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. Prithvi puwar dnb cardiology vijaya hospital chennai myocardial viability 2. Sinusas, in clinical nuclear cardiology fourth edition, 2010. Jul 21, 2017 cellular senescence is causally linked to ageing and has been implicated in a variety of agerelated diseases. This patient has a substantial amount of viable myocardium, and the lv dysfunction is secondary to myocardial stunning, hibernation and remodeling. Initial studies, although favorable, lacked sufficient power and sample size to provide conclusive outcomes of viability. Effects of hemodialysis on cardiac function christopher w. Mcintyre1,2 1department of renal medicine, derby city hospital. 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. The term myocardial hibernation was first coined by rahimtoola when commenting on the results of the large randomised trials of coronary artery surgery. These modalities can be used to distinguish between. These abnormalities can be visualised with echocardiography, cardiac magnetic resonance imaging cmr, nuclear medicine pet or ventriculography. Shivalkar b, flameng w, szilard m, pislaru s, borgers m, vanhaecke j. Pdf delineation of myocardial stunning and hibernation.
Adequate investigation and prompt treatment are essential. Hemodialysisinduced repetitive myocardial injury results. In cardiology, hibernating myocardium is a state when some segments of the myocardium exhibit abnormalities of contractile function. 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. Assessment of myocardial viability in patients with heart. In patients with coronary artery disease, one of the most powerful determinants of prognosis is left ventricular function. Noninvasive characterization of stunned, hibernating. To investigate the role of norepinephrine in the development of shortterm myocardial hibernation. Repeated stunning precedes myocardial hibernation in.
Reversible mitochondria1 changes of unknown sig niftcance as viewed by electron microscopy 6. 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. Coronary artery disease can result in acute and chronic myocardial perfusion deficits. This hypoperfusion can result in impaired myocardial. There are now multiple reversible perfusion defects with transient lv dilation.
Myocardial tissue was evaluated to assess myocyte size, nuclear density, and proliferation indexes in. Imaging modalities have become frontline methods in the assessment of viable myocardial tissue, with the aim to stratify patients into optimal treatment pathways. Selection of patients in early pregnancy for progestational. In the dog, a coronary occlusion lasting less than 20 minutes does not result in any myocardial necrosis. The brief regional myocardial functional and electrophysiological alterations related to myocardial stunning were initially observed after brief coronary artery occlusion in dogs 12. Contrast echocardiography european society of cardiology. 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. Jul 19, 2008 new data on the composition and origin of bottom sediments in the southern mendeleev ridge, arctic ocean.
Standard conventional thrice weekly hd as a cause of repetitive myocardial stunning might lead to such a process, resulting in chronic lv dysfunction. 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. Revascularization of chronic hibernating myocardium. When a grizzly bear hibernates, its heart rate drops to 1 0. Role of norepinephrine in development of shortterm. Basic aspects ischemic preconditioning, myocardial stunning, and hibernation. 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. Autophagy in ischemic preconditioning and hibernating. Myocardial stunning, hibernation and preconditioning. Profound underestimation of glucose uptake by 18 f2deoxy2fluoroglucose in reperfused rat heart muscle. 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.
Now, pipelines are bristling with exciting new directacting antiviral drugs, many of which are in latestage clinical trials. 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. This phenomenon has been observed both in experimental animal models and, more recently, in man. Effects of hemodialysis on cardiac function kidney. We examined the effect of hdinduced repetitive myocardial stunning. Pet cmr holds promise in its potential to combine perfusion. Hearts were removed from rats and set up as isometrically beating or shortterm hibernation. Remote myocardium after experimental perioperative. Characterization of hibernating and stunned myocardium. The aim of this work is smnd study of metamorphic alteration of massive gabbronorites from the monchetundra pluton.
Supported by research grants hd 0048706 and hd 0080401 from the institute of child health and human development, u. Core topics in cardiac anesthesia, edited by jonathan h mackay and joseph e arrowsmith, 2nd ed. The processes involved in this include myocardial stunning and hibernation, remodelling, and neuroendocrine activation. New data on the composition and origin of bottom sediments in. 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. 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. Myocardial hibernation, like stunning, exists in an enormous num ber of patients with ischemic heart dis ease. 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. Stunned vs hibernating myocardium jama jama network.
