Ambulatory Measurements Research Articles

Occurrence and morphology of ventricular arrhythmias in apparently normal hearts in relation to late gadolinium enhancement on cardiovascular magnetic resonance.

Cardiac magnetic resonance (CMR) is the gold standard for evaluating myocardial fibrosis. Few studies have explored the association between ventricular arrhythmias (VAs) and fibrosis in apparently normal hearts. We aimed to investigate the association between the occurrence and morphology of VAs and left ventricular late gadolinium enhancement (LV-LGE) in patients without known structural heart diseases. This study enrolled 78 patients with apparently normal hearts who underwent 24-h ambulatory Holter electrocardiogram (ECG) and CMR examinations simultaneously. The presence and extent of LGE was determined using CMR imaging and compared based on occurrence and morphology of VAs. The clinical characteristics were also recorded and calculated. LV-LGE was observed in 19 (37.3%) and 4 (14.8%) patients with and without VAs, respectively (P = 0.039). It was more frequently observed in patients with polymorphic VAs (P = 0.024). The polymorphic VAs had a higher tendency of LGE extent than monomorphic VAs, while the difference did not reach statistical significance (P = 0.055). In multivariable analyses, the presence of polymorphic VAs [hazard ratio (HR) 11.19, 95% CI 1.64-76.53, P = 0.014] and hypertension (HR 4.64, 95% CI 1.08-19.99, P = 0.039) were associated with greater prevalence of LV-LGE. In patients without structural heart diseases, besides hypertension, multiple VA morphologies on Holter ambulatory ECG measurements is another important marker of increased incidence of myocardial fibrosis.

Associations between toxic elements and blood pressure parameters in adolescents

BackgroundBoth exposure to toxic elements and hypertension (HT) are a global health problem. We planned to examine the associations between some toxic elements in urine, and blood pressure (BP) and its diurnal changes in adolescents. MethodsIn this cross-sectional study, 48 adolescents who were newly diagnosed with HT and 38 adolescents with age-appropriate BP and normal physical examination were included. Anthropometric measurements, urinary toxic elements, carotid intima media thickness (cIMT), and office and 24-hour ambulatory BP measurements (ABPM) of participants were taken. Urinary elements levels were studied with ICP-MS. Elements were grouped in tertiles according to urinary levels. Logistic regression analyses were performed to show the interactions. ResultsUrinary cadmium, mercury, lead, and arsenic were found to be at detectable level in 90.7%, 69.8%, 91.9% and 100% of the participants, respectively. Univariate analyses showed that elevated daytime systolic and/or diastolic BP was associated with urinary cadmium and mercury. No association between urinary toxic elements and nighttime BP was found. When height and body mass index z-scores adjusted for, age, gender, and all four urinary creatinine-corrected toxic elements analyzed, multiple logistic regression revealed that there was an association between mercury (high vs. low; AOR:3.85) and office HT, and mercury (high vs. low; AOR:6.18) and cadmium (middle vs. low; AOR: 13.38) were associated with “elevated 24-hour systolic BP and/or diastolic BP”, and “elevated 24-hour mean arterial BP” in ABPM. ConclusionThere are complex relationships between toxic elements and BP parameters in adolescents, and more studies are needed to define the evolution of these relations.

Measuring medically unjustified hospitalizations in Switzerland

BackgroundInappropriate use of acute hospital beds is a major topic in health politics. We present here a new approach to measure unnecessary hospitalizations in Medicine and Pediatrics.MethodsThe necessity of a hospital admission was determined using explicit criteria related to the recorded diagnoses. Two indicators (i.e. “unjustified” and “sometimes justified” stays) were applied to more than 800,000 hospital stays and a random sample of 200 of them was analyzed by two clinicians, using routine data available in medical statistics. The validation of the indicators focused on their precision, validity and adjustment, as well as their usefulness (i.e. interest and risk of abuse).ResultsRates, adjusted for case mix (i.e. age of patient, admission planned or not), showed statistically significant differences among hospitals. Only 6.5% of false positives were observed for “unjustified stays” and 17% for “sometimes justified stays”. Respectively 7 and 12% of stays had an unknown status, due to a lack of sufficiently precise data. Considering true positives only, almost one third of medical and pediatric stays were classified as not strictly justified from a medical point of view in Switzerland. Among these stays, about one fifth could have probably been avoided without risk. To enable a larger ambulatory shift, recommendations were made to strengthen the ambulatory care, notably regarding post-emergency follow-up, cardiac and pulmonary functions’ monitoring, pain management, falls prevention, and specialized at-home services that should be offered.ConclusionWe recommend using “unjustified stays” and “sometimes justified stays” indicators to monitor inappropriate hospitalizations. The latter could help the planning of reinforced ambulatory care measures to pursue the ambulatory shift. Nonetheless, we clearly advise against the use of these two indicators for hospitals financing purposes.

