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Entropy (Basel, Switzerland) Mar 2022How the complexity or irregularity of heart rate variability (HRV) changes across different sleep stages and the importance of these features in sleep staging are not...
How the complexity or irregularity of heart rate variability (HRV) changes across different sleep stages and the importance of these features in sleep staging are not fully understood. This study aimed to investigate the complexity or irregularity of the RR interval time series in different sleep stages and explore their values in sleep staging. We performed approximate entropy (ApEn), sample entropy (SampEn), fuzzy entropy (FuzzyEn), distribution entropy (DistEn), conditional entropy (CE), and permutation entropy (PermEn) analyses on RR interval time series extracted from epochs that were constructed based on two methods: (1) 270-s epoch length and (2) 300-s epoch length. To test whether adding the entropy measures can improve the accuracy of sleep staging using linear HRV indices, XGBoost was used to examine the abilities to differentiate among: (i) 5 classes [Wake (W), non-rapid-eye-movement (NREM), which can be divide into 3 sub-stages: stage N1, stage N2, and stage N3, and rapid-eye-movement (REM)]; (ii) 4 classes [W, light sleep (combined N1 and N2), deep sleep (N3), and REM]; and (iii) 3 classes: (W, NREM, and REM). SampEn, FuzzyEn, and CE significantly increased from W to N3 and decreased in REM. DistEn increased from W to N1, decreased in N2, and further decreased in N3; it increased in REM. The average accuracy of the three tasks using linear and entropy features were 42.1%, 59.1%, and 60.8%, respectively, based on 270-s epoch length; all were significantly lower than the performance based on 300-s epoch length (i.e., 54.3%, 63.1%, and 67.5%, respectively). Adding entropy measures to the XGBoost model of linear parameters did not significantly improve the classification performance. However, entropy measures, especially PermEn, DistEn, and FuzzyEn, demonstrated greater importance than most of the linear parameters in the XGBoost model.300-s270-s.
PubMed: 35327890
DOI: 10.3390/e24030379 -
NPJ Digital Medicine Feb 2021Understanding day-to-day variations in symptoms and medication management can be important in describing patient centered outcomes for people with constipation. Patient...
Understanding day-to-day variations in symptoms and medication management can be important in describing patient centered outcomes for people with constipation. Patient Generated Health Data (PGHD) from digital devices is a potential solution, but its utility as a tool for describing experiences of people with frequent constipation is unknown. We conducted a virtual, 16-week prospective study of individuals with frequent constipation from an online wellness platform that connects mobile consumer digital devices including wearable monitors capable of passively collecting steps, sleep, and heart rate data. Participants wore a Fitbit monitoring device for the study duration and were administered daily and monthly surveys assessing constipation symptom severity and medication usage. A set of 38 predetermined day-level behavioral activity metrics were computed from minute-level data streams for steps, sleep and heart rate. Mixed effects regression models were used to compare activity metrics between constipation status (irregular or constipated vs. regular day), medication use (medication day vs. non-medication day) and the interaction of medication day with irregular or constipation days, as well as to model likelihood to treat with constipation medications based on daily self-reported symptom severity. Correction for multiple comparisons was performed with the Benjamini-Hochberg procedure for false discovery rate. This study analyzed 1540 enrolled participants with completed daily surveys (mean age 36.6 sd 10.0, 72.8% female, 88.8% Caucasian). Of those, 1293 completed all monthly surveys and 756 had sufficient Fitbit data density for analysis of activity metrics. At a daily-level, 22 of the 38 activity metrics were significantly associated with bowel movement or medication treatment patterns for constipation. Participants were measured to have fewer steps on irregular days compared to regular days (-200 steps, 95% CI [-280, -120]), longer periods of inactivity on constipated days (9.1 min, 95% CI [5.2, 12.9]), reduced total sleep time on irregular and constipated days (-2.4 min, 95% CI [-4.3, -0.4] and -4.0 min, 95% CI [-6.5, -1.4], respectively). Participants reported greater severity of symptoms for bloating, hard stool, difficulty passing, and painful bowel movements on irregular, constipation and medication days compared to regular days with no medication. Interaction analysis of medication days with irregular or constipation days observed small increases in severity compared to non-medication days. Participants were 4.3% (95% CI 3.2, 5.3) more likely to treat with medication on constipated days versus regular. No significant increase in likelihood was observed for irregular days. Daily likelihood to treat increased for each 1-point change in symptom severity of bloating (2.4%, 95% CI [2.0, 2.7]), inability to pass (2.2%, 95% CI [1.4, 3.0]) and incomplete bowel movements (1.3%, 95% CI [0.9, 1.7]). This is the first large scale virtual prospective study describing the association between passively collected PGHD and constipation symptoms and severity at a day-to-day granularity level. Constipation status, irregular or constipated, was associated with a number of activity metrics in steps and sleep, and likelihood to treat with medication increased with increasing severity for a number of constipation symptoms. Given the small magnitude of effect, further research is needed to understand the clinical relevance of these results. PGHD may be useful as a tool for describing real world patient centered experiences for people with constipation.
