In nondialysis patients, repeated ischemia leads to chronic reduction in left ventricular lv function. These natural pathophysiologic responses, which compensate for ischemia, can be used to differentiate ischemic tissue from healthy tissue. Imaging techniques for the assessment of myocardial hibernation. Statistics for near independence in multivariate extreme.
In patients with ischemic heart disease, hibernating myocardium has been defined as a flowmetabolism mismatch in the presence of contractile dysfunction and is thought to represent the adaptation of the myocardial tissue to chronic or repetitive ischemia 35. Core topics in cardiac anesthesia, edited by jonathan h mackay and joseph e arrowsmith, 2nd ed. Stunning, hibernation, and calcium in myocardial ischemia. Coronary artery disease acute coronary syndrome undergo revascularisation procedures improved survival increased number of patients with residual lv dysfunction undergoing progressive lv remodeling and congestive heart failure dr prithvi puwar. Hibernating myocardium is viable, and this viability can be determined with a variety of imaging techniques that depict either the presence of myocardial tissue that contracts if stimulated appropriately or the persistence of metabolic activity within the region of dysfunctional myocardium. When a severe reduction of coronary blood flow persists for more than. Now, pipelines are bristling with exciting new directacting antiviral drugs, many of which are in latestage clinical trials. The aim of this work is smnd study of metamorphic alteration of massive gabbronorites from the monchetundra pluton. Profound underestimation of glucose uptake by 18 f2deoxy2fluoroglucose in reperfused rat heart muscle.
The term myocardial hibernation was first coined by rahimtoola when commenting on the results of the large randomised trials of coronary artery surgery. Repeated stunning precedes myocardial hibernation in progressive multiple coronary artery obstruction. Myocardial ischaemia, reperfusion, hiber nation, stunning. These abnormalities can be visualised with echocardiography, cardiac magnetic resonance imaging cmr, nuclear medicine pet or ventriculography. The brief regional myocardial functional and electrophysiological alterations related to myocardial stunning were initially observed after brief coronary artery occlusion in dogs 12. Supported by research grants hd 0048706 and hd 0080401 from the institute of child health and human development, u.
Mechanism of contractile dysfunction in stunning hibernating myocardium is a state of persistently impaired myocardial and left ventricular function at rest due to reduced coronary blood flows. Ischemic preconditioning, myocardial stunning, and hibernation. Myocardial stunning is characterized by a condition of postischemic mechanical dysfunction that persists after reperfusion despite the absence of irreversible injury. Basic aspects ischemic preconditioning, myocardial stunning, and hibernation. This patient has a substantial amount of viable myocardium, and the lv dysfunction is secondary to myocardial stunning, hibernation and remodeling. Here the sestamibi images are displayed in rows 1, 3, 5 and 7, and the rest thallium images in rows 2, 4, 6 and 8. There is some evidence that both myocardial stunning and hibernation can coexist, and some authors even favor the concept that myocardial hibernation is caused by repeated episodes of stunning. A wall motion abnormality at rest which improves during a low. If, however, myocardial stunning is severe, involves large parts of the left ventricle and thus impairs global left ventricular function, it can be reversed with inotropic agents and procedures. Revascularization in patients with severe left ventricular. Figure 583 phenomena of myocardial stunning, hibernation, and ischemia preconditioning are part of the spectrum of myocardial ischemia and reperfusion resulting in programmed cell survival.
After total ischemia occurs, the myocardium switches immediately from aerobic glycolysis to anaerobic glycolysis resulting in the reduced ability to produce high energy phosphates such as. Google scholar shivalkar b, flameng w, szilard m, pislaru s, borgers m, vanhaecke j. Revascularization of chronic hibernating myocardium. Contrast echocardiography european society of cardiology. Assessment of myocardial viability in patients with heart. Repeated stunning precedes myocardial hibernation in. Adequate investigation and prompt treatment are essential. Hemodialysis hdinduced regional wall motion abnormalities rwmas are common in hd patients and driven by ischemia. Rahimtoola in 1985 to describe a state of left ventricular dysfunction at rest caused by reduced coronary blood flow, which can be reversed by restoring myocardial oxygen supply or reducing myocardial oxygen demand. Myocardial hibernation and myocardial stunning are pathophysiologic entities that may coexist in patients with ischemic.
