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Heart Rhythm Apr 2019
Topics: Aged; Electrocardiography; Female; Heart Rate; Humans; Sick Sinus Syndrome
PubMed: 30929673
DOI: 10.1016/j.hrthm.2018.11.004 -
Computers in Biology and Medicine Mar 2023Mortality prediction is crucial to evaluate the severity of illness and assist in improving the prognosis of patients. In clinical settings, one way is to analyze the...
Mortality prediction is crucial to evaluate the severity of illness and assist in improving the prognosis of patients. In clinical settings, one way is to analyze the multivariate time series (MTSs) of patients based on their medical data, such as heart rates and invasive mean arterial blood pressure. However, this suffers from sparse, irregularly sampled, and incomplete data issues. These issues can compromise the performance of follow-up MTS-based analytic applications. Plenty of existing methods try to deal with such irregular MTSs with missing values by capturing the temporal dependencies within a time series, yet in-depth research on modeling inter-MTS couplings remains rare and lacks model interpretability. To this end, we propose a bidirectional time and multi-feature attention coupled network (BiT-MAC) to capture the temporal dependencies (i.e., intra-time series coupling) and the hidden relationships among variables (i.e., inter-time series coupling) with a bidirectional recurrent neural network and multi-head attention, respectively. The resulting intra- and inter-time series coupling representations are then fused to estimate the missing values for a more robust MTS-based prediction. We evaluate BiT-MAC by applying it to the missing-data corrupted mortality prediction on two real-world clinical datasets, i.e., PhysioNet'2012 and COVID-19. Extensive experiments demonstrate the superiority of BiT-MAC over cutting-edge models, verifying the great value of the deep and hidden relations captured by MTSs. The interpretability of features is further demonstrated through a case study.
Topics: Humans; Time Factors; COVID-19; Heart Rate; Neural Networks, Computer
PubMed: 36774888
DOI: 10.1016/j.compbiomed.2023.106586 -
Heart Rhythm Jul 2020
Topics: Adult; Electrocardiography; Heart Conduction System; Heart Rate; Humans; Male; Tachycardia
PubMed: 32616294
DOI: 10.1016/j.hrthm.2020.01.021 -
European Journal of Internal Medicine Dec 2008Delta 9-tetrahydrocannabinol (THC) is the major active component of cannabis. Cardiovascular effects of THC have previously been reported: tachycardia after intake, but...
BACKGROUND
Delta 9-tetrahydrocannabinol (THC) is the major active component of cannabis. Cardiovascular effects of THC have previously been reported: tachycardia after intake, but also bradycardia at higher doses. The purpose of this study was, firstly, to investigate the frequency and irregularity of heart rate in a group of cannabis users in their natural surroundings. We also compared THC-positive drivers with a regular pulse with THC-positive drivers with an irregular pulse.
METHODS
The division of Forensic Toxicology and Drug Abuse (DFTDA) at the Norwegian Institute of Public Heath analyzes blood samples from all drivers suspected of driving under the influence of drugs. We studied pulse rate and regularity in 502 THC-positive drivers who tested negative for other substances. As a control group, we randomly selected 125 drug-negative cases from the database of the DFTDA; no alcohol, narcotics, or medicinal drugs of abuse were detected.
RESULTS
The Delta9-THC-positive drivers had a higher mean pulse rate than the control group [82.8 beats/min (SD 16.3) versus 75.6 beats/min (SD 9.2)] and more cases with tachycardia were detected in the Delta9-THC-positive group (19.4% versus 1.6%). There was only one driver with an irregular heart beat in the control group, while there were nine among the Delta9-THC-positive drivers. The drivers with an irregular pulse were over-represented amongst those with the lowest blood Delta9-THC concentrations.
CONCLUSION
This report represents a large study of subjects in a real-life situation and includes observations on pulse frequency, regularity, and blood Delta9-THC concentration. A substantial fraction of Delta9-THC-positive drivers had tachycardia, but there was no correlation between blood Delta9-THC concentration and pulse rate in the present study. We had no further diagnostic information on the cause of the pulse irregularities, but our results indicate that occasional users of cannabis tend to have irregular heart rates at low THC concentrations and at low pulse rates.
