• ##### sudden cardi
• He undertook residency training in anesthesiology and fellowship training in cardiac anesthesiology and in critical care medicine at The Johns Hopkins Hospital in Baltimore, MD. He joined the faculty at Johns Hopkins in 1995, where he practiced cardiac anesthesiology, ICU medicine, and led an NIH-funded research program aimed at the genetics of cardiac rhythm disorders, such as sudden cardiac death. (wikipedia.org)
• ##### ventricular
• Studies have shown celivarone is capable of cardioversion and of maintaining normal sinus cardiac rhythms and that it is effective in hypokalemic, vasotonic, and stretch-induced atrial fibrillation, as well as ischemic and reperfusion ventricular fibrillation. (wikipedia.org)
• T-tubules are found in both atrial and ventricular cardiac muscle cells (cardiomyocytes), in which they develop in the first few weeks of life. (wikipedia.org)
• The short- and long-term use of this therapy enhances the strength of ventricular contraction and therefore the heart's pumping capacity by modulating (adjusting) the myocardial contractility. (wikipedia.org)
• However, a study has been initiated in order to obtain FDA approval, and continued access has been granted by the FDA Based on the approval of Cardiac contractility modulation devices, the therapy is a treatment option for patients that are at least 18 years old who suffer from heart failure symptoms due to left ventricular systolic dysfunction (LVSD) despite adequate medical treatment. (wikipedia.org)
• ##### skeletal muscle cells
• Unlike the action potential in skeletal muscle cells, the cardiac action potential is not initiated by nervous activity. (wikipedia.org)
• ##### heart's
• Heart patches, on the other hand, could conceivably be implanted over the dead muscle and remain active for a long time, providing more strength for contractions and a smooth path for the heart's electrical signals to travel through. (scitechdaily.com)
• By revealing this robust homing mechanism, which causes cardiac stem cells to home to and repair the heart's damaged muscle, the findings could lead to less invasive treatments or even preventative measures aimed at maintaining or increasing the activity of the heart's own cardiac stem cells. (scitechdaily.com)
• Disruptions in ion flow affect the heart's ability to contract by altering the resting membrane potential, affecting the cell's ability to conduct or transmit an action potential (AP), or by affecting the rate or force of contraction. (wikipedia.org)
• Rather, the aim is to enhance the heart's natural contraction (the native cardiac contractility) sustainably over long periods of time. (wikipedia.org)
• ##### situ
• Effects of crude oil on in situ cardiac function in young adult mahi-mahi (Coryphaena hippurus). (semanticscholar.org)
• The intrinsic variability of the cellular matrix is also shown to affect emergent patterns of rhythmicity, providing insights into the origins of arrhythmogenic $${\text{Ca}}^{2+}$$ perturbations in cardiac tissue in situ . (springer.com)
• ##### contractility
• Lead (Pb2+) poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. (semanticscholar.org)
• Similarly, gain of function of Na+ and Ca2+ channels results in delayed repolarization, and Ca2+ overload causing increased Ca2+ binding to cardiac troponin C, more actin-myosin interactions and causing an increased contractility, respectively. (wikipedia.org)
• The Cardiac contractility modulation treatment is delivered by a pacemaker-like device that applies non-excitatory electrical signals NES, adjusted to and synchronized with the electrical action in the cardiac cycle. (wikipedia.org)
• Other than a pacemaker, which delivers an electrical signal with the intention to result in cardiac contraction, the Cardiac contractility modulation treatment applies the NES, adjusted to and synchronized with the electrical action in the cardiac cycle. (wikipedia.org)
• Furthermore, unlike most interventions that increase cardiac contractility, the Cardiac contractility modulation is not associated with an unfavorable increase in oxygen demand by the heart (measured in terms of Myocardial Oxygen Consumption or MVO2). (wikipedia.org)
• A meta-analysis in 2014 and an overview of device-based treatment options in heart failure in 2013 concluded that Cardiac contractility modulation treatment is safe, that it is generally beneficial to patients and that the treatment increases the exercise tolerance (ET) and quality of life (QoL) of patients. (wikipedia.org)
• Furthermore, preliminary long-term survival data shows that Cardiac contractility modulation is associated with lower long-term mortality in heart failure patients when compared with expected rates among similar patients not treated with Cardiac contractility modulation. (wikipedia.org)
• Based on the results of clinical trials, Cardiac contractility modulation devices are approved and available for clinical use in all European Union countries and in Australia, Turkey, India and Hong Kong, as well as in other countries that recognize CE marking for medical devices. (wikipedia.org)