Management of Adults with Newly Diagnosed Atrial Fibrillation with and without CKD.

Atrial fibrillation (AF) is highly prevalent in CKD and is associated with worse cardiovascular and kidney outcomes. Limited data exist on use of AF pharmacotherapies and AF-related procedures by CKD status. We examined a large "real-world" contemporary population with incident AF to study the association of CKD with management of AF. We identified patients with newly diagnosed AF between 2010 and 2017 from two large, integrated health care delivery systems. eGFR (≥60, 45-59, 30-44, 15-29, <15 ml/min per 1.73 m2) was calculated from a minimum of two ambulatory serum creatinine measures separated by ≥90 days. AF medications and procedures were identified from electronic health records. We performed multivariable Fine-Gray subdistribution hazards regression to test the association of CKD severity with receipt of targeted AF therapies. Among 115,564 patients with incident AF, 34% had baseline CKD. In multivariable models, compared with those with eGFR >60 ml/min per 1.73 m2, patients with eGFR 30-44 (adjusted hazard ratio [aHR] 0.91; 95% CI, 0.99 to 0.93), 15-29 (aHR, 0.78; 95% CI, 0.75 to 0.82), and <15 ml/min per 1.73 m2 (aHR, 0.64; 95% CI, 0.58-0.70) had lower use of any AF therapy. Patients with eGFR 15-29 ml/min per 1.73 m2 had lower adjusted use of rate control agents (aHR, 0.61; 95% CI, 0.56 to 0.67), warfarin (aHR, 0.89; 95% CI, 0.84 to 0.94), and DOACs (aHR, 0.23; 95% CI, 0.19 to 0.27) compared with patients with eGFR >60 ml/min per 1.73 m2. These associations were even stronger for eGFR <15 ml/min per 1.73 m2. There was also a graded association between CKD severity and receipt of AF-related procedures (vs eGFR >60 ml/min per 1.73 m2): eGFR 30-44 ml/min per 1.73 (aHR, 0.78; 95% CI, 0.70 to 0.87), eGFR 15-29 ml/min per 1.73 m2 (aHR, 0.73; 95% CI, 0.61 to 0.88), and eGFR <15 ml/min per 1.73 m2 (aHR, 0.48; 95% CI, 0.31 to 0.74). In adults with newly diagnosed AF, CKD severity was associated with lower receipt of rate control agents, anticoagulation, and AF procedures. Additional data on efficacy and safety of AF therapies in CKD populations are needed to inform management strategies.

The Association between Exposure to Residential Indoor Volatile Organic Compounds and Measures of Central Arterial Stiffness in Healthy Middle-Aged Men and Women.

It is well reported that individuals spend up to 90% of their daily time indoors, with between 60% to 90% of this time being spent in the home. Using a cross-sectional study design in a population of 111 healthy adults (mean age: 52.3 ± 9.9 years; 65% women), we investigated the association between exposure to total volatile organic compounds (VOCs) in indoor residential environments and measures of central arterial stiffness, known to be related to cardiovascular risk. Indoor VOC concentrations were measured along with ambulatory measures of pulse pressure (cPP), augmentation index (cAIx) and cAIx normalized for heart rate (cAIx75), over a continuous 24-h period. Pulse wave velocity (cfPWV) was determined during clinical assessment. Multiple regression analysis was performed to examine the relationship between measures of arterial stiffness and VOCs after adjusting for covariates. Higher 24-h, daytime and night-time cAIx was associated with an interquartile range increase in VOCs. Similar effects were shown with cAIx75. No significant effects were observed between exposure to VOCs and cPP or cfPWV. After stratifying for sex and age (≤50 years; >50 years), effect estimates were observed to be greater and significant for 24-h and daytime cAIx in men, when compared to women. No significant effect differences were seen between age groups with any measure of arterial stiffness. In this study, we demonstrated that residential indoor VOCs exposure was adversely associated with some measures of central arterial stiffness, and effects were different between men and women. Although mechanistic pathways remain unclear, these findings provide a possible link between domestic VOCs exposure and unfavourable impacts on individual-level cardiovascular disease risk.