When a severe reduction of coronary blood flow persists for more than. Repeated stunning precedes myocardial hibernation in progressive multiple coronary artery obstruction. Myocardial stunning is characterized by a condition of postischemic mechanical dysfunction that persists after reperfusion despite the absence of irreversible injury. 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. 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. Stunning is potentially an important complication of myocardial reperfusion.
The two most plausible hypotheses used to explain the pathogenetic mechanisms of myocardial stunning are calcium and oxyradical hypotheses. Public health service, and by grant at451 1780 from the division of biology and medicine, atomic energy commission. Myocardial ischaemia, reperfusion, hiber nation, stunning. Sorry, we are unable to provide the full text but you may find it at the following locations. Pdf myocardial stunning is a temporary postischemic cardiac. 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. The term hibernating myocardium was first proposed by s. Hdinduced myocardial ischemia may initiate the same process. Myocardial stunning is the reversible reduction of function of heart contraction after reperfusion not accounted for by tissue damage or reduced blood flow. In nondialysis patients, repeated ischemia leads to chronic reduction in left ventricular lv function. 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. Stunning, hibernation, and the myocardial substrate.
T he recent spectacular progress in the treatment of coronary artery disease has led to a growing awareness of the contractile abnormalities that accompany. As the coronary artery lumen gradually narrows, blood flow is reduced and a myocardial adaption to ischemia evolves. 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. New paradigms of coronary artery disease hibernation. The difficulty in developing chronic experimental models of coronary artery stenosis has hampered our detailed understanding of the multiple. The mafic rocks of the pluton are unevenly metamorphosed up to amphibolite facies with the formation of garnet, hornblende, and other minerals.
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. Google scholar shivalkar b, flameng w, szilard m, pislaru s, borgers m, vanhaecke j. Studies of myocardial function after coronary bypass. First, coronary artery bypass surgery or angioplasty could reduce the impact of. Stunned myocardium is defined as viable myocardium that exhibits prolonged postischemic dysfunction. Statistics for near independence in multivariate extreme.
Myocardial stunning an overview sciencedirect topics. Although myocardial contraction is depressed, metabolic balance is maintained, myocytes remain viable and myocardial contraction can be restored with myocardial revascularization. Stunning, hibernation, and calcium in myocardial ischemia. Pdf current interpretation of myocardial stunning researchgate. Hibernating myocardium represents a chronic myocardial dysfunction at rest associated with reduced coronary perfusion. Hemodialysis hdinduced regional wall motion abnormalities rwmas are common in hd patients and driven by ischemia. Delineation of myocardial stunning and hibernation by positron emission tomography in advanced coronary artery disease.
Myocardial hibernation and myocardial stunning are pathophysiologic entities that may coexist in patients with ischemic. Ischemic preconditioning, myocardial stunning, and hibernation. Imaging techniques for the assessment of myocardial hibernation. Terzano, vaginal cytology as a prognostic method in pregnancy disorders acta cytol 3. This results in the electromechanical uncoupling of energy generation from contraction that characterizes myocardial stunning. 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. Ischemic preconditioning, myocardial stunning, and. These natural pathophysiologic responses, which compensate for ischemia, can be used to differentiate ischemic tissue from healthy tissue. Revascularization in patients with severe left ventricular. This paper has been widely cited, i believe, because of two developments in the 1980s. 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.
Department of medicine, johns hopkins university school of medicine, baltimore, md 21205. Stimulation of the ventricle to contract with several inolropes including dopamine, isoproterenol, epin ephrine, calcium, hydralazine, and. Myocardial hibernation in terms of the flowfunction relationship. Bojan vrtovec, in stem cell and gene therapy for cardiovascular disease, 2016. Paleoproterozoic layered pgebearing monchetundra pluton. A wall motion abnormality at rest which improves during a low. Ischaemic left ventricular lv dysfunction can arise from myocardial stunning, hibernation, or necrosis. Jun 28, 20 it has been 25 years since the hepatitis c virus hcv was discovered. The treatment of heart failure and left ventricular dysfunction post myocardial infarction requires the same multidisciplinary, integrated network approach that we. 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. Myocardial stunning and hibernation statpearls ncbi bookshelf. Myocardial hibernation may represent a functional adaptation to chronic hypoperfusion that can be reversed with restoration of regional mbf the smart heart hypothesis.
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