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Francica A, Tonelli F, Rossetti C, Tropea I, Luciani GB, Faggian G, Dobson GP, Onorati F. Cardioplegia between Evolution and Revolution: From Depolarized to Polarized Cardiac Arrest in Adult Cardiac Surgery. J Clin Med 2021; 10:jcm10194485. [PMID: 34640503 PMCID: PMC8509840 DOI: 10.3390/jcm10194485] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Accepted: 09/28/2021] [Indexed: 12/12/2022] Open
Abstract
Despite current advances in perioperative care, intraoperative myocardial protection during cardiac surgery has not kept the same pace. High potassium cardioplegic solutions were introduced in the 1950s, and in the early 1960s they were soon recognized as harmful. Since that time, surgeons have minimized many of the adverse effects by lowering the temperature of the heart, lowering K+ concentration, reducing contact K+ time, changing the vehicle from a crystalloid solution to whole-blood, adding many pharmacological protectants and modifying reperfusion conditions. Despite these attempts, high potassium remains a suboptimalway to arrest the heart. We briefly review the historical advances and failures of finding alternatives to high potassium, the drawbacks of a prolonged depolarized membrane, altered Ca2+ intracellular circuits and heterogeneity in atrial-ventricular K+ repolarization during reanimation. Many of these untoward effects may be alleviated by a polarized membrane, and we will discuss the basic science and clinical experience from a number of institutions trialling different alternatives, and our institution with a non-depolarizing adenosine, lidocaine and magnesium (ALM) cardioplegia. The future of polarized arrest is an exciting one and may play an important role in treating the next generation of patients who are older, and sicker with multiple comorbidities and require more complex operations with prolonged cross-clamping times.
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Affiliation(s)
- Alessandra Francica
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
- Correspondence: ; Tel.: +39-3356213738
| | - Filippo Tonelli
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Cecilia Rossetti
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Ilaria Tropea
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Giovanni Battista Luciani
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
| | - Geoffrey Phillip Dobson
- Heart and Trauma Research Laboratory, College of Medicine and Dentistry, James Cook University, Townsville 4811, Australia;
| | - Francesco Onorati
- Division of Cardiac Surgery, University of Verona Medical School, 37126 Verona, Italy; (F.T.); (C.R.); (I.T.); (G.B.L.); (G.F.); (F.O.)
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Lindinger MI, Cairns SP. Regulation of muscle potassium: exercise performance, fatigue and health implications. Eur J Appl Physiol 2021; 121:721-748. [PMID: 33392745 DOI: 10.1007/s00421-020-04546-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 10/29/2020] [Indexed: 12/30/2022]
Abstract
This review integrates from the single muscle fibre to exercising human the current understanding of the role of skeletal muscle for whole-body potassium (K+) regulation, and specifically the regulation of skeletal muscle [K+]. We describe the K+ transport proteins in skeletal muscle and how they contribute to, or modulate, K+ disturbances during exercise. Muscle and plasma K+ balance are markedly altered during and after high-intensity dynamic exercise (including sports), static contractions and ischaemia, which have implications for skeletal and cardiac muscle contractile performance. Moderate elevations of plasma and interstitial [K+] during exercise have beneficial effects on multiple physiological systems. Severe reductions of the trans-sarcolemmal K+ gradient likely contributes to muscle and whole-body fatigue, i.e. impaired exercise performance. Chronic or acute changes of arterial plasma [K+] (hyperkalaemia or hypokalaemia) have dangerous health implications for cardiac function. The current mechanisms to explain how raised extracellular [K+] impairs cardiac and skeletal muscle function are discussed, along with the latest cell physiology research explaining how calcium, β-adrenergic agonists, insulin or glucose act as clinical treatments for hyperkalaemia to protect the heart and skeletal muscle in vivo. Finally, whether these agents can also modulate K+-induced muscle fatigue are evaluated.
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Affiliation(s)
- Michael I Lindinger
- Research and Development, The Nutraceutical Alliance, Burlington, ON, L7N 2Z9, Canada
| | - Simeon P Cairns
- SPRINZ, School of Sport and Recreation, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, 1020, New Zealand.
- Health and Rehabilitation Research Institute, Faculty of Health and Environmental Sciences, Auckland University of Technology, Auckland, 1020, New Zealand.
