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Global Cardiology Science & Practice 2014The heart is a mechanically-active organ that dynamically senses its own mechanical environment. This environment is constantly changing, on a beat-by-beat basis, with... (Review)
Review
The heart is a mechanically-active organ that dynamically senses its own mechanical environment. This environment is constantly changing, on a beat-by-beat basis, with additional modulation by respiratory activity and changes in posture or physical activity, and further overlaid with more slowly occurring physiological (e.g. pregnancy, endurance training) or pathological challenges (e.g. pressure or volume overload). Far from being a simple pump, the heart detects changes in mechanical demand and adjusts its performance accordingly, both via heart rate and stroke volume alteration. Many of the underlying regulatory processes are encoded intracardially, and are thus maintained even in heart transplant recipients. Over the last three decades, molecular substrates of cardiac mechanosensitivity have gained increasing recognition in the scientific and clinical communities. Nonetheless, the processes underlying this phenomenon are still poorly understood. Stretch-activated ion channels (SAC) have been identified as one contributor to mechanosensitive autoregulation of the heartbeat. They also appear to play important roles in the development of cardiac pathologies - most notably stretch-induced arrhythmias. As recently discovered, some established cardiac drugs act, in part at least, via mechanotransduction pathways suggesting SAC as potential therapeutic targets. Clearly, identification of the molecular substrate of cardiac SAC is of clinical importance and a number of candidate proteins have been identified. At the same time, experimental studies have revealed variable-and at times contrasting-results regarding their function. Further complication arises from the fact that many ion channels that are not classically defined as SAC, including voltage and ligand-gated ion channels, can respond to mechanical stimulation. Here, we summarise what is known about the molecular substrate of the main candidates for cardiac SAC, before identifying potential further developments in this area of translational research.
PubMed: 25405172
DOI: 10.5339/gcsp.2014.19 -
Biological Psychology Jul 2022This paper reviews the many functions of the vagus nerve, to understand how they interact in daily life and what might be accomplished by therapeutical electrical... (Review)
Review
This paper reviews the many functions of the vagus nerve, to understand how they interact in daily life and what might be accomplished by therapeutical electrical stimulation. A short historical introduction on the discovery and name-giving of the cranial nerves numbers 9-12 is followed by an overview of the functions that are under lower brain stem control: heart (rate, contractility), intestine (swallowing, peristalsis and glands secretions, feeling of satiety), lungs (bronchoconstriction, lung-irritant and stretch receptor signaling), blood pressure (by vascular wall stress sensing) and blood gases by specialized receptors. Key in the review is the physiology behind beat-by-beat heart rate variations, how everyday life is reflected in its variability, from exciting moments to quiet sleep, with the 'common faint' or vasovagal collapse as extreme example. Next, the recently proposed role of the vagus nerve in limiting inflammation is discussed. This has led to adoption of an earlier developed technique for epilepsy treatment, i.e., electrical stimulation of one vagus nerve bundle in the neck, but now for immune diseases like rheumatoid arthritis and the scope is even widening to depression and cluster headache. However, the problem in application of whole vagus nerve stimulation is the lack of specificity: there is no way to titrate the stimulation to an observable effect variable. All nerves in the bundle, incoming and outgoing, can be 'hit', leading to side-effects which limit the intended application.
Topics: Blood Pressure; Electric Stimulation; Heart Rate; Humans; Vagus Nerve; Vagus Nerve Stimulation
PubMed: 35688294
DOI: 10.1016/j.biopsycho.2022.108378 -
International Journal of Epidemiology Apr 2017The Saguenay Youth Study (SYS) is a two-generational study of adolescents and their parents (n = 1029 adolescents and 962 parents) aimed at investigating the aetiology,...
The Saguenay Youth Study (SYS) is a two-generational study of adolescents and their parents (n = 1029 adolescents and 962 parents) aimed at investigating the aetiology, early stages and trans-generational trajectories of common cardiometabolic and brain diseases. The ultimate goal of this study is to identify effective means for increasing healthy life expectancy. The cohort was recruited from the genetic founder population of the Saguenay Lac St Jean region of Quebec, Canada. The participants underwent extensive (15-h) phenotyping, including an hour-long recording of beat-by-beat blood pressure, magnetic resonance imaging of the brain and abdomen, and serum lipidomic profiling with LC-ESI-MS. All participants have been genome-wide genotyped (with ∼ 8 M imputed single nucleotide polymorphisms) and a subset of them (144 adolescents and their 288 parents) has been genome-wide epityped (whole blood DNA, Infinium HumanMethylation450K BeadChip). These assessments are complemented by a detailed evaluation of each participant in a number of domains, including cognition, mental health and substance use, diet, physical activity and sleep, and family environment. The data collection took place during 2003-12 in adolescents (full) and their parents (partial), and during 2012-15 in parents (full). All data are available upon request.
