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Metabolic Response during Impending Myocardial Infarction II. Clinical Implications By M. F. OLIVER, M.D. Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 SUMMARY The immediate local metabolic response of the myocardium to acute regional ischemia is determined by an interaction of various influences. These include: (1) the extent of and the variability in reduction of blood flow; (2) the degree and persistence of hypoxia; and (3) the effects of local release of catecholamines, particularly in relation to loss of intracellular potassium. The subsequent metabolic response of the myocardium is partly dependent on the degree of impairment locally of normal myocardial metabolism and partly on the systemic reaction to increased catecholamine activity and hence on: (1) adipose tissue lipolysis; (2) hepatic and muscle glycogenolysis; (3) insulin suppression; and (4) growth hormone and cortisol activity. These determine the extent of the uptake from blood of FFA and glucose by the ischemic myocardium. There is increasing evidence that high arterial concentrations of FFA can depress myocardial performance by leading to ventricular arrhythmias and decreased contractility. This effect probably depends on a critical interaction between the local concentration of FFA, catecholamines, and hypoxia. Metabolic intervention in the management of heart attacks should accordingly be directed toward reducing mobilization of adipose tissue FFA and increasing myocardial glycolytic activity. THE IMMEDIATE MYOCARDIAL and systemic metabolic responses to a "heart attack" result from acute myocardial ischemia rather than from myocardial infarction. The essential difference between these conditions is that ischemia can disappear spontaneously and is potentially reversible therapeutically. There are difficulties in studying the immediate consequences of myocardial ischemia in man, since many episodes probably occur without recognizable symptoms and many patients die before they can summon medical aid. Indeed, the median time of death after the onset of symptoms of impending infarction is about 2 hours,l and well before the morphologic characteristics of myocardial infarction can be identified. It is just for this reason that understanding of the metabolic and electrophysiologic consequences of acute From the Department of Cardiology, Infirmary, Edinburgh, Scotland. Circulation, Volume XLV, February 1972 myocardial ischemia is so vital. The problem is compounded by the fact that most studies of experimentally-induced myocardial ischemia have little analogy with ischemia occurring spontaneously in the aging and extensively arteriosclerotic human heart. Further, angina induced by exercise, pacing, or hypoxia does not lead to the same degree of systemic disturbance as prolonged ischemia due to acute coronary occlusion. The purpose of this paper is to review, in the context of acute heart attacks in man, the probable immediate local metabolic response in the myocardium, the general systemic metabolic response, and the effect of each on myocardial rhythmicity and contractility. Immediate Local Metabolic Response This is primarily determined by acute myocardial ischemia and secondarily by local catecholamine release. Royal 491 492 Ischemia Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 In the acutely ischemic and inifareting myocardium, there is likely to be hypoxia of xvarying degrees rather than extensive anoxia. The myocardium beyond the site of coronary artery occlusion probably undergoes rapid changes wvith collateral vessels opening and closing as thrombi occur locally, with some areas of poor perfusion recovering as intravascular pressure improves and with others becoming temporarily or permanently starved as flow ceases altogether. There can be little static in the-myocardium during the first hour after occlusion, and this is emphasized by the heterogeneity of pathologic change after experimental coronary artery occlusion.' Perfusion of viable myocardial tissue depends on the interaction of many influences and the balance obtained between opposing forces. For example, the immediate decrease in local pressure in the arteries distal to the area of partial or complete block will directly reduce perfusion and stimulate inflow from collateral vessels. Again, metabolic changes (see below) can cause vasodilatation through release of adenosine, and catecholamines can cause vasodilation and vasoconstriction. Spreading thrombus formation in arteries under low pressure, a decrease in stroke output, and raised left ventricular systolic and diastolic pressure can all impair local perfusion. The high oxygen content of venous blood leaving the ischemic area and the reasonably well-maintained epicardial (but not endocardial) oxygen tension emphasize that it is hvpoxia rather