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Rivaud MR, Baartscheer A, Verkerk AO, Beekman L, Rajamani S, Belardinelli L, Bezzina CR, Remme CA. Enhanced late sodium current underlies pro-arrhythmic intracellular sodium and calcium dysregulation in murine sodium channelopathy. Int J Cardiol 2018; 263:54-62. [PMID: 29754923 DOI: 10.1016/j.ijcard.2018.03.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/23/2018] [Accepted: 03/09/2018] [Indexed: 12/20/2022]
Abstract
BACKGROUND Long QT syndrome mutations in the SCN5A gene are associated with an enhanced late sodium current (INa,L) which may lead to pro-arrhythmic action potential prolongation and intracellular calcium dysregulation. We here investigated the dynamic relation between INa,L, intracellular sodium ([Na+]i) and calcium ([Ca2+]i) homeostasis and pro-arrhythmic events in the setting of a SCN5A mutation. METHODS AND RESULTS Wild-type (WT) and Scn5a1798insD/+ (MUT) mice (age 3-5 months) carrying the murine homolog of the SCN5A-1795insD mutation on two distinct genetic backgrounds (FVB/N and 129P2) were studied. [Na+]i, [Ca2+]i and Ca2+ transient amplitude were significantly increased in 129P2-MUT myocytes as compared to WT, but not in FVB/N-MUT. Accordingly, INa,L wassignificantly more enhanced in 129P2-MUT than in FVB/N-MUT myocytes, consistent with a dose-dependent correlation. Quantitative RT-PCR analysis revealed intrinsic differences in mRNA expression levels of the sodium/potassium pump, the sodium/hydrogen exchanger, and sodium‑calcium exchanger between the two mouse strains. The rate of increase in [Na+]i, [Ca2+]i and Ca2+ transient amplitude following the application of the Na+/K+-ATPase inhibitor ouabain was significantly greater in 129P2-MUT than in 129P2-WT myocytes and was normalized by the INa,L inhibitor ranolazine. Furthermore, ranolazine decreased the incidence of pro-arrhythmic calcium after-transients elicited in 129P2-MUT myocytes. CONCLUSIONS In this study we established a causal link between the magnitude of INa,L, extent of Na+ and Ca2+ dysregulation, and incidence of pro-arrhythmic events in murine Scn5a1798insD/+ myocytes. Furthermore, our findings provide mechanistic insight into the anti-arrhythmic potential of pharmacological inhibition of INa,L in patients with LQT3 syndrome.
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Affiliation(s)
- Mathilde R Rivaud
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Antonius Baartscheer
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Arie O Verkerk
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands; Department of Medical Biology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Leander Beekman
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | | | | | - Connie R Bezzina
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands
| | - Carol Ann Remme
- Heart Center, Department of Clinical and Experimental Cardiology, Academic Medical Center, Meibergdreef 15, 1105AZ Amsterdam, The Netherlands.
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Sicouri S, Belardinelli L, Antzelevitch C. Effect of autonomic influences to induce triggered activity in muscular sleeves extending into the coronary sinus of the canine heart and its suppression by ranolazine. J Cardiovasc Electrophysiol 2018; 30:230-238. [PMID: 30302862 DOI: 10.1111/jce.13770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Revised: 10/01/2018] [Accepted: 10/05/2018] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Extrasystoles arising from the muscular sleeves associated with the pulmonary veins (PV), superior vena cava (SVC), and coronary sinus (CS) are known to precipitate atrial fibrillation (AF). The late sodium channel current (INa ) inhibitor ranolazine has been reported to exert antiarrhythmic effects in canine PV and SVC sleeves by suppressing late phase 3 early and delayed after depolarization (EAD and DAD)-induced triggered activity induced by parasympathetic and/or sympathetic stimulation. The current study was designed to extend our existing knowledge of the electrophysiological and pharmacologic properties of canine CS preparations and assess their response to inhibition of late INa following autonomic stimulation. METHODS Transmembrane action potentials were recorded from canine superfused CS using standard microelectrode techniques. Acetylcholine (ACh, 1 µM), isoproterenol (Iso, 1 µM), high calcium ([Ca2+ ]o = 5.4 mM), or a combination were used to induce EADs, DADs, and triggered activity. RESULTS Action potentials (AP) recorded from the CS displayed short and long AP durations (APD), with and without phase 4 depolarization (n = 19). Iso induced DAD-mediated triggered activity. The combination of sympathetic and parasympathetic agonists resulted in late phase 3 EAD-induced triggered activity in all CS preparations. Ranolazine (5-10 µM) suppressed late phase 3 EAD- and DAD-induced triggered activity in 8 of 8 preparations. Subthreshold stimulation induced a prominent hyperpolarization that could be suppressed by atropine. CONCLUSIONS Our results suggest the important role of parasympathetic innervation in the activity of the CS. Autonomic influences promote DAD- and late phase-3-EAD-mediated triggered activity in canine CS, thus generating extrasystolic activity capable of initiating atrial arrhythmias. Ranolazine effectively suppresses these triggers.
