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)

This study examined mainly the adverse effects of 201Tl myocardial scintigraphy with dipyridamole (D-Tl) in 73 elderly patients over 70 years old in comparison with those in 65 younger patients. Fifty-five of 73 elderly patients (75%) and 49 of 65 younger patients (75%) had a persistent or dipyridamole-induced perfusion defect on D-Tl. The hemodynamic changes induced by dipyridamole as well as the incidence of cardiac and noncardiac adverse effects were similar in both groups and no serious adverse effect occurred in either group. Secondly, we examined the procedure's usefulness for detecting ischemic heart disease in elderly and younger patients. Dipyridamole induced perfusion defect was noted in 21 elderly patients and in 24 younger patients (N.S.). Among the patients in whom coronary angiography was performed, significant coronary artery stenosis was found in 5 of 8 elderly patients and 17 of 20 young patients (N.S.). In patients with one or two-vessel disease, the area with dipyridamole induced ischemia was concordant with the stenotic area seen on coronary angiography in 3 of 3 elderly patients and 12 of 13 younger patients (N.S.). Thus, the safety and usefulness of D-Tl for detecting myocardial ischemia were comparable in elderly and young patients.
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PMID:Safety and accuracy of dipyridamole thallium myocardial scintigraphy in elderly patients. 841 31

Percutaneous transluminal coronary angioplasty (PTCA) represents a suitable model to establish myocardial ischemia in man. Balloon inflation usually is accompanied by a significant deterioration in left ventricular systolic and diastolic properties. A brief episode of ischemia followed by reperfusion termed preconditioning has been identified as a mechanism rendering the myocardium more resistant to ischemia. Adenosine is considered as important mediator of preconditioning. Dipyridamole represents an important drug interfering with myocardial adenosine metabolism by inhibiting its cellular reuptake. The aim of this study was to investigate if an intracoronary infusion of dipyridamole represents a suitable tool in preventing the deterioration of left ventricular performance and hemodynamics during PTCA. In 20 patients undergoing elective coronary angioplasty of a major vessel assessment of angiographic left ventricular performance and left ventricular hemodynamics was performed before, during and after coronary angioplasty. Patients were randomly allocated to study group 1 receiving an intracoronary infusion of dipyridamole prior to PTCA and study group 2 where conventional pretreatment was performed. In study group 3 intracoronary dipyridamole infusion was performed in 10 patients with coronary artery disease during coronary angiography in order to evaluate its effect on baseline hemodynamics and left ventricular performance. Dipyridamole-pretreatment resulted in a significant preservation of systolic and diastolic left ventricular performance during PTCA, as documented by an uneffected global ejection fraction (in comparison to a deterioration of 29.2% in study group 2) and an increment in diastolic stiffness of only 12.7% (in comparison to an increment of 57.3% in study group 2). Furthermore, a significant prolongation of achievable balloon-inflation times of 48.4% could be obtained in study group 1. In addition, incidence of arrhythmias seemed to be reduced in study group 1. Apart from two cases of coronary steal phenomenon no significant side effects of dipyridamole infusion could be detected. Finally, in study group 3 dipyridamole-pretreatment per se induced a significant amelioration of angiographically assessed left ventricular systolic performance.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Pharmacologic myocardial protection during percutaneous transluminal coronary angioplasty (PTCA) by intracoronary dipyridamole: hemodynamic, contractile and dynamic ventricular consequences]. 857 41

Platelet aggregation and plasma serotonin were studied during ischemia-reperfusion of the small intestine in dogs. Blood was withdrawn from the superior mesenteric vein before and 1 h after ischemia, then 5, 30 and 60 min after reperfusion. Dipyridamole (5 mg/kg body weight) and coenzyme Q10 (CoQ10; 10 mg/kg body weight) were administered intravenously 5 min before reperfusion, following 1 h ischemia, in order to investigate their effects on platelet function and free serotonin. Ischemia-reperfusion resulted in an increased local free serotonin concentration together with an enhanced platelet response to ADP, collagen and arachidonic acid. Administration of dipyridamole and CoQ10 prior to reperfusion prevented, at least in part, augmented platelet activation and serotonin release. It appeared that dipyridamole was more potent than CoQ10. Our results may indicate a possible protective effect of dipyridamole on enhanced platelet activation during ischemia-reperfusion in dogs.
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PMID:Plasma serotonin and platelet aggregation during ischemia-reperfusion in dogs: effect of dipyridamole and coenzyme Q10. 869 77