Stunning, hibernation, and the myocardial substrate. Paleoproterozoic layered pgebearing monchetundra pluton. Sinusas, in clinical nuclear cardiology fourth edition, 2010. In patients with coronary artery disease, one of the most powerful determinants of prognosis is left ventricular function. To investigate the role of norepinephrine in the development of shortterm myocardial hibernation.
Delineation of myocardial stunning and hibernation by positron emission tomography in advanced coronary artery disease. Stimulation of the ventricle to contract with several inolropes including dopamine, isoproterenol, epin ephrine, calcium, hydralazine, and. The processes involved in this include myocardial stunning and hibernation, remodelling, and neuroendocrine activation. We examine inference under the model and develop tests for independence of extremes of the marginal variables, both when the thresholds are fixed, and when. Hibernating myocardium an overview sciencedirect topics. Myocardial tissue was evaluated to assess myocyte size, nuclear density, and proliferation indexes in. Studies of myocardial function after coronary bypass. This paper has been widely cited, i believe, because of two developments in the 1980s. These modalities can be used to distinguish between. Department of medicine, johns hopkins university school of medicine, baltimore, md 21205. As the coronary artery lumen gradually narrows, blood flow is reduced and a myocardial adaption to ischemia evolves. Jun 28, 20 it has been 25 years since the hepatitis c virus hcv was discovered. Myocardial hibernation may represent a functional adaptation to chronic hypoperfusion that can be reversed with restoration of regional mbf the smart heart hypothesis. Stunned myocardium is defined as viable myocardium that exhibits prolonged postischemic dysfunction.
The term hibernating myocardium was first proposed by s. Pdf current interpretation of myocardial stunning researchgate. In cardiology, hibernating myocardium is a state when some segments of the myocardium exhibit abnormalities of contractile function. Effects of hemodialysis on cardiac function christopher w. Remote myocardium after experimental perioperative. Pdf delineation of myocardial stunning and hibernation. This phenomenon has been observed both in experimental animal models and, more recently, in man. Stunning is potentially an important complication of myocardial reperfusion. Read repeated stunning precedes myocardial hibernation in progressive multiple coronary artery obstruction, journal of the american college of cardiology on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Stunned vs hibernating myocardium jama jama network. Although myocardial contraction is depressed, metabolic balance is maintained, myocytes remain viable and myocardial contraction can be restored with myocardial revascularization. Sorry, we are unable to provide the full text but you may find it at the following locations.
Pet cmr holds promise in its potential to combine perfusion. When a grizzly bear hibernates, its heart rate drops to 1 0. Pdf myocardial stunning is a temporary postischemic cardiac. Myocardial hibernation, like stunning, exists in an enormous num ber of patients with ischemic heart dis ease. Prithvi puwar dnb cardiology vijaya hospital chennai myocardial viability 2. Myocardial hibernation in terms of the flowfunction relationship. Coronary artery disease can result in acute and chronic myocardial perfusion deficits. The mafic rocks of the pluton are unevenly metamorphosed up to amphibolite facies with the formation of garnet, hornblende, and other minerals. Myocardial hibernation implies the concept of tissue viability, which can be diagnosed by imaging modalities that detect either the presence of contraction reserve or the persistence of metabolic activity within chronically dysfunctional myocardial regions see kim and shah on page 7. Myocardial stunning, hibernation and preconditioning.
Initial studies, although favorable, lacked sufficient power and sample size to provide conclusive outcomes of viability. This hypoperfusion can result in impaired myocardial. There are now multiple reversible perfusion defects with transient lv dilation. Myocardial stunning and hibernation statpearls ncbi bookshelf.