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Affiliation(s)
- Serge Sicouri
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, New York.,Cardiovascular Research Program, Lankenau Institute for Medical Research, Wynnewood, Pennsylvania
| | | | - Charles Antzelevitch
- Department of Experimental Cardiology, Masonic Medical Research Laboratory, Utica, New York.,Cardiovascular Research Program, Lankenau Institute for Medical Research, Wynnewood, Pennsylvania.,Lankenau Heart Institute, Wynnewood, Pennsylvania.,Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania
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Robert T, Algalarrondo V, Mesnard L. Hyperkaliémie sévère ou menaçante : le diable est dans les détails. ACTA ACUST UNITED AC 2015. [DOI: 10.1007/s13546-015-1125-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Dobson GP, Faggian G, Onorati F, Vinten-Johansen J. Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era? Front Physiol 2013; 4:228. [PMID: 24009586 PMCID: PMC3755226 DOI: 10.3389/fphys.2013.00228] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2013] [Accepted: 08/05/2013] [Indexed: 12/16/2022] Open
Abstract
Despite surgical proficiency and innovation driving low mortality rates in cardiac surgery, the disease severity, comorbidity rate, and operative procedural difficulty have increased. Today's cardiac surgery patient is older, has a "sicker" heart and often presents with multiple comorbidities; a scenario that was relatively rare 20 years ago. The global challenge has been to find new ways to make surgery safer for the patient and more predictable for the surgeon. A confounding factor that may influence clinical outcome is high K(+) cardioplegia. For over 40 years, potassium depolarization has been linked to transmembrane ionic imbalances, arrhythmias and conduction disturbances, vasoconstriction, coronary spasm, contractile stunning, and low output syndrome. Other than inducing rapid electrochemical arrest, high K(+) cardioplegia offers little or no inherent protection to adult or pediatric patients. This review provides a brief history of high K(+) cardioplegia, five areas of increasing concern with prolonged membrane K(+) depolarization, and the basic science and clinical data underpinning a new normokalemic, "polarizing" cardioplegia comprising adenosine and lidocaine (AL) with magnesium (Mg(2+)) (ALM™). We argue that improved cardioprotection, better outcomes, faster recoveries and lower healthcare costs are achievable and, despite the early predictions from the stent industry and cardiology, the "cath lab" may not be the place where the new wave of high-risk morbid patients are best served.