Blood pressure and glomerular filtration rate in youth with tuberous sclerosis complex.

Hypertension may present with increased frequency in young patients with kidney disease associated with TSC. Routine ambulatory BP measurement should be part of the annual clinical assessment in patients with TSC. • Nearly half of the patients with TSC have a premature decline in their renal function in their fifth decade of life. • Hypertension and hyperfiltration have been proposed as modifiable factors of progression of renal decline in patients with TSC-related renal disease. • Hypertension is prevalent in youth with tuberous sclerosis complex. • SBP levels have a positive relation with GFR levels within the normal range of GFRDTPA values.

AMBULATORY BLOOD PRESSURE VARIABILITY IN YOUNG ADULTS WITH LONG-COVID SYNDROME.

The aim: To perform an overall assessment of BP and BP variability using ambulatory measurements in young adults with long COVID syndrome. Materials and methods: We enrolled young patients with diagnosed long-COVID syndrome (n = 58, mean age 23.07 ± 1.54 years), compared with an age-matched healthy subjects who had not suffered from COVID-19 (n = 57, mean age 22.9 ± 1.83 years). Patients with long-COVID syndrome had recovered from mild/moderate illness and none had required hospitalization. Ambulatory 24 hours blood pressure (AMBP) parameters (mean BP, daytime BP, nighttime BP, pulse pressure, nocturnal systolic BP dipping, dipper status) were measured in all participants. The variability of systolic BP (SBP) and diastolic BP (DBP) values was assessed by the following common metrics, including the average real variability (ARV), the coefficient of variation (CV), the standard deviation (SD), and the weighed SD of SBP and DBP. Results: The average values of 24-hour ambulatory blood pressure, mean BP, daytime and nighttime systolic BP, diastolic BP and pulse pressure were found to be significantly different among patients with long COVID syndrome and control group. Group analyses showed that this difference was in SBP mean values (127.1 ± 6.65 mmHg and 115.93 ± 6.24 mmHg respectively) and DBP mean values (73.31 ± 5.30 mmHg and 68.79 ± 5.5 mmHg respectively) mainly at night. PP values at daytime were almost similar among groups, but PP values at nighttime were higher in patients with long-COVID syndrome (53.8 (52.44- 55.14) mmHg and 47.14 (46.45 - 47.88) mmHg respectively). Nocturnal SBP dipping was better in control group than in patients with long-COVID syndrome ( 5.3 ± 5.68 and 3.1 ± 3.79 mmHg respectively). Only 13 (22.4%) patients with long-COVID syndrome had normal dip-per status while more than half - 38 (66.7%) in healthy subjects. The values of ARV of SBP and DBP over 24-hour, awake, and asleep time frames were found to be greater in patients with long COVID syndrome than healthy controls (p < 0.05). Conclusions: Patients with long- COVID syndrome have higher BP mean values of 24-hour ABPM particularly at nightime, significant blood pressure BP variability, which increases the risk of cardiovascular events in future. Nevertheless, the further prospective investigations is warranted to investigate the potential mechanisms and causality associations.

Blood Pressure Variability: Mechanisms, Measurement, Subtypes, and Clinical Implications

The complex topic of short- and long-term blood pressure (BP) variability confounds the diagnosis, classification, and management of hypertension. True pathophysiologic BP variation (systematic and non-systematic deviations between- and within-individuals) is related to heart rate, respiration, complex responses of the sympathetic nervous system, vascular reactivity, and arterial stiffness. Measurement errors (systematic biases and random error) further compound the analysis. Most studies use serial clinic BP values, 24-hour ambulatory BP recordings, or home BP values with standard statistical indicators (standard deviation, variance, or coefficient of variation) or absolute real variability (mean difference of successive values). Clinical impact in retrospective secondary analyses includes a modest increase in cardiovascular disease (CVD) risk (equivalent to a few mmHg in mean systolic BP) yet questions remain whether adjustment for mean BP is needed. BP variability is reduced to a small degree by calcium antagonists and increased by ACE inhibitors, beta-blockers, and alpha-blockers but no interventional trial has addressed the question of whether reducing BP variability confers CVD risk protection. BP variability is not specifically discussed in practice guidelines but it is tacitly acknowledged by recommendations to repeat BP measurements, standardize technique, and confirm the hypertension diagnosis by home or ambulatory BP measurements to account for the “white coat effect.” There is no formal consensus on how to quantitate or manage BP variability despite a real-world need for better diagnostic and therapeutic guidance. Practitioners should thus focus on control of (mean) BP using combinations of agents that improve CVD outcomes. Future consensus guidance should directly address BP variability and should include educational materials for physicians, patient-contact staff, and patients.

