Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since the advent of ambulatory ST-segment monitoring, it has been established that silent ischemia is common in patients with various coronary artery disease syndromes, and such silent episodes represent up to 80% of all ischemic episodes. It appears to be associated with an adverse prognosis when compared with similarly characterized patients without silent ischemia during daily life. Silent ischemia does not, however, bother the patients, by virtue of the fact that it is silent, and therefore treatment of such ischemia must be justified by an improved outlook for the patient, rather than symptom relief. There is no direct evidence to date that silent ischemia is associated with acute myocardial infarction or sudden cardiac death in a cause-and-effect relationship, or that reduction or eradication of silent ischemia will lead to an improved prognosis for the patient; indeed, we have been unable to demonstrate any significant improvement in outlook when using the various antianginal/antiischemic agents at our disposal. Until we can demonstrate a benefit to the patient by detecting and treating silent ischemia, we should not waste large resources attempting to eradicate something whose significance we do not understand.
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PMID:Can we really justify the treatment of silent ischemia in 1992? No! 139 Mar 22

Coronary thrombolysis with streptokinase or tissue plasminogen activator is useful for the treatment of acute myocardial infarction in selected patients. This treatment is associated with local hemorrhagic complications and age-related cerebral hemorrhage. Coronary thrombolysis is contraindicated in patients with transient cerebral ischemia and stroke, arterial hypertension, cerebral trauma, cerebral aneurysms, and arteriovenous malformations, because of the risk of cerebral hemorrhage. We report the occurrence of a cerebral hemorrhage related to cerebral amyloid angiopathy in a patient who underwent thrombolysis and treatment with heparin for acute myocardial infarction. Despite normal coagulation parameters, the cerebral hematoma enlarged over 36 hours, as documented by sequential computed tomographic scans, to produce significant mass effect, which prompted surgical evacuation. Histological examination of the resected specimen demonstrated the strong affinity for Congo red and yellow-green birefringence that are characteristic of cerebral amyloid angiopathy. Hemostasis was difficult to achieve, as the divided or disrupted amyloid-laden cortical vessels failed to vasoconstrict, their contractile elements replaced by amyloid beta protein. The patient died of recurrent myocardial ischemia 3 days postoperatively. The incidence of cerebral amyloid angiopathy increases with advancing age. It must be considered as a potential source of cerebral hemorrhage in elderly patients undergoing thrombolysis for cardiac ischemia. Such an occurrence presents a difficult challenge because cardiac function is compromised, the coagulation profile may be altered, the cerebral hematoma is life threatening, and intracranial hemostasis is difficult to achieve.
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PMID:Cerebral hemorrhage from amyloid angiopathy and coronary thrombolysis. 140 40

In a consecutive series of 123 men (aged 55 +/- 8 years) with a recent first acute myocardial infarction (AMI), 24-hour ambulatory ST-segment monitoring was performed early after discharge (day 11 +/- 5), 6 months (day 185 +/- 6) and 1 year (day 368 +/- 8) after AMI. No difference in the prevalence of transient myocardial ischemia was found between the 3 recordings (17, 17 and 20%), and most ischemic episodes were silent (98, 100 and 97%). In the early postinfarction period, a peak of ischemic activity was demonstrated between 6 P.M. and midnight (40 of 93 episodes [43%]). Over time, the maximal occurrence of ischemia gradually advanced toward the morning hours with a peak activity between 6 A.M. and noon at 1-year follow-up (32 of 73 episodes [44%]). Significantly more patients (16 of 21 [76%]) had ischemia from 6 P.M. to midnight at discharge compared with the findings 1 year later (9 of 23 patients [39%]) (p < 0.03). An opposite trend was found regarding patients who exhibited ischemic episodes in the hours from 6 A.M. to noon: 10 of 21 patients (48%) early after discharge versus 17 of 23 patients (74%) at 1-year follow-up (p = not significant). Results from the 6-month recording displayed characteristics between the findings from discharge and 1-year ambulatory monitoring. The pathophysiologic processes underlying the observations from this study are unknown. The change in circadian periodicity could not be explained from differences in heart rate variation patterns or medical antianginal treatment among the 3 recordings.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Changing circadian variation of transient myocardial ischemia during the first year after a first acute myocardial infarction. 141 31

