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Journal of Cardiovascular... Sep 2021Charge density mapping of atrial fibrillation (AF) reveals dynamic localized rotational activation (LRA), irregular activation (LIA) and focal firing (FF). Their spatial...
BACKGROUND
Charge density mapping of atrial fibrillation (AF) reveals dynamic localized rotational activation (LRA), irregular activation (LIA) and focal firing (FF). Their spatial stability, conduction characteristics and the optimal duration of mapping required to reveal these phenomena and has not been explored.
METHODS
Bi-atrial mapping of AF propagation was undertaken using AcQMap (Acutus Medical) and variability of activation patterns quantified up to a duration of 30 s. The frequency of each pattern was quantified at each unique point of the chamber over two separate 30-s recordings before ablation and R calculated to quantify spatial stability. Regions with the highest frequency were identified at increasing time durations and compared to the result over 30 s using Cohen's kappa. Properties of regions with the most stable patterns were assessed during sinus rhythm and extrastimulus pacing.
RESULTS
In 21 patients, 62 paired LA and RA maps were obtained. LIA was highly spatially stable with R between maps of 0.83 (0.71-0.88) compared to 0.39 (0.24-0.57), and 0.64 (0.54-0.73) for LRA and FF, respectively. LIA was most temporally stable with a kappa of >0.8 reached by 12 s. LRA showed greatest variability with kappa >0.8 only after 22 s. Regions of LIA were of normal voltage amplitude (1.09 mv) but showed increased conduction heterogeneity during extrastimulus pacing (p = .0480).
CONCLUSION
Irregular activation patterns characterized by changing wavefront direction are temporally and spatially stable in contrast with LRA that is transient with least spatial stability. Focal activation appears of intermediate stability. Regions of LIA show increased heterogeneity following extrastimulus pacing and may represent fixed anatomical substrate.
Topics: Atrial Fibrillation; Catheter Ablation; Heart Atria; Heart Conduction System; Heart Rate; Humans
PubMed: 34260134
DOI: 10.1111/jce.15170 -
Ultrasound in Obstetrics & Gynecology :... Dec 2022Fetal heart-rate irregularities occur in 1-2% of pregnancies and are usually caused by premature atrial contractions (PAC). Although PAC are considered benign, they may... (Meta-Analysis)
Meta-Analysis Review
OBJECTIVE
Fetal heart-rate irregularities occur in 1-2% of pregnancies and are usually caused by premature atrial contractions (PAC). Although PAC are considered benign, they may be associated with cardiac defects and tachyarrhythmia. We aimed to determine the incidence of congenital heart defects (CHDs) and complications in fetuses with PAC.
METHODS
This was a systematic review and meta-analysis conducted in accordance with the PRISMA statement for reporting items for systematic reviews and meta-analyses. MEDLINE and EMBASE were searched from 1990 to June 2021 to identify studies on fetuses with PAC. The primary outcome was CHD; secondary outcomes were complications using the endpoints supraventricular tachyarrhythmia (SVT), cardiac failure and intrauterine fetal demise. Meta-analysis of proportions was performed, subdivided into high-risk and low-risk populations based on reason for referral. Pooled incidences with 95% CIs were calculated.
RESULTS
Of 2443 unique articles identified, 19 cohort studies including 2260 fetuses were included. The pooled incidence of CHD in fetuses with PAC was 2.8% (95% CI, 1.5-4.1%), when 0.6% is the incidence expected in the general population. The pooled incidence of CHD was 7.2% (95% CI, 3.5-10.9%) in the high-risk population and 0.9% (95% CI, 0.0-2.0%) in the low-risk population. SVT occurred in 1.4% (95% CI, 0.6-3.4%) of fetuses diagnosed with PAC. Cardiac failure was described in 16 fetuses (1.4% (95% CI, 0.5-3.5%)), of which eight were CHD-related. Intrauterine fetal demise occurred in four fetuses (0.9% (95% CI, 0.5-1.7%)) and was related to CHD in two cases.
