Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151744 (myocardial ischemia)
 31,282 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Theophylline-induced variations of cardiac metabolism have been investigated by determining concentrations of various energetic substrates and of high-energy phosphates in myocardial tissue, the repeated sampling of myocardium being made possible by an extracorporal circulation system. When administered in therapeutic, or even slightly higher doses, theophylline does not modify triglyceride, glycerol and free fatty acid content or phosphocreatine and ATP content in subepicardial and subendocardial layers, but it does lower glycogen and raise lactate concentration. Consequently, the changes in anaerobic glycolysis due to myocardial ischemia may be enhanced if, as is probably the case, theophylline fails to restore the supply of oxygen.
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PMID:Myocardial biochemical modifications induced by theophylline with reference to its value as antianginal drug. 48 94

Anticholinergics (in particular, ipratropium bromide [Atrovent]) are first-line therapy in patients with chronic obstructive pulmonary disease (COPD). Although more studies are needed to support the use of combination therapy, adding an inhaled beta agonist to the therapeutic regimen is reasonable in patients who remain symptomatic and need quick relief. Patients frequently receive inadequate amounts of drug with standard doses delivered by metered-dose inhalers, often as the result of improper technique, so symptomatic patients may require higher doses. Caution is recommended when the dose of inhaled sympathomimetics is increased in COPD patients with ischemic heart disease or tachyarrhythmias. The addition of an oral sympathomimetic is seldom necessary. Theophylline may be considered in outpatients who remain symptomatic despite their use of inhaled bronchodilators, but heart disease, seizure disorders, and gastroesophageal reflux are contraindications. Corticosteroid therapy remains controversial but can be helpful in patients who still have severe disease despite maximum bronchodilator therapy. Antibiotics can be of benefit in COPD patients undergoing an exacerbation who have increasing dyspnea, cough, and phlegm production.
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PMID:Drug treatment of COPD. Controversies about agents and how to deliver them. 134 54

A case of severe myocardial ischaemia complicated by syncopal ventricular tachycardia during injection of Dipyridamole for stress Thallium myocardial scintigraphy in a coronary patient is reported. Myocardial ischaemia (chest pain, ECG changes) is classically rare (30% of cases) and usually benign during Dipyridamole injection, and either regress spontaneously or after administration of Theophylline. However, the possibility of serious complications such as this justifies the same criteria of strict surveillance as for classical exercise stress testing.
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PMID:[Severe ischemic ventricular arrhythmia during dipyridamole scintigraphy]. 189 21

The intravenous infusion of adenosine provokes anginalike chest pain. To establish its origin, an intracoronary infusion of increasing adenosine concentrations was given in 22 patients with stable angina pectoris. During adenosine infusion, 20 patients had chest pain without electrocardiographic signs of ischemia. They all reported that the chest pain was similar to their usual anginal pain. In 10 of the 22 patients adenosine was also infused into the right atrium, but it never produced symptoms at the doses that had provoked chest pain during intracoronary infusion. In seven other patients, the intracoronary adenosine infusion was repeated after intravenous administration of aminophylline, an antagonist of adenosine P1-receptors. Aminophylline decreased the severity of adenosine-induced chest pain (assessed with a visual analog scale) from 42 +/- 22 to 23 +/- 17 mm (p less than 0.002). In the remaining five of the 22 patients, monitoring of blood oxygen saturation in the coronary sinus during intracoronary adenosine administration showed that maximum coronary vasodilation was achieved at doses lower than those responsible for chest pain. A single-blind, placebo-controlled, randomized trial of the effect of aminophylline on exercise-induced chest pain was also performed in 20 other patients with stable angina. Aminophylline, compared with placebo, decreased the severity of chest pain at peak exercise from 67 +/- 21 to 51 +/- 23 mm (p less than 0.02), despite the achievement of a similar degree of ST-segment depression. Finally, the effect of intravenous adenosine was compared in 10 patients with predominantly painful myocardial ischemia and in 10 patients with predominantly silent ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of adenosine in pathogenesis of anginal pain. 237 17

