PMID: 2419705Dec 21, 1985

Model of mechanical alternans in the mammalian myocardium

Journal of Theoretical Biology
D AdlerY Mahler

Abstract

A model is proposed to elucidate the cause and mechanism of mechanical alternans in cardiac muscle in terms of discrete calcium movements. Mechanical alternans, the cause of which lies within the borders of excitation-contraction-coupling (ECC), is analyzed. In this case, the "input" of the ECC system (the action potentials and intervals) is constant while the "output" (contractile force) oscillates between two constant values, indicating that the system has a "memory" with two "internal states". It is proposed that these two "states" are associated with a part of the sarcoplasmic reticulum ("releasable terminal") containing the readily releasable calcium. A mechanism of "calcium-concentration-dependent threshold" is suggested to govern the "release function", i.e. the release of calcium from the "releasable terminal" to the myofilaments. The "release function" is analyzed in both the linear and the non-linear cases and its implication on the initiation of sustained and transient mechanical alternans are described. The dependence of mechanical alternans on a disturbance is also explained. The model response resembles the experimental observations of mechanical alternans in mammalian myocardium in the following manners: abrupt t...Continue Reading

Citations

Jan 1, 1994·Heart and Vessels·J ArakiH Suga
Jun 1, 1992·Mathematical Biosciences·G Fruchter, S Ben-Haim
Apr 13, 2006·Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences·G IribeDenis Noble
Jun 5, 2012·American Journal of Physiology. Heart and Circulatory Physiology·Michael Nivala, Zhilin Qu
Feb 6, 2007·American Journal of Physiology. Heart and Circulatory Physiology·Leonid Livshitz, Y Rudy
Feb 16, 2002·The Japanese Journal of Physiology·Ju MizunoH Suga
Sep 13, 2013·Pacing and Clinical Electrophysiology : PACE·Takeshi KashimuraTohru Minamino
Jan 21, 1991·Journal of Theoretical Biology·G Fruchter, S Ben-Haim
Dec 2, 2004·Experimental Physiology·David A EisnerA W Trafford
Sep 6, 2005·Cell Calcium·Mary E DíazDavid A Eisner
Dec 4, 2003·Biophysical Journal·Y ShiferawA Karma
Jun 1, 1991·IEEE Transactions on Bio-medical Engineering·E A ClancyR J Cohen
Mar 4, 2014·Circulation. Arrhythmia and Electrophysiology·Robert KimLarisa G Tereshchenko
Nov 11, 2003·The Japanese Journal of Physiology·J ShimizuH Suga
Jul 19, 2000·American Journal of Physiology. Heart and Circulatory Physiology·J ShimizuH Suga
Jan 15, 2002·American Journal of Physiology. Heart and Circulatory Physiology·Ju MizunoH Suga
Feb 17, 2001·American Journal of Physiology. Heart and Circulatory Physiology·S SuzukiH Suga

Related Concepts

Metazoa
Calcium
Canis familiaris
Premature Cardiac Complex
Pulse Rate
Myocardial Contraction
Sarcoplasmic Reticulum

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Neural Activity: Imaging

Imaging of neural activity in vivo has developed rapidly recently with the advancement of fluorescence microscopy, including new applications using miniaturized microscopes (miniscopes). This feed follows the progress in this growing field.

The Tendon Seed Network

Tendons are rich in the extracellular matrix and are abundant throughout the body providing essential roles including structure and mobility. The transcriptome of tendons is being compiled to understand the micro-anatomical functioning of tendons. Discover the latest research pertaining to the Tendon Seed Network here.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Incretins

Incretins are metabolic hormones that stimulate a decrease in glucose levels in the blood and they have been implicated in glycemic regulation in the remission phase of type 1 diabetes. Here is the latest research.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Long COVID-19

“Long Covid-19” describes illness in patients who are reporting long-lasting effects of the SARS-CoV-19 infection, often long after they have recovered from acute Covid-19. Ongoing health issues often reported include low exercise tolerance and breathing difficulties, chronic tiredness, and mental health problems such as post-traumatic stress disorder and depression. This feed follows the latest research into Long Covid.

Spatio-Temporal Regulation of DNA Repair

DNA repair is a complex process regulated by several different classes of enzymes, including ligases, endonucleases, and polymerases. This feed focuses on the spatial and temporal regulation that accompanies DNA damage signaling and repair enzymes and processes.