than anoxia that determines the immediate local metabolic response. In addition, it is regional hypoxia compounded by reduction and not cessation in coronary flow-in other words, regional myocardial ischemia in a heart where flow to other areas is not impaired. The persistence of myocardial ischemia, the degree of adaptation to it, and the critical nature of certain affected sites (Purkinje tissue) may all be more important than its- extent in relation to the subsequent onset of ventricular arrhvthmias and acute failure. In an accompanying paper, Opie` has OLIVER described the metabolism of glucose and free fatty acids (FFA) in the normally oxygenated heart and the adjustments that probably occur in ischemia. The evidence for accelerated glycolysis and anaerobic energy production is reviewved. One of the difficulties we haxve at present is understanding exactly how these intracellular metabolic events trigger off ain arrhvthibia or lead to acuite heart failure. Two resultant acute changes which require emplhasis are reduction in extriacellular pH4 aind release of mvocardial catecholamine stores. Reduction of pH is probably due mostly to release of hydrogen ions during hydrolysis of ATP at a greater rate thaln it is synthesized and perhaps from accumulation of hydrogen ions associated with lactate release aind accumulation of FFA. Very little is known about changes in intracellular pH but reduction could oc'CuIrl v ery locally and lead to local cellulai damnacge. Acidosis has been shown to suppress pacemaker and contractile perfor mance in the anoxic isolated rat heart.) Release of imivocardial catecholamines maya be theo mlost important of all the adverse influences and responsible for many of the local metabolic changes. Local Catecholamine Release Experimentally it has been showin that activation of sympathetic receptors in the mvocardium can occuI immediately as a resuilt of mvocardial isehemia or of an1 inicrease in coronlary artery pressure: a very rapid spinlal reflex, abolished by sectioninig of differeint fibers to the stellate ganglia, takes place witlh stimulation of differenit sympathetic fibers to the myocardium.; Release occurs of epinephriie anid inorepiinephrinie, stored in granules on the preterminal svmpathetic fibers. Catecholamines are released within minutes into the circulation in most dogs after coronary artery ligation.7 Depletion of catecholamines from ischemic and infarcted areas of the myocardium wJas first reported in man from histochemical studies," and this has been observed experimentally as sooin as half an hour after ligation of a coronary arterv.10 The view that local catecholamine activity can lead to early myocardial damage seems reasonable in consideration of the many reports of Circulation, VoluwIe XLV. Februar 1972 METABOLIC RESPONSE DURING MI ( II ) Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 morphologic changes following the administration of catecholamines.1 1 2 Catecholamine stimulation of phosphorylase activity is well described8 and can occur within 1 min of producing total myocardial ischemia..'8 Together with a rise in orthophosphate, this is probably the immediate and initial stimulus to glycogeniolysis. Catecholamine stimulation also leads to anl inicrease in succinlic and lactic dehydrogeniase activity in the ischemic area of the myocardium with efflux inlto the coronary sinlus. Histochemical or morphologic changes do niot occur wheni coronary artery ligationi is not associated wvith catecholaminie release.14 Certain local metabolic changes could result from local catecholamine activity. These include glycogenolysis and glycolysis. Hydrolvsis of stored triglyceride can occur since catecholamines activate a myocardial lipase.'5 This local effect of catecholamines may be particularly important in humans, since there is much more triglyceride stored in our hearts compared with that in most animals." In the presence of severe hypoxia, an increase in the intracellular concentration of FFA could result. Any decrease in carrier protein would exaggerate the effects of intracellular FFA accumulation. Weakly bound FFA could combine with acyl-CoA and also form cation salts. It has been hypothesized that these could harm cell and mitochondrial membranes as a result of detergent action.'7 Increased concentrations of FFA can also depress mitochondrial oxidative metabolism.'