Pleomorphic ventricular tachycardia is characterized by QRS complexes with repeated variation in polarity, amplitude, and regularity. When associated with prolongation of the QT interval, the term torsades de pointes is used to describe the arrhythmia. It usually is seen clinically in association with class IA antiarrhythmic drugs such as quinidine and procainamide, bradycardia, hypokalemia, and, much less often, other drugs and electrolyte disorders as well as a result of congenital and neurogenic causes. It also may accompany acute myocardial infarction or ischemia. We describe four patients in whom pleomorphic ventricular tachycardia was observed as the presenting rhythm or during the course of resuscitation in out-of-hospital cardiac arrest. In all four patients, acute myocardial ischemia appeared to be the provocative mechanism. Therapeutic implications include an awareness of the unusual behavior of this arrhythmia, especially its propensity to terminate spontaneously. Such awareness may prevent the delivery of unnecessary defibrillatory shocks.
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PMID:Out-of-hospital pleomorphic ventricular tachycardia and resuscitation: association with acute myocardial ischemia and infarction. 833 47

Acute coronary occlusion during PTCA represents a significant procedural complication occurring in approximately 4-5% of cases, most frequently because of coronary dissection, spasm, or thrombosis. In these cases the first step in the management of acute ischemia is 1) a brief evaluation of its hemodynamic consequences and 2) the assessment and treatment of its cause. Spasm and intracoronary thrombus formation are usually readily identifiable and treatable using intracoronary nitroglycerin and thrombolytic therapy. In our catheterization laboratory the current approach to occlusive coronary dissection is represented by the use of autoperfusion dilatation catheters and by stent application. The atherectomy devices and the laser "welding" of the dissected intimal segment represent other alternatives that are still under clinical evaluation in this particular setting. If coronary occlusion is refractory to these efforts and coronary blood flow is not reestablished rapidly, emergency coronary bypass surgery is required to salvage jeopardized myocardium. In this case myocardial ischemia may be lessened by the insertion of an intra-aortic balloon pump. In our experience, the incidence of death (4%) and myocardial infarction (37%) for emergency CABG after a failed angioplasty, is similar to that reported by other Authors. The duration of myocardial ischemia and the presence of cardiogenic shock before operation are the most important determinants of major complications such as death and acute myocardial infarction.
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PMID:[Surgical indications and results of myocardial revascularization in complications of PTCA]. 142 76

In two groups of patients, coronary artery bypass surgery for angina pectoris included internal mammary artery (IMA) sequential grafts (group I) or single grafts (group II). At postoperative angiography all grafts were patent. In addition, the patients received on average 1.8 vein grafts into other coronary arteries. The mean interval to postoperative follow-up was 9.5 years in group I and 9.7 years in group II. The preoperative incidence of acute myocardial infarction was 44% and 45% in groups I and II. Exercise thallium scan at follow-up showed IMA graft-related ischemia in 33% of the patients with sequential graft and in 64% of those with single graft (ns). Our results indicated that sequential IMA grafts functioned at least as well as single grafts and maintained adequate myocardial supply even 10 years postoperatively. Internal mammary arteries are superior graft material and can be recommended both as single and as sequential graft in coronary artery bypass surgery.
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PMID:Long-term blood flow potentials in sequential internal mammary artery grafts. Exercise thallium scan for myocardial perfusion study. 143 38

