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)

Six patients with advanced arteriosclerosis obliterans in the lower extremities were subjected to an exercise test on a tread mill with and without dipyridamole treatment. Prostacyclin (PGI2) release was measured by the concentration of its stable metabolite, 6-keto-prostaglandin F1 alpha in plasma. All the patients suffered from ischemic pain during both tests, but no changes were seen in plasma 6-keto-PGF1 alpha. Dipyridamole did not affect the physical performance. Our results suggest that atherosclerotic vessels do not increase PGI2 production in response to ischemia and that a single dose of dipyridamole does not change PGI2 production.
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PMID:Lack of effect of ischemia and dipyridamole on prostacyclin production in arteriosclerosis obliterans. 704 Nov 95

Four drugs that inhibit platelet function have been evaluated for their antithrombotic effects in humans. These are aspirin, dipyridamole, hydroxychloroquine and sulphinpyrazone. Aspirin has been shown to reduce the number of transient ischemic attacks (TIA), stroke and death in patients with multiple TIA. The reduction in TIA was greatest in males who were normotensive and when there was an angiographically demonstrated lesion in the carotid artery that accounted for the symptoms. Aspirin reduced venous thrombosis and non-fatal and fatal pulmonary embolism in patients after surgery for fractured hip and after elective hip replacement. There is evidence that the prophylactic effect of aspirin may be greater in male patients. Aspirin reduced the frequency of arteriovenous shunt thrombosis. Aspirin abolished symptoms in patients with peripheral ischemia associated with thrombocytosis and spontaneous platelet aggregation. There is no conclusive evidence at the present time that aspirin is effective in patients with coronary artery artery disease. Dipyridamole in combination with oral anticoagulants is effective in reducing the frequency of systemic embolism in patients with prosthetic heart valve replacement but is ineffective in patients with transient cerebral ischemic attacks or for the prevention of venous thromboembolism. Hydroxychloroquine was effective in reducing postoperative venous thrombosis in patients undergoing general abdominothoracic surgery but the evidence that it was effective in patients undergoing orthopaedic surgery is inconclusive. Sulphinpyrazone may be effective in reducing the frequency of sudden cardiac deaths in patients in the first year after myocardial infarction when it is started within 25 to 35 days after the infarction. Sulphinpyrazone reduced the incidence of arteriovenous shunt thrombosis in patients undergoing chronic hemodialysis and in combination with anticoagulants, it reduced the frequency of recurrent venous thrombosis. There have been no large scale trials of platelet suppressant drugs in clinical cancer and successful treatment of thromboembolic disorders cannot be used to predict success in the treatment of malignant disease.
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PMID:Antithrombotic effects of drugs which suppress platelet function: their potential in prevention growth of tumour cells. 705 Oct 35

Dipyridamole-echocardiography may be considered, at this time, an useful test not only in post-infarction risk stratification, but also in diagnosis and functional evaluation of coronary artery disease, having a satisfying sensibility (67%) and a very high specificity (96%). We report a particular case of "false positive" with a review of the literature. The patient, male, aged 45, without important risk factors for coronary artery disease, experimented recurrent events of spontaneous chest pain, typical per angina pectoris. Physical examination, chest roentgenogram and blood samples were normal. Slight signs of subendocardial ischemia, lateral, were present at ECG. Forced hyperpnea resulted in onset of chest pain, with increase of ECgraphic signs of ischemia; resolution of both was obtained with sublingual nitrate administration. A stress test with myocardial flow scintigraphic assessment using sestaMIBI, was performed: ECG showed significant ST downsloping at low workload (1-11 steps of Bruce protocol) and radionuclide tomography showed reversible hypoperfusion in anterior and septal regions. High dose dipyridamole-echocardiography test (a first bolus of 0.56 mg/kg in 4', followed after 4' by a second bolus of 0.28 mg/kg) gave these results: basal echocardiogram was normal; after first bolus of dipyridamole apical hypokinesia appeared; after second bolus complete akinesia was observed. ECG showed subendocardial injury wave and the patient experimented typical anginal pain. Clinical, electrocardiographic and echocardiographic changes were immediately reversed after intravenous bolus of aminophylline, 240 mgs. Coronary arteriography was performed: coronary arteries were angiographically normal, without even any marginal irregularity: left ventricle was normal in volume, wall kinesis and ejection fraction. Dipyridamole is a powerful ischemic stressor.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Problem of false positives in dipyridamole-echocardiography test. Description of a case and review of the literature]. 770 May 41