`8 There is much evidence linking increased catecholamine activity with serious arrhythmias in experimental animals19-22 and in man, and measures designed to reduce the action of catecholamines on the myocardium such as cardiac denervation 2 or ,8-adrenergic blockade'!' decrease the arrhythmogenic tendency. The mechanisms through which these changes trigger an arrhythmia are not clear. During mvocardial isehemia, potassium and phosphate loss occurs24 but this loss of ions is enihaniced by large conicenitrationis of norepinephrinie although reversed by low concentrationls of norepiinephrine.25 Presumably there is irregularity of potassium loss, anid marked (irculation. Volume XLV, February 1972 493 difference in the gradienits of cationl conlcenltration across cell membranes may xvell exaggerate the temporal discrepancy in recovery of excitability kniowiv to exist between Purkinje tissue anid venitricular muscle and to the initiationi of arrhythmias.21" A further factor of importaince is the movemeAnt of extracellular fluid inlto the ischemic cell causinlg sxvellinlg anid further reductioni of initracellular potassium concenitration.Systemic Metabolic Response This is mainly determined by increased plasma catecholaminie concentrationls (fig. 1). When acute coronary artery occlusion leads to symptoms, aid this is not always the case, there is stimulation of postganglionic sympathetic nerve endings with release of norepinephrine, and of the adrenal medulla with release of epinephrine. Both catecholarmines are present in high concentrations in plasma28 and urine2t} during the first 24-48 hours after the onset of symptoms. The concentrations of these catecholamines in plasma reach high levels withini the first fexv hours after the onset of symptoms and later appear to be related to the severity of the infarct. Norepiniephrine acts through ,3-adreenergic receptors to activate the adeniylcyclase system in adipose tissue causing conversioni of ATP to cyclic AMP, and cyclic AMP activates a lipolytic system leading to hydrolysis of stored triglycerides to diglycerides, FFA, and also glycerol. While some reesterification of FFA occurs, the net effect is release of FFA and glycerol into the eirculation.") In acute myocardial infarction, plasma FFA concentrations are elevated xvithin 4 hours of the onset of symptoms.:' The highest values are found on the first day, and by the sixth day normal values are usually reached.32 Glycerol levels are also elevated. There is a close relationship betweein blood catecholamine anid FFA values in myocardial infare- tionl.34 Epinephrine has a weak effect on adipose tissue lipolysis but its main action at this time is to stimulate glycogenolysis in liver and muscle 'with elevation of blood glucose levels. Epinephrine also suppresses f-cell activity in OLIVER 494 Acute mvocardial ischemia .Pain and "stress" of, ACTH- Cortisol Adrenal medulla Postganglionic sympathetic I nerves Norepinephrine Epinephrine Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 Gluconeogenesis Suppiression of insulin secretion Growth hormione Adipose tissue lipolysis Hepatic and muscle glycogenolysis Plasma free fatty acids + Plasn3a glycerol + Plasma glucose + Figure 1 Schemratic diagram illustrating some of the systemic metabolic responses which occur during inmpending myocardial infarction. Many of these interact, and the diagram is deliberately simplified. the pancreas35 with a decrease in insulin secretion leading to further elevation of blood glucose. Thus, hyperglycemia occurs after acute myocardial infarction, and more than half of these patients have an abnormal glucose tolerance test during the first 72 hours of the attack.36, Reduction of insulin secretion has been demonstrated in patients after acute myocardial infarction following an intravenous glucose load37 and an intravenous tolbutamide test.38 The degree of failure in these responses has been positively correlated with the severity of the illness and with the presence of cardiogenic shock. Cortisol secretion 39 and plasma growth-hormone levels40 are increased during the first 24 hours after the onset of acute myocardial infarction. As the clinical condition improves, the degree of glucose intolerance diminishes and insulin secretion increases. In the second week plasma insulin levels are above normal,40 and at this stage the anabolic effect of insulin in enhancing the transport of amino acids into cells and their incorporation into protein is important for repair of the injured myocardium. Cortisol stimulates the breakdown of protein for gluconeogenic purposes and also the key gluconeogenic enzymes, but it is doubtful whether these actions operate until the acute period has passed. These increases in plasma FFA and glucose usually allow ischemic myocardial cells to be perfused with sufficient concentrations of substrates to ensure the survival of many. However, an excessive response, which rnay no longer he optimal, can occur in some patients. Plasma FFA can be elevated beyond the concentration when they are carried by the two principal binding sites on albumin-a 2:1 molar ratio is exceeded when plasma FFA levels are greater than 1200 jgEq/liter, and occasionally levels in the Circulation, Volunie XLV, February 1972 METABOLIC RESPONSE DURING MI (II) Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 