• At the present time, Cardiac contractility modulation therapy is not approved for clinical use in the United States. (wikipedia.org)
• Further clinical research are under way to identify which patient group within the scope of the device approval benefits most from Cardiac contractility modulation treatment. (wikipedia.org)
• Most clinical studies on Cardiac contractility modulation therapy have involved heart failure patients who were classified initially as NYHA Class II, III or IV and had a normal QRS duration (QRS duration ≤ 120 ms). The efficacy of Cardiac contractility modulation on patients in an earlier stage of heart failure has not yet been studied. (wikipedia.org)
• A subsequent evaluation study (subgroup analysis) has already suggested a particular patient group that responds exceptionally well to Cardiac contractility modulation therapy. (wikipedia.org)
• Although studies on Cardiac contractility modulation therapy have focused on patients with a normal QRS duration (i.e. ≤ 120 ms), it is possible to use the therapy in patients who meet the treatment indication but who do not have a normal QRS duration. (wikipedia.org)
• ##### diseases
• The topics include the entire range of cardiac diseases and emphasize the economic impact on decision-making. (bookdepository.com)
• Accordingly, developing the ability to regulate cAMP-mediated signaling through Epac may lead to remarkable new therapies for the treatment of cardiac diseases. (springer.com)
• ##### conduction system
• In the same way that the walls of a house contain electrical wires and plumbing, cardiac muscle also contains specialised cells for conducting electrical signals rapidly (the cardiac conduction system), and blood vessels to bring nutrients to the muscle cells and take away waste products (the coronary arteries, veins and capillary network). (wikipedia.org)
• ##### improvement in cardiac
• This therapy is intended for the treatment of patients with moderate to severe heart failure (NYHA class II-IV) with symptoms despite optimal medical therapy who can benefit from an improvement in cardiac output. (wikipedia.org)
• ##### Biology
• Part of the Cardiac and Vascular Biology book series (Abbreviated title: Card. (springer.com)
• ##### Membrane
• Transverse tubules (T-tubules) are extensions of the cell membrane that penetrate into the centre of skeletal and cardiac muscle cells. (wikipedia.org)
• T-tubules are tubules formed from the same phospholipid bilayer as the surface membrane or sarcolemma of skeletal or cardiac muscle cells. (wikipedia.org)
• In cardiac muscle cells, as the action potential passes down the T-tubules it activates L-type calcium channels in the T-tubular membrane. (wikipedia.org)
• Cardiomyocytes contain T-tubules, pouches of membrane that run from the surface to the cell's interior which help to which improve the efficiency of contraction. (wikipedia.org)
• In skeletal and cardiac muscle cells, however, these receptors are located within structures known as T-tubules, that are extensions of the plasma membrane penetrating deep into the cell (see figure 1). (wikipedia.org)
• This is because, the Ca2+ that enters the cell via the DHPR in response to the action potential, stimulates both muscle contraction and calcium release from the SR. The Ca2+ released during the spark, then activates two other ion channels on the membrane. (wikipedia.org)
• The cardiac action potential is a brief change in voltage (membrane potential) across the cell membrane of heart cells. (wikipedia.org)
• ##### pathophysiology
• This chapter summarizes the role of AKAPs in cardiomyocytes, with a focus on the intersection of compartmentalized signaling and cardiac pathophysiology. (springer.com)
• The finding that cAMP signalling is compartmentalised and that distinct, spatially segregated pools of cAMP mediate different functional effects in the heart may provide a rationale for what appear to be contrasting effects of this pathway on cardiac physiology and pathophysiology. (springer.com)
• ##### regulation
• Cardiac calsequestrin (CASQ2) plays an integral role in cardiac regulation. (wikipedia.org)
• Activation of particular VGCCs allows Ca2+ to rush into the cell, which, depending on the cell type, results in activation of calcium-sensitive potassium channels, muscular contraction, excitation of neurons, up-regulation of gene expression, or release of hormones or neurotransmitters. (wikipedia.org)
• ##### action potentials
• The cardiac action potential differs from action potentials found in other types of electrically excitable cells, such as nerves. (wikipedia.org)
• ##### cellular
• If the cardiac stem cells are replaced the heart repairs itself, leading to complete cellular, anatomical and functional heart recovery, with the heart returning to normal and pumping at a regular rate. (scitechdaily.com)
• Cardiac function in an endothermic fish: cellular mechanisms for overcoming acute thermal challenges during diving. (semanticscholar.org)