The intravenous dipyridamole test is considered a safe procedure with a very low incidence of severe cardiac effects and is routinely used in the diagnosis and prognosis of coronary artery disease. We report the case of a 63-year-old female with negative exercise stress test who developed prolonged and extensive myocardial ischemia after the high-dose intravenous dipyridamole echocardiography test. Aminophylline and nitroglycerin were employed but were ineffective and the patient was successfully treated with systemic thrombolysis. At coronary angiography, 48 hours later, a 50% stenosis in the proximal LAD was documented. We stress that high-dose intravenous dipyridamole can induce a severe ischemic response whose occurrence is unpredictable according to the pre-test clinical features.
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PMID:[Prolonged myocardial ischemia after the high-dose dipyridamole test]. 262 Aug 5

We have recently reported that coronary microembolization sustains myocardial ischemia with hyperemic response of coronary blood flow (CBF) induced by massive release of adenosine from the ischemic myocardium. In this study, we tested the hypothesis that this hyperemic flow caused by released adenosine improves myocardial ischemia. In eight dogs (control), microspheres (5.0 X 10(4)/ml of base-line CBF) were repetitively injected until CBF decreased toward zero, and the changes in CBF, fractional shortening, lactate extraction ratio (LER), and adenosine release were studied. In 15 other dogs, an identical procedure was done with an intracoronary infusion of prazosin (4 micrograms.kg-1.min-1, n = 8) or theophylline (0.1 mg.kg-1.min, n = 7) to elucidate the effect of adenosine, since prazosin inhibits release of adenosine from ischemic myocardium and theophylline blocks adenosine receptors. In 16 other dogs, hemodynamic and metabolic parameters were examined with and without these drugs after a single injection of microspheres (1.0 X 10(5)/ml of base-line CBF). In the control group, CBF increased to 170 +/- (SE) 14% of the base-line CBF at 16-30% of maximal embolization. In contrast, intracoronary infusion of prazosin markedly attenuated adenosine release and hyperemic response and significantly deteriorated both fractional shortening and LER. Theophylline also significantly attenuated the hyperemic response and tended to decrease both fractional shortening and LER. A salutary effect of adenosine release was further confirmed by the improvement of ischemic changes in the same dog after withdrawal of prazosin and theophylline associated with an increase in CBF. Thus we conclude that adenosine released from ischemic myocardium improves ischemia in microembolization through the hyperemic response.
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PMID:Adenosine-induced hyperemia attenuates myocardial ischemia in coronary microembolization in dogs. 275 Sep 40

To investigate the pathophysiology of acute embolization of small coronary vessels and the role of adenosine in this abnormality, regional coronary blood flow (CBF), coronary vascular resistance, arteriovenous O2 difference, lactate extraction ratio, and adenosine release were studied in 39 anesthetized open-chest dogs after acute coronary embolization with microspheres of three different diameters (15 +/- 1, 94 +/- 8, and 293 +/- 23 microns). In 16 dogs, the left anterior descending coronary artery was embolized by repetitive injections of 15-microns microspheres, up to 4.4 +/- 0.4 X 10(5)/g myocardium; at this point CBF, determined by the electromagnetic flowmeter at the proximal site of the artery, was reduced toward zero. Up to 37% of total embolization, resting CBF increased to 175 +/- 36% of control; thereafter it decreased almost linearly as the extent of embolization was increased. After embolization, coronary arteriovenous O2 difference was significantly (P less than 0.01) decreased with a marked release of adenosine in the coronary vein. Despite a hyperemic flow response of CBF in the embolized area, myocardial ischemia was not prevented; maximal increase in CBF after 100-microns microsphere embolization (141 +/- 11% of control CBF, n = 6) was significantly (P less than 0.05) less than that in 15-micron microsphere embolization, whereas 300-microns microsphere embolization minimally increased CBF (123 +/- 13%, P greater than 0.1; n = 5). Hyperemic flow remained unchanged for at least 3 h when adenosine was persistently released. Theophylline significantly attenuated this response. These results indicate that in embolization with microspheres less than 300 microns in diameter, hyperemic response of coronary blood flow occurs, probably due to the hyperemia of nonoccluded vessels in the adjacent area of ischemic foci to adenosine released from the ischemic myocardium.
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PMID:Role of adenosine in hyperemic response of coronary blood flow in microembolization. 395 41