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)

Thirty-eight patients underwent left ventricular angiography and coronary arteriography within the first 6 hours of inferior myocardial infarction, in an attempt at intracoronary thrombolysis with streptokinase. Twenty-three of these patients presented with ST segment depression of more than 1 mm on the anterior leads (V1 to V4) of ECGs done immediately before the attempt at thrombolysis (group I), whereas 15 did not (group II). Quantitative analysis of left ventricular angiography showed an ejection fraction significantly lower in group I (51 +/- 10%) than in group II (59 +/- 7%; p less than 0.01). This difference was the result of inferior hypokinesia which was larger both in surface area (group I = 11.5 +/- 6.5 cm2; group II = 4.2 +/- 2.7 cm2; p less than 0.001) and in percentage of ventricular perimeter (group I = 46 +/- 14%; group II = 27 +/- 12%; p less than 0.001). The prevalence of a left anterior descending artery lesion and the degree of stenosis were the same in both groups. The success rate of thrombolysis was not significantly different. However, in cases of persistent success, there was an improvement of regional contraction only in group I, as opposed to absence of change in group II. These results suggest that patients with inferior myocardial infarction and ST anterior depression have an extensive ischemic area rather than anterior wall ischemia. An attempt at coronary thrombolysis seems to be worthwhile only in these patients, as it results in appreciable myocardial salvage when successful.
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PMID:Anterior ST depression in inferior myocardial infarction: correlation with results of intracoronary thrombolysis. 395 56

The prognostic significance of programmed ventricular stimulation and its usefulness in relation to other forms of invasive and noninvasive testing was evaluated in 150 survivors of acute myocardial infarction. Ventricular tachyarrhythmias of 6 beats or more were induced in 35 (23%) patients. No significant differences existed between patients with inducible ventricular tachyarrhythmias and those without inducible ventricular tachycardia with respect to occurrence of spontaneous ventricular arrhythmias in the acute and early recovery phase of infarction or predischarge exercise-induced ischemia or arrhythmias, severity of coronary artery disease, or degree of left ventricular dysfunction. A higher incidence of inferior myocardial infarction was observed in patients with inducible ventricular tachycardia when compared with those without inducible ventricular tachycardia (66% vs 41%, p less than .01). During a mean follow-up of 10 +/- 5 months (range 2 to 19), there were two sudden deaths, three nonsudden deaths, and two additional patients developed sustained ventricular tachyarrhythmias. There was no significant difference between patients with and those without inducible ventricular tachyarrhythmias with respect to the occurrence of these events. In this study population, a lower mean ejection fraction (p less than .01), the presence of a ventricular aneurysm (p less than .05), and exercise-induced ventricular premature contractions (p less than .05) were predictors of sudden death and of spontaneous ventricular tachycardia. Thus, the findings of this study do not support the hypothesis that the induction of ventricular tachyarrhythmias in patients recovering from acute myocardial infarction identifies a group at high risk for sudden cardiac death.
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PMID:Programmed ventricular stimulation in survivors of an acute myocardial infarction. 401 3

Functional risk stratification has been a fruitful new approach to classification and management of patients with acute myocardial infarction. Risk is divided into the functional categories: (1) left ventricular dysfunction; (2) ventricular arrhythmias; and (3) ischemia. Diastolic and systolic left ventricular dysfunction and perhaps aneurysm formation are independent indicators of death. Holter ECG recording of spontaneous ventricular arrhythmias or ventricular arrhythmias induced by programmed ventricular stimulation can identify patients who have a higher risk of dying. Ischemic risk can be identified with accuracy in patients with first inferior myocardial infarction. Coronary angiography is indicated to establish ischemic risk for the following situations (1) angina pectoris with ST depression; (2) non-Q wave infarction (3) inferior infarct with positive exercise test; and (4) anterior infarction with left ventricular ejection fraction between 20% and 40%.
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PMID:Risk stratification after myocardial infarction. 409 72

To assess various factors associated with anterior S-T segment depression during acute inferior myocardial infarction, 47 consecutive patients with electrocardiographic evidence of a first transmural inferior infarction were studied prospectively with radionuclide ventriculography an average of 7.3 hours (range 2.9 to 15.3) after the onset of symptoms. Thirty-nine patients (Group I) had anterior S-T depression in the initial electrocardiogram and 8 (Group II) did not have such "reciprocal" changes. There was no difference between the two groups in left ventricular end-diastolic or end-diastolic volume index or left ventricular ejection fraction. Stroke volume index was greater in Group I than in Group II. There were no group differences in left ventricular total or regional wall motion scores. A weak correlation existed between the quantities (mV) or inferior S-T segment elevation and reciprocal S-T depression. No relation between anterior S-T segment depression and the left ventricular end-diastolic volume index could be demonstrated; the extent of left ventricular apical and right ventricular wall motion abnormalities, both frequently associated with inferior infarction, did not correlate with the quantity of anterior S-T depression. These data show that anterior S-T segment depression occurs commonly during the early evolution of transmural inferior infarction, is not generally a marker of functionally significant anterior ischemia and cannot be used to predict left ventricular function in individual patients. Anterior S-T segment depression may be determined by reciprocal mechanisms.
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PMID:Clinical implications of anterior S-T segment depression in patients with acute inferior myocardial infarction. 628 33