• To probe these mechanisms, we have simulated cellular interactions on large scale arrays that mimic cardiac tissue, and where individual cells are represented by a mathematical model of intracellular $${\text{Ca}}^{2+}$$ dynamics. (springer.com)
• ##### mechanism
• The homing mechanism shown by our research could lead to a less invasive treatment whereby cardiac stem cells are injected through a vein in the skin (intravenously). (scitechdaily.com)
• Thus due to the unique cardiac myosin activation mechanism, omecamtiv mecarbil could safely improve cardiac function within tolerated doses. (wikipedia.org)
• ##### potassium
• Inotropic and arrhythmogenic effects of potassium-depleted solutions on mammalian cardiac muscle. (springer.com)
• ##### mitochondria
• Cardiac muscle cells contain many mitochondria which provide the energy needed for the cell in the form of adenosine triphosphate (ATP), making them highly resistant to fatigue. (wikipedia.org)
• ##### myosin
• Omecamtiv mecarbil (INN), previously referred to as CK-1827452, is a cardiac-specific myosin activator. (wikipedia.org)
• Chemical energy in the form of ATP is converted into mechanical energy which allows myosin to strongly bind to actin and produce a power stroke resulting in sarcomere shortening/contraction. (wikipedia.org)
• This enhances effective myosin cross-bridge formation and duration, while the velocity of contraction remains the same. (wikipedia.org)
• ##### Mutations
• Mutations resulting in loss of function of K+ channels can result in delayed repolarization of the cardiac muscle cells. (wikipedia.org)
• ##### efficiency
• This may be explained by the beneficial effect the therapy has in improving cardiac efficiency. (wikipedia.org)
• ##### muscle relaxation
• It does this by binding to the SERCA and decreasing its attraction (affinity) to calcium, therefore preventing calcium uptake into the SR. Failure to remove Ca2+ from the cytosol, prevents muscle relaxation and therefore means that there is a decrease in muscle contraction too. (wikipedia.org)
• ##### cytosol
• As a result, 99% of the calcium added to the cytosol of a cardiomyocyte during each cardiac cycle becomes bound to calcium buffers, creating a relatively small change in free calcium. (wikipedia.org)
• ##### cells
• Fewer than one percent of the injected cells survive and remain in the heart, and even fewer become cardiac muscle cells. (scitechdaily.com)
• A newly published study shows for the first time that if cardiac stem cells are eliminated, the heart is unable to repair itself after damage. (scitechdaily.com)
• Also, if the cardiac stem cells are removed and re-injected, they naturally 'home' to and repair the damaged heart, a discovery that could lead to less-invasive treatments and even early prevention of heart failure in the future. (scitechdaily.com)
• The study, funded by the European Commission Seventh Framework Program (FP7), set out to establish the role of cardiac stem cells (eCSCs) by first removing the cells from the hearts of rodents with heart failure. (scitechdaily.com)
• In these cases it could be possible to replace the damaged cardiac stem cells or add new ones by growing them in the laboratory and administering them intravenously. (scitechdaily.com)
• Dr Ellison added: 'Understanding the role and potential of cardiac stems cells could pave the way for a variety of new ways to prevent and treat heart failure. (scitechdaily.com)
• These new approaches involve maintaining or increasing the activity of cardiac stem cells so that muscle tissue in the heart can be renewed with new heart cells, replacing old cells or those damaged by wear and tear. (scitechdaily.com)
• The cardiac stem cells naturally home to the heart because the heart is their home - they know to go there. (scitechdaily.com)
• Next steps include clinical trials, due to start early 2014, aimed at assessing the effectiveness of cardiac stem cells for preventing and treating heart failure in humans. (scitechdaily.com)
• Movement of ions, particularly Na+, Ca2+ and K+, causes depolarizations of cell membranes in node cells, which are then transmitted to cardiac muscle cells to induce contraction. (wikipedia.org)
• In cardiac muscle cells, T-tubules are between 20 and 450 nanometers in diameter and are usually located in regions called Z-discs where the actin filaments anchor within the cell. (wikipedia.org)
• Cardiac muscle cells or cardiomyocytes are the contracting cells which allow the heart to pump. (wikipedia.org)
• Viewed through a microscope, cardiac muscle cells are roughly rectangular, measuring 100-150μm by 30-40μm. (wikipedia.org)
• The regular organisation of myofibrils into sarcomeres gives cardiac muscle cells a striped or striated appearance when looked at through a microscope, similar to skeletal muscle. (wikipedia.org)
• However, the electrical signals increase the influx of calcium ions into the cardiac muscle cells (cardiomyocytes). (wikipedia.org)
• All cardiac muscle cells are electrically linked to one another, by structures known as gap junctions (see below) which allow the action potential to pass from one cell to the next. (wikipedia.org)
