Ambulatory blood pressure measurements

Ambulatory blood pressure monitoring (ABPM) has emerged as a valuable clinical and research tool in the assessment of pediatric hypertension. Large databases of 24-hour blood pressure monitorings in healthy children are under development for establishing normal reference values analogous to the Task Force data for casual blood pressure. In the clinical setting, pediatric studies using ABPM to evaluate elevated blood pressure have shown that the prevalence of white coat hypertension in children is similar to that reported in adults. Furthermore, 24-hour blood pressure parameters are correlated with hypertensive end-organ injury such as left ventricular hypertrophy. ABPM has allowed detailed assessment of circadian blood pressure patterns that show early subtle abnormalities in some high-risk groups and normal patterns in other groups previously thought to be at high risk. These studies will assist in the practice of evidence-based medicine regarding pediatric hypertension that will improve the long-term care that pediatricians provide to their patients.     

Ambulatory blood pressure monitoring in children

Recently there have been great advances in the use of ambulatory blood pressure monitoring (ABPM) in children. A major boost has been the publication of normative data for blood pressure in children. ABPM has been able to detect significant differences in blood pressure in many disease states including chronic renal failure, polycystic kidney disease and post renal transplantation and has helped in identifying both white coat hypertension and masked hypertension. Current evidence does suggest that sole reliance on clinic blood pressure might not be always appropriate and ABPM has a definite role in pediatric hypertension.     

Is ABPM clinically useful after pediatric solid organ transplantation?

When ambulatory blood pressure monitoring (ABPM) is performed in populations with a high risk for secondary hypertension, such as solid organ transplant recipients, hypertension or abnormalities in circadian blood pressure variability are often discovered even in patients with normal office blood pressure (BP). To discuss whether ABPM should be routinely assessed in pediatric solid organ recipients, the available information on pathological findings, association of ABPM abnormalities with outcome parameters, and treatment options is reviewed. ABPM is a useful tool to optimize therapy in the large proportion of transplant recipients with confirmed hypertension. Whether the use of ABPM on a routine basis should be recommended for pediatric transplantation patients without office hypertension remains to be determined.     

Ambulatory blood pressure monitoring in children and adolescents. Current insights into a new technique

Ambulatory blood pressure monitoring (ABPM) is a new technique recently introduced into paediatrics. Devices with auscultatory blood pressure measurement may be more precise but give more erroneous readings than those with oscillometric measurement. For the interpretation of the results, mean day- and night-time values should be calculated according to patients' diaries and gender- and height-specific percentiles for ABPM measurements should be used to define hypertension. The use of "blood pressure load" as the percentage of single readings above a given upper level is not standardised in children and adolescents. A nocturnal blood pressure decline of less than 10% is defined as "non-dipping", although this is an arbitrary definition whose prognostic value is not evaluated in paediatric patients. Several studies showed that ABPM in children is superior in detecting "white-coat'-hypertension, shows a better reproducibility and is a better prognostic factor for left ventricular mass compared to casual blood pressure measurements. Clinical studies show the value of ABPM in obese children, in children with renal diseases, on dialysis therapy and after renal transplantation as well as in diabetic children or in children after surgical repair of aortic coarctation. Ambulatory blood pressure monitoring in children and adolescents has grown to a valuable method for the daily management of patients with suspected or established hypertension. However, there is still a lot of work before all technical problems are solved and international guidelines can be published which are based on evidence from follow-up studies.     

动态血压监测在儿童肾脏疾病中的临床研究

目的 研究儿童肾脏疾病中的动态血压(ABP)的特点.方法 以33例肾脏疾病患儿为研究对象,采用ABPM6100仪进行动态血压测量(ABPM),受试对象均未服用降压药物.以1997年德国1141名健康儿童的ABP值作为正常参考值.结果 夜间高血压发生率高于日间高血压发生率;夜间收缩/舒张压负荷(29.1±34.5)%/(24.9±34.3)%和指数(0.95±0.11)/(0.90±0.18)明显大于日间收缩/舒张压负荷(12.9±23.6)%/(9.3±19.1)%和指数(0.88±0.09)/(0.77±0.12);肾脏疾病患儿夜间收缩/舒张压下降率为(6.6±6.0)%/(8.8±10.2)%,明显低于正常值(13±6)%/(23±9)%;高达24例(72.7%)患儿夜间收缩压和(或)舒张压下降率为"非杓型",即使在正常血压者中也有72.7%的"非杓性"发生率.在33例患儿中随机血压(CBP)升高者5例,均有ABP升高;CBP正常者28例,但其中6例ABP升高.结论 ABPM能发现儿童肾脏疾病中的夜间高血压和血压昼夜节律的异常,为调整用药时机和更全面有效地控制血压提供依据,弥补了传统血压测量的不足;并能发现隐匿性高血压,可以早期发现高血压前期,从而有利于随访和尽早干预.     

