytime period (6AM to 10PM) and the nighttime period (10PM to 6AM). Thus, blood pressure values obtained using a non-invasive ambulatory monitoring device are reproducible in the majority of normotensive control subjects.     

Is usual measurement of blood pressure meaningful?

BACKGROUND: Standardized measurement of blood pressure is widely recommended but rarely applied in usual clinical practice. OBJECTIVE: To determine the differences resulting from physicians using standardized and usual (casual) techniques for measurement of blood pressure. METHODS: Blood pressures measured by a research nurse, ambulatory blood pressure monitoring and echocardiographic estimation of left ventricular mass index were used as standards for comparison. RESULTS: Use of casual technique resulted in blood pressure readings higher than those obtained by standardized technique, namely 6.2 (3.1-9.3) systolic and 3.9 (2.4-5.4) diastolic mmHg [means (95% confidence intervals)], and readings that were more variable. Sixty-two patients (42%) were classified normotensive by standardized techniques but hypertensive by physicians casual technique. When standardized technique was used 22 patients (15%) were classified hypertensive but blood pressure readings in normal range were obtained by usual technique. Measurements obtained using standardized technique were less variable and were significantly correlated to left ventricular mass index. CONCLUSION: Using standardized technique is important if one is to classify the blood pressures of patients correctly. Use of usual or casual technique results in higher, more variable readings that are not related to left ventricular mass index. Results of this study strongly support recommendations that standardized technique should be used for assessing the cardiovascular risk of all adult patients.     

Sex differences in casual and ambulatory blood pressure responses to extreme changes in dietary sodium

OBJECTIVE: To compare the awake ambulatory and seated casual blood pressure responses to extreme changes in dietary sodium during a 4-month period between borderline hypertensive men (n = 24, aged 51+/- 7 years) and women (n = 8, aged 47+/- 8 years). METHODS: Seated casual and awake ambulatory (over an average of 9 h, n = 32 readings) blood pressures were recorded at the end of 1-month trials of low (24 +/- mmol/day for men, 32 +/- 19 mmol/day for women) and high (330 +/- 101 mmol/day for men, 298 +/- 76 for women) intakes of dietary sodium. There was a 1-month interim period between the two trial periods and energy and potassium intake were maintained constant over the entire course of the study. RESULTS: Among men, there was a similar average increase in blood pressure on going from the low- to the high-sodium diets according to the two methods of measurement, but among women there was a significant difference between the methods, such that the change in ambulatory blood pressure was less than the change in casual blood pressure. Women's casual blood pressure increased by 14/7 mmHg more than did their ambulatory blood pressure, whereas men's ambulatory blood pressure increased by 5/2 mmHg more than did their casual blood pressure (sex difference P < 0.009 for systolic and P < 0.037 for diastolic blood pressures). Finally, there was at best only modest concordance between changes in casual and ambulatory blood pressures between diets in individual patients, regardless of their sex, although men were more likely to have similar changes in their casual and ambulatory measurements than were women. CONCLUSION: The determination of the sensitivity of blood pressure to dietary sodium intake may depend upon how blood pressure is measured. There may also be an interaction between sex and blood pressure measurement technique that could affect the determination of salt-sensitivity differences between men and women.     

老年原发性高血压患者血压晨峰与左心室肥厚的关系

目的探讨老年原发性高血压患者血压晨峰与左心室肥厚的关系。方法选择老年原发性高血压患者80例,根据24 h动态血压监测分为2组:血压晨峰值≥55 mm Hg(1 mm Hg=0.133 kPa)为晨峰组,血压晨峰值<55mm Hg为非晨峰组,每组40例,均常规行超声心动图检查,计算左心室重量指数(LVMI)。结果晨峰组24h、昼间、夜间收缩压及血压晨峰均明显高于非晨峰组(P<0.05),晨峰组LVMI明显高于非晨峰组;左心室肥厚比例明显高于非晨峰组(P<0.05)。结论老年原发性高血压患者血压晨峰与左心室肥厚密切相关。     