PubMed: 33594206
DOI: 10.1038/s41746-021-00391-x -
International Journal of Molecular... Aug 2023Atrial fibrillation (AF) is a prevalent cardiac condition predominantly affecting older adults, characterized by irregular heartbeat rhythm. The condition often leads to... (Review)
Review
Atrial fibrillation (AF) is a prevalent cardiac condition predominantly affecting older adults, characterized by irregular heartbeat rhythm. The condition often leads to significant disability and increased mortality rates. Traditionally, two therapeutic strategies have been employed for its treatment: heart rate control and rhythm control. Recent clinical studies have emphasized the critical role of early restoration of sinus rhythm in improving patient outcomes. The persistence of the irregular rhythm allows for the progression and structural remodeling of the atria, eventually leading to irreversible stages, as observed clinically when AF becomes permanent. Cardioversion to sinus rhythm alters this progression pattern through mechanisms that are still being studied. In this review, we provide an in-depth analysis of the pathophysiological mechanisms responsible for maintaining AF and how they are modified during sinus rhythm restoration using existing therapeutic strategies at different stages of clinical investigation. Moreover, we explore potential future therapeutic approaches, including the promising prospect of gene therapy.
Topics: Humans; Aged; Atrial Fibrillation; Heart Rate; Tics; Heart Diseases; Heart Atria
PubMed: 37629037
DOI: 10.3390/ijms241612859 -
Current Cardiology Reports Jan 2022Bicuspid aortic valve (BAV) disease is the most common congenital heart defect worldwide. When severe, symptomatic aortic stenosis ensues, the treatment has increasingly... (Review)
Review
PURPOSE OF REVIEW
Bicuspid aortic valve (BAV) disease is the most common congenital heart defect worldwide. When severe, symptomatic aortic stenosis ensues, the treatment has increasingly become transcatheter aortic valve replacement (TAVR). The purpose of this review is to identify BAV classification and imaging methods, outline TAVR outcomes in BAV anatomy, and discuss how computational modeling can enhance TAVR treatment in BAV patients.
RECENT FINDINGS
TAVR use in BAV patients, when compared to use in tricuspid aortic valves, showed lower device success rate, and there remains no long-term randomized trial data. It has been reported that BAV patients with severe calcification increase the rate of complications. Additionally, the asymmetrical morphology of BAVs often results in asymmetric stent geometries which have implications for increased thrombosis risk and decreased durability. These adverse outcomes are currently very difficult to predict from routine pre-procedural imaging alone. Recently developed patient specific experimental and computational techniques have the potential to assist in filling knowledge gaps in the mechanisms of these complications and provide more information during preclinical planning for better TAVR selection in low surgical risk BAV patients. Efficacy of TAVR for irregular BAV anatomies remains concerning due to the lack of a long-term randomized trial data, their increased rate of short-term complications, and signs that long-term durability could be an issue. More knowledge on identifying which BAV anatomies are at greater risk for these adverse outcomes can potentially improve patient selection for TAVR versus SAVR in low surgical risk BAV patients.
Topics: Aortic Valve; Aortic Valve Stenosis; Bicuspid Aortic Valve Disease; Constriction, Pathologic; Heart Valve Diseases; Humans; Mitral Valve Stenosis; Transcatheter Aortic Valve Replacement; Treatment Outcome
PubMed: 35099762
DOI: 10.1007/s11886-021-01617-w -
Veterinary Journal (London, England :... Feb 2021Atrial fibrillation (AF) is suspected by an irregularly irregular rhythm during auscultation at rest and should be confirmed by electrocardiography. Heart rate... (Review)
Review
Atrial fibrillation (AF) is suspected by an irregularly irregular rhythm during auscultation at rest and should be confirmed by electrocardiography. Heart rate monitoring is potentially interesting for AF detection by horse owners, based on the disproportionally high heart rate during exercise or increased heart rate variability. Echocardiography and laboratory analysis are useful to identify underlying cardiac disease. Horses with severe cardiac disease should not undergo cardioversion due to the risk of recurrence. Cardioversion is recommended especially in horses performing high intensity exercise or showing average maximal heart rates higher than 220 beats per min or abnormal ventricular complexes during exercise or stress. Pharmacological cardioversion can be performed using quinidine sulphate administered orally, with an overall mean reported success rate around 80%. Other therapeutic drugs have been described such as flecainide, amiodarone or novel atrial specific compounds. Transvenous electrical cardioversion (TVEC) is performed by delivering a shock between two cardioversion catheters positioned in the left pulmonary artery and right atrium, with a success rate of >95%. After cardioversion, most horses return to their previous level of performance. However, the recurrence rate after pharmacological or electrical cardioversion is up to 39%. Recurrence has been related to previous unsuccessful treatment attempts, valvular regurgitation and the presence of atrial premature depolarisations or low atrial contractile function after cardioversion. Large atrial size and long AF duration have also been suggested as risk factors. Different approaches for preventing recurrence have been described such as the administration of sotalol, however, large clinical studies have not been published.