region of 2000 ,Eq/liter have been recorded. When the FFA/albumin ratio increases, fatty acids are progressively more weakly bound to albumin, and there is an exponential relationship between increases in FFA/albumin ratio and FFA entry into the cell.41 In dogs during extensive myocardial ischemia, there is a proportionately greater myocardial uptake of FFA when compared with that of glucose and pyruvate and with myocardial oxygen consumption despite reduced coronary flow.24 This relatively larger uptake of FFA is reflected in an increase in the oxygenextraction ratio for FFA from 77% in the control period to 101% during ischemia and a decrease in the oxygen-extraction ratio for glucose from 33 to 25%. In patients with a severe systemic response to acute myocardial infarction, insulin suppression can be almost complete, and this will reduce the availability of glucose to myocardial cells in spite of the rise which occurs in plasma glucose levels. In addition, there is recent evidence that glucose uptake by the myocardium in normal resting man is inversely related to FFA levels42 and perhaps less dependent on insulin than was previously thought. Thus, ischemic myocardial cells may in some patients be exposed to an unusually high FFA/glucose ratio as a result of a marked systemic metabolic response. Effect of Local and Systemic Metabolic Response on Myocardial Performance The two chief complications of myocardial ischemia or infarction are serious ventricular arrhythmias and pump failure. The former occur soon after the onset of symptoms and the latter may either occur early as so-called cardiogenic shock when it is associated with a poorly understood set of vascular reflexes or later as left or progressive right ventricular failure. In this section, consideration will be given to the relationship of the local and general metabolic changes on the development of arrhythmias and on myocardial contractility. Arrhythmias Reference has already been made to the relationship between increased catecholamine Circulation, Volume XLV, February 1972 495 activity and arrhythmias, and in recent years the possibility has arisen that high plasma FFA levels may have an independent arrhythmogenic action. This is a potentially important concept and is based on the following evidence. In patients with acute myocardial infarction, a positive relationship has been reported between the incidence of serious ventricular arrhythmias and of early deaths with plasma FFA levels above 1200 ,iEq/liter,31'43 although this has not been observed by all investigators.21 44 In similar patients, a positive correlation between plasma glycerol levels and arrhythmias has also been observed.33 FFA can cause arrhythmias in other species without changes in catecholamine activity. In the normal dog, intravenous infusions of FFA as their sodium salts can cause conduction defects45 although not ventricular arrhythmias; in geese, elevation of FFA by glucagon produced ventricular arrhythmias and myocardial necrosis;46 and, in isolated perfused rat-heart preparations, octanoate produced arrhythmias.47 Investigations had been made of the effects on cardiac rhythm of increased arterial FFA, elevated by heparin induction of plasma lipolysis independently of catecholamine activity, in dogs in which myocardial infarction was produced experimentally. In studies in which occlusion of the circumflex coronary artery was produced in a closed-chest preparation with subsequent infarction of the lateral wall of the left ventricle, marked elevation of plasma FFA was usually associated with the development of frequent ventricular ectopic systoles and sometimes with ventricular tachycardia or even ventricular fibrillation.48' 4 In a comparable set of studies, however, conducted in dogs in which an apical branch of the anterior descending artery was ligated with consequent production of a small infarct at the apex of the left ventricle, marked elevation of plasma FFA by use of the same system for inducing plasma lipolysis was not associated with any increase in the incidence of serious ventricular arrhythmias.50 An explanation for these apparently contradictory results is not immediately forthcoming. It is important to 496 OLIVER Table 1 Main Differences in Experimental Design between Edinburgh and London in Relation to Induction of Arrhythniias by Elevation of Arterial FFA and through Administration of Initralipid and Heparin Parameter Lonnlon Edinburgh Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 FFA levels (,uEq, liter) 2t0-)() 6000 2000-600(0 ArrihyTthmia Yes No AI omgrels (sometimes ii idernlouirished) Greyhounds (differeint life Subj ects historv, exercise, habits, physiologic hypertrophy of heart, anid perhaps differ enit feeding) AMaterial Closed-chest preparation Openi-chest and pericardectomy Maini (circultmflex Branich of aniterior desceniding