Topics: Adult; Automobile Driving; Cannabis; Case-Control Studies; Dronabinol; Female; Hallucinogens; Heart Rate; Humans; Male; Substance Abuse Detection; Tachycardia
PubMed: 19046727
DOI: 10.1016/j.ejim.2007.06.031 -
Annals of the New York Academy of... Dec 2001Approximate entropy (ApEn) is a recently formulated family of parameters and statistics quantifying regularity (orderliness) in serial data, with developments within... (Review)
Review
Approximate entropy (ApEn) is a recently formulated family of parameters and statistics quantifying regularity (orderliness) in serial data, with developments within theoretical mathematics as well as numerous applications to multiple biological contexts. We discuss the motivation for ApEn development, from the study of inappropriate application of dynamical systems (complexity) algorithms to general time-series settings. ApEn is scale invariant and model independent, evaluates both dominant and subordinant patterns in data, and discriminates series for which clear feature recognition is difficult. ApEn is applicable to systems with at least 50 data points and to broad classes of models: it can be applied to discriminate both general classes of correlated stochastic processes, as well as noisy deterministic systems. Moreover, ApEn is complementary to spectral and autocorrelation analyses, providing effective discriminatory capability in instances in which the aforementioned measures exhibit minimal distinctions. Representative ApEn applications to human aging studies, based on both heart rate and endocrinologic (hormonal secretory) time series, are featured. Heart rate (HR) studies include gender- and age-related changes in HR dynamics in older subjects, and analyses of "near-SIDS" infants. Endocrinologic applications establish clear quantitative changes in joint LH-testosterone secretory dynamics in older versus younger men (a "partial male menopause"), via cross-ApEn, a related two-variable asynchrony formulation; a disruption in LH-FSH-NPT (penile tumescence) synchrony in older subjects; and changes in LH-FSH secretory dynamics across menopause. The capability of ApEn to assess relatively subtle disruptions, typically found earlier in the history of a subject than mean and variance changes, holds the potential for enhanced preventative and earlier interventionist strategies.
Topics: Algorithms; Animals; Discriminant Analysis; Female; Health Status; Heart Rate; Humans; Male; Models, Theoretical; Rats; Sex Factors
PubMed: 11797860
DOI: 10.1111/j.1749-6632.2001.tb02755.x -
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 -
Medicine Sep 2022Aim of the study was to evaluate the effect of high and irregular heart rate on the image quality and on the radiation exposure using a 256-row, 16-cm wide detector...
Aim of the study was to evaluate the effect of high and irregular heart rate on the image quality and on the radiation exposure using a 256-row, 16-cm wide detector computed tomography (CT) system. Between March and December 2019, 349 patients undergoing CT coronary angiography (CTCA) were prospectively enrolled. Patients were divided into 2 study groups; Group 1 included patients with a regular heart rate of ≤70 bpm, while Group 2 included patients with an irregular heart rhythm or heart rate of >70 bpm. In all patients, image quality score and radiation dose were analyzed and recorded. In Group 1, there were a total of 195 patients, while in Group 2, there were 154 patients. Of the 349 patients, 299 of them had a regular heart rhythm (85.7%) and 50 (14.3%) had an irregular heart rhythm. Mean heart rate during scanning was 59 ± 7 bpm in Group 1 and 80 ± 12 bpm in Group 2. Mean effective dose of CTCA in Group 1 (1.2 ± 0.8 mSv) was lower than in Group 2 (1.9 ± 1.2 mSv, P < .001). Mean image quality (Likert score) of Group 1 was significantly higher than in Group 2 (4.1 vs 3.4, P < .001). CT scanner with 16-cm wide detector enables low-radiation exposure during CTCA even at high heart rate or irregular heart rhythm. Good CTCA image quality and low dose are related to low heart rate.
Topics: Coronary Angiography; Heart Rate; Humans; Radiation Dosage; Tomography Scanners, X-Ray Computed; Tomography, X-Ray Computed
PubMed: 36123855
DOI: 10.1097/MD.0000000000030583 -
Scientific Reports Nov 2023A medical check-up during driving enables the early detection of diseases. Heartbeat irregularities indicate possible cardiovascular diseases, which can be determined...