We have often experienced false positive results of the stress Thallium-201 myocardial scintigraphy (TL) for the evaluation of artery bypass graft patency after coronary artery bypass surgery (CABG). The purpose of this study is to clarify the frequency and the clinical significance of this findings. Sixty-two patients undergoing coronary angiography (CAG) after CABG were studied. These patients had undergone at total of 156 bypasses (artery grafts 108, saphenous vein grafts 48, mean bypass grafts number 2.65/cases), and the mean period from CABG to TL was 41.6 +/- 34 days. The territories of stress induced ischemia were divided into 3 territories; left anterior descending (LAD), right coronary artery (RCA), and left circumflex (LCX) territories. Patency of the bypass grafts was estimated on the absence of transient perfusion defect (TPD) on TL images. The incidence of false positive results was higher in Dipyridamole TL (38%) than in Exercise TL (18%) and higher in LAD territories (38%) than in RCA (11%) and LCX (13%) territories. All false positive cases showed no evidence of chest pain and significant ST-T change during stress TL test. High incidence of false positive results of stress TL test was observed for the evaluation of artery bypass graft patency after CABG.
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PMID:[High incidence of false positive results of thallium-201 myocardial stress scintigraphy for the evaluation of artery bypass graft patency after CABG]. 773 57

Stroke is the third leading cause of death in the United States. Efforts directed at reversing acute cerebral ischemia are promising but are hampered by multiple logistic and physiologic barriers. Prevention of stroke, therefore, remains of critical importance. Primary prevention is accomplished through reduction of risk factors and the appropriate use of warfarin or aspirin in patients with cardiac sources of emboli such as atrial fibrillation. Secondary prevention is designed to reduce the risk of stroke in patients with known stroke precursors, including transient ischemia, reversible ischemic deficits, and completed stroke. Aspirin and ticlopidine are two antiplatelet agents with an established role in secondary stroke prevention. In a major North American clinical trial, ticlopidine demonstrated superior efficacy to aspirin for the prevention of recurrent stroke, particularly in the first year following a stroke. Dipyridamole has not been shown to be useful for stroke prevention. The role of warfarin in the prevention of recurrent noncardiogenic stroke remains controversial and is currently under investigation. Stroke prevention remains an important challenge, and therapy should be individualized to achieve optimal results.
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PMID:Stroke prevention therapies and management of patient subgroups. 788 86

The role of endogenous adenosine on the functional recovery of the heart reversibly injured by ischemia/reperfusion (stunned myocardium) was studied in in vivo canine hearts. Anesthetized open-chest dogs (n = 37) were subjected to 15-min left anterior descending artery (LAD) occlusion followed by 60-min reperfusion. Group 1 (n = 13) received saline and group 3 (n = 9) received an adenosine potentiator, dipyridamole (20 micrograms/kg/min, i.v.), from 15 min before LAD occlusion for 45 min. Group 2 (n = 8) and group 4 (n = 7) were pretreated with an adenosine blocker, 8-phenyltheophilline (8-PT; 10 mg/kg, i.v.), before the saline or dipyridamole infusion, respectively. Interstitial levels of adenosine and its metabolites were measured using cardiac microdialysis technique. Regional cardiac function in the ischemic area was assessed by segment shortening (%SS) with ultrasonic crystals. The dialysate concentration of adenosine in the ischemic region increased from 0.32 to 1.90 microM by the 15-min LAD occlusion in group 1. Dipyridamole enhanced this increase in adenosine to 5.51 microM, with a significant improvement of %SS (36.8 vs. 61.0% at 60 min after reperfusion in group 1 and group 3, respectively; each preischemic level: 100%). Pretreatment with 8-PT did not modify the change of adenosine level in groups 2 and 4, however, significantly deteriorated %SS compared with groups 1 and 3, respectively. Hemodynamic parameters were not statistically different among 4 groups throughout the experiment. Thus, endogenous adenosine was clearly demonstrated to protect stunned myocardium against ischemia/reperfusion. The enhancement of cardiac interstitial level of adenosine with adenosine potentiators, such as dipyridamole, may be expected to ameliorate cardiac function during coronary recanalization therapy or cardiac surgery.
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PMID:[A study on the interstitial level of endogenous adenosine and its cardioprotective effect during ischemia/reperfusion in the canine heart]. 795 2

The use of pharmacologic stress testing for detecting and assessing ischemic heart disease (IHD) is reviewed. Methods of diagnosing IHD are designed to emulate conditions that increase myocardial oxygen demand in order to identify areas of ischemia and atherosclerotic lesions and to evaluate their functional or anatomical importance. Diagnostic methods can be divided into functional assessment with stress testing and anatomical assessment with coronary angiography. Physical stressors, such as exercise or atrial pacing, or pharmacologic stressors, such as vasodilators or beta-adrenergic-receptor agonists, can be used in stress testing. Electrocardiography, thallium planar scintigraphy, echocardiography, and other techniques are used to evaluate the response to stress testing. Unlike exercise stress testing, pharmacologic testing does not require physical exertion. Adenosine, dipyridamole, and dobutamine are the principal agents used in pharmacologic stress testing. Adenosine and dipyridamole mediate coronary artery vasodilation. Adenosine, a direct agonist, has a rapid onset and short duration of action. Dipyridamole, the only agent with approved labeling for use in stress testing, inhibits adenosine indirectly. Dobutamine increases cardiac output and heart rate as well as promoting coronary artery vasodilation. Clinical trials show that all three drugs can be used safely and effectively in patients after acute myocardial infarction or before vascular surgery and in individuals with risk factors for or symptoms of IHD. The sensitivity and specificity of pharmacologic stress testing for detecting IHD are at least as high as those of exercise testing. Minor adverse effects, including chest pain, headache, and facial flushing, are common, but major adverse effects are rare. Pharmacologic stress testing can be used in patients who cannot undergo exercise testing and offers a noninvasive alternative to coronary angiography.
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PMID:Pharmacologic stress testing: experience with dipyridamole, adenosine, and dobutamine. 816 Jun 85