IoT Healthcare System Fused with Ambulatory and Non-conscious Biomedical Measurements: Towards New Development in Medical and Welfare Fields

IoT Healthcare System Fused with Ambulatory and Non-conscious Biomedical Measurements: Towards New Development in Medical and Welfare Fields

Serum aldosterone and urine electrolytes dynamics in response to DASH diet intervention - An inpatient mechanistic study.

Dietary approach to stop hypertension (DASH) diet reduces blood pressure (BP) as effectively as one antihypertensive drug, yet its mechanism of action was never fully characterized. We designed a translational inpatient trial to elucidate the biological pathway leading from nutritional change, through hormonal response, reversal of urine electrolytes ratio, to BP reduction. A single-center open-label interventional trial. Volunteers were admitted for 14 days, transitioning from an American-style diet to DASH diet. Vital signs, blood, and urine samples were collected daily. Participants completed two 24-hour ambulatory BP measurements (ABPM) and two 24-hour urine collections on days 1 and 10. Nine volunteers completed the protocol. During inpatient stay, serum aldosterone increased from day 0 (mean 8.3 ± 5.0) to day 5 (mean 17.8 ± 5.8) after intervention and decreased on day 11 (mean 11.5 ± 4.7) despite continuous exposure to the same diet (p-value = 0.002). Urine electrolyte ratio ([Na]/[K]) decreased significantly from a mean of 3.5 to 1.16 on day 4 (p < 0.001). BP by 24-hour ABPM decreased by a mean of 3.7 mmHg systolic BP and 2.3 mmHg diastolic BP from day 1 to 10. Shifting from a high-sodium/low-potassium diet to the opposite composition leads to aldosterone increase and paradoxical BP reduction. Urine electrolyte ratio reflects nutritional changes and should guide clinicians in assessing adherence to lifestyle modification.

Deriving Normative Data on 24-Hour Ambulatory Blood Pressure Monitoring for South Asian Children (ASHA): A Clinical Research Protocol.

Background:The global prevalence of hypertension in children and adolescents has increased over the past 2 decades and is the strongest predictor of adult hypertension. South Asians have an increased prevalence of metabolic syndrome associated risk factors including abdominal obesity, diabetes, and hypertension. All these factors contribute to their increased cardiovascular disease burden. Accurate and early identification of hypertension in South Asian children is a necessary aspect of cardiovascular disease prevention. Ambulatory blood pressure monitoring (ABPM) is considered the gold-standard for pediatric blood pressure (BP) measurement. However, its utilization is limited due to the lack of validated normative reference data in diverse, multiethnic pediatric populations.Objective:The primary objective is to establish normative height-sex and age-sex-specific reference values for 24-h ABPM measurements among South Asian children and adolescents (aged 5-17 years) in Ontario and British Columbia, Canada. Secondary objectives are to evaluate differences in ABPM measurements by body mass index classification, to compare our normative data against pre-existing data from German and Hong Kong cohorts, and to evaluate relationships between habitual movement behaviors, diet quality, and ABPM measurements.Design:Cross-sectional study, quasi-representative sample.Setting:Participants will be recruited from schools, community centers, and places of worship in Southern Ontario (Greater Toronto and Hamilton area, including the Peel Region) and Greater Vancouver, British Columbia.Participants:We aim to recruit 2113 nonoverweight children (aged 5-17 years) for the primary objective. We aim to recruit an additional 633 overweight or obese children to address the secondary objectives.Measurements:Ambulatory BP monitoring measurements will be obtained using Spacelabs 90217 ABPM devices, which are validated for pediatric use. The ActiGraph GT3X-BT accelerometer, which has also been validated for pediatric use, will be used to obtain movement behavior data.Methods:Following recruitment, eligible children will be fitted with 24-h ABPM and physical activity monitors. Body anthropometrics and questionnaire data regarding medical and family history, medications, diet, physical activity, and substance use will be collected. Ambulatory BP monitoring data will be used to develop height-sex- and age-sex-specific normative reference values for South Asian children. Secondary objectives include evaluating differences in ABPM measures between normal weight, overweight and obese children; and comparing our South Asian ABPM data to existing German and Hong Kong data. We will also use compositional data analysis to evaluate associations between a child’s habitual movement behaviors and ABPM measures.Limitations:Bloodwork will not be performed to facilitate recruitment. A non-South Asian comparator cohort will not be included due to feasibility concerns. Using a convenience sampling approach introduces the potential for selection bias.Conclusions:Ambulatory BP monitoring is a valuable tool for the identification and follow-up of pediatric hypertension and overcomes many of the limitations of office-based BP measurement. The development of normative ABPM data specific to South Asian children will increase the accuracy of BP measurement and hypertension identification in this at-risk population, providing an additional strategy for primary prevention of cardiovascular disease.