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Affiliation(s)
- Geoffrey P. Dobson
- Department of Physiology and Pharmacology, Heart and Trauma Research Laboratory, James Cook UniversityTownsville, QLD, Australia
| | - Giuseppe Faggian
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Francesco Onorati
- Division of Cardiac Surgery, University of Verona Medical SchoolVerona, Italy
| | - Jakob Vinten-Johansen
- Cardiothoracic Research Laboratory of Emory University Hospital Midtown, Carlyle Fraser Heart CenterAtlanta, GA, USA
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Sicouri S, Blazek J, Belardinelli L, Antzelevitch C. Electrophysiological characteristics of canine superior vena cava sleeve preparations: effect of ranolazine. Circ Arrhythm Electrophysiol 2012; 5:371-9. [PMID: 22407414 DOI: 10.1161/circep.111.969493] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND In addition to extrasystoles of pulmonary vein (PV) origin, those arising from the superior vena cava (SVC) can precipitate atrial fibrillation (AF). The present study evaluates the electrophysiological properties of canine SVC sleeve preparations and the effect of ranolazine on late phase 3 early and delayed afterdepolarization (EAD and DAD)-induced triggered activity in SVC sleeves and compares SVC and PV sleeve electrophysiological properties. METHODS AND RESULTS Action potentials (APs) were recorded from superfused SVC and PV sleeves using microelectrode techniques. Acetylcholine (1 μmol/L), isoproterenol (1 μmol/L), high calcium ([Ca(2+)](o)=5.4 mmol/L), or a combination were used to induce EADs, DADs, and triggered activity. A marked diversity of action potential characteristics was observed in the SVC sleeve, including action potentials with short and long APs, with and without phase 4 depolarization. Rapid pacing induced hyperpolarization, accentuating the slope of phase 4 depolarization. Phase 4 depolarization and rapid pacing-induced hyperpolarization were reduced or eliminated after atropine (10 μmol/L) or ranolazine (10 μmol/L). APs displaying phase 4 depolarization (n=19) had longer APDs, smaller amplitude and V(max), and a more positive take-off potential than APs lacking phase 4 depolarization (n=15). Ranolazine (5-10 μmol/L) eliminated late phase 3 EAD- and DAD-induced triggered activity as well as isoproterenol-induced automaticity elicited in SVC sleeves. Compared with PV, SVC sleeves display phase 4 depolarization, smaller V(max), and longer APs. CONCLUSIONS Autonomic influences promote spontaneous automaticity and triggered activity in SVC sleeves, thus generating extrasystolic activity capable of initiating atrial arrhythmias. Ranolazine can effectively suppress these triggers.
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Affiliation(s)
- Serge Sicouri
- Masonic Medical Research Laboratory, Utica, NY 13501-1787, USA.
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Pathophysiologic changes due to TASER® devices versus excited delirium: Potential relevance to deaths-in-custody? J Forensic Leg Med 2011; 18:145-53. [PMID: 21550562 DOI: 10.1016/j.jflm.2011.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 01/13/2011] [Accepted: 01/26/2011] [Indexed: 11/21/2022]
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Overgaard J, Gesser H, Wang T. Tribute to P. L. Lutz: cardiac performance and cardiovascular regulation during anoxia/hypoxia in freshwater turtles. ACTA ACUST UNITED AC 2008; 210:1687-99. [PMID: 17488932 DOI: 10.1242/jeb.001925] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Freshwater turtles overwintering in ice-covered ponds in North America may be exposed to prolonged anoxia, and survive this hostile environment by metabolic depression. Here, we review their cardiovascular function and regulation, with particular emphasis on the factors limiting cardiac performance. The pronounced anoxia tolerance of the turtle heart is based on the ability to match energy consumption with the low anaerobic ATP production during anoxia. Together with a well-developed temporal and spatial energy buffering by creatine kinase, this allows for cellular energy charge to remain high during anoxia. Furthermore, the turtle heart is well adapted to handle the adverse effects of free phosphate arising when phosphocreatine stores are used. Anoxia causes tenfold reductions in heart rate and blood flows that match the metabolic depression, and blood pressure is largely maintained through increased systemic vascular resistance. Depression of the heart rate is not driven by the autonomic nervous system and seems to arise from direct effects of oxygen lack and the associated hyperkalaemia and acidosis on the cardiac pacemaker. These intra- and extracellular changes also affect cardiac contractility, and both acidosis and hyperkalaemia severely depress cardiac contractility. However, increased levels of adrenaline and calcium may, at least partially, salvage cardiac function under prolonged periods of anoxia.
