Post-extrasystolic potentiation of ischemic myocardium by atrial stimulation

Diamond, George A.; Forrester, James S.; deLuz, Protasio L.; Wyatt, H.L.; Swan, H. J. C.

doi:10.1016/0002-8703(78)90464-7

Cited by 144 publications

(57 citation statements)

References 35 publications

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“…Hibernation is a concept coined by Diamond 22 and popularized by Rahimtoola 23 to explain how myocardium supplied by a vessel with a fixed stenosis can remain alive and persistently acontractile while receiving deficient arterial flow. Rahimtoola's definition of this condition follows: Hibernation is "a state of persistently impaired myocardial and left ventricular (LV) function at rest due to reduced coronary blood flow that can be partially or completely restored to normal if the myocardial oxygen supply/demand relationship is favorably altered, either by improving blood flow and/or by reducing demand."…”

Section: Relationship Of Stunning To Hibernationmentioning

confidence: 99%

Consequences of Brief Ischemia: Stunning, Preconditioning, and Their Clinical Implications

2001

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Abstract-In experimental studies in the dog, total proximal coronary artery occlusions of up to 15 minutes result in reversible injury, meaning that the myocytes survive this insult. The 15 minutes of ischemia, however, induce numerous changes in the myocardium, including certain monuments to the brief episode of ischemia that may persist for days. One of these monuments is stunned myocardium, which represents "prolonged postischemic contractile dysfunction of myocardium salvaged by reperfusion." The mechanism of stunning involves generation of oxygen radicals as well as alteration in calcium homeostasis and possibly alteration in contractile protein structure. Stunning has been observed in several clinical scenarios, including after percutaneous transluminal coronary angioplasty, unstable angina, stressinduced ischemia, after thrombolysis, and after cardiopulmonary bypass. Oxygen radical scavengers and calcium channel blockers have been shown to enhance function of stunned myocardium in experimental studies, and in a few clinical studies, calcium channel blockers have been shown to ameliorate stunning. Although brief periods of ischemia can contribute to prolonged left ventricular dysfunction and even heart failure, they paradoxically play a cardioprotective role. Episodes of ischemia as short as 5 minutes, followed by reperfusion, protect the heart from a subsequent longer coronary artery occlusion by markedly reducing the amount of necrosis that results from the test episode of ischemia. This phenomenon, called ischemic preconditioning, has been observed in virtually every species in which it has been studied and is a powerful cardioprotective effect. The mechanism of ischemic preconditioning involves both triggers and mediators and involves complex second messenger pathways that appear to involve such components as adenosine, adenosine receptors, the epsilon isoform of protein kinase C, the ATP-dependent potassium channels, as well as others, including a paradoxical protective role of oxygen radicals. Both an early and a late phase of preconditioning have been described, and the mechanisms underlying their induction are under investigation. That preconditioning may occur in humans is suggested by the observations that repetitive balloon inflations in the coronary artery are associated with progressively less chest pain, ST-segment elevation, lactate production, the protective effects of preinfarction angina, the anginal "warm-up phenomenon," and studies performed on human cardiac biopsies that show metabolic properties suggesting preconditioning. Development of pharmacological agents that stimulate second messenger pathways thought to be involved in preconditioning, but without causing ischemia, could result in novel approaches to treating ischemia. Hence, on one hand, brief episodes of ischemia can have a negative effect on the heart: stunning; and on the other hand, they have a protective effect: preconditioning. The future challenge is how to minimize the stunning phenomenon and maximize the preconditioni...

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Section: Relationship Of Stunning To Hibernationmentioning

confidence: 99%

Consequences of Brief Ischemia: Stunning, Preconditioning, and Their Clinical Implications

2001

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“…Experimental (2,3) and clinical studies (4,5) have demonstrated that coronary reperfusion in the setting of AMI reduces the extent of final necrosis and improves ventricular function, favorably influencing the late survival of infarcted patients (6). These effects seem to be independent of the efficiency of intervention (7).…”

Section: Introductionmentioning

confidence: 85%

Rosuvastatin prevents myocardial necrosis in an experimental model of acute myocardial infarction

Dourado

Tsutsui

Landim

et al. 2011

Braz J Med Biol Res

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“…Based on experimental and clinical studies, the concepts of myocardial stunning [6][7][8][9][10] and hibernation [11][12][13] were developed and studied. Stunning refers to temporary depression of cardiac contraction following a bout of ischemia.…”

Section: Pathophysiologic Studiesmentioning

confidence: 99%

Noninvasive assessment myocardial viability: Current status and future directions

Allman

2013

Journal of Nuclear Cardiology

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Observations of reversibility of cardiac contractile dysfunction in patients with coronary artery disease and ischemia were first made more than 40 years ago. Since that time a wealth of basic science and clinical data has been gathered exploring the mechanisms of this phenomenon of myocardial viability and relevance to clinical care of patients. Advances in cardiac imaging techniques have contributed greatly to knowledge in the area, first with thallium-201 imaging, then later with Tc-99m-based tracers for SPECT imaging and metabolic tracers used in conjunction with positron emission tomography (PET), most commonly F-18 FDG in conjunction with blood flow imaging with N-13 ammonia or Rb-82 Cl. In parallel, stress echocardiography has made great progress also. Over time observational studies in patients using these techniques accumulated and were later summarized in several meta-analyses. More recently, cardiac magnetic resonance imaging (CMR) has contributed further information in combination with either late gadolinium enhancement imaging or dobutamine stress. This review discusses the tracer and CMR imaging techniques, the pooled observational data, the results of clinical trials, and ongoing investigation in the field. It also examines some of the current challenges and issues for researchers and explores the emerging potential of combined PET/CMR imaging for myocardial viability.

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Post-extrasystolic potentiation of ischemic myocardium by atrial stimulation

Cited by 144 publications

References 35 publications

Consequences of Brief Ischemia: Stunning, Preconditioning, and Their Clinical Implications

Consequences of Brief Ischemia: Stunning, Preconditioning, and Their Clinical Implications

Rosuvastatin prevents myocardial necrosis in an experimental model of acute myocardial infarction

Noninvasive assessment myocardial viability: Current status and future directions

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