Impaired nocturnal blood pressure dipping in patients with type 2 diabetes mellitus with microvascular complications

Hypertension is a common comorbidity of type 2 diabetes mellitus (T2DM). Both conditions are associated with an increased cardiovascular risk, which is reduced by tight blood pressure (BP) and glycemic control. However, non-dipping BP status continues to be an enduring cardiovascular risk factor in T2DM. This study aimed to investigate the association between microvascular complications of diabetes and nocturnal dipping of BP. We compared 13 type 2 diabetic patients with (DM+) and 67 diabetic patients without (DM−) manifest microvascular disease. BP dipping status was assessed from 24-hour ambulatory BP measurements. DM+ patients were older 60.3 ± 8.7 years vs. 58.3 ± 10.4 years ( P = 0.47). There was no significant difference between the two groups in diabetes control, clinical systolic BP and clinical diastolic BP. Dyslipidemia was significantly more present in DM+, 84.7% vs. 47.8% ( P = 0.015). DM+ patients had significantly higher daytime and 24-hour mean SBP than DM− patients with P = 0.02 and 0.023 respectively. Pulse pressure was significantly ( P = 0.03) higher in DM+. The nocturnal blood pressure profile in DM+ was “non-dipper” and “reverse dipper” respectively in 69% and 15% of patients versus 27% and 11% in DM− ( P = 0.003; P = 0.026). Our findings once again highlighted the importance of ambulatory BP monitoring and targeted antihypertensive therapy directed toward to restore normal circadian BP in patients with T2DM.

Motor proficiency composite scores as a novel biomarker for Alzheimer's disease

AbstractBackgroundMild cognitive impairment (MCI) and Alzheimer's disease (AD) are associated with various motor impairments in ambulatory and manual measures that involve speed, force, and precision. Prior studies suggest that such motor impairments are an early disease marker and predict AD progression. A composite motor score that combines motor measures spreading the breadth of motor domains could be a stronger predictor than individual motor measures. Here, we evaluate associations of motor composite scores with existing AD biomarkers in a combined group of individuals with MCI and AD, and cognitively normal individuals.MethodAll participants, who were classified by ADNI‐2 criteria, completed the following motor measures: 1) grip strength using a hand‐dynamometer; 2) general motor reaction time assessed as the time between the visualization of stimuli on a computer screen and pressing a button; 3) psychomotor speed using the Trail Making Test Part A; 4) unimanual and bimanual finger tapping speed using a keyboard; and 5) drawing speed and accuracy using the computerized Archimedes spiral tracing test. Motor composite scores were defined as the sum of the z‐transformed raw measures. Additionally, participants underwent APOE genotyping to determine the presence of e4 alleles, amyloid PET imaging to quantify amyloid deposition, and structural MRI scanning to obtain hippocampal volume. Correlational analysis was used to test the association between motor composite score and AD biomarkers.ResultTo date, 5 cognitively normal, 7 MCI, and 9 AD subjects completed all assessments. Motor composite scores were significantly and strongly associated with AD biomarker scores (p&lt;.05 and Cohen's d&gt;.8 for all outcomes; see Figure 1). Individuals with more APOE e4 alleles had worse motor composite scores (Rho=‐0.43). Higher amyloid burden was related to worse motor composite scores (r=‐0.51). Larger volume of the left hippocampus correlated with better motor composite scores (r=0.51).ConclusionMotor proficiency, as reflected in composite scores, is strongly associated with established markers of AD. Ongoing work focuses on expanding our sample size to allow for statistical correction for potential confounders such as age, stratify the sample to study potential sex differences, and compare motor scores to neuropsychological test scores collected in this sample.