CONCLUSIONS
Our findings suggest that the risk of CHD in fetuses with PAC is 4-5 times higher than that in the general population. CHD was present more frequently in the high-risk population. Consequently, an advanced ultrasound examination to diagnose PAC correctly and exclude CHD is recommended. Complications of PAC are rare but can result in fetal demise, thus weekly fetal heart-rate monitoring remains advisable to enable early detection of SVT and to prevent cardiac failure. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Topics: Pregnancy; Female; Humans; Fetal Diseases; Premature Birth; Fetal Death; Atrial Premature Complexes; Fetus; Tachycardia; Arrhythmias, Cardiac; Heart Failure
PubMed: 35763619
DOI: 10.1002/uog.26017 -
Journal of the Association For Research... Jun 2021Although pitch is closely related to temporal periodicity, stimuli with a degree of temporal irregularity can evoke a pitch sensation in human listeners. However, the...
Although pitch is closely related to temporal periodicity, stimuli with a degree of temporal irregularity can evoke a pitch sensation in human listeners. However, the neural mechanisms underlying pitch perception for irregular sounds are poorly understood. Here, we recorded responses of single units in the inferior colliculus (IC) of normal hearing (NH) rabbits to acoustic pulse trains with different amounts of random jitter in the inter-pulse intervals and compared with responses to electric pulse trains delivered through a cochlear implant (CI) in a different group of rabbits. In both NH and CI animals, many IC neurons demonstrated tuning of firing rate to the average pulse rate (APR) that was robust against temporal jitter, although jitter tended to increase the firing rates for APRs ≥ 1280 Hz. Strength and limiting frequency of spike synchronization to stimulus pulses were also comparable between periodic and irregular pulse trains, although there was a slight increase in synchronization at high APRs with CI stimulation. There were clear differences between CI and NH animals in both the range of APRs over which firing rate tuning was observed and the prevalence of synchronized responses. These results suggest that the pitches of regular and irregular pulse trains are coded differently by IC neurons depending on the APR, the degree of irregularity, and the mode of stimulation. In particular, the temporal pitch produced by periodic pulse trains lacking spectral cues may be based on a rate code rather than a temporal code at higher APRs.
Topics: Animals; Cochlear Implantation; Cochlear Implants; Hearing; Mesencephalon; Pitch Perception; Rabbits
PubMed: 33891217
DOI: 10.1007/s10162-021-00792-5 -
Frontiers in Physiology 2021Screening the general public for atrial fibrillation (AF) may enable early detection and timely intervention, which could potentially decrease the incidence of stroke....
BACKGROUND
Screening the general public for atrial fibrillation (AF) may enable early detection and timely intervention, which could potentially decrease the incidence of stroke. Existing screening methods require professional monitoring and involve high costs. AF is characterized by an irregular irregularity of the cardiac rhythm, which may be detectable using an index quantifying and visualizing this type of irregularity, motivating wide screening programs and promoting the research of AF patient subgroups and clinical impact of AF burden.
METHODS
We calculated variability, normality and mean of the difference between consecutive RR interval series (denoted as modified entropy scale-MESC) to quantify irregular irregularities. Based on the variability and normality indices calculated for long 1-lead ECG records, we created a plot termed a regularogram (RGG), which provides a visual presentation of irregularly irregular rates and their burden in a given record. To inspect the potency of these indices, they were applied to train and test a machine learning classifier to identify AF episodes in gold-standard, publicly available databases (PhysioNet) that include recordings from both patients with AF and/or other rhythm disturbances, and from healthy volunteers. The classifier was trained and validated on one database and tested on three other databases.
RESULTS
Irregular irregularities were identified using normality, variability and mean MESC indices. The RGG displayed visually distinct differences between patients with vs. without AF and between patients with different levels of AF burden. Training a simple, explainable machine learning tool integrating these three indices enabled AF detection with 99.9% accuracy, when trained on the same person, and 97.8%, when trained on patients from a different database. Comparison to other RR interval-based AF detection methods that utilize signal processing, classic machine learning and deep learning techniques, showed superiority of our suggested method.