Ambulatory blood pressure monitoring in children and adolescents

With recent technological advances, 24-hour ambulatory blood pressure (BP) monitoring (ABPM) has become a useful tool for the evaluation, diagnosis, and management of hypertensive children. It provides a more accurate representation of an individual's BP rather than intermittent casual or office BP measurements. Hence, ABPM is being used more often to assess the BP of children. In this comprehensive review, we provide the reader with the available literature on ABPM, discuss the advantages and limitations of ABPM, and the interpretation of ABPM data. The role of ABPM in various clinical conditions and hypertension research in children is presented.     

Continuous monitoring of blood pressure in children and adolescents,a review of the literature

Continuous or ambulatory blood pressure monitoring (CBPM or ABPM) is becoming a useful tool in the early detection of hypertension in children and adolescents. With increased obesity in pediatrics, chronic diseases such as hypertension, diabetes, dyslipidemia and metabolic syndrome which was more commonly seen in adults in the early years, can now be seen in this population. This review provides the clinical reports of the use of CBPM for diagnosis and management of hypertension in the pediatric population.     

White coat hypertension in children with elevated casual blood pressure

OBJECTIVE: We reviewed our experience using ambulatory blood pressure monitoring (ABPM) in children referred to a hypertension clinic to determine the frequency of pediatric white coat hypertension (WCH). STUDY DESIGN: WCH was defined by 3 different diagnostic criteria: (1) mean 24-hour blood pressure (BP) less than Task Force-defined 95th percentile, (2) mean 24-hour BP less than 95th percentile from pediatric normative ABPM data, and (3) mean 24-hour BP less than ABPM 95th percentile and BP load (percentage of BP readings during 24-hour period exceeding the 95th percentile) less than 25%. RESULTS: Clinic BP values were available in 67 otherwise healthy children who underwent ABPM; 51 had confirmed clinic hypertension by Task Force criteria. WCH frequency in these 51 patients with the stated criteria was 53%, 45%, and 22%, respectively. Elevated BP load was found in 52% (12/23) of patients with normal mean BP. CONCLUSION: These results suggest that many children referred for casual BP elevation have WCH even by strict diagnostic criteria. ABPM may help differentiate WCH from persistent hypertension, thereby avoiding unnecessary diagnostic evaluation and identifying children most likely to benefit from early intervention.     

ABPM vs office blood pressure to define blood pressure control in treated hypertensive paediatric renal transplant recipients

While 24-h ambulatory blood pressure monitoring (ABPM) is an established tool for monitoring antihypertensive therapy in adults, data in children are scarce. We retrospectively analysed whether office blood pressure (BP) is reliable for the diagnosis of BP control in 26 treated hypertensive paediatric renal transplants. Controlled office BP was defined as the mean of three replicate systolic and diastolic BP recordings less than or equal to the 95th age-, sex- and height-matched percentile on the three-outpatient visits closest to ABPM. Controlled ABPM was defined as systolic and diastolic daytime BP < or =95th distribution adjusted height- and sex-related percentile of the adapted ABPM reference. Eight recipients (30%) with controlled office BP were in fact categorized as having non-controlled BP by ABPM criteria. Overall, when office BP and ABPM were compared using the Bland and Altman method, the 95% limits of agreement between office and daytime values ranged from -12.6 to 34.1 mmHg for systolic and -23.9 to 31.7 mmHg for diastolic BP, and the mean difference was 10.7 and 3.9 mmHg respectively. Office readings miss a substantial number of recipients who are hypertensive by ABPM criteria. Undertreatment of hypertension could be avoided if ABPM is applied as an adjunct to office readings.     