Topics: Abdomen; Adolescent; Adult; Blood Pressure; Brain; Cognition; Cohort Studies; Female; Genetic Variation; Humans; Lipids; Magnetic Resonance Imaging; Male; Mental Health; Middle Aged; Parents; Quebec; Substance-Related Disorders
PubMed: 27018016
DOI: 10.1093/ije/dyw023 -
Bulletin of Emergency and Trauma Apr 2022To review the research dimensions of trauma registry data on health policy making. (Review)
Review
OBJECTIVE
To review the research dimensions of trauma registry data on health policy making.
METHODS
PubMed and EMBASE were searched until July 2020. Keywords were used on the search process included Trauma, Injury, Registry and Research, which were searched by using appropriate search strategies. The included articles had to: 1. be extracted from data related to trauma registries; 2- be written in English; 3- define a time period and a patient population; 4- preferably have more details and policy recommendations; and 5- preferably have a discussion on how to improve diagnosis and treatment. The results obtained from the included studies were qualitatively analyzed using thematic synthesis and comparative tables.
RESULTS
In the primary round of search, 19559 studies were retrieved. According to PRISMA statement and also performing quality appraisal process, 30 studies were included in the final phase of analysis. In the final papers' synthesis, 14 main research domains were extracted and classified in terms of the policy implication and research priority. The domains with the highest frequency were "The relationship between trauma registry data and hospital care protocols for trauma patients" and "The causes of Disability Adjusted Life Years (DALYs) due to trauma".
CONCLUSION
Using trauma registry data as a tool for policy-making could be helpful in several ways, namely increasing the quality of patient care, preventing injuries and decreasing their number, figuring out the details of socioeconomic status effects, and improving the quality of researches in practical ways. Also, follow-up of patients after trauma surgery as one of the positive effects of the trauma registry can be the focus of attention of policy-making bodies.
PubMed: 35434165
DOI: 10.30476/BEAT.2021.91755.1286 -
Bulletin of Emergency and Trauma Apr 2017To evaluate the current scientific evidence for the applicability, safety and effectiveness of pathways of enhanced recovery after emergency surgery (ERAS). (Review)
Review
OBJECTIVE
To evaluate the current scientific evidence for the applicability, safety and effectiveness of pathways of enhanced recovery after emergency surgery (ERAS).
METHODS
We undertook a search using PubMed and Cochrane databases for ERAS protocols in emergency cases. The search generated 65 titles; after eliminating the papers not meeting search criteria, we selected 4 cohort studies and 1 randomized clinical trial (RCT). Data extracted for analysis consisted of: patient age, type of surgery performed, ERAS elements implemented, surgical outcomes in terms of postoperative complications, mortality, length of stay (LOS) and readmission rate.
RESULTS
The number of ERAS items applied was good, ranging from 11 to 18 of the 20 recommended by the ERAS Society. The implementation resulted in fewer postoperative complications. LOS for ES patients was shorter when compared to conventional care. Mortality, specifically reported in three studies, was equal or lower with ERAS. Readmission rates varied widely and were generally higher for the intervention group but without statistical significance.
CONCLUSIONS
The studies reviewed agreed that ERAS in emergency surgery (ES) was feasible and safe with generally better outcomes. Lower compliance with some of the ERAS items shows the need for the protocol to be adapted to ES patients. More evidence is clearly required as to what can improve outcomes and how this can be formulated into an effective care pathway for the heterogeneous ES patient.
PubMed: 28507993
DOI: No ID Found -
Folia Medica Cracoviensia Sep 2022Autonomic dysfunction, impaired baroreflex sensitivity (BRS), and deranged circulatory homeostasis have been observed in chronic hyperglycemia and found to be associated...
BACKGROUND
Autonomic dysfunction, impaired baroreflex sensitivity (BRS), and deranged circulatory homeostasis have been observed in chronic hyperglycemia and found to be associated with increased cardiovascular morbidity and mortality. However, the acute effects of hyperglycemia in healthy subjects have been rarely studied. The present study explores the effect of acute hyperglycemia on conventional and unconventional parameters of BRS in healthy young adults.
METHODS
For the estimation of BRS beat-to-beat blood pressure (BP) and electrocardiogram were recorded in forty-two young, healthy subjects during fasting and at 1hr of the oral glucose load. Analysis of BRS was carried out by sequence and spectral method. Number of UP-, DOWN- and ALL-sequences between ramps of BP and RR-interval were calculated as an unconventional measure of BRS along with the other conventional parameters.
