Warming and cooling device using thermoelectric Peltier elements tested on male mice

2019 ◽  
Vol 54 (5) ◽  
pp. 443-451
Author(s):  
Nodir Madrahimov ◽  
Ruslan Natanov ◽  
Abdurasul Khalikov ◽  
Erin C Boyle ◽  
Danny Jonigk ◽  
...  
Keyword(s):  
Normal Sinus Rhythm ◽  
Environmentally Friendly ◽  
Cost Effective ◽  
Precise Control ◽  
Novel Device ◽  
Normal Sinus ◽  
Cardiac Procedures ◽  
Clinical Methods ◽  
Strong Linear Correlation ◽  
Clinical Conditions

Hypothermia is a treatment strategy for different clinical conditions and an essential part of cardiopulmonary bypass in complex cardiac procedures. Clinically, cooling patients is achieved via a mattress and heat exchanger integrated into a membrane oxygenator connected to a waterbed using a refrigerator system based on volatile and toxic liquids. Peltier elements are known as environmentally friendly thermoelectric generators that enable rapid warming and cooling. In this paper, we describe the construction of a novel device for rapid and precise control of mouse warming and cooling using thermoelectric Peltier elements. Six male BALB/c mice were subjected to deep hypothermia and were rewarmed under full physiological monitoring. After rewarming, all animals were observed for two hours, and pathology was evaluated in several organs. All animals tolerated the rapid cooling process well and remained active after rewarming. Temperature-relevant changes were seen via electrocardiography, with heart-rate patterns showing a strong linear correlation to body temperature. No myocardial ischaemia was seen. However, two animals experienced bradycardic atrial fibrillation which spontaneously converted to normal sinus rhythm during rewarming. No histological damage was seen in the heart, liver, kidney or lungs. Our device can effectively be used for heat shock and hypothermia studies in mice, and we foresee no obstacles for its application to other small rodents such as hamsters and young rats. In comparison to known experimental and clinical methods of hypothermia, our device is environmentally friendly, cost-effective and easy to handle, allowing precise control and maintenance of body temperatures ranging from 18℃ to 42℃.

scholarly journals Cost-Effectiveness of Catheter Ablation for Rhythm Control of Atrial Fibrillation

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Gord Blackhouse ◽  
Nazila Assasi ◽  
Feng Xie ◽  
Kathryn Gaebel ◽  
Kaitryn Campbell ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Cost Effectiveness ◽  
Catheter Ablation ◽  
Willingness To Pay ◽  
Normal Sinus Rhythm ◽  
Meta Analysis ◽  
Cost Effective ◽  
Rhythm Control ◽  
Current Evidence ◽  
Normal Sinus

Objective. The objective of this study is to evaluate the cost-effectiveness of catheter ablation for rhythm control compared to antiarrhythmic drug (AAD) therapy in patients with atrial fibrillation (AF) who have previously failed on an AAD.Methods. An economic model was developed to compare (1) catheter ablation and (2) AAD (amiodarone 200 mg/day). At the end of the initial 12 month phase of the model, patients are classified as being in normal sinus rhythm or with AF, based on data from a meta-analysis. In the 5-year Markov phase of the model, patients are at risk of ischemic stroke each 3-month model cycle.Results. The model estimated that, compared to the AAD strategy, ablation had $8,539 higher costs, 0.033 fewer strokes, and 0.144 more QALYS over the 5-year time horizon. The incremental cost per QALY of ablation compared to AAD was estimated to be $59,194. The probability of ablation being cost-effective for willingness to pay thresholds of $50,000 and $100,000 was estimated to be 0.89 and 0.90, respectively.Conclusion. Based on current evidence, pulmonary vein ablation for treatment of AF is cost-effective if decision makers willingness to pay for a QALY is $59,194 or higher.

Chewing reduces sympathetic nervous response to stress and prevents poststress arrhythmias in rats

2011 ◽  
Vol 301 (4) ◽  
pp. H1551-H1558 ◽  
Author(s):  
So Koizumi ◽  
Susumu Minamisawa ◽  
Kenichi Sasaguri ◽  
Minoru Onozuka ◽  
Sadao Sato ◽  
...  
Keyword(s):  
Qt Interval ◽  
Normal Sinus Rhythm ◽  
Cost Effective ◽  
Experimental Period ◽  
Stressful Events ◽  
Effective Treatment Option ◽  
Autonomic Imbalance ◽  
Normal Sinus ◽  
Cost Effective Treatment ◽  
Adrenergic Blocker

Reducing stress is important in preventing sudden death in patients with cardiovascular disease, as stressful events may cause autonomic imbalance and trigger fatal arrhythmias. Since chewing has been shown to inhibit stress-induced neuronal responses in the hypothalamus, we hypothesized that chewing could ameliorate stress-induced autonomic imbalance and prevent arrhythmias. To test this hypothesis, we analyzed changes in radiotelemetered electrocardiograms in rats that were allowed to chew a wooden stick during a 1-h period of immobilization stress. Chewing significantly reduced the occurrence of ventricular premature beats (VPBs) and complex ventricular ectopy after immobilization and prevented stress-induced prolongation of the QT interval of VPBs throughout the 10-h experimental period. It also prevented prolongation of the QRS complex and fluctuations in the QT interval in normal sinus rhythm beats preceding VPBs during both immobilization and in the poststress period. Fast Fourier transform-based spectral analysis of heart-rate variability further showed that chewing significantly inhibited the stress-induced increase in the power ratio of low-to-high frequency activity (LF/HF: a marker of sympathetic activity) during immobilization and in addition was associated with blunting of the stress-induced increase in plasma noradrenaline observed at the termination of immobilization. Similar suppressive effects on the occurrence of VPBs and the LF/HF were observed in rats that were administered the β-adrenergic blocker propranolol before immobilization. These results indicate that chewing can ameliorate sympathetic hyperactivity during stress and prevent poststress arrhythmias and suggest that chewing may provide a nonpharmacological and cost-effective treatment option for patients with a high risk of stress-induced fatal arrhythmia.

