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Current Pharmaceutical Design 2014During the organogenic period of development the cardiovascular system of the embryo fulfills several functions including delivery of oxygen and nutrients and a... (Review)
Review
During the organogenic period of development the cardiovascular system of the embryo fulfills several functions including delivery of oxygen and nutrients and a hemodynamic role necessary for cardiac morphogenesis, angiogenesis and hematopoiesis. It is expected that at each stage of embryonic development there is an ideal embryonic heart rate and contractility that maintains the optimal blood flow and pressure to fulfill these various functions. In vitro rat embryo culture studies have revealed that many therapeutic drugs (antiarrhythmics, antidepressants, antipsychotics and anticonvulsants), that may be taken during human pregnancy, cause a concentrationdependent slowing of the embryonic heart and irregular heart rate at higher concentrations. The concentrations causing bradycardia in vitro are often close to human therapeutic plasma concentrations and raise concern that these drugs can potentially cause embryonic death or malformations, and that current reproductive toxicity testing does not adequately examine possible effects of drugs on the embryo's cardiac function.
Topics: Animals; Bradycardia; Cardiotonic Agents; Drug-Related Side Effects and Adverse Reactions; Embryonic Development; Female; Heart Rate; Humans; Pregnancy; Rats; Risk Factors
PubMed: 24502593
DOI: 10.2174/1381612820666140205151146 -
PloS One 2022The remote photoplethysmography (rPPG) based on cameras, a technology for extracting pulse wave from videos, has been proved to be an effective heart rate (HR)...
The remote photoplethysmography (rPPG) based on cameras, a technology for extracting pulse wave from videos, has been proved to be an effective heart rate (HR) monitoring method and has great potential in many fields; such as health monitoring. However, the change of facial color intensity caused by cardiovascular activities is weak. Environmental illumination changes and subjects' facial movements will produce irregular noise in rPPG signals, resulting in distortion of heart rate pulse signals and affecting the accuracy of heart rate measurement. Given the irregular noises such as motion artifacts and illumination changes in rPPG signals, this paper proposed a new method named LA-SSA. It combines low-rank sparse matrix decomposition and autocorrelation function with singular spectrum analysis (SSA). The low-rank sparse matrix decomposition is employed to globally optimize the components of the rPPG signal obtained by SSA, and some irregular noise is removed. Then, the autocorrelation function is used to optimize the global optimization results locally. The periodic components related to the heartbeat signal are selected, and the denoised rPPG signal is obtained by weighted reconstruction with a singular value ratio. The experiment using UBFC-RPPG and PURE database is performed to assess the performance of the method proposed in this paper. The average absolute error was 1.37 bpm, the 95% confidence interval was -7.56 bpm to 6.45 bpm, and the Pearson correlation coefficient was 98%, superior to most existing video-based heart rate extraction methods. Experimental results show that the proposed method can estimate HR effectively.
Topics: Humans; Heart Rate; Algorithms; Heart Rate Determination; Movement; Motion; Photoplethysmography; Signal Processing, Computer-Assisted
PubMed: 36584011
DOI: 10.1371/journal.pone.0275544 -
Chinese Journal of Integrative Medicine Aug 2017To comprehensively evaluate the health status of 6 volunteers from the Mars 500 Project through analyzing their pulse graphs and determining the changes in...
OBJECTIVE
To comprehensively evaluate the health status of 6 volunteers from the Mars 500 Project through analyzing their pulse graphs and determining the changes in cardiovascular function, degree of fatigue and autonomic nervous function.
METHODS
Six volunteers were recruited; all were male aged 26-38 years (average 31.83±4.96 years). Characteristic parameters reflflecting the status of cardiovascular functions were extracted, which included left ventricular contraction, vascular elasticity and peripheral resistance. The degree of fatigue was determined depending on the difference between the calendar age and biological age, which was calculated through the analysis of blood pressure value and characteristic parameters. Based on the values of pulse height variation and pulse time variation on a 30-s pulse graph, autonomic nervous function was evaluated. All parameters examined were marked on an equilateral polygon to form an irregular polygon of the actual fifigure, then health status was evaluated based on the coverage area of the actual fifigure.
RESULTS
The results demonstrated: (1) volunteers developed weakened pulse power, increased vascular tension and peripheral resistance, and slight decreased ventricular systolic function; (2) the degree of fatigue was basically mild or moderate; and (3) autonomic nervous function was excited but generally balanced.