Hypertension in children: an update on treatment strategies

PURPOSE OF REVIEW: Hypertension is among the more prevalent treatable diseases that afflict children. Pediatric hypertension carries significant short-term morbidity and long-term risk for the development of cardiovascular disease. This review addresses issues significant to the chronic management of hypertension and discusses common pharmacological agents currently used to treat elevated blood pressure in children. RECENT FINDINGS: The recent change in the Federal 2002 Best Pharmaceuticals for Children Act has led to the study and approval of new antihypertensive medications for use in pediatrics. Several antihypertensive medications are commercially available in liquid form or can be extemporaneously compounded for flexible dosing and ease of administration. SUMMARY: The availability of normative blood pressure data and several pharmacologic antihypertensive agents makes early detection and treatment of hypertension in children a realizable goal. The long-term effect of chronic antihypertensive therapy on growth, as well as the prevention of future development of cardiovascular disease, is not fully understood.     

Ambulatory blood pressure monitoring in children with aortic coarctation and kidney transplantation

BACKGROUND: Ambulatory blood pressure monitoring (ABPM) has been found to be of significant importance in clinical practice because numerous blood pressure (BP) measurements may be made throughout the 24-hour period. OBJECTIVE: To assess the clinical utility of ABPM in children with secondary hypertension. METHODS: We studied 37 patients (21 boys and 16 girls), with a mean age of 16.4 +/- 4.1 years, after kidney transplantation and 38 patients (27 boys and 11 girls), with a mean age of 10.2 +/- 2.1 years, after surgical correction of aortic coarctation. Data, expressed as mean +/- SD, were analyzed after dividing the patients into 4 groups. Group A consisted of 25 patients receiving antihypertensive therapy; group B included 12 patients not receiving antihypertensive therapy. Group C included 25 patients operated on before 3 years of age (8 +/- 7 months of age); group D included 13 patients operated on after 3 years of age (74 +/- 29 months of age). RESULTS: In groups A and B, casual BP measurement showed that 16 of 37 patients (43%) were hypertensive; 24-hour ABPM detected a larger number of patients who were hypertensive (23 of 37, 62%); there were 18 in group A and 5 in group B. In groups C and D, casual BP measurement identified 6 of 38 (15%) patients as hypertensive, whereas 24-hour ABPM again identified a higher number (13 of 38, 34%). CONCLUSIONS: Our findings confirm that 24-hour ABPM is more sensitive than casual BP in detecting abnormal BP in patients at high risk for secondary hypertension.     

Home, clinic, and ambulatory blood pressure monitoring in children with chronic renal failure

Ambulatory blood pressure monitoring (ABPM) provides superior information for diagnosis and treatment of pediatric hypertension, but for reasons of practicality, clinic blood pressure measurements (CBP) are still the primary diagnostic tool. Regular home blood pressure measurements (HBP) may be an alternative to ABPM, but this technique awaits validation in practice. We analyzed the concordance of ABPM, CBP and HBP in 118 pediatric patients (3-19 y) with chronic renal failure. HBP readings (10.5 +/- 5.4 per patient) were averaged for one week around the day of ABPM and CBP. Mean arterial pressure (MAP) measured by HBP (84.0 +/- 10 mm Hg) was significantly lower than both CBP (86.1 +/- 14.1 mm Hg, P< 0.05) and daytime ABPM (90.3 +/- 10.4 mm Hg, P< 0.05). HBP detected hypertensive patients with greater specificity (82 versus 70%), but lower sensitivity (52 versus 70%) than CBP. The fraction of patients rated erroneously hypertensive was 23% with CBP, but only 14% with HBP. The 95% limits of agreement with ABPM were narrower for HBP (-23 to10 mm Hg) than for CBP (-30 to 21 mm Hg). CBP, but not HBP measurements, were less precise in the upper BP range. The accuracy of HBP measurements did not change with use over a six months time period. In conclusion, HBP was superior to CBP in predicting ABPM, but neither CBP nor HBP detected hypertension with enough sensitivity or specificity to replace ABPM. The greater specificity of HBP compared with CBP makes it a more suitable tool for diagnosis, rather than screening, of hypertension in children.     

24 hour blood pressure monitoring in healthy and hypertensive children

24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.     

