The force-frequency relationship has intrigued researchers since its discovery by Bowditch in 1871. Many attempts have been made to construct mathematical descriptions of this phenomenon, beginning with the simple formulation of Koch-Wesser and Blinks in 1963 to the most sophisticated ones of today. This property of cardiac muscle is amplified by β-adrenergic stimulation, and, in a coordinated way, the neurohumoral state alters both frequency (acting on the sinoatrial node) as well as force generation (modifying ventricular myocytes). This synchronized tuning is needed to meet new metabolic demands. Cardiac modelers have already linked mechanical and electrical activity in their formulations and showed how those activities feedback on each other. However, now it is necessary to include neurological control to have a complete description of heart performance, especially when changes in frequency are involved. Study of arrhythmias (or antiarrhythmic drugs) based on mathematical models should incorporate this effect to make useful predictions or point out potential pharmaceutical targets.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3776472 | PMC |
http://dx.doi.org/10.1152/advan.00072.2011 | DOI Listing |
ESC Heart Fail
November 2024
German Centre for Cardiovascular Research (DZHK), Partner Site Munich, Munich Heart Alliance (MHA), Munich, Germany.
Aims: No curative treatment is available for RASopathy-associated childhood-onset hypertrophic cardiomyopathy (RAS-CM). Preclinical data and individual reports suggest a beneficial effect of small molecules targeting the RAS-mitogen-activated protein (MAP) kinase (MAPK) pathway in severely affected RAS-CM patients. The aim of this study was to evaluate the biophysical effects of trametinib, rapamycin and dasatinib on cultivated myocardial tissue slices of a paediatric RAS-CM patient using biomimetic cultivation chambers (BMCCs) and to correlate the findings with clinical data.
View Article and Find Full Text PDFBiomed Phys Eng Express
September 2024
College of Medicine, California Northstate University, Elk Grove, Sacramento, CA, United States of America.
. This study addresses the Force-Frequency relationship, a fundamental characteristic of cardiac muscle influenced by-adrenergic stimulation. This relationship reveals that heart rate (HR) changes at the sinoatrial node lead to alterations in ventricular cell contractility, increasing the force and decreasing relaxation time for higher beat rates.
View Article and Find Full Text PDFBiochem Biophys Res Commun
November 2024
Clinical Translational Research Program, RIKEN Center for Biosystems Dynamics Research, Kobe, Japan; Department of Cardiovascular Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address:
Electrical and dynamic stimulation are commonly employed to enhance the maturation of engineered cardiac tissue (ECT) derived from human induced pluripotent stem cells (iPSCs), reflecting the physiological environment of the heart. While electrical stimulation mimics natural bioelectrical signals and dynamic stimulation replicates mechanical forces, the combined effects of these stimuli on ECT maturation have not been thoroughly explored. We hypothesized that simultaneous electro-dynamic stimulation would enhance ECT maturation and function more effectively than either stimulus alone.
View Article and Find Full Text PDFAppl Physiol Nutr Metab
December 2024
Department of Human Health and Nutritional Sciences, College of Biological Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada.
Intense exercise training with insufficient recovery time is associated with reductions in neuromuscular performance. However, it is unclear how single muscle fibre mechanical function and myofibrillar Ca sensitivity contribute to these impairments. We investigated the effects of overload training on joint-level neuromuscular performance and cellular-level mechanical function.
View Article and Find Full Text PDFJ Appl Physiol (1985)
August 2024
School of Kinesiology, Faculty of Health Sciences, University of Western Ontario, London, Ontario, Canada.
The early (≤50 ms) rate of torque development (RTD) is dependent upon the speed of neuromuscular activation; however, few studies have evaluated the determinants of rate of velocity development (RVD), which may be load-dependent. The purpose here was to explore the relationship between stimulation frequency with the early and late (≥100 ms) phase isometric RTD and isotonic RVD. The knee extensors of 16 (five female) young recreationally active participants were stimulated using 14 frequencies from 1 to 100 Hz during isometric and isotonic ("unloaded" and 7.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!