RESULTS
We observed significant alteration of unconventional parameters of autonomic functions [the number of sequences of UP- (p = 0.0039) and ALL-sequences (p = 0.0233) of systolic BP and RR interval; and, UP- (p = 0.0380), DOWN- (p = 0.0417) and ALL-sequences (p = 0.0313) of mean BP and RR- interval] during acute hyperglycemia as compared to the fasting state. However, no significant changes were observed in any of the conventional parameters of BRS during acute hyperglycemia as compared to the fasting state.
CONCLUSIONS
Present study concludes that the unconventional parameters of BRS - the number of sequences between the ramp of BP and RR-interval - change significantly during acute hyperglycemia. However, the conventional parameters do not show significant changes during acute hyperglycemia. We may hypothesize that the relatively constant BRS is maintained at the expense of increased oscillations in the ramp of BP and RR-interval.
Topics: Young Adult; Humans; Baroreflex; Heart Rate; Blood Pressure; Hyperglycemia; Electrocardiography; Acute Disease
PubMed: 36309836
DOI: 10.24425/fmc.2022.142374 -
Annals of Noninvasive Electrocardiology... Sep 2017Cardiac restitution is the ability of the heart to recover from one beat to the next. Ventricular arrhythmia vulnerability can occur when the heart does not properly... (Review)
Review
BACKGROUND
Cardiac restitution is the ability of the heart to recover from one beat to the next. Ventricular arrhythmia vulnerability can occur when the heart does not properly adjust to sudden changes in rate or in hemodynamics leading to excessive temporal and/or spatial heterogeneity in conduction or repolarization. Restitution has historically been used to study, by invasive means, the dynamics of the relationship between action potential duration (APD) and diastolic interval (DI) in sedated subjects using various pacing protocols. Even though the analogous measures of APD and DI can be obtained using the surface ECG to acquire the respective QT and TQ intervals for ECG restitution, this methodology has not been widely adopted for a number of reasons.
METHODS
Recent development of more advanced software algorithms enables ECG intervals to be measured accurately, on a continuous beat-to-beat basis, in an automated manner, and under highly dynamic conditions (i.e., ambulatory or exercise) providing information beyond that available in the typical resting state.
RESULTS
Current breakthroughs in ECG technology will allow ECG restitution measures to become a practical approach for providing quantitative measures of the risks for ventricular arrhythmias as well as cardiac stress in general.
CONCLUSIONS
In addition to a review of the underlying principles and caveats of ECG restitution, a new approach toward an advancement of more integrated restitution biomarkers is proposed.
Topics: Biomarkers; Electrocardiography; Heart; Humans; Tachycardia, Ventricular
PubMed: 28497858
DOI: 10.1111/anec.12460 -
International Journal of Molecular... May 2023Adipose tissue (AT) can be classified into two different types: (i) white adipose tissue (WAT), which represents the largest amount of total AT, and has the main... (Review)
Review
Adipose tissue (AT) can be classified into two different types: (i) white adipose tissue (WAT), which represents the largest amount of total AT, and has the main function of storing fatty acids for energy needs and (ii) brown adipose tissue (BAT), rich in mitochondria and specialized in thermogenesis. Many exogenous stimuli, e.g., cold, exercise or pharmacological/nutraceutical tools, promote the phenotypic change of WAT to a beige phenotype (BeAT), with intermediate characteristics between BAT and WAT; this process is called "browning". The modulation of AT differentiation towards WAT or BAT, and the phenotypic switch to BeAT, seem to be crucial steps to limit weight gain. Polyphenols are emerging as compounds able to induce browning and thermogenesis processes, potentially via activation of sirtuins. SIRT1 (the most investigated sirtuin) activates a factor involved in mitochondrial biogenesis, peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), which, through peroxisome proliferator-activated receptor γ (PPAR-γ) modulation, induces typical genes of BAT and inhibits genes of WAT during the transdifferentiation process in white adipocytes. This review article aims to summarize the current evidence, from pre-clinical studies to clinical trials, on the ability of polyphenols to promote the browning process, with a specific focus on the potential role of sirtuins in the pharmacological/nutraceutical effects of natural compounds.
Topics: Humans; Sirtuins; Polyphenols; PPAR gamma; Obesity; Adipose Tissue, White; Adipose Tissue, Brown; Thermogenesis
PubMed: 37298226
DOI: 10.3390/ijms24119276 -
Annals of Noninvasive Electrocardiology... Sep 2019The differential diagnosis of a supraventricular tachycardia (SVT) is accomplished using a number of pacing maneuvers. The incidence and mechanism of a single...