Ambulatory blood pressure monitoring in children with unilateral multicystic dysplastic kidney

Multicystic dysplastic kidney (MCDK) is one of the most common congenital renal anomalies. Arterial hypertension is a potential complication of MCDK. Blood pressure (BP) has so far been measured only casually and the frequency of hypertension has been estimated to be between 0%–8%. Ambulatory blood pressure monitoring (ABPM) provides more precise information on BP than the casual BP measurement. The aim of this study was to investigate the BP profile in children with MCDK using ABPM. A group of 25 children (16 girls), with a mean age of 7.8 years (range 3.8–17.7 years) were investigated. ABPM was performed using the oscillometric SpaceLabs 90207 device. Hypertension was defined as mean systolic and/or diastolic BP during the day and/or in the night exceeding 95th percentile for ABPM. Five (20%) children showed hypertension, two of them had combined daytime and night-time hypertension and three had isolated nocturnal hypertension, although daytime BP was between the 90th–95th percentile in two of them. Children with ultrasonographical and/or laboratory signs of contralateral kidney abnormalities showed a higher incidence of hypertension than those without abnormalities (two of four versus 3 of 21). The mean night-time systolic and diastolic BP of children with MCDK was significantly higher than in healthy children (+0.50 and +0.54 SDS, respectively, P=0.012 and 0.03, respectively). Three of the hypertensive children were already nephrectomised. All five hypertensive children showed ultrasonographical and/or laboratory signs of contralateral kidney abnormalities. Hypertensive children had significantly higher microalbuminuria than normotensive children (6.9 ± 3.2 mg/mmol creatinine versus 1.8 ± 0.7, P=0.03). The nocturnal BP fall (dip) was attenuated in five children, only one of whom was hypertensive. Conclusion Arterial hypertension in children with multicystic dysplastic kidney is seen more often if based on ambulatory blood pressure monitoring than on casual blood pressure recordings. The main risk factor for developing hypertension is contralateral kidney damage. Ambulatory blood pressure monitoring should be performed in children with multicystic dysplastic kidney, especially in those with contralateral kidney abnormalities. Received: 20 July 1999 and in revised form: 27 November 1999, 24 March 2000, 3 May 2000 Accepted: 3 May 2000     

24 hour blood pressure monitoring in healthy and hypertensive children.

24 Hour ambulatory blood pressure monitoring (ABPM) was performed to provide data on the normal daily blood pressure of healthy schoolchildren and on patients with hypertension. The subjects studied were 123 healthy schoolchildren with a mean (SD) age of 12.5 (1.6) years (range 9.5-14.5 years), 24 children with borderline or mild hypertension, 17 with renal hypertension and normal renal function, 10 with chronic renal failure, and six with a renal allograft. In eight children with definite renal disease a second measurement was performed after treatment modification. The monitor used for ABPM was validated with a mercury column manometer. The mean (SD) of the signed differences of the blood pressure measured by the two methods was -0.19 (1.75) mmHg for the systolic and -0.21 (2.11) mmHg for the diastolic blood pressure (n = 60). Normal values for daytime and night time blood pressure were determined for those aged 10-14 years. The mean (SD) blood pressure of the 123 children was 109 (7)/66 (8) mmHg (systolic/diastolic) for the daytime and 96 (8)/52 (7) mmHg at night time. Of the 24 children with borderline or mild hypertension 14 had a raised blood pressure on ABPM. The circadian rhythm was disturbed in three children of this group. Even children with normal daytime blood pressure had significantly higher systolic blood pressure in the night when compared with the controls. The incidence of disturbed circadian rhythm was higher in the groups with renal hypertension (4/17 in the subgroup with normal renal function, 5/16 in the group with renal failure and/or transplantation). All children undergoing a second ABPM measurement had a lower average blood pressure after treatment adjustment. ABPM measurements were reproducible and accurate. The method provided new data on the physiological circadian variation of blood pressure in healthy children. It proved to be a helpful tool in the diagnosis of hypertension, particularly in the detection of cases of disturbance of the circadian rhythm of blood pressure pattern and individual adjustment of treatment.     

动态血压在儿科的应用

动态血压监测能真实反映患者24h血压的平均水平、日常生活的血压变化和昼夜节律变化,较传统的血压监测有明显的优势.研究已经确定其在识别儿童白大衣性高血压及隐匿性高血压、预测靶器官损害、评价降压药物疗效、鉴别原发性高血压及继发性高血压等方面有一定价值.该文简述动态血压监测在儿科的临床应用.     

Ambulatory blood pressure monitoring: what a pediatrician should know

PURPOSE OF REVIEW: Ambulatory blood pressure monitoring is a useful tool for the evaluation and management of hypertension in children and adolescents. This review provides a basic overview of ambulatory blood pressure monitoring and summarizes the most recent available knowledge regarding its use in the pediatric population. RECENT FINDINGS: Evaluation and validation of ambulatory blood pressure monitoring equipment in children remains limited, although advances in the interpretation of results for this age group have been reported specifically in the area of circadian (24 h) and ultradian (<24 h) variability. Blood pressure is a dynamic phenomenon that varies not only with time but also with changing patient and environmental circumstances. Growing evidence regarding conditions identified when this variability is considered, specifically white coat and masked hypertension, suggests that office blood pressure measurement may not be a sufficient screening test for hypertension-related target-organ damage. SUMMARY: Information regarding ambulatory blood pressure monitoring use in children is increasing, although due to its limitations and expense, it remains a tool primarily utilized by the pediatric sub-specialist.     