Cardiac L-carnitine content, essential for mitochondrial fatty acid transport and ATP-ADP exchange, decreases during ischemia. In animal models, administration of the natural derivative, L-propionylcarnitine, may reduce ischemia and improve cardiac function. To evaluate possible antiischemic effects of L-propionylcarnitine was compared with placebo in a randomized, double-blind, parallel design, in addition to preexisting therapy. Patients with > or = 2 anginal attacks per week and objective signs of ischemia with angina during bicycle exercise testing were included. After an initial 2-week, single-blind placebo phase, 37 patients received 500 mg L-propionylcarnitine tid, and 37 patients received placebo for 6 weeks. Both groups were comparable at baseline. Three patients discontinued the study while on placebo (two because of noncompliance, one because of palpitations) and one while on L-propionylcarnitine (noncompliance). Although heart rate, blood pressure at rest, and maximal exercise were not affected, L-propionylcarnitine increased the time to 0.1 mV ST-segment depression [44 +/- 3 vs. 8 +/- 2 seconds (mean +/- SEM) in the placebo group; p = 0.05], and exercise duration improved by 5% compared with placebo. Anginal attacks and the consumption of nitroglycerin were not affected in either group. Thus, following a 6 week treatment period, L-propionylcarnitine induced additional, albeit marginal, antiischemic effects in anginal patients who were still symptomatic despite maximal conventional antianginal therapy. It is questionable whether in these patients this form of metabolic treatment will achieve great benefit, although in some improvement can be expected.
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PMID:Additional antiischemic effects of long-term L-propionylcarnitine in anginal patients treated with conventional antianginal therapy. 885 Mar 78

Dipyridamole-sestamibi (PMIBI) is recommended prior to vascular surgery in patients with > or = 1 Eagle criteria (Q waves, history of ventricular ectopy, diabetes, advanced age, and/or angina). To review our cardiac morbidity and mortality and the need for preoperative PMIBI, we reviewed 109 consecutive patients with a mean age of 59 years who underwent 145 elective major vascular procedures over a 1-year period. Seventy patients (with a mean of 0.8 Eagle criteria) underwent 92 vascular procedures without preoperative PMIBI and without coronary revascularization. Thirty-one patients (with a mean of 1.1 Eagle criteria) underwent 39 procedures without coronary revascularization following PMIBI, which showed reversible ischemia in seven and a fixed defect in 10; findings were normal in 14. Preoperative coronary bypass or angioplasty was limited to eight patients (14 procedures, mean of 1.6 Eagle criteria) who had unstable angina with (2 patients) or without (6 patients) acute myocardial infarction. There were four perioperative myocardial infarctions (2.8%), seven cardiac events overall (4.8%), and one cardiac death (0.7%). Three (43%) of the seven cardiac events occurred in patients with a normal scan or fixed defect on PMIBI imaging. In the absence of unstable angina, PMIBI had a sensitivity of only 25% and a specificity of 80% for cardiac events. We conclude that among patients without severe cardiac symptoms (1) PMIBI has a very limited ability to identify patients at risk for cardiac complications, and (2) preoperative PMIBI is neither necessary nor cost-effective.
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PMID:Cardiac assessment prior to vascular surgery: is dipyridamole-sestamibi necessary? 887 86

Fast magnetic resonance (MR) imaging techniques have the capability of demonstrating regions of ischemia caused by stenosis. The size of the potentially ischemic area determines the importance of the stenosis. The purpose of this study was to determine the relative values of relaxivity-enhancing and magnetic-susceptibility MR contrast media in detecting and sizing the area at risk in dogs. Eight dogs were subjected to critical left circumflex coronary artery (LCX) stenosis. Sixty sequential inversion-recovery- and driven-equilibrium-prepared fast gradient recalled echo images were acquired during bolus administration of 0.03 mmol/kg gadodiamide or 0.4 mmol/kg sprodiamide in basal and vasodilated (dipyridamole-stress) states. The size of the area at risk was measured and compared with that measured post mortem. In the basal state, gadodiamide and sprodiamide equivalently altered the signal intensities of nonischemic myocardium and the territory of stenosed coronary artery. Dipyridamole produced a significant increase in left anterior descending coronary artery flow with a decrease in LCX flow. The hypoperfused region was observed as a low-and high-signal intensity region after administration of gadodiamide and sprodiamide, respectively. The size of the hypoperfused region was slightly smaller with gadodiamide (37.4% +/- 2.8%) and sprodiamide (34.0% +/- 2.2%) than the true area at risk measured post mortem (41.8% +/- 2.2%; p < 0.05). Dipyridamole perfusion MR imaging with relaxivity or susceptibility contrast media is a noninvasive method to identify and quantify the area at risk in the territory of a stenotic coronary artery. Changes in myocardial signal intensity on fast gradient recalled echo images reflect the augmentation of flow and volume induced with dipyridamole and are consistent with the "steal phenomenon."
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PMID:Quantification of the extent of area at risk with fast contrast-enhanced magnetic resonance imaging in experimental coronary artery stenosis. 889 62