Topics: Animals; Atrial Fibrillation; Horse Diseases; Horses; Prognosis
PubMed: 33468306
DOI: 10.1016/j.tvjl.2020.105594 -
Healthcare (Basel, Switzerland) Sep 2020Arrhythmia may be caused by reduced pulmonary function, and pulse palpation is a useful screening method for the early detection of cardiac arrhythmia. The aim of this...
Arrhythmia may be caused by reduced pulmonary function, and pulse palpation is a useful screening method for the early detection of cardiac arrhythmia. The aim of this study was to investigate the association between reduced pulmonary function and abnormal findings on pulse palpation in 2347 subjects aged ≥65 years using data from a nationwide survey. Pulse palpation was initially performed for 15 s and, if felt to be abnormal, it was performed again for 60 s. The prevalence of irregular pulse (IP) determined by the 60-second palpation was 61 (2.6%). The mean age of subjects with an IP was 73.0 (95% CI 71.7-74.3) years, and 45.8% were male. After adjustment for covariates, forced vital capacity (FVC)/predicted FVC, forced expiratory volume in one second (FEV)/predicted FEV, and the lowest FEV remained significant risk factors for IP. A restrictive or obstructive spirometry pattern was also an independent risk factor for IP. In summary, an IP is more prevalent when pulmonary function is reduced in the elderly, in whom careful pulse palpation may be necessary for the early detection of arrhythmia.
PubMed: 32882921
DOI: 10.3390/healthcare8030312 -
Heart (British Cardiac Society) Apr 2021The diagnostic benefit of using continuous ECG (cECG) for poststroke atrial fibrillation (AF) screening in a primary care setting is unclear. We aimed to assess the...
BACKGROUND AND PURPOSE
The diagnostic benefit of using continuous ECG (cECG) for poststroke atrial fibrillation (AF) screening in a primary care setting is unclear. We aimed to assess the diagnostic yield from screening patients who previously had a stroke with a 7-day Holter monitor.
METHODS
Patients older than 49 years, naive to AF, with an ischaemic stroke over 1 year before enrolment were included. In a primary care setting, all patients were screened for AF using pulse palpation, 12-lead ECG and 7-day Holter monitoring. Further, NT-proBNP was determined at baseline.
RESULTS
7-day Holter monitoring uncovered AF in 17 of 366 patients (4.6% (95% CI 2.7 to 7.3)). The number needed to screen was 22 patients (14-37). 12-lead ECG uncovered AF in 3 patients (0.82% (95% CI 0.17 to 2.4)), and 122 patients had irregular pulse during pulse palpation (33.5% (95% CI 28.7 to 38.2)). When using 7-day Holter monitoring as reference standard, the sensitivity of pulse palpation and 12-lead ECG was 47% (95% CI 23% to 72%) and 18% (95% CI 4% to 43%). High levels (≥400 pg/mL) of NT-proBNP versus low levels (≤200 pg/mL) were not associated with AF in the univariate analysis nor when adjusted for age (OR 2.4 (95% CI 0.5 to 8.4) and 1.6 (95% CI 0.3 to 6.0)).
CONCLUSIONS
A relevant proportion of patients with stroke more than 1 year before inclusion were diagnosed with AF through 7-day Holter monitoring. Given the low sensitivities of pulse palpation and 12-lead ECG, additional cECG may be considered during poststroke primary care follow-up.
Topics: Aged; Atrial Fibrillation; Brain Ischemia; Electrocardiography, Ambulatory; Female; Follow-Up Studies; Heart Rate; Humans; Male; Mass Screening; Primary Health Care; Prospective Studies; Time Factors
PubMed: 32620555
DOI: 10.1136/heartjnl-2020-316904 -
Biophysical Journal Dec 2021Ultrasound focused toward tumors in the presence of circulating microbubbles improves the delivery of drug-loaded nanoparticles and therapeutic outcomes; however, the...
