Mariaconsuelo Valentini

Italian Society of Hypertension Guidelines for Conventional and Automated Blood Pressure Measurement in the Office, at Home and Over 24 Hours

This article offers instructions and recommendations on how to perform blood pressure measurements in the doctor’s office, in the patient’s home and in ambulatory conditions over 24 hours. Great attention is paid to some of the general aspects of blood pressure measurement, including the accuracy of blood pressure measuring devices, the importance of a ‘white-coat effect’, and the need for patient education. This article also deals with a number of practical details, such as the importance of patient’s relaxation and position, arm position and support, arm selection and cuff selection and application. Recommendations are provided on the observer’s position and performance, and on the need to pay attention to specific factors affecting the blood pressure measurement in different patient populations, namely in children, elderly and obese people, pregnant women, patients with arrhythmias and patients on treatment. This article then separately focuses on the characteristics of auscultatory and automated measurements, the latter performed either in the office, at home or over 24 hours in ambulatory settings. Home blood pressure monitoring (HBPM) is becoming increasingly important in the diagnosis and management of arterial hypertension. The importance of HBPM in cardiovascular prevention, related to a deeper involvement of patients in their long-term management, and the wide diffusion of this approach in populations, is not always accompanied by adequate knowledge of how to make proper use of this technique, which emphasizes the need for more precise recommendations. This article summarizes the available evidence and provides recommendations on the use of home blood pressure monitoring in clinical practice and in research. It updates the previous recommendations on the same topic issued in 2000. The main topics addressed include the methodology of HBPM, focusing on measurement conditions and procedures, ranging from patient/subject position, to arm selection, arm position and support, cuff selection and application and data reporting, diagnostic and therapeutic thresholds, clinical applications in hypertension (with specific reference to special populations) and its applications in research. Special attention is given to device validation and selection as well as to patient education and to the need of HBPM to be guided by the physician in charge. The final section deals with the problems related to the implementation of these recommendations in clinical practice. Finally, the methodology and clinical impact of 24-hour ambulatory blood pressure monitoring are also addressed in detail, focusing on the parameters that can be derived from the analysis of 24-hour blood pressure recordings applied both to the diagnostic and prognostic evaluation of hypertensive patients and to the assessment of the effectiveness of antihypertensive treatment in controlling blood pressure through the day and night. Instructions to users on how to properly perform HBPM are provided as an appendix.

Attenuation of haemodynamic, metabolic and energy expenditure responses to isoproterenol in patients with hypertension

Objective Overweight and heightened sympathetic activity are more common in hypertensive than normotensive subjects. β-adrenoceptor down-regulation has been described in hypertension. We tested the hypothesis that chronic sympathetic overactivity impairs β-adrenergic-mediated thermogenesis and thereby favours gain of weight in hypertension. Participants The study included 13 hypertensive subjects aged 35.3 ± 7.9 years and 25 normotensive subjects of control of similar age. Methods To measure β-adrenergically mediated haemodynamic, metabolic and thermogenic responsiveness, increasing doses of isoproterenol diluted in 2.5 ml saline were injected as intravenous boluses (0.1, 0.25, 0.5, 1.0 and 2.0 μg/m2). On a separate day, isoproterenol was infused continuously intravenously in increasing doses (10, 20 and 40 ng/kg per min), each dose for 30 min. Results The sitting heart rate and body mass were greater in hypertensives (P = 0.000, and P = 0.005, respectively). The heart rate responses to 1 and 2 μg/m2 isoproterenol bolus (P = 0.01 and P = 0.03, respectively) were reduced in hypertensives. The energy expenditure (P = 0.002) and oxygen consumption (P = 0.0004) increase with 40 ng/kg per min isoproterenol infusion, and glucose and phosphate responses at both 20 (P = 0.01 and P = 0.05) and 40 (P = 0.001 and P = 0.02) ng/kg per min isoproterenol infusion were attenuated in hypertensives. The baseline heart rate negatively correlated with heart rate (P = 0.015) response to isoproterenol bolus and blood pressure (P = 0.02) response to isoproterenol infusion. The urinary noradrenaline negatively correlated with heart rate response to isoproterenol bolus (P = 0.001), and with systolic blood pressure (P = 0.02) and energy expenditure responsiveness to isoproterenol infusion (P = 0.04). Furthermore, plasma noradrenaline negatively correlated with heart rate responsiveness to isoproterenol bolus (P = 0.004). Conclusions These results show a generalized decrease of β-adrenergic responsiveness in stage 1 hypertension and support the concept that sympathetic overactivity, via down-regulation of β-adrenoceptor-mediated thermogenic responses, may facilitate the development of obesity in hypertension.