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Affiliation(s)
- Johannes Overgaard
- National Environmental Research Institute, Aarhus University, Silkeborg, Denmark
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Overgaard J, Wang T, Nielsen OB, Gesser H. Extracellular Determinants of Cardiac Contractility in the Cold Anoxic Turtle. Physiol Biochem Zool 2005; 78:976-95. [PMID: 16228937 DOI: 10.1086/432853] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2005] [Indexed: 11/03/2022]
Abstract
Painted turtles (Chrysemys picta) survive months of anoxic submergence, which is associated with large changes in the extracellular milieu where pH falls by 1, while extracellular K+, Ca++, and adrenaline levels all increase massively. While the effect of each of these changes in the extracellular environment on the heart has been previously characterized in isolation, little is known about their interactions and combined effects. Here we examine the isolated and combined effects of hyperkalemia, acidosis, hypercalcemia, high adrenergic stimulation, and anoxia on twitch force during isometric contractions in isolated ventricular strip preparations from turtles. Experiments were performed on turtles that had been previously acclimated to warm (25 degrees C), cold (5 degrees C), or cold anoxia (submerged in anoxic water at 5 degrees C). The differences between acclimation groups suggest that cold acclimation, but not anoxic acclimation per se, results in a downregulation of processes in the excitation-contraction coupling. Hyperkalemia (10 mmol L(-1) K+) exerted a strong negative inotropic effect and caused irregular contractions; the effect was most pronounced at low temperature (57%-97% reductions in twitch force). Anoxia reduced twitch force at both temperatures (14%-38%), while acidosis reduced force only at 5 degrees C (15%-50%). Adrenergic stimulation (10 micromol L(-1)) increased twitch force by 5%-19%, but increasing extracellular [Ca++] from 2 to 6 mmol L(-1) had only small effects. When all treatments were combined with anoxia, twitch force was higher at 5 degrees C than at 25 degrees C, whereas in normoxia twitch force was higher at 25 degrees C. We propose that hyperkalemia may account for a large part of the depressed cardiac contractility during long-term anoxic submergence.
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Affiliation(s)
- Johannes Overgaard
- Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, Aarhus, Denmark.
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Andersen JB, Gesser H, Wang T. Acidosis Counteracts the Negative Inotropic Effect of K+on Ventricular Muscle Strips from the ToadBufo marinus. Physiol Biochem Zool 2004; 77:223-31. [PMID: 15095242 DOI: 10.1086/383501] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2003] [Indexed: 11/03/2022]
Abstract
Strenuous activity is associated with acidosis, increased extracellular potassium concentration ([K+]o), and elevated levels of circulating catecholamines. Acidosis and elevated [K+]o are normally considered harmful to cardiac function, and a high sympathetic tone on the heart may lead to arrhythmia. During activity, however, the heart must be able to increase rate and strength of contraction. While the individual effects of [K+]o, acidosis, and adrenaline on contractile properties of cardiac muscle have been characterized for some ectothermic species, less information is available on their interactions. Here we examine the isolated and combined effects of [K+]o, acidosis, and adrenaline on ventricular muscle strips from the toad Bufo marinus. This study showed that increased [K+]o significantly reduced twitch force, while lactic acid significantly increased twitch force and more than counteracted the negative inotropic effects of elevated [K+]o. There was no inotropic effect of Na-lactate (neutralized lactic acid), which suggests that lactic acid stimulated twitch force through reduced pH and not by serving as a substrate. Adrenaline had a positive effect on twitch force in all preparations. Irrespective of treatment, twitch force decreased as stimulation rate increased. During high [K+]o, there was a severe reduction in maximal frequency of toad ventricular strips that was not alleviated by lactic acidosis and/or adrenaline, which suggests that high [K+]o influences twitch force and maximal rate by different mechanisms. In vivo levels of lactic acid, [K+]o, adrenaline, and heart rate previously observed during forced activity in Bufo did not significantly affect the contractile properties of heart muscle strips in vitro. Thus, although [K+]o significantly decreased twitch force, this detrimental effect was more than counteracted by the positive inotropic effect of lactic acid and adrenaline.
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Affiliation(s)
- Johnnie Bremholm Andersen
- Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, Universitetsparken, Building 131, DK-8000 Aarhus C, Denmark.
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Celik S, Bal R, Durgut R. Experimental hyperkalaemia in rabbits: effects of salbutamol and norepinephrine treatments on blood biochemistry and electrocardiography. Acta Vet Hung 2003; 51:331-42. [PMID: 14516161 DOI: 10.1556/avet.51.2003.3.8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The effects of salbutamol and norepinephrine on the electrocardiogram (ECG), serum potassium level and enzyme activities were studied in rabbits with hyperkalaemia; norepinephrine and salbutamol may be therapeutically useful. For induction of hyperkalaemia, 300 mM KCl solution was used and then isotonic saline solution containing 6 microg salbutamol and 3.9 microg norepinephrine per ml were administered. Norepinephrine and salbutamol decreased the serum potassium from 7.36 +/- 0.26 and 7.21 +/- 0.31 mmol/L to 5.62 +/- 0.27 and 4.35 +/- 0.33 mmol/L, respectively, and caused the ECG changes (flatness of P wave, widening of QRS complex and bradycardia) to return to the control conditions (time 0). Norepinephrine, but not salbutamol, decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) to the control levels. These results suggest that monitoring of the enzyme activities might be useful as it yields indexes suitable for evaluating the therapeutic approach with norepinephrine in hyperkalaemia.