CONCLUSION
Visualizing and quantifying irregular irregularities will be of value for both rapid visual inspection of long Holter recordings for the presence and the burden of AF, and for machine learning classification to identify AF episodes. A free online tool for calculating the indices, drawing RGGs and estimating AF burden, is available.
PubMed: 33679450
DOI: 10.3389/fphys.2021.637680 -
Plants (Basel, Switzerland) Apr 2021Pulses are a key component of crop production systems in Southern Australia due to their rotational benefits and potential profit margins. However, cultivation in... (Review)
Review
Pulses are a key component of crop production systems in Southern Australia due to their rotational benefits and potential profit margins. However, cultivation in temperate cropping systems such as that of Southern Australia is limited by low soil water availability and subsoil constraints. This limitation of soil water is compounded by the irregular rainfall, resulting in the absence of plant available water at depth. An increase in the productivity of key pulses and expansion into environments and soil types traditionally considered marginal for their growth will require improved use of the limited soil water and adaptation to sub soil constrains. Roots serve as the interface between soil constraints and the whole plant. Changes in root system architecture (RSA) can be utilised as an adaptive strategy in achieving yield potential under limited rainfall, heterogenous distribution of resources and other soil-based constraints. The existing literature has identified a "'Steep, Deep and Cheap" root ideotype as a preferred RSA. However, this idiotype is not efficient in a temperate system where plant available water is limited at depth. In addition, this root ideotype and other root architectural studies have focused on cereal crops, which have different structures and growth patterns to pulses due to their monocotyledonous nature and determinant growth habit. The paucity of pulse-specific root architectural studies warrants further investigations into pulse RSA, which should be combined with an examination of the existing variability of known genetic traits so as to develop strategies to alleviate production constraints through either tolerance or avoidance mechanisms. This review proposes a new model of root system architecture of "Wide, Shallow and Fine" roots based on pulse roots in temperate cropping systems. The proposed ideotype has, in addition to other root traits, a root density concentrated in the upper soil layers to capture in-season rainfall before it is lost due to evaporation. The review highlights the potential to achieve this in key pulse crops including chickpea, lentil, faba bean, field pea and lupin. Where possible, comparisons to determinate crops such as cereals have also been made. The review identifies the key root traits that have shown a degree of adaptation via tolerance or avoidance to water stress and documents the current known variability that exists in and amongst pulse crops setting priorities for future research.
PubMed: 33916833
DOI: 10.3390/plants10040692 -
Progress in Cardiovascular Diseases 2021The medical community's understanding of the consequences of premature ventricular contractions (PVCs) and PVC-induced cardiomyopathy has been derived mostly from... (Review)
Review
The medical community's understanding of the consequences of premature ventricular contractions (PVCs) and PVC-induced cardiomyopathy has been derived mostly from observational and large population-based studies. Due to the difficulty of predicting the development of PVC-cardiomyopathy, the acute and chronic cardiac effects of PVCs and the mechanism of PVC-cardiomyopathy have been derived from pre-clinical studies with large animal models. Recently, these studies have described myocardial substrates that could potentially increase morbidity and mortality in patients with frequent PVCs and PVC-cardiomyopathy. In this paper, we provide an up-to-date comprehensive review of these pre-clinical and clinical studies.
Topics: Action Potentials; Animals; Cardiomyopathies; Heart Conduction System; Heart Rate; Humans; Prevalence; Prognosis; Risk Factors; Translational Research, Biomedical; Ventricular Premature Complexes
PubMed: 33857575
DOI: 10.1016/j.pcad.2021.04.001 -
Sensors (Basel, Switzerland) Jun 2023The number of people experiencing mental stress or emotional dysfunction has increased since the onset of the COVID-19 pandemic, as many individuals have had to adapt...