Obtaining wheelchair kinematics with one sensor only? The trade-off between number of inertial sensors and accuracy for measuring wheelchair mobility performance in sports

In wheelchair sports, the use of Inertial Measurement Units (IMUs) has proven to be one of the most accessible ways for ambulatory measurement of wheelchair kinematics. A three-IMU configuration, with one IMU attached to the wheelchair frame and two IMUs on each wheel axle, has previously shown accurate results and is considered optimal for accuracy. Configurations with fewer sensors reduce costs and could enhance usability, but may be less accurate. The aim of this study was to quantify the decline in accuracy for measuring wheelchair kinematics with a stepwise sensor reduction. Ten differently skilled participants performed a series of wheelchair sport specific tests while their performance was simultaneously measured with IMUs and an optical motion capture system which served as reference. Subsequently, both a one-IMU and a two-IMU configuration were validated and the accuracy of the two approaches was compared for linear and angular wheelchair velocity. Results revealed that the one-IMU approach show a mean absolute error (MAE) of 0.10 m/s for absolute linear velocity and a MAE of 8.1°/s for wheelchair angular velocity when compared with the reference system. The two-IMU approach showed similar differences for absolute linear wheelchair velocity (MAE 0.10 m/s), and smaller differences for angular velocity (MAE 3.0°/s). Overall, a lower number of IMUs used in the configuration resulted in a lower accuracy of wheelchair kinematics. Based on the results of this study, choices regarding the number of IMUs can be made depending on the aim, required accuracy and resources available.

Transcutaneous CO2 monitoring as indication for inpatient non-invasive ventilation initiation in patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is characterized by profound muscle weakness, including diaphragmatic weakness resulting in hypercapnic respiratory failure. While non-invasive ventilation (NIV) is usually initiated in the home, patients presenting with hypercapnic respiratory failure may be at high risk of adverse outcomes with delays in treatment. We aim to describe the clinical utility of transcutaneous CO2 (TCO2 ) to assess the need for inpatient initiation of NIV. Eight patients from the University of Michigan Pranger ALS clinic were directly admitted to the hospital for urgent initiation of NIV between May 2020-May 2021. A retrospective review of electronic medical records, including pre-hospital pulmonary function assessments, hospitalization blood gases, and NIV use metrics was performed. All eight patients had symptoms of respiratory insufficiency at time of admission, although not all patients had forced vital capacity (FVC) measurements that would identify need for NIV. All patients had measured TCO2 > 45 mmHg. Seven of eight patients had worsening hypercapnia after admission, indicating advanced respiratory failure. All patients were titrated to tolerance of continuous nocturnal NIV while in the hospital, with an average length of stay of 6.5 days (range, 3-8). All patients demonstrated compliance with NIV, >4h, at post-hospital follow-up. Many current ambulatory measurements underestimate, or incompletely evaluate, respiratory dysfunction, and arterial blood gases are not typically readily available. Outpatient TCO2 measurements can serve as a useful screening tool to identify ALS patients who would benefit from inpatient initiation and titration of NIV.

The association between self-reported stress and cardiovascular measures in daily life: A systematic review.

Stress plays an important role in the development of mental illness, and an increasing number of studies is trying to detect moments of perceived stress in everyday life based on physiological data gathered using ambulatory devices. However, based on laboratory studies, there is only modest evidence for a relationship between self-reported stress and physiological ambulatory measures. This descriptive systematic review evaluates the evidence for studies investigating an association between self-reported stress and physiological measures under daily life conditions. Three databases were searched for articles assessing an association between self-reported stress and cardiovascular and skin conductance measures simultaneously over the course of at least a day. We reviewed findings of 36 studies investigating an association between self-reported stress and cardiovascular measures with overall 135 analyses of associations between self-reported stress and cardiovascular measures. Overall, 35% of all analyses showed a significant or marginally significant association in the expected direction. The most consistent results were found for perceived stress, high-arousal negative affect scales, and event-related self-reported stress measures, and for frequency-domain heart rate variability physiological measures. There was much heterogeneity in measures and methods. These findings confirm that daily-life stress-dynamics are complex and require a better understanding. Choices in design and measurement seem to play a role. We provide some guidance for future studies.