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Affiliation(s)
- S Celik
- Department of Biochemistry, Faculty of Veterinary Medicine, University of Mustafa Kemal, 31040 Antakya-Hatay, Turkey.
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Lucía A, Hoyos J, Santalla A, Pérez M, Carvajal A, Chicharro JL. Lactic acidosis, potassium, and the heart rate deflection point in professional road cyclists. Br J Sports Med 2002; 36:113-7. [PMID: 11916893 PMCID: PMC1724475 DOI: 10.1136/bjsm.36.2.113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVE To determine the influence of lactic acidosis, the Bohr effect, and exercise induced hyperkalaemia on the occurrence of the heart rate deflection point (HRDP) in elite (professional) cyclists. METHODS Sixteen professional male road cyclists (mean (SD) age 26 (1) years) performed a ramp test on a cycle ergometer (workload increases of 5 W/12 s, averaging 25 W/min). Heart rate (HR), gas exchange parameters, and blood variables (lactate, pH, P(50) of the oxyhaemoglobin dissociation curve, and K(+)) were measured during the tests. RESULTS A HRDP was shown in 56% of subjects at about 88% of their maximal HR (HRDP group; n = 9) but was linear in the rest (No-HRDP group; n = 7). In the HRDP group, the slope of the HR-workload regression line above the HRDP correlated inversely with levels of K(+) at the maximal power output (r = -0.67; p<0.05). CONCLUSIONS The HRDP phenomenon is associated, at least partly, with exercise induced hyperkalaemia.
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Affiliation(s)
- A Lucía
- Departamento de Ciencias Morfológicas y Fisiología, Universidad Europea de Madrid, Madrid, Spain.
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Nielsen JS, Gesser H. Effects of high extracellular [K+] and adrenaline on force development, relaxation and membrane potential in cardiac muscle from freshwater turtle and rainbow trout. J Exp Biol 2001; 204:261-8. [PMID: 11136612 DOI: 10.1242/jeb.204.2.261] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Increases in extracellular K(+) concentrations reduced the twitch force amplitude of heart muscle from the freshwater turtle (Trachemys scripta elegans) and rainbow trout (Oncorhynchus mykiss). Adrenaline augmented twitch force amplitude and reduced the relative influence of [K(+)]. In the absence of adrenaline, high [K(+)] had less effect in reducing twitch force in turtle than in trout, whereas the reverse was true in the presence of adrenaline. Under anoxic conditions, twitch force was lower in 10 mmol l(−1) than in 2.5 mmol l(−1) K(+) in both preparations, but adrenaline removed this difference. A further analysis of turtle myocardium showed that action potential duration was shorter and resting potential more positive in high [K(+)] than in low [K(+)]. Adrenaline restored the duration of the action potential, but did not affect the depolarisation, which may attenuate Na(+)/Ca(2+) exchange, participating in excitation/contraction coupling. The contractile responses in the presence of adrenaline were, however, similar in both high and low K(+) concentrations when increases in extracellular Ca(2+) were applied to increase the demand on excitation/contraction coupling. The possibilities that adrenaline counteracts the effects of high [K(+)] via the sarcoplasmic reticulum or sarcolemmal Na(+)/K(+)-ATPase were examined by inhibiting the sarcoplasmic reticulum with ryanodine (10 micromol l(−1)) or Na(+)/K(+)-ATPase with ouabain (0.25 or 3 mmol l(−)). No evidence to support either of these possibilities was found. Adrenaline did not protect all aspects of excitation/contraction coupling because the maximal frequency giving regular twitches was lower at 10 mmol l(−1) K(+) than at 2.5 mmol l(−1) K(+).