Ar.tery Treatmenit Occlusion of artery with Ligation of artery balloon catheter Initerruption of arterial ?Stimntiatiuln of arterial sympathetic sympat.hetic nerves imer-ves bv stretching ?In crease Local cateeholaminle ?D1)ecrease concentration Hea.rt rate (beats m-rniii) 120-1-)0 160-180 3.6 4.0 Serutm potassiuim 3.2-3.7 (mEq/liter) Seruim albutmin (g/liter) 2 -3) recognize that there were marked differences in the experimental models and systems of study. These are illustrated in table 1. Differences of potential importance are that Opie and colleagues5" may have conducted their experiments in conditions of reduced sensitivity to the induction of arrhythmias, as a result of pericardectomy which reduces contractile force,51 of reduced local catecholamine concentration due to interruption of the sympathetic supply during ligation of the artery, and of the higher heart rate which could prevent complete manifestation of a parasystolic focus originating in an accelerated "automatic" cell in the Purkinje system. Small doses of norepinephrine, which elevated FFA but did not lead to any hemodynamic changes, reduced the incidence of ventricular ectopic activity and enhanced contractility in dogs with extensive myocardial infarction.24 Whether this can be regarded as evidence against the arrhythmogenic activity of FFA is not clear, since the egress of potassium ions that usually occurs in acute ischemia was reduced in the same experiments. Recently, it has been shown that in- 4-4.5 fusions of FFA/ albumin complex to dogs with experimental myocardial infarction will raise arterial FFA to levels comparable to those seen in patients and lead to serious ventricular arrhythmias.52 Positive findings have been recorded in a majority of dogs. No arrhythmias occurred in dogs with myocardial infarction given plasma infusions under comparable conditions without elevation of FFA. In these studies, no heparin, catecholamine, or lipid emulsion was used. The raised arterial FFA decreased exponentially with time and appear to be utilized physiologically. If further studies confirm these preliminary findings, the case is strong for regarding elevated plasma FFA as arrhythmogenic in the presence of myocardial ischemia. Final interpretation of the various experiments described is not yet possible and should certainly take into account the type of preparation studied, the degree of ischemia (the absolute level of oxygen is crucial to the metabolism of FFA), the extracellular concentrations of FFA, glucose, and insulin, and the chain length of the fatty acids. Metabolically, the conducting system is like white muscle Circulation, Volume XLV, February 1972 497 METABOLIC RESPONSE DURING MI ( II ) Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 and has a lowver capacity to metabolize fatty acids, and more are likely to accumulate there when compared with the rest of the myocardium. This accumulation of FFA in myocardial cells might be exaggerated if there is much leakage and sequestration of albumin in extracellular tissue. Increase in arterial FFA and increased uptake by the ischemic myocardium may be followed by triglyceride deposition if oxidation is incomplete and if there is glucose 3-phosphate available for esterification to take place. Fatty infiltration of the ischemic and infarcted myocardium has been described years ago,53 and experimental evidence is now available of a positive relationship between the degree of elevation of arterial FFA and triglyceride deposition in the ischemic myocardium.54 Myocardial Contractility Myocardial oxygen consumption (MVo,) is determined by a number of factors including intramyocardial tension, the contractile state of the heart, heart rate, the external work performed by the heart, the energy required to activate contraction, and the metabolic status of the myocardium. All of these can be changed sharply by increased catecholamine activity, thus increasing MVo.,. Any marked increase in MV0., could be deleterious to certain critically ischemic areas of myocardium. High levels of FFA can also increase MVo,,. This has been shown in the isolated perfused heart55) and in intact dogs through studies of the effect of high concentrations of arterial FFA produced by plasma lipolysis;i)", local metabolic rate in the left ventricular wall is also increased by elevated arterial FFA."7 The effects of FFA and dextrose on contractility have been compared by studying rat papillary muscle.58 Contractility under well-oxygenated conditions was not altered by equivalent concentrations of FFA or dextrose, but under hypoxic conditions contractility was depressed by concentrations of FFA in the region of 2:1 albumin molar ratio and increased by dextrose. Similarly, dextrose improved mechanical performance in isolated perfused hearts when hypoxic, although not when adequately oxygenated.59 High