A medical check-up during driving enables the early detection of diseases. Heartbeat irregularities indicate possible cardiovascular diseases, which can be determined with continuous health monitoring. Therefore, we develop a redundant sensor system based on electrocardiography (ECG) and photoplethysmography (PPG) sensors attached to the steering wheel, a red, green, and blue (RGB) camera behind the steering wheel. For the video, we integrate the face recognition engine SeetaFace to detect landmarks of face segments continuously. Based on the green channel, we derive colour changes and, subsequently, the heartbeat. We record the ECG, PPG, video, and reference ECG with body electrodes of 19 volunteers during different driving scenarios, each lasting 15 min: city, highway, and countryside. We combine early, signal-based late, and sensor-based late fusion with a hybrid convolutional neural network (CNN) and integrated majority voting to deliver the final heartbeats that we compare to the reference ECG. Based on the measured and the reference heartbeat positions, the usable time was 51.75%, 58.62%, and 55.96% for the driving scenarios city, highway, and countryside, respectively, with the hybrid algorithm and combination of ECG and PPG. In conclusion, the findings suggest that approximately half the driving time can be utilised for in-vehicle heartbeat monitoring.
Topics: Humans; Heart Rate; Signal Processing, Computer-Assisted; Electrocardiography; Algorithms; Neural Networks, Computer; Photoplethysmography
PubMed: 38012195
DOI: 10.1038/s41598-023-47484-z -
Bipolar Disorders Oct 2006The quantification of subtle patterns in sequential data, and their changes, has considerable potential utility throughout psychiatry, including the analyses of mood... (Review)
Review
OBJECTIVES
The quantification of subtle patterns in sequential data, and their changes, has considerable potential utility throughout psychiatry, including the analyses of mood ratings, heart rate, respiratory, and electroencephalographic recordings.
METHODS
Approximate entropy (ApEn), a relatively recently developed statistic quantifying serial irregularity, has been applied in numerous studies throughout mathematics and other fields of study, especially biology.
RESULTS
We discussed applications of ApEn, both extant and potential, of most relevance to psychiatrists. We provided a mechanistic interpretation of lowered ApEn values, and discusses the relationship between ApEn and other (both classical and complexity) measures of serial dynamics. We also briefly discussed cross-ApEn, a thematically similar quantification of two-variable asynchrony that can aid in uncovering subtle disruptions in complicated network dynamics.
CONCLUSIONS
ApEn and cross-ApEn have significant potential to consequentially enhance present statistical methodologies of analysis of psychiatric data, in both clinical and in research settings.
Topics: Adult; Affect; Aged; Arousal; Biological Clocks; Bipolar Disorder; Data Collection; Electroencephalography; Entropy; Female; Heart Rate; Humans; Luteinizing Hormone; Male; Middle Aged; Nonlinear Dynamics; Psychometrics; Testosterone
PubMed: 17042881
DOI: 10.1111/j.1399-5618.2006.00375.x -
Annals of Biomedical Engineering Sep 2017Prophylactic treatment has been proved to reduce hypotension incidence after spinal anesthesia during cesarean labor. However, the use of pharmacological prophylaxis... (Randomized Controlled Trial)
Randomized Controlled Trial
Prophylactic treatment has been proved to reduce hypotension incidence after spinal anesthesia during cesarean labor. However, the use of pharmacological prophylaxis could carry out undesirable side-effects on mother and fetus. Thus, the prediction of hypotension becomes an important challenge. Hypotension events are hypothesized to be related to a malfunctioning of autonomic nervous system (ANS) regulation of blood pressure. In this work, ANS responses to positional changes of 51 pregnant women programmed for a cesarean labor were explored for hypotension prediction. Lateral and supine decubitus, and sitting position were considered while electrocardiographic and pulse photoplethysmographic signals were recorded. Features based on heart rate variability, pulse rate variability (PRV) and pulse transit time (PTT) analysis were used in a logistic regression classifier. The results showed that PRV irregularity changes, assessed by approximate entropy, from supine to lateral decubitus, and standard deviation of PTT in supine decubitus were found as the combination of features that achieved the best classification results sensitivity of 76%, specificity of 70% and accuracy of 72%, being normotensive the positive class. Peripheral regulation and blood pressure changes, measured by PRV and PTT analysis, could help to predict hypotension events reducing prophylactic side-effects in the low-risk population.
Topics: Adult; Anesthesia, Spinal; Cesarean Section; Female; Heart Rate; Humans; Hypotension; Predictive Value of Tests; Pregnancy; Pulse Wave Analysis
PubMed: 28699041
DOI: 10.1007/s10439-017-1864-y