CONCLUSIONS
These volunteers were in the state of sub-health. According to Chinese medicine theories, such symptoms are mainly caused by the weakening of healthy qi, Gan (Liver) failing in free coursing, and disharmony between Gan and Wei (Stomach), which manifests as a weak and string-like pulse.
Topics: Autonomic Nervous System; Fatigue; Health Status; Heart Function Tests; Humans; Myocardial Contraction; Pulse; Time Factors; Vascular Resistance; Ventricular Function; Volunteers
PubMed: 28028716
DOI: 10.1007/s11655-016-2539-5 -
JAMA Internal Medicine Jan 2018
Topics: Atrial Fibrillation; Diagnosis, Differential; Electrocardiography; Female; Heart Rate; Humans; Wolff-Parkinson-White Syndrome; Young Adult
PubMed: 29204599
DOI: 10.1001/jamainternmed.2017.7030 -
Critical Care (London, England) 2009Bacterial infection leading to organ failure is the most common cause of death in critically ill patients. Early diagnosis and expeditious treatment is a cornerstone of... (Review)
Review
Bacterial infection leading to organ failure is the most common cause of death in critically ill patients. Early diagnosis and expeditious treatment is a cornerstone of therapy. Evaluating the systemic host response to infection as a complex system provides novel insights: however, bedside application with clinical value remains wanting. Providing an integrative measure of an altered host response, the patterns and character of heart rate fluctuations measured over intervals-in-time may be analysed with a panel of mathematical techniques that quantify overall fluctuation, spectral composition, scale-free variation, and degree of irregularity or complexity. Using these techniques, heart rate variability (HRV) has been documented to be both altered in the presence of systemic infection, and correlated with its severity. In this review and analysis, we evaluate the use of HRV monitoring to provide early diagnosis of infection, document the prognostic implications of altered HRV in infection, identify current limitations, highlight future research challenges, and propose improvement strategies. Given existing evidence and potential for further technological advances, we believe that longitudinal, individualized, and comprehensive HRV monitoring in critically ill patients at risk for or with existing infection offers a means to harness the clinical potential of this bedside application of complex systems science.
Topics: Bacterial Infections; Critical Illness; Heart Rate; Humans; Observer Variation; Prognosis; Resuscitation
PubMed: 20017889
DOI: 10.1186/cc8132 -
Drugs 2003The clinical relevance and high social costs of atrial fibrillation have boosted interest in rate control as a cost-effective alternative to long-term maintenance of... (Review)
Review
The clinical relevance and high social costs of atrial fibrillation have boosted interest in rate control as a cost-effective alternative to long-term maintenance of sinus rhythm (i.e. rhythm control). Prospective studies show that rate control (coupled with thromboembolic prophylaxis) is a valuable treatment option for all forms of atrial fibrillation. The rationale for rate control is that high ventricular rates, frequently found in atrial fibrillation, lead to haemodynamic impairment, consisting of a variable combination of loss of atrial kick, irregularity in ventricular response and inappropriately rapid ventricular rate, depending on the type of underlying heart disease. Long-term persistence of tachycardia at a high ventricular rate can lead to various degrees of ventricular dysfunction and even to tachycardiomyopathy-related heart failure. Identification of this reversible and often concealed form of left ventricular dysfunction can permit effective management by rate (or rhythm) control. Although acute rate control (to reduce ventricular rate within hours) is still often based on digoxin administration, for patients without left ventricular dysfunction, calcium channel antagonists or beta-adrenoceptor antagonists (beta-blockers) are generally more appropriate and effective. In chronic atrial fibrillation, long-term rate control (to reduce morbidity/mortality and improve quality of life) must be adapted to patients' individual characteristics to grant control during daily activities, including exercise. According to current guidelines, the clinical target of rate control should be a ventricular rate below 80-90 bpm at rest. However, in many patients, assessment of the appropriateness of different drugs should include exercise testing and 24h-Holter monitoring, for which specific guidelines are needed. In practice, rate control is considered a valid alternative to rhythm control. Recent prospective trials (e.g. the Pharmacological Intervention in Atrial Fibrillation [PIAF] and the Atrial Fibrillation Follow-up Investigation of Rhythm Management [AFFIRM] trials) have shown that in selected patients, rate control provides similar benefits, more economically, in terms of quality of life and long-term mortality. The choice of a rate control medication (digoxin, beta-blockers, calcium channel antagonists or possibly amiodarone) or a non-pharmacological approach (mainly atrioventricular node ablation coupled with pacing) must currently be based on clinical assessment, which includes assessing the presence of underlying heart disease and haemodynamic impairment. Definite guidelines are required for each different subset of patients. Rate control is particularly tricky in patients with heart failure, for whom non-pharmacological options can also be considered. The preferred pharmacological options are beta-blockers for stabilised heart failure and digoxin for unstabilised forms.