concenCirculation, Volume XLV, February 1972 trations of FFA in the region of 6:1 FFA/albumin molar ratio depressed myocardial contractility in perfused isovolumic heart preparations. In addition, diastolic pressure increased.';0 A comparable synergism on myocardial contractility has been shown between FFA, using octanoate, and glucose in isolated perfused rat hearts.47 From studies using a nonmetabolized FFA (pent-4-enoic acid), this depression of contractility appears to be mediated directly by FFA or acyl-CoA derivatives rather than their metabolic products.';1 High arterial levels of FFA may therefore induce arrhythmias and depress myocardial contractility during acute myocardial ischemia, particularly if there is a relatively small increase in glucose uptake by the myocardium and marked hypoxia. Additionally, high concentration of FFA can decrease coronary blood flow62 and cause platelet aggregation.63 Metabolic Intervention Control of the extent of the metabolic response might contribute to the management of cardiac arrhythmias and of acute pump failure in myocardial ischemia. The aim should be to reduce elevated plasma FFA levels and to increase intracellular glucose concentrations. One therapeutic approach, not fully explored in man, is to reduce arterial concentrations of FFA. This might be achieved by drugs which reduce adipose tissue lipolysis. ,/-Adrenergie blockade is unlikely to be a satisfactory means of controlling the metabolic response since the inotropic and chronotropic effects of catecholamines can be critically important in the early stages of acute myocardial infarction. A ,8-blocker which has a specific effect in preventing cathecholamine activation of adipose tissue lipolysis would however be of interest. Nicotinic acid also has such an effect,64 but it is usually associated with flushing. The effects of nicotinic acid analogs require to be studied, and one has been shown to have an antiarrhythmic action.49 An alternative approach is to increase the uptake of glucose by the myocardium. The intravenous use of glucose, insulin, and 498 OLIVER Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 potassium to improve uptake of glucose and prevent depletion of potassium is superficially attractive. However, hypervolemia can occur and the results of clinical trials are not impressive.65 This may be due to the fact that these trials have been conducted in unselected groups of patients with acute myocardial infarction. The patients who would be expected to respond optimally are those with a high plasma FFA/glucose ratio. Further, the concentrations of glucose, insulin, and potassium which have been used have been lower than those theoretically and experimentally desirable.66 Increased glucose uptake might also be achieved by the use of glucagon. This substance has been shown to have a positive inotropic action in the management of cardiac failure and following acute myocardial infaretion.Y67 This effect might be due to increased uptake of glucose by myocardial cells or to increased myocardial calcium stores. Potassium and magnesium salts of dl-aspartic acid increase glucose utilization68 and potassium aspartate and tris-aspartate have been reported to lower heparin-induced elevation of plasma FFA. This might be another approach worthy of study. References 1. FULTON PM, JULIAN DG, OLIVER MF: Sudden death and myocardial infarction. In Research 2. 3. 4. 5. 6. 7. on Acute Myocardial Infarction, Monograph no. 27. New York, American Heart Association, 1969 JENN'INCGs RB: Myocardial ischemia: Observations, definitions and speculations. J Molec Cell Cardiol 1: 345, 1970 OpIE LH: Metabolic response during impending myocardial infarction: I. Relevance of studies of glucose and fatty acid metabolism in animals. Circulation 45: 483, 1972 COHEN RA, UHLEY HN: Monitoring the blood pH in acute myocardial infarction: The role of acidosis in arrhythmias. JAMA 198: 947, 1966 GELET TR, ALTSCHULD RA, WEISSLER AM: Effects of acidosis on the performance and nmetabolism of the anoxic heart. Circulation 40 (suppl IV): IV-27, 1969 BROWN AM, MALLIANI A: Spinal sympathetic reflexes initiated by coronary receptors. Amer J Physiol 212: 685, 1971 WOLLENBERGER A, KRAUSE EG, SHABAB L: Endogenous catecholamine mobilization and 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. the shift to anaerobic energy production in the acutely ischaemic myocardium. In International Symposium on Coronary Circulation and Energetics of the Myocardium. Basel, S. Karger, 1967 STASZEWSKA-BARCZAK J, CEREMUZYNSKI L: The continuious estimation of catecholamine release in the early stages of myocardial infarction in the dog. Clin Sci 34: 531, 1968 GAZES PC, RICHARDSON JA, WOODs EF: Norepinephrine and epinephrine content of normal and diseased human hearts. Circulation 11: 593, 1955 RUSSELL RA, CRAFOORD J, HAIRRIs AS: Changes