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)

A recent report showed that during Holter monitoring of patients with syndrome X (typical anginal pain, positive exercise test response [at least 0.1 mV of ST-segment depression], no evidence of coronary spasm and angiographically normal coronary arteries), 50% of episodes of ischemic ST-segment depression were painful. This proportion is considerably higher than that in patients with chronic stable angina, which is about 30%. A significantly lower threshold and tolerance to painful stimuli was seen in a group of patients with chronic stable angina in whom 50% of episodes were painful compared with a group in whom only 5% of episodes were silent. Hence, patients with syndrome X may have enhanced sensitivity to painful stimuli. To investigate whether this difference was due to a lower threshold for painful stimuli in general, 12 patients with syndrome X and 10 (age- and sex-matched) with chronic stable angina were studied using the same battery of painful stimuli. Patients with syndrome X had a significantly lower threshold and tolerance for forearm ischemia (-36%, p less than 0.05, and -40%, p less than 0.001) and electrical skin stimulation (-37%, p less than 0.01, and -35%, p less than 0.001); the cold pressor test did not show significant differences (-7%, p = 0.391, and -1%, p = 0.818). Thus, patients with syndrome X in this study had significantly lower threshold and tolerance values for forearm ischemia and for electrical skin stimulation. These differences in sensitivity to pain may partly explain a higher incidence of painful ischemic episodes detected by ambulatory electrocardiographic monitoring during unrestricted daily life.
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PMID:Pain threshold and tolerance in women with syndrome X and women with stable angina pectoris. 363 Sep 32

Twenty patients with chronic stable angina pectoris, proved coronary artery disease, positive treadmill stress test response, and at least 2 episodes of ischemia per day underwent 72 hours of Holter monitoring during daily activities. During this period they had 389 ischemic episodes: 104 (27%) symptomatic and 285 (73%) silent. Marked variability was observed between patients in the number of ischemic episodes (range 2 to 15 per day, mean 6.5), duration of ischemia (range 6 to 419 minutes/day, mean 76.5), maximal ST depression (range 1 to 6 mm, mean 3.4) and heart rate at the beginning of ST depression (range 75 to 105 beat/min, mean 91). The day-to-day variability in individual patients between the different days in the number of ischemic episodes was 36%, in duration 51%, and in maximal degree of ST depression 31%. Only 9% variability was noted in heart rate at the beginning of ST depression. Similar day-to-day variability in individual patients was noted in the symptomatic and silent episodes. For clinical purposes of evaluation of ischemia during daily activities, 1 day of monitoring appears to be sufficient because within the first day, 78% of the maximal number of ischemic episodes, 64% of their duration, and 84% of the maximal degree of ST depression were detected. However, for evaluation of anti-ischemic drugs at least 2 monitoring days are required.
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PMID:Day-to-day variability of myocardial ischemic episodes in coronary artery disease. 367 1

The ejection fraction (EF) of the left ventricle was measured by radionuclide ventriculography in 64 patients during an acute cerebrovascular accident. Sixteen patients (12 with coronary artery disease) died within two weeks of the onset of symptoms and had only one EF measurement. In the remaining 48 patients, the EF was also measured two weeks and three months after the acute event. The ejection fraction of the patient who died soon after the acute stroke (52 +/- 18) was significantly lower than that of the patients who survived (64 +/- 10) (p less than 0.01). Of the patients who survived, 28 without history of coronary disease had an EF of 67 +/- 10 during the acute event. It was significantly higher than that measured after two weeks (60 +/- 10) p less than 0.01). In 10 patients with history of chronic stable angina pectoris, the EF (59 +/- 10) was significantly lower in the first study compared to that measured in the second (69 +/- 10) (p less than 0.02). Ten patients with no evidence of ischemia but with a history of myocardial infarction had a higher EF (61 +/- 11) during the first study as compared to the second (51 +/- 11) (p less than 0.05). In all patients there was no significant difference in the EF measurements between the second and the third study. It is suggested that the EF response of the left ventricle of the heart to the acute cerebrovascular accident is similar to that observed in a stress test.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ejection fraction response of the left ventricle of the heart to acute cerebrovascular accident in patients with coronary artery disease. 373 40