Ultrasound focused toward tumors in the presence of circulating microbubbles improves the delivery of drug-loaded nanoparticles and therapeutic outcomes; however, the efficacy varies among the different properties and conditions of the tumors. Therefore, there is a need to optimize the ultrasound parameters and determine the properties of the tumor tissue important for the successful delivery of nanoparticles. Here, we propose a mesoscopic model considering the presence of entropic forces to explain the ultrasound-enhanced transport of nanoparticles across the capillary wall and through the interstitium of tumors. The nanoparticles move through channels of variable shape whose irregularities can be assimilated to barriers of entropic nature that the nanoparticles must overcome to reach their targets. The model assumes that focused ultrasound and circulating microbubbles cause the capillary wall to oscillate, thereby changing the width of transcapillary and interstitial channels. Our analysis provides values for the penetration distances of nanoparticles into the interstitium that are in agreement with experimental results. We found that the penetration increased significantly with increasing acoustic intensity as well as tissue elasticity, which means softer and more deformable tissue (Young modulus lower than 50 kPa), whereas porosity of the tissue and pulse repetition frequency of the ultrasound had less impact on the penetration length. We also considered that nanoparticles can be absorbed into cells and to extracellular matrix constituents, finding that the penetration length is increased when there is a low absorbance coefficient of the nanoparticles compared with their diffusion coefficient (close to 0.2). The model can be used to predict which tumor types, in terms of elasticity, will successfully deliver nanoparticles into the interstitium. It can also be used to predict the penetration distance into the interstitium of nanoparticles with various sizes and the ultrasound intensity needed for the efficient distribution of the nanoparticles.
Topics: Drug Delivery Systems; Humans; Microbubbles; Nanoparticles; Neoplasms; Pharmaceutical Preparations
PubMed: 34757075
DOI: 10.1016/j.bpj.2021.10.036 -
PLOS Digital Health Dec 2022Our current understanding of human physiology and activities is largely derived from sparse and discrete individual clinical measurements. To achieve precise, proactive,...
Our current understanding of human physiology and activities is largely derived from sparse and discrete individual clinical measurements. To achieve precise, proactive, and effective health management of an individual, longitudinal, and dense tracking of personal physiomes and activities is required, which is only feasible by utilizing wearable biosensors. As a pilot study, we implemented a cloud computing infrastructure to integrate wearable sensors, mobile computing, digital signal processing, and machine learning to improve early detection of seizure onsets in children. We recruited 99 children diagnosed with epilepsy and longitudinally tracked them at single-second resolution using a wearable wristband, and prospectively acquired more than one billion data points. This unique dataset offered us an opportunity to quantify physiological dynamics (e.g., heart rate, stress response) across age groups and to identify physiological irregularities upon epilepsy onset. The high-dimensional personal physiome and activity profiles displayed a clustering pattern anchored by patient age groups. These signatory patterns included strong age and sex-specific effects on varying circadian rhythms and stress responses across major childhood developmental stages. For each patient, we further compared the physiological and activity profiles associated with seizure onsets with the personal baseline and developed a machine learning framework to accurately capture these onset moments. The performance of this framework was further replicated in another independent patient cohort. We next referenced our predictions with the electroencephalogram (EEG) signals on selected patients and demonstrated that our approach could detect subtle seizures not recognized by humans and could detect seizures prior to clinical onset. Our work demonstrated the feasibility of a real-time mobile infrastructure in a clinical setting, which has the potential to be valuable in caring for epileptic patients. Extension of such a system has the potential to be leveraged as a health management device or longitudinal phenotyping tool in clinical cohort studies.
PubMed: 36812648
DOI: 10.1371/journal.pdig.0000161 -
Cardiology 2023Space travel imposes significant gravitational and radiation stress on both cellular and systemic physiology, resulting in myriad cardiovascular changes that have not...
INTRODUCTION
Space travel imposes significant gravitational and radiation stress on both cellular and systemic physiology, resulting in myriad cardiovascular changes that have not been fully characterized.
METHODS
We conducted a systematic review of the cellular and clinical adaptations of the cardiovascular system after exposure to real or simulated space travel in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The PubMed and Cochrane databases were searched in June 2021 for all peer-reviewed articles published since 1950 related to the following search terms entered in separate pairs: "cardiology and space" and "cardiology and astronaut." Only cellular and clinical studies in English concerning the investigation of cardiology and space were included.
RESULTS
Eighteen studies were identified, comprising 14 clinical and 4 cellular investigations. On the genetic level, pluripotent stem cells in humans and cardiomyocytes in mice displayed increased beat irregularity, with clinical studies revealing a persistent increase in heart rate after space travel. Further cardiovascular adaptations included a higher frequency of orthostatic tachycardia but no evidence of orthostatic hypotension, after return to sea level. Hemoglobin concentration was also consistently decreased after return to Earth. No consistent change in systolic or diastolic blood pressure or any clinically significant arrhythmias were observed during or after space travel.
CONCLUSION
Changes in oxygen carrying capacity, blood pressure, and post-flight orthostatic tachycardia may serve as reasons to further screen for pre-existing anemic and hypotensive conditions among astronauts.
Topics: Humans; Animals; Mice; Space Flight; Astronauts; Heart; Blood Pressure; Tachycardia
PubMed: 37302388
DOI: 10.1159/000531466