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)

We tested the safety and the usefulness of intravenous urokinase (2 million units administered over 30 min) in 44 patients with refractory unstable angina, defined as persistence of ischemic episodes during 48-h Holter monitoring (Phase 1) despite maximal medical therapy. After thrombolysis, recurrence of ischemia was observed during a week of observation in the CCU, including two 24-h Holter monitorings at the beginning and the end of the week (Phase 2). Seventeen patients completed the observation period without either symptomatic or asymptomatic ischemic episodes (Group A); the remaining 27 continued to manifest ischemia (Group B). No bleeding complications occurred. Within a 6-month follow-up, 2 patients of Group A had recurrence of unstable angina while in Group B, 19 patients had refractory angina or a major cardiac event [10 patients underwent coronary artery bypass surgery (CABG) or percutaneous transluminal coronary angioplasty (PTCA) for refractory angina (p less than 0.001), 6 other patients with refractory angina continued medical therapy, one patient had a myocardial infarction, and two patients died]. In Phase 1 the duration of total ischemia (min/24 h) was a relevant prognostic marker: higher duration correlated with adverse clinical outcome (p less than 0.01). In comparison to Phase 1, duration of total ischemia in Phase 2 was significantly reduced in both groups (16.9 +/- 19.6 vs. 25.4 +/- 17.7; p less than .001). A percent value expressing this variation was calculated for each patient: the variation thus obtained again gave information on the clinical outcome--the greater the reduction, the lower the risk of cardiac events (p less than .001).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Thrombolytic therapy in refractory unstable angina: the role of Holter monitoring. 167 54

Esmolol is a new cardioselective beta blocker with unique pharmacokinetic properties resulting in a half-life of only 9 minutes. The present multicenter, randomized, placebo-controlled study examined the hemodynamic and antiischemic effects of this compound given as an adjunctive to conventional medical therapy in 113 patients with unstable angina. Fifty-nine patients received esmolol and 54 received matching placebo infusions. Esmolol was titrated in a step-wise manner at dosages of 2 to 24 mg/min until a 25% reduction in the double product was achieved; thereafter, esmolol was continuously infused for up to 72 hours. Esmolol caused a significant and persistent decline in heart rate and blood pressure throughout the entire study period. Clinical events, such as development of acute myocardial infarction or the need for urgent revascularization, occurred in 3 esmolol compared with 9 placebo patients (p = 0.06). There was also a trend toward reduction of silent ischemia as judged by Holter monitoring (mean [+/- standard deviation] duration/patient/24 hours, 21 +/- 81 minutes in the esmolol and 35 +/- 128 minutes in the placebo groups). Esmolol-related adverse effects were mostly cardiovascular in origin and could be managed promptly by downward dose titration or cessation of drug infusion. Thus, esmolol appears to be a safe and effective drug for patients with unstable angina because it permits a large degree of flexibility in adapting the desired level of beta blockade to the patient's changing clinical presentation.
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PMID:Usefulness of esmolol in unstable angina pectoris. European Esmolol Study Group. 167 36

Although the efficacy of long-term administration of antithrombotic agents in unstable angina has been established, short-term effects on myocardial ischemia are unknown. A retrospective analysis was performed in 47 patients undergoing three-channel continuous ST segment monitoring as part of a multicenter trial using esmolol in unstable angina, in which 20 patients received a continuous heparin infusion during the initial assessment of chest pain. Concomitant medications included calcium channel blockers, beta-adrenergic blockers, nitrates, and aspirin in the majority of patients. Clinical variables between the heparin and no heparin groups were similar, except for fewer males and fewer total artery occlusions in the heparin group. No significant differences in the incidence or duration of ischemia were found in a 36 +/- 16 hour monitoring period. Forty percent of the heparin group had 35 episodes of ischemia with a mean of 11 +/- 10 minutes per episode and a total ischemic time of 48 +/- 39 minutes per patient with ischemia. Forty-four percent of the no heparin group had 47 episodes of ischemia with a mean of 13 +/- 13 minutes per episode and a total ischemic time of 58 +/- 47 minutes per patient with ischemia. Multiple linear regression analysis to adjust for intergroup differences did not alter the results. Eighty-five percent of all episodes were asymptomatic. Clinical events, such as episodes of chest pain, emergency coronary arteriography, or coronary revascularization, were also similar between groups. Thus the short-term administration of heparin did not alter the incidence or duration of ischemia in patients with unstable angina.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Failure of adjuvant heparin to reduce myocardial ischemia in the early treatment of patients with unstable angina. 168 22