Topics: Animals; Anti-Arrhythmia Agents; Atrial Fibrillation; Disease Management; Heart Failure; Heart Rate; Humans; Monitoring, Physiologic
PubMed: 12834366
DOI: 10.2165/00003495-200363140-00005 -
Current Opinion in Cardiology Mar 2006The aim of this article is to provide a perspective on rate control in atrial fibrillation which emphasizes patient wellbeing (exercise tolerance, symptoms, quality of... (Comparative Study)
Comparative Study Review
PURPOSE OF REVIEW
The aim of this article is to provide a perspective on rate control in atrial fibrillation which emphasizes patient wellbeing (exercise tolerance, symptoms, quality of life) over attempts to reduce resting or exercise heart rate to an arbitrary range.
RECENT FINDINGS
Recent trials of rhythm versus rate control strategies of treatment in patients with atrial fibrillation suggest that rate control is a viable first line strategy in many patients. The adverse consequences of atrial fibrillation with rapid ventricular response are partly due to factors other than rate itself, such as irregularity of ventricular response, and variable changes in autonomic nervous system output. Digoxin, calcium channel blockers, and beta-blockers cause a similar reduction in resting heart rate. Beta blockers are the most potent at reducing exercise heart rate, followed by calcium channel blockers and digoxin. Exercise tolerance is occasionally improved by digoxin, sometimes improved by calcium channel blockers and not improved by (and sometimes decreased by) beta-blockers. Information about quality of life with different rate control regimens is sparse.
SUMMARY
Rate control in atrial fibrillation provides important benefits to patients in terms of symptoms, quality of life and prevention of late consequences of uncontrolled rate (such as tachycardia induced cardiomyopathy). Restricting treatment objectives to achievement of a specific heart rate range on resting or exercise electrocardiogram may result in lack of patient benefit or worsened symptoms. Understanding the nuances of rate control when treating individual patients and interpreting existing evidence allows patients to experience the most benefit from this treatment strategy.
Topics: Anti-Arrhythmia Agents; Atrial Fibrillation; Electrocardiography; Exercise; Heart Failure; Heart Rate; Hemodynamics; Humans; Quality of Life; Randomized Controlled Trials as Topic; Rest
PubMed: 16470141
DOI: 10.1097/01.hco.0000210303.33866.c7 -
BMC Geriatrics Sep 2017Atrial fibrillation (AF) is often asymptomatic and undiagnosed until an ischaemic stroke occurs. An irregular pulse is a key manifestation of AF. We assessed whether... (Clinical Trial)
Clinical Trial
BACKGROUND
Atrial fibrillation (AF) is often asymptomatic and undiagnosed until an ischaemic stroke occurs. An irregular pulse is a key manifestation of AF. We assessed whether pulse self-palpation is feasible in screening of AF.
METHODS
Altogether 205 residents of Lieto municipality aged ≥75 years were randomized in 2012 to receive brief education on pulse palpation focusing on evaluating rhythm regularity. Self-detected pulse irregularity and new AF diagnoses were recorded, and the subjects' quality of life and use of health care services were assessed during a three-year follow-up.
RESULTS
The subjects' median age was 78.2 [3.8] years, and 89 (43.4%) were men. Overall, 139 (68%) subjects had initial good motivation/capability for regular palpation. At four months, 112 (80.6%) subjects with good and 26 (39.4%) with inadequate motivation/capability palpated their pulse daily. At 12 months, 120 (58.5%) and at 36 months, 69 (33.7%) subjects palpated their pulse at least weekly. During the intervention, 67 (32.7%) subjects reported pulse irregularity. New AF was found in 10 (4.9%) subjects, 7 (70%) of whom had reported pulse irregularity. Pulse irregularity independently predicted new AF, but only one (0.5%) subject with new AF sought undelayed medical attention due to pulse irregularity. Quality of life and number of outpatient clinic visits remained unchanged during follow-up.