scholarly journals The Utilisation of Payment Models Across the HIV Continuum of Care: Systematic Review of Evidence

2021 ◽  
Author(s):  
Tiago Rua ◽  
Daniela Brandão ◽  
Vanessa Nicolau ◽  
Ana Escoval
Keyword(s):  
Positive Impact ◽  
Cost Effective ◽  
Relative Magnitude ◽  
Hiv Care ◽  
People Living With Hiv ◽  
Hiv Continuum Of Care ◽  
Clinical Conditions ◽  
Study Designs ◽  
Living With Hiv ◽  
Payment Models

AbstractThe increasing chronicity and multimorbidities associated with people living with HIV have posed important challenges to health systems across the world. In this context, payment models hold the potential to improve care across a spectrum of clinical conditions. This study aims to systematically review the evidence of HIV performance-based payments models. Literature searches were conducted in March 2020 using multiple databases and manual searches of relevant papers. Papers were limited to any study design that considers the real-world utilisation of performance-based payment models applied to the HIV domain. A total of 23 full-text papers were included. Due to the heterogeneity of study designs, the multiple types of interventions and its implementation across distinct areas of HIV care, direct comparisons between studies were deemed unsuitable. Most evidence focused on healthcare users (83%), seeking to directly affect patients' behaviour based on principles of behavioural economics. Despite the variability between interventions, the implementation of performance-based payment models led to either a neutral or positive impact throughout the HIV care continuum. Moreover, this improvement was likely to be cost-effective or, at least, did not compromise the healthcare system’s financial sustainability. However, more research is needed to assess the durability of incentives and its appropriate relative magnitude.

scholarly journals TASK-1 current is inhibited by phosphorylation during human and canine chronic atrial fibrillation

2015 ◽  
Vol 308 (2) ◽  
pp. H126-H134 ◽  
Author(s):  
Erin Harleton ◽  
Alessandra Besana ◽  
Parag Chandra ◽  
Peter Danilo ◽  
Tove S. Rosen ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Normal Sinus Rhythm ◽  
Human Subjects ◽  
Phosphorylation Site ◽  
Chronic Atrial Fibrillation ◽  
Resting Membrane Potential ◽  
Atrial Remodeling ◽  
Protein Levels ◽  
Atrial Tissue ◽  
Normal Sinus

Atrial fibrillation (AF) is a common arrhythmia with significant morbidities and only partially adequate therapeutic options. AF is associated with atrial remodeling processes, including changes in the expression and function of ion channels and signaling pathways. TWIK protein-related acid-sensitive K+ channel (TASK)-1, a two-pore domain K+ channel, has been shown to contribute to action potential repolarization as well as to the maintenance of resting membrane potential in isolated myocytes, and TASK-1 inhibition has been associated with the induction of perioperative AF. However, the role of TASK-1 in chronic AF is unknown. The present study investigated the function, expression, and phosphorylation of TASK-1 in chronic AF in atrial tissue from chronically paced canines and in human subjects. TASK-1 current was present in atrial myocytes isolated from human and canine hearts in normal sinus rhythm but was absent in myocytes from humans with AF and in canines after the induction of AF by chronic tachypacing. The addition of phosphatase to the patch pipette rescued TASK-1 current from myocytes isolated from AF hearts, indicating that the change in current is phosphorylation dependent. Western blot analysis showed that total TASK-1 protein levels either did not change or increased slightly in AF, despite the absence of current. In studies of perioperative AF, we have shown that phosphorylation of TASK-1 at Thr383 inhibits the channel. However, phosphorylation at this site was unchanged in atrial tissue from humans with AF or in canines with chronic pacing-induced AF. We conclude that phosphorylation-dependent inhibition of TASK-1 is associated with AF, but the phosphorylation site responsible for this inhibition remains to be identified.

Complications of the Mustard Operation

1986 ◽  
Vol 8 (4) ◽  
pp. 106-126
Keyword(s):  
Heart Block ◽  
Normal Sinus Rhythm ◽  
Venous Blood ◽  
Resting Heart Rate ◽  
Normal Sinus ◽  
Mustard Operation ◽  
Mitral Orifice ◽  
The Mean ◽  
Degree Heart Block

Eight pediatric cardiac centers pooled clinical and ECG data from 372 patients who survived the Mustard operation (intraatrial baffle directing pulmonary venous blood to the tricuspid orifice and systemic venous blood to the mitral orifice) for at least 3 months. The follow-up period ranged from 0.4 to 15.9 years, and the mean age at operation was 2 years. The mean resting heart rate for patients who had the Mustard operation was consistently lower than age-matched controls. During the year of operation, 76% of patients had normal sinus rhythm; this percentage declined yearly to 57% by the end of the eighth postoperative year. Active arrhythmias increased after the tenth year. Second or third-degree heart block occurred in 33% of patients during the year of operation and changed very little thereafter. Of the total 372 patients, 39 received pacemakers, 52% during the year of surgery and 48% evenly distributed throughout the follow-up period.

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