Hypertension in pediatric kidney transplantation

Arterial hypertension (HTN) in children after kidney transplantation is an important risk factor not only for graft loss but also for cardiovascular morbidity and mortality. The prevalence of posttransplant HTN ranges between 60% and 90%. The etiology of posttransplant HTN is multifactorial and includes residual chronic native kidney disease, immunosuppressive therapy, and chronic allograft dysfunction among other causes. Clinic blood pressure (BP) should be measured at each outpatient visit. However, ambulatory blood pressure monitoring (ABPM) is the gold standard method for BP evaluation in children after kidney transplantation, as it often reveals masked and nocturnal HTN; given this, it should be regularly performed in each transplanted child. All classes of antihypertensive drugs are used in the treatment of posttransplant HTN because it has never been proven that one class is better than another. However, in several retrospective studies, the use of calcium channel blockers is associated with better graft function. The optimal target BP for transplanted children is still a matter of debate; it is recommended to target the same BP as for healthy children, that is, <95th percentile. Control of HTN in transplanted children remains poor – only 20%–50% of treated children have normal BP. There is a great potential for improvement of antihypertensive treatment that could potentially result in improvement of both graft and patient survival in children after kidney transplantation.     

Twenty-four-hour ambulatory blood pressure profiles in liver transplant recipients

Twenty-four-hour ambulatory blood pressure monitoring (ABPM) has proven to have better reproducibility than office blood pressure (BP) and is increasingly used for the study of hypertension in children and adolescents. The aim of our study was to assess 24-h BP profiles and to compare the results of office BP measurements with ABPM in stable liver transplant recipients transplanted before the age of 18 yr. ABPM was performed in 29 patients (nine males, 20 females), aged 3.9-24.8 yr (median 10.8 yr). The investigation was conducted 1.1-11.5 yr (median 5.1 yr) following transplantation. ABPM confirmed hypertension in one out of three office hypertensive patients. Seven patients (24%), whose office BP recordings were within the normotensive range, were reclassified as hypertensive. Non-dippers (n = 17), arbitrarily defined as patients with less than 10% nocturnal fall in BP, were similarly distributed among patients with ambulatory normotension and ambulatory hypertension (chi(2), p = 0.79). In addition, non-dippers showed a negative correlation between 24-h total urinary albumin excretion and both systolic and diastolic nocturnal decline in BP (Rho = -0.48, p < 0.05 and Rho = -0.86, p < 0.01, respectively). Our study found office BP readings to be poorly representative of 24-h BP profile. Larger studies are needed to confirm our observations as well as to determine whether routine BP measurements in the follow-up of paediatric liver transplant recipients should be based solely on office BP.     

Masked hypertension and allograft function in pediatric and young adults kidney transplant recipients

Masked hypertension is a common complication of pediatric kidney transplantation. While office hypertension is known to be associated with worse short‐ and long‐term graft function, the role of masked hypertension in allograft dysfunction is not clear. We conducted a retrospective cross‐sectional analysis of 77 consecutive pediatric kidney transplant recipients who had routine 24‐h ambulatory blood pressure monitoring with the aims to estimate the prevalence of masked hypertension and examine its association with allograft function. Masked hypertension was defined as a 24‐h systolic or diastolic blood pressure load ≥25%. Twenty‐nine percent of patients had masked hypertension. Patients with masked hypertension had significantly lower allograft function estimated using the creatinine‐based Schwartz‐Lyon formula, a cystatin C‐based formula, and combined cystatin C and creatinine‐based formulas than patients with normal blood pressure (all p values <0.05). In a multivariable analysis, masked hypertension remained independently associated with worse allograft function after adjustment for age, sex, race, time post‐transplant, rejection history, antihypertensive treatment, and hemoglobin level. We conclude that in young kidney transplant recipients, masked hypertension is common and is associated with worse allograft function. These results support the case for routine ambulatory blood pressure monitoring as the standard of care in these patients to detect and treat masked hypertension.