BACKGROUND
The differential diagnosis of a supraventricular tachycardia (SVT) is accomplished using a number of pacing maneuvers. The incidence and mechanism of a single ventricular premature beat (VPB) on initiation and termination of tachycardia were evaluated during programmed electrical stimulation (PES) of the heart in patients with the two most common regular SVTs: atrioventricular re-entrant tachycardia (AVNRT) and orthodromic atrioventricular tachycardia (AVRT).
METHODS
Three hundred and thirty-seven consecutive patients aged above 18 years with an inducible sustained AVNRT or AVRT were prospectively enrolled. Patients with more than one tachyarrhythmia mechanism were excluded. Two hundred and seventeen patients (64.4%) had typical slow/fast AVNRT and 120 (35.6%) had an orthodromic AVRT using a rapidly conducting accessory pathway for V-A conduction. In this cross-sectional study, we specifically report the analysis of tachycardia induction and termination by a single VPB.
RESULTS
Tachycardia induction with a single VPB during sinus rhythm was seen in 7 of 120 AVRT and in only one of the 217 patients with AVNRT, (5.8% vs. 0.3%, p < 0.05). When a single VPB was delivered during basic ventricular pacing these values were 28% versus 4%, respectively, (p < 0.001). Termination of tachycardia by a single VPB was observed in nine (4.1%) patients with AVNRT and in 57 (47.5%) with AVRT (p < 0.001).
CONCLUSION
Initiation of SVT by a single VPB during sinus rhythm was uncommon and favored AVRT. Termination of SVT by a single VPB was commonly seen in AVRT but rarely in AVNRT. These findings can be of help when interpreting a noninvasive arrhythmia event recording.
Topics: Adult; Cross-Sectional Studies; Diagnosis, Differential; Electrocardiography; Female; Humans; Male; Middle Aged; Prospective Studies; Tachycardia, Supraventricular; Ventricular Premature Complexes
PubMed: 30993813
DOI: 10.1111/anec.12650 -
Heart (British Cardiac Society) Jun 2021To improve the echocardiographic assessment of heart failure in patients with atrial fibrillation (AF) by comparing conventional averaging of consecutive beats with an...
OBJECTIVE
To improve the echocardiographic assessment of heart failure in patients with atrial fibrillation (AF) by comparing conventional averaging of consecutive beats with an index-beat approach, whereby measurements are taken after two cycles with similar R-R interval.
METHODS
Transthoracic echocardiography was performed using a standardised and blinded protocol in patients enrolled in the RATE-AF (RAte control Therapy Evaluation in permanent Atrial Fibrillation) randomised trial. We compared reproducibility of the index-beat and conventional consecutive-beat methods to calculate left ventricular ejection fraction (LVEF), global longitudinal strain (GLS) and E/e' (mitral E wave max/average diastolic tissue Doppler velocity), and assessed intraoperator/interoperator variability, time efficiency and validity against natriuretic peptides.
RESULTS
160 patients were included, 46% of whom were women, with a median age of 75 years (IQR 69-82) and a median heart rate of 100 beats per minute (IQR 86-112). The index-beat had the lowest within-beat coefficient of variation for LVEF (32%, vs 51% for 5 consecutive beats and 53% for 10 consecutive beats), GLS (26%, vs 43% and 42%) and E/e' (25%, vs 41% and 41%). Intraoperator (n=50) and interoperator (n=18) reproducibility were both superior for index-beats and this method was quicker to perform (p<0.001): 35.4 s to measure E/e' (95% CI 33.1 to 37.8) compared with 44.7 s for 5-beat (95% CI 41.8 to 47.5) and 98.1 s for 10-beat (95% CI 91.7 to 104.4) analyses. Using a single index-beat did not compromise the association of LVEF, GLS or E/e' with natriuretic peptide levels.
CONCLUSIONS
Compared with averaging of multiple beats in patients with AF, the index-beat approach improves reproducibility and saves time without a negative impact on validity, potentially improving the diagnosis and classification of heart failure in patients with AF.
Topics: Aged; Aged, 80 and over; Atrial Fibrillation; Biomarkers; Diastole; Echocardiography, Doppler, Pulsed; Female; Heart Failure; Humans; Male; Natriuretic Peptide, Brain; Peptide Fragments; Reproducibility of Results; Stroke Volume; Systole; Ventricular Function, Left
PubMed: 33692093
DOI: 10.1136/heartjnl-2020-318557