The introduction of positron emission tomography (PET) as a powerful imaging modality has played a major role in the understanding of the pathophysiological bases for cerebrovascular disorders. PET is the only technique that allows measurement of regional cerebral blood flow, blood volume, oxygen extraction fraction, and oxygen and glucose metabolism with detail and accuracy. Using PET, these physiological parameters can be measured to determine the extent of the disease from the early stages of cerebrovascular disorders to acute cerebral infarction. Significant hemodynamic and metabolic abnormalities are noted in chronic ischemia, but no structural changes are noted on anatomic images. PET studies have shown that in many patients in the early phases (10 to 12 hours) of clinically diagnosed acute stroke, a substantial area of ischemia exists, which, if untreated, will become irreversibly damaged. Similar to the results achieved in patients with acute myocardial infarction, appropriate intervention in patients with cerebrovascular disorders may significantly reduce the extent of injury to the brain. PET also has been useful in predicting functional recovery and monitoring the effects of various therapeutic approaches. Although functional imaging of the brain with single photon emission computed tomography can successfully be used in the investigation of several disorders of the brain, its role in cerebrovascular disorders is quite limited. PET is a unique modality that studies ischemic diseases of the brain, and it potentially could play a significant role in the management of patients with cerebrovascular disease. This will be further realized when aggressive approaches are used routinely in the future.
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PMID:Positron emission tomography in cerebrovascular disorders. 143 68

The in-hospital and short-term follow-up results of a conservative coronary angioplasty approach in 354 consecutive patients treated after thrombolysis for acute myocardial infarction were compared with results obtained in 408 control noninfarcted patients treated for the classical indication of myocardial ischemia. Only 20% of the study patients underwent angioplasty during the initial hospitalization period and the clinical success rate was 93% versus 95% in the control group (p = NS). No significant differences in the total number of in-hospital untoward events were observed (10.2% and 7.6%, respectively). During a 7.4 +/- 1.5 month follow-up period, the total number of adverse events was only 16.9% in the study patients but it was 27.8% in the control group (p < 0.001). There were no significant differences in death, myocardial infarction, or coronary surgery as individual events, but repeat angioplasty was less frequent in the study group (14.0% versus 21.5%, p < 0.01). Thus in-hospital results in patients undergoing angioplasty on a deferred basis after thrombolysis for myocardial infarction were largely comparable with those results obtained in noninfarcted patients. Moreover, short-term clinical follow-up events were reduced when compared with the control group, an observation apparently largely related to the subgroup without clinical evidence of residual ischemia.
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PMID:The conservative coronary angioplasty strategy after thrombolysis for acute myocardial infarction: immediate and short-term results. 144 76

To evaluate the potential for hyperbaric oxygen (HBO) to produce transient improvement in function in areas of myocardium ischemic at rest (hibernating myocardium), 24 patients were studied within 1 week of acute myocardial infarction. Results were compared with single-photon emission computed tomography (SPECT) thallium-201 exercise scintigraphy. Echocardiography demonstrated improved contraction following HBO in 20 of 62 damaged left ventricular segments in 12 of 24 patients. Thirteen of the 28 segments and 9 of the 14 patients showing reversible ischemia on SPECT imaging showed improvement with HBO. There were eight segments with apparently normal resting contraction that showed a reversible thallium defect. Of 42 segments with fixed contraction abnormalities following HBO, eight had reversible thallium defects, four had normal thallium kinetics, and 30 had fixed thallium defects. Thus hyperbaric oxygen can demonstrate improvement in function in some segments of left ventricle after infarction. There is some overlap with viability as determined by thallium studies, but the two techniques may be complementary in describing myocardial ischemia.
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PMID:Myocardial hibernation identified by hyperbaric oxygen treatment and echocardiography in postinfarction patients: comparison with exercise thallium scintigraphy. 144 80

A patient was admitted because of an acute myocardial infarction which evolved with heart failure and postinfarction angina. A pattern consistent with dynamic left ventricular outflow obstruction was found. It disappeared after coronary angioplasty was performed on the vessel responsible for the ischemia.
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PMID:Acute myocardial ischemia resulting in dynamic obstruction to the left ventricular outflow relieved by successful angioplasty. 145 72


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