The influence of rhythm dispersion on the mean amplitude of rat and rabbit papillary muscle contractions and isovolumic contractions of canine heart has been investigated. In rabbit ventricular myocardium which shows a steep force-frequency relationship in the 0.3--1.0 s-1 range of frequencies, the increased rhythm dispersion of stimulation produces a rise in the mean amplitude of contractions. The inotropic effect of rhythm dispersion is more pronounced at higher frequencies of stimulation. The inotropic effect of activation may reach 30-40%. The increased rhythm dispersion reduces the mean value of systolic pressure in isovolumic canine heart. It is suggested that the inotropic effect of rhythm dispersion may be due to non-linearity of the force-frequency relationships.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Heart rate variability biofeedback in a global study of the most common coherence frequencies and the impact of emotional states.
Sci Rep
January 2025
HeartMath Institute, Boulder Creek, CA, 95006, USA.
This global study analyzed data from the largest dataset ever studied in the Heart Rate Variability (HRV) biofeedback field, comprising 1.8 million user sessions collected from users of a mobile app during 2019 and 2020. We focused on HRV Coherence, which is linked to improved emotional stability and cognitive function.
View Article and Find Full Text PDFSubclavian Ansae Stimulation on Cardiac Hemodynamics and Electrophysiology in Atrial Fibrillation: A Target for Sympathetic Neuromodulation.
JACC Clin Electrophysiol
December 2024
St Bartholomew's Hospital, Barts Health NHS Trust, London, United Kingdom; William Harvey Research Institute, Queen Mary University of London, London, United Kingdom. Electronic address:
Background: The sympathetic autonomic nervous system plays a major role in arrhythmia development and maintenance. Historical preclinical studies describe preferential increases in cardiac sympathetic tone upon selective stimulation of the subclavian ansae (SA), a nerve cord encircling the subclavian artery.
Objectives: This study sought to define, for the first time, the functional anatomy and physiology of the SA in humans using a percutaneous approach.
Safety Study and Compositional Analysis of the Svarnvir-IV Tablet With Special Reference to Its Therapeutic Utility in SARS-CoV-2.
Cureus
December 2024
School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, IND.
Aim Traditional Ayurvedic herbo-mineral medicines have proven their potential in managing COVID-19. Cell-based assays of the Svarnvir-IV tablet demonstrated the virucidal activity against SARS-CoV-2 and its therapeutic action, along with safety in cytotoxicity, has been proved. In the present study, in vivo, safety profile and compositional analysis of the Svarnvir-IV tablet were performed.
View Article and Find Full Text PDFA probabilistic modeling framework for the prediction of spontaneous premature beats and reentry initiation.
Heart Rhythm
January 2025
Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, Food and Drug Administration, Silver Spring, Maryland. Electronic address:
Background: Spontaneously occurring life-threatening reentrant arrhythmias result when a propagating premature beat encounters a region with significant dispersion of refractoriness. Although localized structural tissue heterogeneities and prescribed cell functional gradients have been incorporated into computational electrophysiologic models, a quantitative framework for the evolution from normal to abnormal behavior that occurs by disease is lacking.
Objective: The purpose of this study was to develop a probabilistic modeling framework representing the complex interplay of cell function and tissue structure in health and disease that predicts the emergence of premature beats and the initiation of reentry.
Existing emotion-driven music generation models heavily rely on labeled data and lack interpretability and controllability of emotions. To address these limitations, a semi-supervised emotion-driven music generation model based on category-dispersed Gaussian mixture variational autoencoders is proposed. Initially, a controllable music generation model is introduced, which disentangles and manipulates rhythm and tonal features, enabling controlled music generation.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!