The number of people experiencing mental stress or emotional dysfunction has increased since the onset of the COVID-19 pandemic, as many individuals have had to adapt their daily lives. Numerous studies have demonstrated that mental health disorders can pose a risk for certain diseases, and they are also closely associated with the problem of mental workload. Now, wearable devices and mobile health applications are being utilized to monitor and assess individuals' mental health conditions on a daily basis using heart rate variability (HRV), typically measured by the R-to-R wave interval (RRI) of an electrocardiogram (ECG). However, portable or wearable ECG devices generally require two electrodes to perform bipolar limb leads, such as the Einthoven triangle. This study aims to develop a single-arm ECG measurement method, with lead I ECG serving as the gold standard. We conducted static and dynamic experiments to analyze the morphological performance and signal-to-noise ratio (SNR) of the single-arm ECG. Three morphological features were defined, RRI, the duration of the QRS complex wave, and the amplitude of the R wave. Thirty subjects participated in this study. The results indicated that RRI exhibited the highest cross-correlation (R = 0.9942) between the single-arm ECG and lead I ECG, while the duration of the QRS complex wave showed the weakest cross-correlation (R = 0.2201). The best SNR obtained was 26.1 ± 5.9 dB during the resting experiment, whereas the worst SNR was 12.5 ± 5.1 dB during the raising and lowering of the arm along the z-axis. This single-arm ECG measurement method offers easier operation compared to traditional ECG measurement techniques, making it applicable for HRV measurement and the detection of an irregular RRI.
Topics: Humans; Pandemics; COVID-19; Wearable Electronic Devices; Electrocardiography; Heart Rate
PubMed: 37447668
DOI: 10.3390/s23135818 -
Work (Reading, Mass.) 2017Cynicism, as a personality trait, has adverse effects on health. The question was asked whether cynical attitudes that develop due to work-related stress correlate with...
BACKGROUND
Cynicism, as a personality trait, has adverse effects on health. The question was asked whether cynical attitudes that develop due to work-related stress correlate with stress levels and whether it has a negative influence on health.
OBJECTIVES
To investigate associations of the cynicism subscale scores of the Maslach Burnout Inventory-General Survey (MBI-GS) with levels of stress, anxiety, questionnaire-based physical health and with a number of physiological health risk indicators.
METHODS
Cynicism, anxiety, questionnaire-based physical health scores, as well as allostatic load, heart rate variability and C-reactive protein, were assessed in 27 males working between 40 and 80 irregular hours per week.
RESULTS
Cynicism scores related to stress levels (r = 0.411, p = 0.030). Effects of work-related cynicism on physical health were suggested by negative associations with questionnaire-based scores on physical health (r = -0.383, p = 0.044) and heart rate variability indicators (r = -0.379, p = 0.047 to r = -0.496, p = 0.007), and by positive associations with anxiety levels (r = 0.408, p = 0.031), heart rate (r = 0.449, p = 0.017), BMI (r = 0.426, p = 0.024) allostatic load (r = 0.360, p = 0.065) and levels of the inflammatory marker C-reactive protein (r = 0.407, p = 0.035).
CONCLUSIONS
Cynicism, as reflected by the MBI-GS, increases with increased stress levels and could contribute to the decline in the health reported for burnout.
Topics: Anxiety Disorders; Burnout, Professional; C-Reactive Protein; Heart Rate; Humans; Male; Personality; Risk Factors; Stress, Psychological; Surveys and Questionnaires
PubMed: 28339417
DOI: 10.3233/WOR-172518 -
Prediction of atrial fibrillation using a home blood pressure monitor with a high-resolution system.Open Heart Sep 2022The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a...
OBJECTIVE
The usefulness of screening for atrial fibrillation (AF) using several home blood pressure (BP) monitors has been reported. We evaluated the accuracy of a high-resolution system (HiRS) for AF prediction and its usefulness when installed in home BP monitors.