Do we need out-of-office blood pressure in every patient?

Purpose of review The limitations affecting office blood pressure readings have spurred the development of techniques for measuring blood pressure out of a clinical environment. The increasing use of home and ambulatory blood pressure monitoring has allowed the identification of specific blood pressure patterns related either to a discrepancy between office and out-of-office blood pressure or to alterations in the 24-h blood pressure profiles. This review offers an update on the most recent data published on the above issues. Recent findings A critical overview is provided on recent data published on blood pressure patterns suggested to have clinical relevance. These include white coat hypertension, the so-called masked hypertension, enhanced overall blood pressure variability over 24 h, a steeper morning blood pressure surge and a blunted or an excessive blood pressure fall at night. Summary All of these different conditions have been variably reported to carry prognostic implications, and may represent specific targets for antihypertensive treatment. Their identification and management require information on out-of-office blood pressure, which suggests that self blood pressure monitoring at home or 24-h ambulatory blood pressure monitoring should be used more frequently in clinical practice, following the indications issued in recent guidelines.

Effects of selective and nonselective beta-blockade on 24-h ambulatory blood pressure under hypobaric hypoxia at altitude

Background Little is known about the effects of cardiovascular drugs at high altitude. Objective To assess 24-h blood pressure (BP) and heart rate (HR) during short-term altitude exposure in healthy normotensive persons treated with carvedilol or nebivolol. Methods Participants were randomized in double-blind to placebo, nebivolol 5 mg once daily or carvedilol 25 mg b.i.d. Tests were performed at sea level (baseline and after 2 weeks treatment) and on second to third day at altitude (Monte Rosa, 4559 m), still on treatment. Data collection included conventional BP, 24-h ambulatory BP monitoring (ABPM), oxygen saturation (SpO2), Lake Louise Score and adverse symptoms score. Results Twenty-four participants had complete data (36.4 ± 12.8 years, 14 men). Both beta-blockers reduced 24-h BP at sea level. At altitude 24-h BP increased in all groups, mainly due to increased night-time BP. Twenty-four-hour SBP at altitude was lower with carvedilol (116.4 ± 2.1 mmHg) than with placebo (125.8 ± 2.2 mmHg; P < 0.05) and intermediate with nebivolol (120.7 ± 2.1 mmHg; NS vs. others). Rate of nondipping increased at altitude and was lower with nebivolol than with placebo (33 vs. 71%; P = 0.065). Side effects score was higher with carvedilol than with placebo (P = 0.04), and intermediate with nebivolol. SpO2 at altitude was higher with placebo (86.1 ± 1.2%) than with nebivolol (81.7 ± 1.1%; P = 0.07) or carvedilol (81.1 ± 1.1%; P = 0.04). Conclusions Both carvedilol and nebivolol partly counteract the increase in BP at altitude in healthy normotensive individuals but are associated with a lower SpO2. Carvedilol seems more potent in this regard, whereas nebivolol more effectively prevents the shift to a nondipping BP profile and is better tolerated.

Effects of beta-blockade on exercise performance at high altitude: a randomized, placebo-controlled trial comparing the efficacy of nebivolol versus carvedilol in healthy subjects.