ST-segment depression in the anterior precordial leads is seen in roughly one-half of patients with first acute inferior myocardial infarction. Concomitant stenosis of the left anterior descending artery can be detected angiographically in approximately 50% of all patients with inferior infarction whether or not precordial ST-segment depression is present. The presence of precordial ST-segment depression identifies a subgroup of patients with inferior myocardial infarction who have a lower left ventricular ejection fraction and quantitatively more severe abnormalities involving the posterolateral and inferoseptal segments. The contribution of anterior wall ischemia to the genesis of the precordial pattern remains problematic; although most studies to date have not supported this viewpoint, careful quantitative thallium perfusion studies have not been done. Short-term mortality and morbidity seem less favorable in the presence of precordial ST-segment depression, but this has not been substantiated by all authors.
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PMID:Precordial ST-segment depression in acute inferior myocardial infarction: innocent bystander or a high risk indicator? 661 22

In order to evaluate the clinical significance of thallium (Tl)-201 myocardial imaging for diagnosing the right ventricular (RV) ischemia, we studied the relationship of right ventricular free wall (RVFW) appearance on myocardial images to coronary arteriographic findings. Patients were divided into 3 groups as follows: 1) normal control (NC) group (19 cases) without angiographically documented coronary artery disease; 2) non-RCA group (18 cases) with significant coronary artery lesion restricted to the left coronary artery (LCA); and 3) RCA group (36 cases) with significant right coronary artery (RCA) stenosis regardless of underlying LCA disease. After the patients had exercised up to 80-85% of the predicted maximal heart rate, immediate and 3-4 hour delayed myocardial images were obtained. As for presence or absence of the RV ischemia on images, the RVFW appearance in 30 degrees and 60 degrees left anterior oblique (LAO) views were assessed carefully. On the immediate images, all patients except one in the NC group and all except 3 in the non-RCA group demonstrated 'continuous visualization' of the RVFW in both views. In the RCA group, 6 showed 'non-visualization' and 11 'defective visualization' of the RVFW in 30 degrees LAO view. In 60 degrees LAO view, 6 presented 'non-visualization' and other 6 'defective visualization' of the RVFW. On the delayed images, although none of the patients in the groups NC and non-RCA demonstrated redistribution phenomenon of the RVFW, 4 patients in the RCA group showed redistribution of Tl-201 into the RVFW. Non- and defective visualization of the RVFW on the immediate images were related to the proximally located RCA lesion, previous history of inferior myocardial infarction and high grade RCA stenosis. Collateral vessels seemed to protect the RVFW against the development of exercise induced ischemia and affect the occurrence of redistribution of Tl-201 into the RVFW. In conclusion, stress Tl-201 myocardial imaging enables us to estimate the myocardial blood flow of the RV and is a useful non-invasive method in the evaluation of RV ischemia.
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PMID:Clinical significance of the right ventricular free wall appearance on stress Tl-201 myocardial images in ischemic heart disease. 665 95

Although stress thallium (T1)-201 myocardial imaging has been used for evaluation of the ischemic lesion of the left ventricle, there are few reports on the usefulness of this method for the assessment of the right ventricle in ischemic heart disease. The patients (pts) fell into three distinct groups according to the findings of the coronary arteriogram: normal control group (16 cases) without angiographically documented coronary artery disease; non-RCA group (16 cases) with a significant stenosis (greater than or equal to 75% narrowing) in the left coronary artery but free of a significant right coronary artery (RCA) stenosis; RCA group (28 cases) with a significant RCA stenosis regardless of the presence or absence of a significant left coronary artery lesion. After the pts were exercised to 80-85% of the expected maximum heart rate, immediate and delayed (3 to 4 hrs) T1-201 myocardial images were obtained. The images of the right ventricular free wall ( RVFW ) in 30 degrees and 60 degrees left anterior oblique (LAO) projections were evaluated visually with regard to the presence or absence of a defective T1-201 uptake, degree of the radioactivity and redistribution phenomenon of the RVFW . On immediate images, all normal controls and 13 pts in non-RCA group had continuous visualization of the RVFW . In RCA group, the RVFW was not visualized in five and 11 showed defective visualization of the RVFW in the 30 degrees LAO projection. In 60 degrees LAO projection, the RVFW was not visualized in six and five had defective visualization. On delayed images in RCA group, two pts who had no inferior myocardial infarction (MI) had redistribution of T1-201 into the RVFW . Defective visualization of the RVFW on the image was associated with location of the RCA lesion, history of inferior MI and degree of RCA stenosis. Collateral circulation seemed to protect the RVFW against the development of exercise-induced ischemia and affect the occurrence of redistribution of T1-201 into the RVFW . The RVFW findings on images improved the sensitivity for identifying the pts with RCA disease, compared with the LV findings alone. Thus, stress T1-201 myocardial imaging is able to visualize the myocardial blood flow of the RVFW and may provide a useful non-invasive method in the evaluation of right ventricular ischemia.
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PMID:[Clinical significance of stress thallium-201 myocardial scintigraphy for evaluation of right ventricular ischemia]. 667 74