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Affiliation(s)
- J S Nielsen
- Department of Zoophysiology, Institute of Biological Sciences, University of Aarhus, DK-8000 Aarhus C, Denmark
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Sejersted OM, Sjøgaard G. Dynamics and consequences of potassium shifts in skeletal muscle and heart during exercise. Physiol Rev 2000; 80:1411-81. [PMID: 11015618 DOI: 10.1152/physrev.2000.80.4.1411] [Citation(s) in RCA: 345] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Since it became clear that K(+) shifts with exercise are extensive and can cause more than a doubling of the extracellular [K(+)] ([K(+)](s)) as reviewed here, it has been suggested that these shifts may cause fatigue through the effect on muscle excitability and action potentials (AP). The cause of the K(+) shifts is a transient or long-lasting mismatch between outward repolarizing K(+) currents and K(+) influx carried by the Na(+)-K(+) pump. Several factors modify the effect of raised [K(+)](s) during exercise on membrane potential (E(m)) and force production. 1) Membrane conductance to K(+) is variable and controlled by various K(+) channels. Low relative K(+) conductance will reduce the contribution of [K(+)](s) to the E(m). In addition, high Cl(-) conductance may stabilize the E(m) during brief periods of large K(+) shifts. 2) The Na(+)-K(+) pump contributes with a hyperpolarizing current. 3) Cell swelling accompanies muscle contractions especially in fast-twitch muscle, although little in the heart. This will contribute considerably to the lowering of intracellular [K(+)] ([K(+)](c)) and will attenuate the exercise-induced rise of intracellular [Na(+)] ([Na(+)](c)). 4) The rise of [Na(+)](c) is sufficient to activate the Na(+)-K(+) pump to completely compensate increased K(+) release in the heart, yet not in skeletal muscle. In skeletal muscle there is strong evidence for control of pump activity not only through hormones, but through a hitherto unidentified mechanism. 5) Ionic shifts within the skeletal muscle t tubules and in the heart in extracellular clefts may markedly affect excitation-contraction coupling. 6) Age and state of training together with nutritional state modify muscle K(+) content and the abundance of Na(+)-K(+) pumps. We conclude that despite modifying factors coming into play during muscle activity, the K(+) shifts with high-intensity exercise may contribute substantially to fatigue in skeletal muscle, whereas in the heart, except during ischemia, the K(+) balance is controlled much more effectively.
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Affiliation(s)
- O M Sejersted
- Institute for Experimental Medical Research, University of Oslo, Ullevaal Hospital, Oslo, Norway.
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Koyama Y, Koike A, Yajima T, Kano H, Marumo F, Hiroe M. Effects of 'cool-down' during exercise recovery on cardiopulmonary systems in patients with coronary artery disease. JAPANESE CIRCULATION JOURNAL 2000; 64:191-6. [PMID: 10732850 DOI: 10.1253/jcj.64.191] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The effects of 'cool-down' during exercise recovery on cardiovascular and respiratory systems have not been fully clarified. The recovery of respiratory gasses was compared in cardiac patients after maximal exercise during which subjects either performed a cool-down or rested. Twenty-one patients (61+/-10 years) with coronary artery disease performed 2 symptom-limited incremental exercise tests on a cycle ergometer: one with a cool-down and the other without during recovery from the maximal exercise test. Expired gasses were analyzed on a breath-by-breath basis throughout the test and for 6min of recovery. Without a cool-down, the ventilatory equivalent for O2 (VE/O2) increased dramatically during recovery compared with the resting values or those of peak exercise: 44.5+/-7.7 at rest, 44.0+/-10.6 at peak exercise and 63.3+/-14.5 after 2min of recovery. End-tidal PO2 (P(ET)O2) also increased significantly during recovery. However, the overshoot phenomenon of these variables was attenuated when cool-down exercise was performed during recovery. The high ratio of VE/VO2 reflects ventilation perfusion (VA/Q) unevenness and P(ET)O2 is an index of arterial PO2. Thus, it is suggested that cool-down exercise during recovery after maximal exercise testing provides beneficial effects on the respiratory system by decreasing the VA/Q unevenness and relative hyperventilation that are observed when cool-down exercise is not performed.