AIMS Exposure to high altitude (HA) hypoxia decreases exercise performance in healthy subjects. Although β-blockers are known to affect exercise capacity in normoxia, no data are available comparing selective and nonselective β-adrenergic blockade on exercise performance in healthy subjects acutely exposed to HA hypoxia. We compared the impact of nebivolol and carvedilol on exercise capacity in healthy subjects acutely exposed to HA hypobaric hypoxia. METHODS In this double-blind, placebo-controlled trial, 27 healthy untrained sea-level (SL) residents (15 males, age 38.3 ± 12.8 years) were randomized to placebo (n = 9), carvedilol 25 mg b.i.d. (n = 9), or nebivolol 5 mg o.d. (n = 9). Primary endpoints were measures of exercise performance evaluated by cardiopulmonary exercise testing at sea level without treatment, and after at least 3 weeks of treatment, both at SL and shortly after arrival at HA (4559 m). RESULTS HA hypoxia significantly decreased resting and peak oxygen saturation, peak workload, VO(2) , and heart rate (HR) (P < 0.01). Changes from SL (no treatment) differed among treatments: (1) peak VO(2) was better preserved with nebivolol (-22.5%) than with carvedilol (-37.6%) (P < 0.01); (2) peak HR decreased with carvedilol (-43.9 ± 11.9 beats/min) more than with nebivolol (-24.8 ± 13.6 beats/min) (P < 0.05); (3) peak minute ventilation (VE) decreased with carvedilol (-9.3%) and increased with nebivolol (+15.2%) (P= 0.053). Only peak VE changes independently predicted changes in peak VO(2) at multivariate analysis (R= 0.62, P < 0.01). CONCLUSIONS Exercise performance is better preserved with nebivolol than with carvedilol under acute exposure to HA hypoxia in healthy subjects.

Parental Hyperdynamic Circulation Predicts Insulin Resistance in Offspring The Tecumseh Offspring Study

Controversy surrounds the pathogenetic mechanisms of the relationship between hyperdynamic circulation and insulin resistance. Two hundred eight children and young adults (mean age, 17.2+/-3.0 years; range, 11 to 26 years) from the Tecumseh Offspring Study whose parents had been assessed with Doppler echocardiography at the age of 34 years during the previous Tecumseh Blood Pressure Study were considered for this analysis. Offspring data were stratified according to tertiles of parental cardiac index. Parents in the top cardiac index tertile had increased heart rate (P=0.001), stroke volume (P=0.0001), left ventricular fractional shortening (P=0.02), and plasma epinephrine (P=0.02) compared with parents in the other tertiles. Body mass index (BMI) and blood pressure were similar in all groups. Offspring of parents with a high cardiac index had greater BMI (P=0.001), skinfold thickness (P=0.008), and waist/hip ratio (P=0.02), higher diastolic blood pressure (P=0.02) and plasma insulin level (P=0.001), and higher heart rate during Stroops color test (P=0.02) than offspring of parents with a lower cardiac index. In a multivariate regression analysis, offspring BMI was predicted by parental BMI and cardiac index (P=0.0001 and 0.003, respectively). The mother-child relationship explained most of the cardiac index-BMI association. In summary, parental hyperdynamic circulation was an important predictor of overweight, abnormal fat distribution, increased blood pressure, and hyperinsulinemia in offspring. Our results illustrate the complexity of interaction between a genetic tendency and its phenotypic expression. We speculate that the degree of beta-adrenergic responsiveness may be a major determinant of the phenotypic differences between the parents and offspring found in this study.

Genetic contribution to the variance in left ventricular mass: The Tecumseh offspring study