Hearts were removed from rats and set up as isometrically beating or shortterm hibernation. Myocardial stunning is the reversible reduction of function of heart contraction after reperfusion not accounted for by tissue damage or reduced blood flow after total ischemia occurs, the myocardium switches immediately from aerobic glycolysis to anaerobic glycolysis resulting in the reduced ability to produce high energy phosphates such as atp and creatinine phosphate. Mcintyre1,2 1department of renal medicine, derby city hospital. The treatment of heart failure and left ventricular dysfunction post myocardial infarction requires the same multidisciplinary, integrated network approach that we. Imaging modalities have become frontline methods in the assessment of viable myocardial tissue, with the aim to stratify patients into optimal treatment pathways.
Noninvasive characterization of stunned, hibernating. In the dog, a coronary occlusion lasting less than 20 minutes does not result in any myocardial necrosis. Role of norepinephrine in development of shortterm. Myocardial stunning is the reversible reduction of function of heart contraction after reperfusion not accounted for by tissue damage or reduced blood flow. Remote myocardium after experimental perioperative myocardial infarction academic dissertation to be presented, with the permission of the board of the school of medicine of the university of tampere, for public discussion in the small auditorium of building m, pirkanmaa hospital district, teiskontie 35, tampere, on 11 march 2016, at 12 oclock.
Shivalkar b, flameng w, szilard m, pislaru s, borgers m, vanhaecke j. Effects of hemodialysis on cardiac function kidney. Autophagy in ischemic preconditioning and hibernating. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. The difficulty in developing chronic experimental models of coronary artery stenosis has hampered our detailed understanding of the multiple. This results in the electromechanical uncoupling of energy generation from contraction that characterizes myocardial stunning. Hibernating myocardium represents a chronic myocardial dysfunction at rest associated with reduced coronary perfusion. Ischemic preconditioning, myocardial stunning, and. Ischaemic left ventricular lv dysfunction can arise from myocardial stunning, hibernation, or necrosis. Reversible mitochondria1 changes of unknown sig niftcance as viewed by electron microscopy 6. New data on the composition and origin of bottom sediments in. Find an answer to your question when a grizzly bear hibernates, its heart rate drops to 1 0 1010 beats per minute, which is 2 0 % 20%20, percent of its normal.
New paradigms of coronary artery disease hibernation. T he recent spectacular progress in the treatment of coronary artery disease has led to a growing awareness of the contractile abnormalities that accompany. Bojan vrtovec, in stem cell and gene therapy for cardiovascular disease, 2016. If however, myocardial stunning is severe, and it involves large parts of the lv and thus impairs global lv function, it can be reversed with inotropic agents and procedures. We examined the effect of hdinduced repetitive myocardial stunning. Hdinduced myocardial ischemia may initiate the same process. Characterization of hibernating and stunned myocardium.
Jul 21, 2017 cellular senescence is causally linked to ageing and has been implicated in a variety of agerelated diseases. Jul 19, 2008 new data on the composition and origin of bottom sediments in the southern mendeleev ridge, arctic ocean. Terzano, vaginal cytology as a prognostic method in pregnancy disorders acta cytol 3. Selection of patients in early pregnancy for progestational. However, the statement pertaining to postinfarction cardiogenic shock that acute revascularization should result in immediate improvement in the function of the ischemic areas and of. Hemodialysisinduced repetitive myocardial injury results. The two most plausible hypotheses used to explain the pathogenetic mechanisms of myocardial stunning are calcium and oxyradical hypotheses. We propose a multivariate extreme value threshold model for joint tail estimation which overcomes the problems encountered with existing techniques when the variables are near independence. First, coronary artery bypass surgery or angioplasty could reduce the impact of. Public health service, and by grant at451 1780 from the division of biology and medicine, atomic energy commission. In contrast, hibernation is an important complication of myocardial ischemia. Standard conventional thrice weekly hd as a cause of repetitive myocardial stunning might lead to such a process, resulting in chronic lv dysfunction. Myocardial stunning and hibernation myocardial ischemia occurs when there is an imbalance between myocardial oxygen supply and demand, and this is usually a result of atherosclerosis. Myocardial stunning an overview sciencedirect topics.
503 432 538 786 1302 141 386 355 1228 1262 592 1 1096 1210 1473 818 211 1061 165 52 1460 304 1043 385 1006 843 1101 1144 1311 856 1256 972 1434 691 291 52 997 756 39 1113 398 310 1057