• ##### dynamics
• Entrainment phenomena are shown to be linked to both intracellular $${\text{Ca}}^{2+}$$ and coupling-specific dynamics in a synergistic manner. (springer.com)
• ##### Muscular Contraction
• Toxin III has been shown to cause muscular contraction with subsequent paralysis in the crab Carcinus maenas. (wikipedia.org)
• ##### isoform
• RyR2 was originally purified from cardiac muscle (it is the major isoform expressed there), but is also robustly expressed in neurons, and in visceral and arterial smooth muscle. (biomedcentral.com)
• Each of the TnT isoform genes is linked to one of the three troponin I isoform genes encoding the inhibitory subunit of the troponin complex, in chromosomal DNA to form three gene pairs: The fast skeletal muscle TnI (fsTnI)-fsTnT, ssTnI-cardiac (cTnT) and cTnI-ssTnT gene pairs. (wikipedia.org)
• Two MLC20 isoforms are found in smooth muscle, and they are encoded by different genes, but only one isoform participates in contraction. (wikipedia.org)
• ##### improvement in cardiac
• This therapy is intended for the treatment of patients with moderate to severe heart failure (NYHA class II-IV) with symptoms despite optimal medical therapy who can benefit from an improvement in cardiac output. (wikipedia.org)
• ##### ventricular
• In fact, genetic mutations in either of these two proteins, or alterations in the environment that promotes their functional coupling, are known to cause ventricular arrhythmias, hypercontractures and/or pathological remodeling of cellular structures. (biomedcentral.com)
• This causes peripheral edema (blood pooling), which the sympathetic nervous system tries to correct by overstimulating the cardiac myocytes, leading to left ventricular hypertrophy, another characteristic of chronic heart failure. (wikipedia.org)
• The short- and long-term use of this therapy enhances the strength of ventricular contraction and therefore the heart's pumping capacity by modulating (adjusting) the myocardial contractility. (wikipedia.org)
• However, a study has been initiated in order to obtain FDA approval, and continued access has been granted by the FDA Based on the approval of Cardiac contractility modulation devices, the therapy is a treatment option for patients that are at least 18 years old who suffer from heart failure symptoms due to left ventricular systolic dysfunction (LVSD) despite adequate medical treatment. (wikipedia.org)
• ##### contractility
• Hypoxia and hypertrophy are the most frequent pathophysiological consequence of congenital heart disease (CHD) which can induce the alteration of Ca 2+ -regulatory proteins and inhibit cardiac contractility. (biomedcentral.com)
• The Cardiac contractility modulation treatment is delivered by a pacemaker-like device that applies non-excitatory electrical signals NES, adjusted to and synchronized with the electrical action in the cardiac cycle. (wikipedia.org)
• Other than a pacemaker, which delivers an electrical signal with the intention to result in cardiac contraction, the Cardiac contractility modulation treatment applies the NES, adjusted to and synchronized with the electrical action in the cardiac cycle. (wikipedia.org)
• In Cardiac contractility modulation therapy, electrical stimulation is applied to the cardiac muscle during the absolute refractory period. (wikipedia.org)
• In contrast to other electrical stimulation treatments for heart failure, such as pacemaker therapy or implantable cardioverter defibrillators (ICD), Cardiac contractility modulation does not affect the cardiac rhythm directly. (wikipedia.org)
• Rather, the aim is to enhance the heart's natural contraction (the native cardiac contractility) sustainably over long periods of time. (wikipedia.org)
• Furthermore, unlike most interventions that increase cardiac contractility, the Cardiac contractility modulation is not associated with an unfavorable increase in oxygen demand by the heart (measured in terms of Myocardial Oxygen Consumption or MVO2). (wikipedia.org)
• A meta-analysis in 2014 and an overview of device-based treatment options in heart failure in 2013 concluded that Cardiac contractility modulation treatment is safe, that it is generally beneficial to patients and that the treatment increases the exercise tolerance (ET) and quality of life (QoL) of patients. (wikipedia.org)
• Furthermore, preliminary long-term survival data shows that Cardiac contractility modulation is associated with lower long-term mortality in heart failure patients when compared with expected rates among similar patients not treated with Cardiac contractility modulation. (wikipedia.org)
• Based on the results of clinical trials, Cardiac contractility modulation devices are approved and available for clinical use in all European Union countries and in Australia, Turkey, India and Hong Kong, as well as in other countries that recognize CE marking for medical devices. (wikipedia.org)