Time of day to monitor ambulatory blood pressure affects the outcome

OBJECTIVES: The reproducibility of blood pressure variables from ambulatory blood pressure monitoring (AMBP) initiated at the same time of day (SAME: 1700-1900 h) was compared with the reproducibility of blood pressure variables when monitoring was initiated at opposite times of day (OPP: randomized, morning=0700-0900 h and evening=1700-1900 h). It was hypothesized that the reproducibility for SAME (n=18) would be no different than the reproducibility for OPP (n=13). METHODS: The order of AMBP sessions was randomized. The Accutracker II was used to determine average blood pressures, Crest (CrBP), Trough (TrBP), and TrBP : CrBP ratio; Averages were divided into 24-h, daytime (0600-2200 h), and night-time (2200-0600 h) for both systolic and diastolic blood pressures. A paired t-test with an intraclass correlation was used to determine the reproducibility of AMBP for both SAME and OPP. A chi-square was used to compare the distribution of reproducible AMBP variables between SAME and OPP. Significance was at P<0.05. RESULTS: The reproducibility of AMBP variables for SAME and OPP was a significantly different for systolic blood pressure. All of the ambulatory systolic variables measured in the SAME group were reproducible except for the TrBP : CrBP, whereas only the systolic night-time averages of the OPP group were reproducible. Similarly all of the ambulatory diastolic variables measured in the SAME group were reproducible except for TrBP : CrBP, whereas 24-h, night-time averages, and TrBP were reproducible in the OPP group. CONCLUSIONS: Ambulatory blood pressure variables were consistently higher when the monitoring session began in the morning hours.     

Comparison of antihypertensive therapies by noninvasive techniques

We compared the antihypertensive effects of the beta-blocker atenolol and the converting enzyme inhibitor lisinopril during 12 weeks of treatment in patients with mild to moderate essential hypertension. Atenolol (n = 10) significantly decreased conventionally measured blood pressure from 144/103 to 135/93 mm Hg and lisinopril (n = 9) from 150/104 to 130/92 mm Hg. Based on data derived from automated 24-h ambulatory blood pressure monitoring, atenolol decreased the average whole-day systolic pressure by 18 +/- 6 mm Hg (p less than 0.02) and the diastolic pressure by 11 +/- 2 mm Hg (p less than 0.01). Lisinopril produced decreases of 27 +/- 5 mm Hg (p less than 0.01) and 13 +/- 2 mm Hg (p less than 0.001). Examination of the 24-h blood pressure patterns showed that the efficacies of the two drugs were similar. Each appeared to be effective throughout the whole-day monitoring period, although only lisinopril significantly decreased blood pressure during the final four-h period (4 AM to 8 AM) preceding the next day's dose. Neither drug produced significant echocardiographic changes in left ventricular wall thickness or muscle mass during the short-term treatment. Lisinopril and atenolol effectively decrease blood pressure during a 24-h period. Moreover, we found that automated whole-day blood pressure monitoring is a useful tool for comparing the efficacy and duration of action of differing antihypertensive agents.     

Assessment of patients with office hypertension by 24-hour noninvasive ambulatory blood pressure monitoring

To assess the discrepancy between casual (office) and home blood pressure readings in patients performing home blood pressure monitoring, we analyzed office, home, and 24-hour ambulatory blood pressure and heart rates in 19 patients in a prospective four-week study. After the month of study, the average difference between mean office and manual home blood pressures in this office hypertensive group was 30 +/- 17/20 +/- 6 mm Hg. The blood pressures taken in the office were substantially greater than the 24-hour average blood pressures and ambulatory blood pressures during work or while at home (awake). An analysis of the automatic monitor readings while in the doctor's office and at 15-minute intervals after leaving the office showed a progressive reduction in blood pressure and heart rate during the first hour after leaving the office. A mean 24-hour blood pressure of less than 130/80 mm Hg was found in 13 (68%) patients. These data suggest that patients with office hypertension are usually normotensive but may have a persistent and recurrent pressor response in a medical care setting. Ambulatory blood pressure monitoring provides confirmation of not only the office-home disparity, but also suggests that stress other than office visits fails to elicit a hypertensive response.