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Affiliation(s)
- Y Koyama
- The Second Department of Internal Medicine, Tokyo Medical and Dental University, Japan
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O'Neill M, Ryan DM, Paterson DJ. Effect of verapamil on restoration of cardiac performance in raised [K+]o by adrenergic stimulation in the rabbit. ACTA PHYSIOLOGICA SCANDINAVICA 1995; 154:367-76. [PMID: 7572234 DOI: 10.1111/j.1748-1716.1995.tb09920.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Modulation of the L-type calcium channel by catecholamines improves action potential parameters in single ventricular myocytes depolarized by high [K+]o Tyrode. Whether this modulation is important in offsetting the negative effects of hyperkalaemia in the whole heart is not known. We tested the effects of the calcium channel antagonist, verapamil, on restoration of cardiac performance by adrenergic stimulation in high [K+]o in anaesthetized rabbits and isolated perfused working rabbit hearts. Raised [K+]o decreased SBP, LVP and LVdP/dtmax in vivo ([K+]a 8.6 +/- 0.2 mM; n = 10) and aortic flow (AF) in the isolated heart (8 mM [K+]o Tyrode; n = 25). However, the negative effects of raised [K+]a were offset by isoprenaline (Iso, 1 microgram kg-1 min-1 i.v.) in vivo and by noradrenaline (NA, 80 nM) in the isolated heart. Verapamil (0.15 mg kg-1 i.v.; 15 nM isolated heart) markedly potentiated the negative inotropic effects of raised [K+]o in both preparations. Verapamil attenuated the effect of isoprenaline in vivo but in the isolated heart, the protective effect of NA in 8 mM [K+] Tyrode (AF 97 +/- 10 mL min-1 in 8 mM [K+]o compared with AF 141 +/- 8.5 mL min-1 in 8 mM [K+]o + NA) was offset by the drug (90 +/- 8 mL min-1 in 8 mM [K+]o + NA + V). Furthermore, verapamil abolished aortic flow in 8 mM [K+]o alone. These findings suggest that the heart may be critically dependent on modulation of intracellular calcium in order to tolerate concentrations of K+ similar to those seen during a short burst of intensive exercise ([K+]a 8.6 mM).
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Affiliation(s)
- M O'Neill
- University Laboratory of Physiology, Oxford, UK
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O'Neill M, Paterson DJ. Role of the sympathetic nervous system in cardiac performance during hyperkalaemia in the anaesthetized pig. ACTA PHYSIOLOGICA SCANDINAVICA 1995; 153:1-11. [PMID: 7625163 DOI: 10.1111/j.1748-1716.1995.tb09828.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Cardiovascular performance was studied in 18 alpha-chloralose anaesthetized pigs when arterial potassium ([K+]a) was raised to levels observed in heavy exercise. The effects of hyperkalaemia were then studied during cardiac sympathetic nerve stimulation or during an infusion of noradrenaline. Elevation of [K+]a up to ca. 10 mM caused a progressive decline in cardiovascular performance. However, right cardiac sympathetic nerve stimulation elevated all cardiovascular parameters in the presence of raised [K+]a and offset the negative cardiac effects of hyperkalaemia. Electrical pacing of the right atrium to heart rates (HRs) equivalent to those observed during right cardiac sympathetic nerve stimulation did not offset the depressive effects of hyperkalaemia and, indeed, hastened the decline in cardiovascular performance. Infusion of noradrenaline (1 microgram kg min-1 i.v.) during hyperkalaemia caused an increase in all cardiovascular parameters similar to that seen during sympathetic nerve stimulation. After propranolol (0.5 mg kg-1 i.v.), sympathetic nerve stimulation slightly increased HR, systolic blood pressure (SBP) and dP/dtmax. Elevation of [K+]a occurred more rapidly after propranolol, but the heart was still protected from hyperkalaemia during cardiac sympathetic stimulation. Infusion of noradrenaline elicited arrhythmias in six pigs. Infusion of KCl reduced the incidence of arrhythmias and in some cases abolished them. These findings may be related to how the heart is protected from exercise-induced changes in potassium and catecholamines.
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Affiliation(s)
- M O'Neill
- University Laboratory of Physiology, Oxford, UK
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Ryan DM, Paterson DJ. Effect of ouabain and verapamil on restoration of contraction by adrenaline during high K+ in the frog heart. ACTA PHYSIOLOGICA SCANDINAVICA 1994; 151:417-9. [PMID: 7976414 DOI: 10.1111/j.1748-1716.1994.tb09762.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- D M Ryan
- University Laboratory of Physiology, Oxford, UK
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