• At the present time, Cardiac contractility modulation therapy is not approved for clinical use in the United States. (wikipedia.org)
• Further clinical research are under way to identify which patient group within the scope of the device approval benefits most from Cardiac contractility modulation treatment. (wikipedia.org)
• Most clinical studies on Cardiac contractility modulation therapy have involved heart failure patients who were classified initially as NYHA Class II, III or IV and had a normal QRS duration (QRS duration ≤ 120 ms). The efficacy of Cardiac contractility modulation on patients in an earlier stage of heart failure has not yet been studied. (wikipedia.org)
• A subsequent evaluation study (subgroup analysis) has already suggested a particular patient group that responds exceptionally well to Cardiac contractility modulation therapy. (wikipedia.org)
• Although studies on Cardiac contractility modulation therapy have focused on patients with a normal QRS duration (i.e. ≤ 120 ms), it is possible to use the therapy in patients who meet the treatment indication but who do not have a normal QRS duration. (wikipedia.org)
• ##### mechanism
• Recent concepts about the molecular basis of muscle contraction, is explained on the basis of cross bridge mechanism, which also includes sliding filament process. (kypho.com)
• ##### sudden cardi
• Hypertrophic cardiomyopathy (HCM) is one of the major cardiac genetic disorders among South Asians, leading to contractile dysfunction, heart failure, and sudden cardiac death. (frontiersin.org)
• ##### cytosol
• It does this by binding to the SERCA and decreasing its attraction (affinity) to calcium, therefore preventing calcium uptake into the SR. Failure to remove Ca2+ from the cytosol, prevents muscle relaxation and therefore means that there is a decrease in muscle contraction too. (wikipedia.org)
• ##### duration
• ATX-II prolongs the duration of the cardiac action potential, as demonstrated in cultured embryonic chicken cardiac muscle cells. (wikipedia.org)
• ##### influx
• For example, the sodium-calcium exchanger uses energy from the electrochemical gradient of sodium by coupling the influx of sodium into cell (and down its concentration gradient) with the transport of calcium out of the cell. (wikipedia.org)
• However, the electrical signals increase the influx of calcium ions into the cardiac muscle cells (cardiomyocytes). (wikipedia.org)
• ##### genetic
• Alpha actin is also expressed as distinct genetic isoforms such as smooth muscle, cardiac muscle and skeletal muscle specific isoforms of alpha actin. (wikipedia.org)
• ##### mechanical
• Ultimately, muscle contraction revolves around a charged atom (ion), calcium (Ca2+), which is responsible for converting the electrical energy of the action potential into mechanical energy (contraction) of the muscle. (wikipedia.org)
• There are also lots of actin (mainly β-actin) that does not take part in contraction, but that polymerizes just below the plasma membrane in the presence of a contractile stimulant and may thereby assist in mechanical tension. (wikipedia.org)
• ##### membrane
• In skeletal and cardiac muscle cells, however, these receptors are located within structures known as T-tubules, that are extensions of the plasma membrane penetrating deep into the cell (see figure 1). (wikipedia.org)
• Cardiac and skeletal muscle cells, contain structures called transverse tubules (T-tubules), which are extensions of the cell membrane that travel into the centre of the cell. (wikipedia.org)
• ##### efficiency
• This may be explained by the beneficial effect the therapy has in improving cardiac efficiency. (wikipedia.org)
• ##### functional
• The structural and functional communication between the voltage sensor and the RyR dictate the magnitude of Ca 2+ release from the SR, and thus the force of contraction. (biomedcentral.com)
• ##### muscle cells
• In muscle cells, for example, an action potential is the first step in the chain of events leading to contraction. (wikipedia.org)
• ##### regulatory light chain
• The MLC20 is also known as the regulatory light chain and actively participates in muscle contraction. (wikipedia.org)
• ##### rapidly
• Both forms of calsequestrin are phosphorylated by casein kinase 2, but the cardiac form is phosphorylated more rapidly and to a higher degree. (wikipedia.org)
• ##### cell
• They play an important role in signal transduction pathways, where they act as a second messenger, in neurotransmitter release from neurons, in contraction of all muscle cell types, and in fertilization. (wikipedia.org)
• Contraction ends when the Ca2+ is removed from the cell. (wikipedia.org)
• ##### known
• T-tubules are closely associated with a specific region of the SR, known as the terminal cisternae in cardiac muscle or junctional SR in skeletal muscle, with a distance of roughly 12 nanometers, separating them. (wikipedia.org)
• In this phase of the cardiac cycle, electrical signals cannot trigger new cardiac muscle contractions, hence this type of stimulation is known as a non-excitatory stimulation. (wikipedia.org)