We evaluated the recently proposed concern that ECG anterior ST segment depression in patients with acute inferior wall myocardial infarction represents an additional area of ischemia and therefore implies worsened prognosis. We studied patients enrolled in the Aspirin Myocardial Infarction Study (AMIS), ages 30 to 69 years, who sustained an inferior myocardial infarction within 6 months from the start of the study. Two hundred nineteen patients who met those criteria were followed for an average of 38.2 months. One hundred ten patients had significant anterior lead ST depression (greater than or equal to 0.1 mV) during their acute inferior infarction and their 3-year mortality rate was 9.1%. One hundred nine patients had no anterior ST abnormality and a mortality rate of 10.1% (p = ns). Only one patient with significant depression had a subsequent anterior wall myocardial infarction. Anterior ST depression correlated closely with the magnitude of inferior ST segment elevation. Since ST depression does not alter long-term mortality but relates to magnitude of ST elevation, it probably represents a reciprocal change.
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PMID:Anterior ST segment depression during acute inferior myocardial infarction: evidence for the reciprocal change theory. 688 Oct 25

Serial imaging of the myocardium in the resting state after intravenous administration of thallium-201 can be employed to differentiate between ischemia or under-perfusion and myocardial infarction or scar. Redistribution of thallium with filling-in of defects on delayed images or rest can be observed in myocardial regions supplied by stenotic coronary arteries (greater than or equal to 70% narrowing). These myocardial segments usually exhibit normal or hypokinetic wall motion. Persistent defects over a two to three hour imaging period at rest correlate highly with Q waves on the electrocardiogram and akinetic or dyskinetic wall motion on ventriculography. Thallium scintigraphy can be successfully utilized for detecting and localizing acutely infarcted myocardium. Sensitivity for infarct detection is higher in the first 24 hours after the onset of chest pain, although with computer-assisted quantitative analysis of images sensitivity for late detection (ten to fourteen days post myocardial infarction) may be improved. Multivessel disease can be predicted in many patients with acute inferior myocardial infarction by demonstrating anteroseptal wall defects with delayed redistribution on rest images prior to hospital discharge. Patients who demonstrate inferior wall persistent defects (infarction) with anterior wall redistribution (hypoperfusion/ischemia) have a worse prognosis characterized by an increased frequency of recurrent angina and infarction compared to the group with only inferior defects. Thallium scintigraphy may also be useful in assessing myocardial infarct size. Patients with large defects during the acute phase of infarction have significantly higher early and late mortality.
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PMID:Thallium-201 scintigraphy at rest in ischemia and infarction. 746 85

Binding of a variety of ligands for brain excitatory amino acid receptors was examined in membrane preparations extensively washed and treated with Triton X-100 that were obtained from the hippocampus and cerebral cortex of gerbils that survived for different periods after transient global brain ischemia. Bilateral occlusion of the carotid arteries for 5 min did not affect the binding of [3H](+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-imi ne (MK-801) to an open ion channel associated with the N-methyl-D-aspartate (NMDA)-sensitive subclass in both central structures of gerbils that survived for 1 to 4 weeks after the injury when determined at equilibrium in the presence of 3 different endogenous agonists including L-glutamic acid (Glu), glycine (Gly) and spermidine at maximally effective concentrations. In contrast, the ischemic occlusion significantly diminished [3H]MK-801 binding when determined before equilibrium in the presence of the 3 stimulants in hippocampal membranes without altering that in cortical membrane 2 weeks after the insult, so that the initial association rates were invariably reduced by more than 60%. Moreover, the occlusion not only reduced the binding of both [3H]Glu and [3H]D,L-(E)-2-amino-4-propyl-5-phosphono-3-pentenoic acid to the NMDA domain on the NMDA receptor ionophore complex, but also decreased the binding of both [3H]Gly and [3H]5,7-dichlorokynurenic acid to the Gly domain. However, the insult did not induce any detectable changes under the experimental conditions employed in either the binding of [3H]DL-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) to the AMPA-sensitive subclass or the binding of kainic acid (KA) to the KA-sensitive subclass in both central regions of animals that survived for 2 weeks. These results suggest that transient global brain ischemia may predominantly impair neuronal and/or glial cells enriched of the NMDA receptor ionophore complex in gerbil hippocampus.
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PMID:Excitatory amino acid receptor binding in hippocampus of gerbils with transient global brain ischemia. 768 42


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