in myocardial composition after coronary ar-tery ligation. Amer J Physiol 200: 955, 1961 SELYE H: The humoral production of cardiac infarcts. Brit Med j 1: 599, 1958 RAAB W: Emotional and sensory stress factors in myocardial pathology: Neurogenic and hormonal mechanisms in pathogenesis, therapy anid prevention. Amer Heart J 72: 538, 1966 WOLLENBERGER A, KRAUSE EC: Metabolic contiol characteristics of the acuitely ischemic myocardium. Amer- J Cardiol 22: 349, 1968 HERBACZYNSKA-CEDRO K: The influences of adrenaline secretion on the enzymes in heart muscle after acute coronary occlusion in dogs. Cardiovasc Res 4: 168, 1970 KRUGER FA, LEIGHTY EG, WEISSLER AM: Catecholamine stimulation of myocardial lipolysis and fatty acid reesterification. J Clin Invest 46: 1080, 1967 GLOSTER J, HARRIS P: The lipid composition on mitochondrial and microsomal fractions of human myocardial homogenates. Cardiovasc Res 3: 45, 1969 KURIEN VA, OLIVER MF: A metabolic cause for arrhythmias during acute myocardial hypoxia. Lancet 1: 813, 1970 BjORNTORP P, ELLIS HA, BRADFORD RH: Albumin antagonism of fatty acid effects on oxidation and phosphorylation reactions in rat liver mitochondria. J Biol Chem 239: 339, 1969 MAILING FM, MORAN NC: Ventricular arrhythmias induced by sympathomimetic amine in unanesthetized dogs following coronary artery occlusion. Circ Res 5: 409, 1957 CEREMIUZYNSMI L, STASZEWSKA-BARCZAK J, HERBACZY.NSKA-CEDRo K: Cardiac rhythmi disturbances and the release of catecholamines aftel acuite coronary occlusion in dogs. Cardiovasc Res 3: 190, 1969 21. JEWITT DE, MERCER CJ, REID D, VALOPRI C, THOMAS N, SHILLINGFORtD JP: Free noradrenaline and adrenaline excretion in relation to the development of cardiac arrhythmias and heart Circulation, Volume XLV. February 1972 499 METABOLIC RESPONSE DURING MI (II) failure in patients with acute myocardial infarction. Lancet 1: 635, 1969 22. NELSON PG: Effect of heparin on serum free fatty acids, plasma catecholamines and the incidence of arrhythmias following acute myocardial infarction. Brit Med J 3: 735, 1970 23. SCHAAL SF, WALLACE AG, SEALY WC: Protective influence of cardiac denervation against arrhythmias of myocardial infarction. Cardiovasc Res 3: 241, 1969 35. 36. 37. 24. REGAN TJ, HARMAN MA, LEHAN PH, BURKE 25. Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 26. 27. 28. 29. 30. 31. 32. 33. 34. WM, OLDEWURTEL HA: Ventricular arrhythmias and K transfer during myocardial ischemia and intervention with procaine amide, insulin or glucose solution. J Clin Invest 46: 1957, 1967 REGAN TJ, MARKOR A, OLDEWURTEL HA, BURKE WM: Myocardial metabolism and function during ischemia: Response to L-noradrenaline. Cardiovasc Res 4: 334, 1970 HAN J, MOE GK: Nonuniform recovery of excitability in ventricular muscle. Circ Res 14: 44, 1964 TAGGART P, SLATER JDH: Significance of potassium in the genesis of arrhythmias in induced cardiac ischaemia. Brit Med J 3: 195, 1971 GAZES PC, RICHARDSON JA, WOODs EF: Plasma catecholamine concentration in myocardial infarction and angina pectoris. Circulation 19: 657, 1959 VALORI C, THOMAS M, SHILLINGFORD JP: Free noradrenaline and adrenaline excretion in relation to clinical syndromes following myocardial infarction. Amer J Cardiol 20: 605, 1967 STEINBERG D, VAUGHAN M: Release of free fatty acids, from adipose tissue in relation to rates of triglyceride synthesis. In Handbook of Physiology, Sec 5: Adipose Tissue, edited by Renold AE, Cahill GF Jr. Washington, American Physiological Society, 1965 KURIEN VA, OLIVER MF: Serum free fatty acids after acute myocardial infarction and cerebral vascular occlusion. Lancet 2: 122, 1966 GUPTA DK, YOUNG R, JEwIrr DE, HARTOG M, OPIE LH: Increased plasma free fatty acid compositions and their significance in patients with acute myocardial infarction. Lancet 2: 1209, 1969 CARLSTRN-I S, CHRISTENSSON B: Plasma glycerol after acute myocardial infarction. Brit Heart J 33: 884, 1971 MUIESAN G, PORCELLATI C, RENZINI V, BRUNORI CA, VALORI C, GIGLI G: Relationship between plasma catecholamines and free fatty acid concentrations in patients with acute myo- Circulation, Volume XLV, February 1972 38. 39. cardial infarction. (Abstr) Cardiovasc Res 4: 226, 1970 PORTE D, CRABOR AL, KUZUYA T, WILLIAMS RH: The effect of epinephrine on immunoreactive insulin levels in man. J Clin Invest 45: 228, 1966 DATEY KK, NANDA NC: Hyperglycemia after acute myocardial infarction. New Eng J Med 276: 262, 1967 ALLISON SP, CHAMBERLAIN MJ, HINTON P: Intravenous glucose tolerance, insulin, glucose and free fatty acid levels after myocardial infarction. Brit Med J 4: 776, 1969 TAYLOR SH, SAXTON C, MAJID PA, DYKES JRW, GHOSH P, STOKER JB: Insulin secretion following myocardial infarction. Lancet 2: 1373, 1969 LOGAN RW, MURDOCH WR: Blood levels of hydrocortisone transaminases and cholesterol after acute myocardial infarction. Lancet 2: 521, 1966 