Silent myocardial ischemia is a frequent finding when Holter monitoring is done in patients with advanced coronary disease. Silent ischemia is associated with a worse prognosis in patients with stable or unstable angina, survivors of myocardial infarction, and populations at risk for coronary disease. Whether medical therapy for silent ischemia improves prognosis is not known. In a randomized, placebo-controlled, multicenter trial of 60 patients with documented coronary disease, positive exercise tests, and ischemic episodes on Holter monitoring, long-acting diltiazem reduced ischemic episodes by 50% compared to placebo, from a mean of 5.6 to 2.8 (p less than 0.0001). Efficacy was maintained over 24 h and diltiazem also significantly improved exercise test parameters. Three smaller studies also demonstrated that diltiazem effectively reduces ambulatory ischemia; however, results with nifedipine are conflicting, with several studies showing no benefit. In contrast, beta-blockers reliably reduce ischemic episodes. The role of medical therapy for silent ischemia will be clarified only when its effect upon morbidity and mortality are determined.
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PMID:Role of diltiazem in the treatment of silent myocardial ischemia. 172 37

We prospectively compared the differences in perioperative cardiac ischemic events in 140 patients undergoing major abdominal (n = 53) versus infrainguinal (n = 87) vascular operations. Preoperative dipyridamole thallium cardiac scintigraphy was performed in a subset of 38 of these patients, with treating physicians blinded to the test results. Myocardial ischemia was measured during operation with use of continuous 12-lead electrocardiography (ECG) and transesophageal echocardiography. Continuous two-lead ambulatory ECG (Holter monitoring) was performed before, during, and after operation for 4 days. Outcome events were cardiac death, nonfatal myocardial infarction, unstable angina, ventricular tachycardia, and congestive heart failure. Results of the study indicated that most demographic variables, such as age, hypertension, cigarette smoking, serum cholesterol, were comparable between patients having aortic or infrainguinal arterial operations. However, in the infrainguinal group more patients had diabetes, second vascular operations, angina pectoris, heart failure, dysrhythmias, and used digitalis. Abnormalities in preoperative Holter monitoring, ECGs, and thallium scan abnormalities were equivalent between groups. During operation, whereas Holter and ECG abnormalities were comparable, more patients undergoing aortic procedures suffered ischemia as determined by transesophageal echocardiography (26% vs 10%, p = 0.019). After operation there were 21 (24%) outcome events in patients having infrainguinal bypasses compared with 15 (28%) patients having aortic procedures (p = NS). Ischemia by Holter monitoring (n = 133) occurred after operation in 46 (57%) patients having infrainguinal operations compared with 16 (31%) patients having aortic reconstructions (p = 0.005). Because preoperative cardiac disease and adverse cardiac outcomes occurred with similar or even greater frequency in both groups of patients, we conclude that the risk for postoperative cardiac ischemic events in lower extremity vascular operations is at least as great as for aortic operations.
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PMID:Comparison of cardiac morbidity between aortic and infrainguinal operations. Study of Perioperative Ischemia (SPI) Research Group. 173 96

The prognostic value of silent ischemia during a symptom-limited predischarge exercise test (ET) was evaluated in 740 men after an episode of unstable angina or non-Q wave myocardial infarction. The 51% of patients with ST depression at the ET had a higher rate of myocardial infarction or death after 1 year (18%) compared with those without ST depression (9%; p less than 0.01). This increased risk was not influenced by the presence or absence of pain at the ET: 18.3% in patients with painful ischemia compared with 18.1% in patients with silent ischemia. However, ST depression combined with pain at the ET predicted a higher incidence of class III or IV angina at follow-up (43.9% compared with 16.7% in the group with asymptomatic ST depression; p less than 0.001). Because revascularization in addition to alleviating symptoms also enhances the prognosis in certain groups of patients, selections for coronary angiography and possible revascularization should not be made only on the basis of symptoms but also on the presence of myocardial ischemia, whether symptomatic or not.
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PMID:The predictive value of silent ischemia at an exercise test before discharge after an episode of unstable coronary artery disease. RISC Study Group. 173 66