METHODS
In patients with paroxysmal, persistent or permanent AF, ECG recording and BP measurements were performed simultaneously. The relationship between ECG rhythm diagnosis and pulse irregularity recognition, using a home BP monitor with HiRS, was investigated. The severity of a pulse disturbance during BP measurement was displayed as an irregular pulse rhythm symbol (IPRS) in three instances. The IPRS was not displayed if the pulse was regular, turned on if there was a weak variation in the pulse, and blinked if there was a strong variation in the pulse.
RESULTS
One hundred and seven patients (44 paroxysmal AF, 63 persistent or permanent AF) were enrolled, and a total of 333 recordings were analysed. The rhythms recorded by each ECG were 73 sinus regular rhythms, 35 extrasystoles, 222 AFs and 3 atrial flutters. Sensitivity and specificity for the prediction of any arrhythmia by the IPRS display of the BP monitor were 95.8% (95% CI 92.6% to 97.6%) and 96.8% (95% CI 92.6% to 100%), respectively. In addition, sensitivity and specificity for the prediction of AF were 100% (95% CI 97.5% to 100%) and 74.8% (95% CI 65.6% to 82.5%), respectively. Sensitivity and specificity for the prediction of AF by the IPRS blinking display were 88.3% (95% CI 83.3% to 92.2%) and 94.6% (95% CI 88.6% to 98.0%%), respectively. IPRS exhibited lighting or blinking during AF occurrence; however, during sinus rhythm, IPRS was not displayed in 72 out of 73 recordings.
CONCLUSION
The IPRS device predicted AF with precision and may be particularly useful for predicting an arrhythmia attack in patients with paroxysmal AF.
Topics: Atrial Fibrillation; Blood Pressure Monitors; Electrocardiography; Heart Rate; Humans; Sensitivity and Specificity
PubMed: 36170999
DOI: 10.1136/openhrt-2022-002006 -
Clinical Cardiology May 2021The 2020 European Society of Cardiology atrial fibrillation guidelines recommend opportunistic screening for atrial fibrillation by pulse taking or ECG rhythm strip in...
BACKGROUND
The 2020 European Society of Cardiology atrial fibrillation guidelines recommend opportunistic screening for atrial fibrillation by pulse taking or ECG rhythm strip in those aged over 65 years.
HYPOTHESIS
We aimed to compare the diagnostic accuracy of pulse palpation to ECG rhythm strip when screening for atrial fibrillation. A secondary aim was to investigate whether participants with palpitations were more likely to be diagnosed with new atrial fibrillation.
METHODS
The study population were 75/76 year old individuals that participated in the STROKESTOP II study, a Swedish screening study for atrial fibrillation. Pulse palpation of the radial pulse for 30 sec was performed by healthcare professionals and recorded as regular or irregular. Thereafter a 30-sec single-lead ECG was registered. Patients were asked also if they had a history of palpitations.
RESULTS
Of the 6159 participants included in the study, 461 (7.5%) had irregular pulse. Twenty-two (4.8%) of those with irregular pulse were diagnosed with atrial fibrillation on single-lead ECG rhythm strip. Among those with regular pulse, 6 (0.1%) cases of new atrial fibrillation were found. The sensitivity of the pulse palpation test was 78.6% and positive predictive value 4.8%. The proportion of newly diagnosed atrial fibrillation was not different between those with and without history of palpitations.
CONCLUSION
Pulse palpation was inferior to single-lead ECG when screening for atrial fibrillation. We therefore advocate the use of single-lead ECG rather than pulse palpation when screening for atrial fibrillation. Palpitations did not predict atrial fibrillation.
Topics: Aged; Aged, 80 and over; Atrial Fibrillation; Cohort Studies; Electrocardiography; Female; Heart Rate; Humans; Male; Mass Screening; Palpation
PubMed: 33724492
DOI: 10.1002/clc.23595