40. LEBOVITz HE, SHULTZ KT, MATTHEWS ME, SCHEELE R: Acute metabolic responses to myocardial infarction. Circulation 39: 171, 1969 41. SPECTOR AA: The transport and utilization of free fatty acid. Ann NY Acad Sci 149: 768, 1968 42. LASSERS BW, WAHLQVIST ML, KAIJSER L, CARLSON LA: Relationship in man between plasma free fatty acids and myocardial metabolism of carbohydrate substrates. Lancet 2: 448, 1971 43. OLIVER MF, KURIEN VA, GREENWOOD TW: Relation between serum free fatty acids and arrhythmias and death after acute myocardial infarction. Lancet 1: 710, 1968 44. RUTENBERG HA, SOLOFF LA: Serum free fatty acids and arrhythmias after acute myocardial infarction. Lancet 1: 198, 1970 45. SOLOFF LA: Arrhythmias following infusions of fatty acids. Amer Heart J 80: 671, 1970 46. HOAK JC, CONNOR WE, WARNER ED: Toxic effects of glucagon-induced acute lipid mobilization in geese. J Clin Invest 47: 2701, 1968 47. OPIE LH: Effect of fatty acids on contractility and rhythm of the heart. Nature 227: 1055, 1970 48. KURIEN VA, YATES PA, OLIVER MF: Free fatty acids, heparin and arrhythmias during experimental myocardial infarction. Lancet 2: 185, 1969 49. KURIEN VA, YATES PA, OLIVER MF: The role of free fatty acids in the production of ventricular arrhythmias after acute coronary artery occlusion. Europ J Clin Invest 1: 225, 1971 50. OPIE LH, NORRIS RM, THOMAS M, HOLLAND HA, OWEN B, VAN NORDEN S: Failure of high concentrations of serum free fatty acids to OLIVER 500 provoke arrhythmias in experimental myocardial infarction. Lancet 1: 818, 1971 51. KAYE MP, RANDALL WC: Mechanism of decreased myocardial contractile force after epicardectomy. Cardiovasc Res 5: 154, 1970 52. OLIVER MF, YATES PA: Induction of ventricular arrhythmias by elevation of arterial free fatty acids in experimental myocardial infarction. In Effect of Hypoxia and Ischaemia on Myocardial Metabolism." Basel, S. Karger, in press 53. WARTMAN WB, JENNINGS RB, YOKOYAMA HO, CLABAUGH GF: Fatty changes in the myocardium in early experimental infarction. Arch Path (Chicago) 3: 318, 1957 61. 62. 63. 54. JURAND J, YATES PA, OLIVER MF: Myocardial Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 55. 56. 57. 58. lipids in normal dogs, after experimental infarction and following elevation of arterial free fatty acids. J Molec Cell Cardiol. In press CHALLONER DR, STEINBERG D: Effect of fatty acids on the oxygen consumption of perfused rat heart. Amer J Physiol 210: 280, 1966 Mjos OD: Effect of free fatty acids on myocardial function and oxygen consumption. (Abstr) Cardiovasc Res 4: 220, 1970 MJos OD, KJEKSHUS J: Increased local metabolic rate in the intact dog heart by free fatty acids. Scand J Clin Lab Invest. In press HENDERSON AH, BRUTSAERT DL, PARhILEY WW, SONNENBLICK EH: Myocardial mechanics in papillary muscles of the rat and cat. Amer J Physiol 217: 1273, 1969 59. WEISSLE:R AM, KRUCER FA, BABA N, SCARPELLI DC, LEIGHTON RF, GALLIMORE JK: Role of anaerobic metabolism in the preservation of functional capacity and structure of anoxic myocardium. J Clin Invest 47: 403, 1968 AH, CRAIG RJ, GORLIN R, SONNENBLICK EH: Free fatty acids and myocardial function in perfused rat hearts. Cardiovasc Res 4: 466, 1970 HENDERSON AH, MOST AS, PARMLEY WW, GORLIN R, SONNENBLICK EH: Depression of myocardial contractility in rats by free fatty acids during hypoxia. Circ Res 26: 439, ,1970 SEVEREID L, CONNOR WE, LONG JP: The depressant effect of fatty acids on the isolated rabbit heart. Proc Soc Exp Biol Med 131: 1239, 1969 HOAK JC, SPECTOR AA, FRY GL, WARNER ED: Effect of free fatty acids on ADP-induced platelet aggregation. Nature 228: 1330, 1970 CARLSON LA, ORO L: The effect of nicotinic acid on the plasma free fatty acids: Demonstration of a metabolic type of sympathicolysis. Acta Med Scand 172: 641, 1962 MEDICAL RESEARCH COUNCIL WORKING PARTY ON THE TREATMENT OF MYOCARDIAL INFARCTION: Potassium, glucose and insulin treatment for acute myocardial infarction. Lancet 2: 1355, 1968 SODI-PALLARES DN, DE LEON JP, BISTENI A, MEDRANO GA: Potassium, glucose and insulin in myocardial infarction. Lancet 1: 1315, 1969 PARMLEY WW, SONNENBLICK EH: Glucagon: A new agent in cardiac therapy. Amer J Cardiol 27: 298, 1971 GRAVILESCU S, DANCIU T, FIAT F, PoP T: Effect of potassium and tris-aspartate on heparin-induced serum free fatty acids elevation in man. Agressologie 11: 6, 501, 1970 60. HENDERSON 64. 65. 66. 67. 68. (To be continued in March CIRCULATION) Circulation, Volume XLV, February 1972 Metabolic Response during Impending Myocardial Infarction: II. Clinical Implications M. F. OLIVER Downloaded from http://circ.ahajournals.org/ by guest on June 15, 2017 Circulation. 1972;45:491-500 doi: 10.1161/01.CIR.45.2.491 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 1972 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. 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