Distinct Circadian Assessments From Wearable Data Reveal Social Distancing Promoted Internal Desynchrony Between Circadian Markers.

Mobile measures of human circadian rhythms (CR) are needed in the age of chronotherapy. Two wearable measures of CR have recently been validated: one that uses heart rate to extract circadian rhythms that originate in the sinoatrial node of the heart, and another that uses activity to predict the laboratory gold standard and central circadian pacemaker marker, dim light melatonin onset (DLMO). We first find that the heart rate markers of normal real-world individuals align with laboratory DLMO measurements when we account for heart rate phase error. Next, we expand upon previous work that has examined sleep patterns or chronotypes during the COVID-19 lockdown by studying the effects of social distancing on circadian rhythms. In particular, using data collected from the Social Rhythms app, a mobile application where individuals upload their wearable data and receive reports on their circadian rhythms, we compared the two circadian phase estimates before and after social distancing. Interestingly, we found that the lockdown had different effects on the two ambulatory measurements. Before the lockdown, the two measures aligned, as predicted by laboratory data. After the lockdown, when circadian timekeeping signals were blunted, these measures diverged in 70% of subjects (with circadian rhythms in heart rate, or CRHR, becoming delayed). Thus, while either approach can measure circadian rhythms, both are needed to understand internal desynchrony. We also argue that interventions may be needed in future lockdowns to better align separate circadian rhythms in the body.

Pediatrician Adherence to Guidelines for Diagnosis and Management of High Blood Pressure

To assess pediatrician adherence to the 2017 American Academy of Pediatrics' clinical practice guideline for high blood pressure (BP). Pediatric primary care practices (n=59) participating in a quality improvement collaborative submitted data for patients with high BP measured between November 2018 and January 2019. Baseline data included patient demographics, BP, body mass index (BMI), and actions taken. Logistic regression was used to test associations between patient BP level and BMI with provider adherence to guidelines (BP measurement, counseling, follow-up, evaluation). A total of 2677 patient charts were entered for analysis. Only 2% of patients had all BP measurement steps completed correctly, with fewer undergoing 3-limb and ambulatory BP measurement. Overall, 46% of patients received appropriate weight, nutrition, and lifestyle counseling. Follow-up for high BP was recommended or scheduled in 10% of encounters, and scheduled at the appropriate interval in 5%. For patients presenting with their third high BP measurement, 10% had an appropriate diagnosis documented, 2% had appropriate screening laboratory tests conducted, and none had a renal ultrasound performed. BMI was independently associated with increased odds of counseling, but higher BP was associated with lower odds of counseling. Higher BP was independently associated with an increased likelihood of documentation of hypertension. In this multisite study, adherence to the 2017 American Academy of Pediatrics' guideline for high BP was low. Given the long-term health implications of high BP in childhood, it is important to improve primary care provider recognition and management. ClinicalTrials.gov: NCT03783650.

Acute Aerobic Exercise Induces Short-Term Reductions in Ambulatory Blood Pressure in Patients With Hypertension: A Systematic Review and Meta-Analysis.

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Miniaturization of a Finger-Worn Blood Pressure Instrument.

Blood pressure monitoring using a traditional arm cuff device is often inconvenient and possibly painful. We present a miniature cuffless tonometric finger probe system, that uses the oscillometric method to measure blood pressure (BP). A small enough device could be used for convenient ambulatory measurement and be worn during sleep with minimal discomfort. In addition to BP, the device is able to collect arterial pulse wave data that can further be used to derive other cardiovascular parameters, such as heart rate (HR), heart rate variability (HRV) and central aortic systolic pressure (CASP). The device uses a motor controlled press that is used to apply pressure to the finger tip to measure the oscillometric response. We verified the functionality of the device by proof-of-concept measurements. Lastly we evaluate methods for further developing the concept and discuss the future directions.