CONCLUSION
Pulse palpation can be learned also by the elderly, but it is challenging to form a continuing habit. The low persistence of pulse self-palpation limits its value in the screening of AF, and strategies to promote persistence and research on alternative screening methods are needed.
TRIAL REGISTRATION
http://www.ClinicalTrials.gov identifier: NCT01721005. The trial was registered retrospectively on October 26, 2012.
Topics: Aged; Aged, 80 and over; Ambulatory Care; Atrial Fibrillation; Feasibility Studies; Female; Finland; Follow-Up Studies; Heart Rate; Humans; Male; Palpation; Patient Education as Topic; Self Care; Self-Examination
PubMed: 28915862
DOI: 10.1186/s12877-017-0607-0 -
Journal of Cardiac Failure Jan 2020Atrial fibrillation (AF) is common in chronic heart failure, and some have advocated intensive rate and/or rhythm control strategies for these patients. However, the... (Review)
Review
BACKGROUND AND METHODS
Atrial fibrillation (AF) is common in chronic heart failure, and some have advocated intensive rate and/or rhythm control strategies for these patients. However, the loss of atrial systole and irregularity of the ventricular response has not been shown to contribute to the progression of heart failure, and the presence or rate of long-standing AF in patients with chronic heart failure does not have prognostic significance.
RESULTS
In randomized clinical trials, pharmacological rhythm control has not been shown to be superior to rate-control in influencing long-term outcomes, but the use of membrane-active antiarrhythmic drugs can increase the risk of both pump failure and arrhythmic deaths in patients with heart failure. Additionally, intensive efforts to slow the ventricular rate in AF can potentially cause clinically inapparent bradyarrhythmias, which can trigger rate-dependent lethal rhythm disturbances or hemodynamic abnormalities. In patients with AF, a more stringent approach to rate control (target rate <80/min) is not superior to a more lenient strategy (target rate <110/min) on the risk of major events. Little is known about the effects of catheter ablation of long-standing AF in established heart failure, particularly in patients with a preserved or a meaningfully reduced ejection fraction, but ablation can add to the fibrotic burden of the left atrium and impair its capacitance functions.
CONCLUSIONS
For all of these reasons, the management of heart failure and long-standing AF should be primarily directed to slowing of the progression of their underlying cardiomyopathic process rather than the treatment of the arrhythmia. In addition, patients should receive long-term oral anticoagulation with non-vitamin K-antagonist oral anticoagulants to reduce the risk of thromboembolic events. The utility of intensive rate and rhythm control interventions for long-standing AF in patients with established heart failure requires further study.
Topics: Anti-Arrhythmia Agents; Anticoagulants; Atrial Fibrillation; Cardiac Catheterization; Chronic Disease; Disease Management; Female; Heart Failure; Heart Rate; Humans; Male; Randomized Controlled Trials as Topic
PubMed: 31465842
DOI: 10.1016/j.cardfail.2019.08.011 -
Annals of the New York Academy of... 1990Excitation and impulse propagation in cardiac tissues are dependent on the heart rate and can occur in extremely complex patterns. In this chapter we present the results...
Excitation and impulse propagation in cardiac tissues are dependent on the heart rate and can occur in extremely complex patterns. In this chapter we present the results of Purkinje fiber experiments and of computer simulations using an ionic (Beeler & Reuter) model for the ventricular cell. We have studied the global rate-dependent behavior of cardiac cells through a systematic analysis of their response to single as well as repetitive depolarizing stimuli, and determined the role of nonlinearity in the mechanism(s) of their behaviors. To this end, we devised an analytical difference equation model of cardiac cell excitation which could be used to predict simple as well as chaotic behavior of both the Purkinje fiber and the Beeler & Reuter cell, depending on the stimulation rate. Both experimental and modeling results suggest that the presence of supernormal recovery in cell excitability establishes sufficient nonlinearity so that, during repetitive stimulation, the dynamics of cell response may be regular and predictable when the stimulus magnitude is either very small or very large, or they may be chaotic and very unpredictable when the stimulus magnitude is intermediate. The overall results suggest that the application of nonlinear systems theory to electrophysiology may have importance in the understanding of cardiac rhythm and conduction disturbances, and may have clinical implications as well.
Topics: Animals; Computer Simulation; Electric Stimulation; Electrophysiology; Heart; Heart Rate; In Vitro Techniques; Membrane Potentials; Models, Cardiovascular; Purkinje Fibers; Sheep
PubMed: 2221692
DOI: 10.1111/j.1749-6632.1990.tb37307.x