This study evaluates dipyridamole stress echocardiography in silent ischemia. Fourteen patients with previous coronary artery bypass grafting (group A) and 16 patients with healed myocardial infarction (group B) were studied. All had > or = 1 mm ST depression without chest pain during bicycle exercise testing. Left ventricular wall motion was analyzed using a computerized display of digital systolic cineloops with a high frame rate. Test results were compared with coronary angiography. Dipyridamole echocardiography accurately identified patients with significant coronary artery stenosis in both groups (3 of 4 in group A, 11 of 14 in group B). Retrograde flow to the occluded native artery was associated with positive results on dipyridamole testing in 6 of 7 patients in group A and all 3 in group B. Sensitivity, specificity and diagnostic accuracy for detecting significant coronary stenosis or occlusions with retrograde flow was 78, 100 and 83%, respectively. Patients with angiographic multivessel disease had a significantly larger increase in wall motion score index during dipyridamole stress than patients with 0- or 1-vessel disease, 0.18 +/- 0.11 versus 0.05 +/- 0.18 (p < 0.05). Two patients developed symptomatic bradycardia and hypotension during dipyridamole infusion. It is concluded that dipyridamole echocardiography accurately identifies myocardial regions with restricted coronary flow. Stress echocardiography is a valuable tool for assessing coronary flow in silent ischemia.
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PMID:Digital dipyridamole stress echocardiography in silent ischemia after coronary artery bypass grafting and/or after healing of acute myocardial infarction. 824 37

Ischaemia plays an important role in the pathogenetic mechanism of various neuropathies. To study the possible vasodilating effects of dipyridamole on peripheral nerve vessels, morphometric analysis of endoneurial vessels was undertaken in rat sciatic and tibial nerves after chronic dipyridamole treatment. Each rat was injected with 4 mg/kg of dipyridamole intraperitoneally twice daily for 5 days/week and once daily during the weekend for a period of 6 weeks. The mean luminal area and perimeter of endoneurial vessels in the sciatic nerve were significantly greater in dipyridamole-treated animals than in controls. The total fascicular area and densities of endoneurial vessels were not significantly different between experimental and control groups. This study demonstrated that daily administration of dipyridamole over a 6 week period caused endoneurial vessels to dilate resulting in increased luminal area and perimeter. Dipyridamole might be a potent therapeutic agent for peripheral neuropathies attributed to nerve ischaemia.
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PMID:Vasodilating effect of dipyridamole on rat endoneurial vessels: morphometric study. 831 14

Arterial hypertension is the most frequent cause of a disturbance of coronary microcirculation. Inspite of having normal epicardial coronary arteries, patients with arterial hypertension often have symptoms of angina pectoris and a positive exercise tolerance test. The angina pectoris-symptoms in patients with arterial hypertension are due to functional and structural alterations of the coronary microcirculation. Consequently, an antihypertensive therapy should not only aim at lowering blood pressure and reversing myocardial hypertrophy, but also improve coronary microcirculation in order to avoid the consequences of chronic ischemia on the myocardium. Until now, only experimental studies have indicated that antihypertensive therapy can improve coronary flow reserve. To determine to what extent under clinical conditions coronary flow reserve can be improved, in hypertensive patients maximal coronary blood flow, minimal coronary resistance, and coronary reserve (Dipyridamol) were studied before and after a long-term antihypertensive treatment (9-12 months) with the ACE-inhibitor enalapril (10-20 mg/d). To assess the chronic effects rather than the acute effects of the antihypertensive pharmacon, the coronary microcirculation was studied after intermission of medical therapy for a period of 1 week. Along with a decrease in LV muscle mass by about 8%, coronary reserve was improved after enalapril by 48%. It is likely that the observed increase in coronary reserve is related to the reversal of structural vascular abnormalities at the level of the coronary microcirculation. Consequently, it seems that reparation of hypertensive remodeling of the coronary microcirculation can be induced by ACE-inhibitor therapy.
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PMID:ACE-inhibitors and coronary microcirculation. 835 38


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