Intracoronary (i.c.) thrombus is a frequent finding in patients with unstable angina (UA). Accordingly, thrombolytic treatment could be beneficial, as resolution of thrombus might result in increased delivery of blood flow to the ischemic regions. To test this hypothesis, we studied 13 patients with active UA and ST-segment shift in the anterior leads. Coronary angiography was performed and great cardiac vein blood flow (GCVF; thermodilution) was measured in all patients 25 +/- 14 h after the last chest pain episode. Following angiography, patients received i.v. urokinase (UK: 1,000,000 IU/30 min); aortic pressure and GCVF were measured before and every 10 min following drug infusion, for a total time of 90 min. At baseline angiography, 5 of 13 patients (Group 1) had evidence of i.c. thrombus (intraluminal filling defect or thrombotic subocclusion) in the ischemia-related left coronary artery, whereas 8 patients (Group 2) did not. Group analysis showed that UK increased GCVF and decreased anterior coronary resistance in Group 1 (respectively, from 86 +/- 33 to 114 +/- 41 ml/min: p less than 0.005; and from 1.37 +/- 0.68 to 1.01 +/- 0.44 mmHg/ml/min: p less than 0.05) but not in Group 2 (both: p = NS). In conclusion, UK has been shown to increase regional coronary blood flow in selected patients presenting with active UA, as well as evidence of i.c. thrombus at early angiography. Heterogeneity of angiographic findings could explain controversies in trials dealing with thrombolysis in UA.
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PMID:Coronary hemodynamic effects of systemic thrombolysis in patients with unstable angina. 173 10

Despite predictions that 201Tl imaging would be completely supplanted by the new 99mTc perfusion agents, thallium perfusion imaging is alive and well. In fact, in the past year, important new information on thallium imaging continued to emerge. Among the new data, the reinjection of a "booster" dose of 201Tl after the redistribution images has been heralded as a breakthrough that would equal positron-emission tomography in the prediction of myocardial viability. Pharmacologic coronary vasodilation has been increasingly popular, especially since the approval of intravenous dipyridamole by the Food and Drug Administration and in view of recent studies showing that adenosine is a very attractive alternative to dipyridamole in patients who cannot exercise. Beyond the undisputed diagnostic value of dipyridamole-thallium imaging, data on risk stratification continue to accumulate for patients receiving peripheral vascular surgeries as well as for those recovering from a myocardial infarction. The advent of single-photon emission CT in combination with 201Tl imaging allows improved quantification of jeopardized myocardium. This technique has now been used increasingly to complement the information obtained from coronary angiography by the determination of the functional significance of known coronary stenoses. Recent studies have shown marked heterogeneity in the extent of jeopardized myocardium in patients with coronary artery disease. Equally important have been recent reports on the high prevalence of silent ischemia in patients undergoing 201Tl exercise scintigraphy. Technical progress has also enhanced the diagnostic capability of 201Tl imaging, allowing sharper identification of perfusion defects and quantification of reversible myocardial ischemia precipitated by exertion. Finally, one of the most exciting areas of research in thallium scintigraphy is its established prognostic value in patients with stable angina or those recovering from a myocardial infarction. Recently, these prognostic data have also been extended to patients with unstable angina or those receiving thrombolytic therapy.
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PMID:201Tl myocardial perfusion imaging. 175 Dec 90

The diagnostic and prognostic value of symptom limited exercise tests (ET) performed before discharge and after one month were compared in men admitted to hospital after an episode of unstable angina or a non-Q-wave myocardial infarction (MI). A 'Positive ET' was defined as either a maximal work load below 100 W or ST-depression greater than or equal to 0.1 mV in 1-2 leads below 130 W or ST-depression greater than or equal to 0.1 mV in more than 2 leads at any load at the ET. During follow-up, severe angina was the only indication for coronary angiography and revascularization. There were no significant differences in diagnostic findings between the tests--Positive ET in 47% and Negative ET in 25% at both ETs. The occurrence of MI or death and the need of revascularization were related to signs of ischemia at both ETs. There were no differences in prognostic value between the early and late tests regarding MI or death or future severe angina during the 11 months' follow-up after the one month ET. However, half (10%) of the overall event rate (20%) during the one year follow-up occurred during the first months. The risk of these events could be identified by the predischarge but, for obvious reasons, not by the one month ET. Therefore, the present study suggests that a symptom limited ET should be performed before discharge in men stabilized after an episode of unstable angina or non-Q-wave MI.
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PMID:Should the exercise test (ET) be performed at discharge or one month later after an episode of unstable angina or non-Q-wave myocardial infarction? 175 61

When severely ischemic myocardium is reperfused, prolonged myocardial dysfunction--a phenomenon named myocardial stunning--frequently occurs. Stunning also occurs in a variety of other situations. These include myocardium located adjacent to infarcted tissue, transient increase in myocardial O2 demands in the presence of incomplete coronary obstruction, during both systole and diastole, in isolated perfused hearts rendered ischemic or anoxic, and in a variety of clinical situations, such as following ischemic arrest in cardiac surgery, thrombolytic reperfusion, and after episodes of severe ischemia in Prinzmetal's angina or unstable angina. Although the fundamental mechanism(s) responsible for myocardial stunning has not been elucidated, in experimental preparations calcium antagonists, free-radical scavengers, and neutrophil depletion have each been found to be helpful in minimizing it.
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PMID:Stunning of the myocardium: an update. 175 30


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