Objective To estimate the contribution of heredity to the variance in left ventricular mass (LVM), and to ascertain whether genetic factors may interact with non-genetic factors in promoting LVM growth. Subjects and setting The study population consisted of 290 healthy parents and 251 healthy children living in Tecumseh, Michigan, USA. Main outcome measure Correlation of parents’ LVM with offsprings LVM adjusting for a number of clinical variables. Methods LVM in parents and offspring was measured with M-mode echocardiography by the same investigators. Results Parents unadjusted LVM was unrelated to offspring unadjusted LVM , but after removing the confounding effect of age, sex, anthropometric measurements, systolic blood pressure, plasma insulin and urinary sodium excretion, parent–child correlation for LVM was 0.28 (P = 0.006). The relative contribution of parental-adjusted LVM and of several offspring phenotypic and environmental variables on offspring LVM was evaluated by multivariable regression analysis. When age, gender, anthropometric measurements and systolic blood pressure were accounted for, adjusted LVM of parents explained only 1.6% of the total variance in offspring LVM. However, after inclusion of insulin and urinary sodium in the model heredity explained 7.6% of the total variance in offspring LVM, and its predictive power was second only to that of childs height. Furthermore, an interactive effect of parental LVM with offspring systolic blood pressure was found on childs left ventricular mass. Conclusion Heredity can explain a small, but definite proportion of the variance in LVM. Higher blood pressure favors the phenotypic expression of the genes that regulate LVM growth.

Sex and acetazolamide effects on chemoreflex and periodic breathing during sleep at altitude.

OBJECTIVE Nocturnal periodic breathing occurs more frequently in men than in women with various clinical and pathophysiologic conditions. The mechanisms accounting for this sex-related difference are not completely understood. Acetazolamide effectively counteracts nocturnal periodic breathing, but it has been investigated almost exclusively in men. Our aim was to explore possible determinants of nocturnal periodic breathing in a high-altitude setting both in men and in women. We hypothesized that increased hypoxic chemosensitivity in men could be associated with the development of nocturnal periodic breathing at altitude more frequently than in women, and that acetazolamide, by leftward shifting the CO2 ventilatory response, could improve nocturnal periodic breathing at altitude in a sex-independent manner. METHODS Forty-four healthy lowlanders (21 women), randomized to acetazolamide or placebo, underwent cardiorespiratory sleep studies at sea level off treatment and under treatment on the first night after arrival at a 4,559-m altitude. Hypoxic and hypercapnic chemosensitivities were assessed at sea level. RESULTS Men, more frequently than women, exhibited increased hypoxic chemosensitivity and displayed nocturnal periodic breathing at altitude. Acetazolamide leftward shifted the CO2 set point and, at altitude, improved oxygenation and reduced periodic breathing in both sexes, but to a larger extent in men. Hypoxic chemosensitivity directly correlated with the number of apneas/hypopneas at altitude in the placebo group but not in the acetazolamide group. CONCLUSIONS The greater severity of periodic breathing during sleep displayed by men at altitude could be attributed to their increased hypoxic chemosensitivity. Acetazolamide counteracted the occurrence of periodic breathing at altitude in both sexes, modifying the apneic threshold and improving oxygenation. TRIAL REGISTRY EU Clinical Trials Register, EudraCT; No.: 2010-019986-27; URL: https://www.clinicaltrialsregister.eu.

Heritability of left atrial size in the Tecumseh population.

Background  Little is known about the determinants of atrial size, and no study has analyzed whether genetic factors are involved in the pathogenesis of LA enlargement.

Measurement of heart rate and respiratory rate using a textile-based wearable device in heart failure patients

Changes in heart rate (HR) and respiratory rate (RespR) may be used as markers of early decompensation in chronic heart failure (CHF) patients monitored at home. Aiming at improving quality of care and at reducing hospitalization rate and health care costs in CHF, progress in technology has led to the development of small portable and even wearable devices for the acquisition and transmission of relevant vital signs to a remote monitoring centre. This paper describes a signal acquisition and processing system, based on a wearable textile-based device with sensors for the measurement of one-lead ECG and chest movement, and focuses on the algorithms for HR and RespR evaluation. An electronic board collects and transmits these signals to a PDA, which sends them via Wi-Fi to a home gateway where the HR and the RespR time series are produced. The home gateway packs the data with other vital signs collected by using different devices and sends them in XML format to a central repository where a clinical decision support system can use them for the detection of early decompensation episodes. The system has successfully overcome a preliminary test phase and is ready for more extensive tests in a real clinical environment.