Anginal symptoms alone are not a reliable guide to the extent of patients' ischaemic heart disease and silent episodes of ischaemia are associated with increased morbidity and mortality. It is becoming apparent that effective treatment of ischaemia will have to target the pattern of ischaemic events seen in patients' daily lives and treatment strategies are now being developed which aim to eliminate both silent and symptomatic episodes of ischaemia over the whole 24-h period. For example, the Circadian Anti-ischaemia Program in Europe (CAPE) trial has shown that significant improvements in objective and subjective measures of ischaemia occurred over 24 h when the once-daily third-generation dihydropyridine calcium antagonist amlodipine was added to background medical therapy. In addition, the Canadian Amlodipine/Atenolol in Silent Ischaemia Study (CASIS) has clearly shown the complementary effects of combination therapy with amlodipine and the long-acting beta-blocker atenolol. Ongoing and future outcome studies will determine the impact of such approaches on the prognosis for patients with ischaemic heart disease.
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PMID:Treatment effects on the total ischaemic burden and prognostic implications. 896 Apr 59

Intravenous dipyridamole induces angina pectoris (AP) in some patients with significant coronary artery disease (CAD). The aim of this prospective study was to identify the angiographic, nuclear, and clinical determinants. The authors examined 50 patients consecutively with significant CAD on coronary angiography. All antiischemic medications were stopped twenty-four hours (nitrates only 6 hours) before injection of dipyridamole (0.84 mg/kg). ECGs were taken before, during, and after this injection. The regional myocardial activity of Tc-99m-Sestamibi at rest and after dipyridamole injection was measured with single-photon emission computed tomography (SPECT). During dipyridamole injection 20 patients had AP, of whom 15 had ST segment depression on ECG (P < 0.001). The only significant difference on coronary angiography between patients with dipyridamole-induced AP and those without AP was the presence of collaterals (P < 0.05). In patients with AP and collaterals, ECG and SPECT changes were always noted in the collateralized territory. Subgroup analysis showed that patients without previous myocardial infarction (MI, n = 17, P < 0.05) or nontransmural MI (n = 17, P < 0.05) had a good correlation between collaterals and AP, whereas patients with a history of transmural MI (n = 16) did not. No further significant variables could be found as a predictor of AP after dipyridamole injection. These findings suggest that AP during dipyridamole stress test is due to ischemia, which is not related to the severity of CAD. Ischemia is probably due to coronary steal to the collateralized territory in patients without transmural MI. Dipyridamole-induced angina pectoris is predictive for collaterals and may indicate viability in patients with MI.
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PMID:Dipyridamole-induced angina pectoris during sestamibi stress test in patients with significant coronary artery disease: clinical, angiographic, and nuclear determinants. 911 78

A daily nitrate-free interval (NFI) lasting 4-7 hours was instituted in four patients with severe congestive heart failure secondary to myocardial ischemia who were awaiting orthotopic heart transplantation. The duration of intravenous nitroglycerin therapy ranged from 14-55 days, and the maximum dosage was 50-400 microg/minute. Anginal events occurred more frequently during the NFI than during intravenous therapy. An NFI of 8-12 hours reduces tolerance in patients with congestive heart failure and stable angina. However, the experience in these patients with recurrent ischemia does not support its use to prevent ischemic events during hospitalization.
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PMID:Intravenous nitroglycerin tolerance in patients with ischemic cardiomyopathy and congestive heart failure. 946 95

Even in the era of coronary stenting, acute coronary artery occlusion continues to represent a significant limitation of percutaneous transluminal coronary angioplasty (PTCA). Despite application of heparin and aspirin, abrupt vessel closure still occurs in 2-8%, depending on the definition applied. Especially patients receiving PTCA for acute coronary syndromes are at high risk for abrupt vessel closure. The formation of an intracoronary thrombus plays a central role in the pathogenesis of abrupt vessel closure. Dipyridamole induces dilatation of coronary arteries and prevents platelet aggregation by a mechanism that differs from that of aspirin. The primary purpose of the study was to evaluate whether adjunctive local intracoronary therapy with dipyridamole could reduce the incidence of coronary artery occlusion following PTCA. Secondary endpoints were defined as myocardial infarction, necessity for bypass grafting, and death. In 939 PTCA procedures performed for stable angina and in 155 angioplasty procedures for acute coronary syndromes (unstable angina, acute myocardial infarction), patients were randomized to receive conventional pretreatment consisting of heparin 15,000 I.E. and aspirin 500 mg i.v. or additional intracoronary infusion of dipyridamole (0.5 mg/kg body weight). Dipyridamole was applied in 550 interventions (455 interventions in men, 95 interventions in women, age = 59.2 +/- 8.4; 74 emergency procedures); conventional pretreatment was performed in 544 interventions (444 interventions in men, 100 interventions in women, age 58.3 +/- 7.9; 81 emergency procedures). Intracoronary application of dipyridamole resulted in a significant reduction in the incidence of abrupt vessel closure following PTCA. This significant reduction was observed in patients presenting with stable ischemia as well as in patients receiving PTCA for acute coronary syndromes. Concerning secondary end points, intracoronary application of dipyridamole did not affect the need for bypass grafting or the incidence of death following PTCA. Intracoronary application of dipyridamole was associated with a reduction in the incidence of myocardial infarction following PTCA which, however, failed to reach significance.
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PMID:[Intracoronary dipyridamole reduces the incidence of acute coronary vessel occlusion in percutaneous transluminal coronary angioplasty--a prospective randomized study]. 949 93


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