Numerous hemodynamic, electrocardiographic, metabolic and radionuclide measurements in various subsets of patients with coronary artery disease (CAD) reveal that ischemia does not always occur on the basis of increases in myocardial oxygen consumption. Continuous hemodynamic monitoring indicates that most episodes of myocardial ischemia are not preceded by increases in such major determinants of oxygen consumption as heart rate or blood pressure, but that these usually increase in response to the development of ischemia. The development of pain during ischemia is a late feature and most episodes are silent. There are no significant differences in the hemodynamic characteristics of symptomatic versus asymptomatic episodes of myocardial ischemia in patients with angina at rest or between those associated with ST-segment depression and those with ST-segment elevation. Continuous Holter recordings analyzed by compact analog technique in hospitalized and ambulatory patients with ischemic heart disease indicate that in both unstable and chronic stable angina, over two-thirds of myocardial ischemic episodes are clinically silent. Symptomatic and silent episodes do not differ significantly with respect to duration. Most symptomatic and asymptomatic episodes are not triggered by increases in the determinants of oxygen demand. Such episodes may arise on the basis of a critical reduction in the lumen of the diseased coronary artery leading to a primary reduction in blood flow. Intermittent obstruction due to changes in coronary vasomobility or possibly formation of thrombi may be a common mechanism for the pathogenesis of myocardial ischemia in patients with a varying spectrum of coronary artery lesions. At present, the precise clinical and prognostic significance of silent ischemia in CAD is not completely defined.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hemodynamic and electrocardiographic correlates of symptomatic and silent myocardial ischemia: pathophysiologic and therapeutic implications. 375 1

All patients with chronic stable angina presumed to be due to coronary artery disease should undergo exercise stress testing early in evaluation for evidence of high-risk coronary disease. If the exercise stress test shows early positive findings, patients should undergo cardiac catheterization to exclude left main coronary vessel disease and three-vessel disease with concomitant left ventricular dysfunction. Patients with unstable angina who are subsequently stabilized on medical therapy should undergo a limited exercise stress test before discharge from the hospital to identify those at high risk. An ambulatory ECG is also helpful in evaluating for evidence of silent ischemia in these patients.
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PMID:Evaluation of the patient with angina pectoris. 377 60

Comparative clinical trials have already enabled to appreciate the clinical efficacy of trimetazidine (TMZ) during chronic coronary angina. Two recent controlled studies have been done in patients with chronic stable angina, and conducted in double blind versus placebo, with randomized assignment of the treatments. They showed that TMZ administered either in a single dose (60 mg), or for one month at a daily dose of 60 mg, enabled on the one hand an improvement of the stress ability: increase of the total work (respectively 31 and 38 per cent), and of the duration of the stress (17 per cent in an average), and on the other hand, the recession of the myocardial ischemic threshold: increase in the time of appearance of a 1 mm sub-shift of ST (respectively 7 and 17 per cent). The absence of alteration, in each of the placebo and trimetazidine groups, of the cardiac frequency and systolic arterial blood pressure at rest and the double product on exertion, suggested a different mechanism of action from the usual anti-angina medications. Many experimental works have been able to show that trimetazidine has an intra-cellular "anti-ischemic" activity and a cardioprotective effect which would be present during ischemic phases. The anti-ischemic activity would counteract the harmful effects of hypoxia by maintaining cellular energetic reserves, and by decreasing the deadly membrane effects of the free radicals, particularly passive permeability to potassium. In the same experimental conditions of ischemia, the cardioprotective effect is demonstrated by the decrease of the creatine kinase leakage and the upholding or the rapid recovery of the myocardial electric activity.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Current concepts in cellular ischemia: role of trimetazidine]. 380 Feb 88

The sensitivity of dipyridamole--2-dimensional (2-D) echocardiography was assessed for detection and localization of ischemia in 21 patients with severe chronic stable angina pectoris, a clearly positive exercise stress test response and multivessel coronary atherosclerosis. Regional wall motion during dipyridamole infusion (0.6 mg/kg intravenously over 4 minutes) was compared with control and recovery by 2 blinded observers in consensus. Transient regional wall motion abnormalities were observed in 11 patients. Angina and ST-segment changes occurred in 9 of these 11 patients with positive responses, but in none of those who showed no transient abnormality of regional wall motion. Localization of regional wall motion abnormalities correlated well with angiographic severity of coronary lesions. Endocardial area contraction, evaluated by a computerized system, was reduced significantly after dipyridamole administration in patients with a positive response (from 51 +/- 10% to 35 +/- 11%, p less than 0.001), whereas it did not change significantly in the others (from 43 +/- 6% to 42 +/- 8%). In the 11 patients with a positive response, coronary reserve assessed by exercise testing (modified Bruce protocol) was more impaired than in those with a negative response (time to 1 mm of ST depression 177 +/- 148 seconds and 472 +/- 179 seconds, respectively, p less than 0.01). In patients with severe angina and multivessel coronary artery disease, dipyridamole--2-D echocardiography appears to identify the vessel in which flow reserve is most limited. Although this information may be valuable, indications for the test are restricted to patients with severely limited exercise capacity.
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PMID:Limitations of dipyridamole-echocardiography in effort angina pectoris. 381 69

Holter monitoring of ST-segment changes is a unique method of studying the character of transient myocardial ischemia that occurs during ordinary daily life. The electrocardiographic signal is a reliable marker of ischemia in defined populations of patients with angina and coronary disease, but should be interpreted with caution outside of these groups. Detailed studies in patients with chronic stable angina have shown that transient ischemia is frequently silent and prolonged, and may occur without evidence of physical exertion. Analysis of underlying changes in regional myocardial perfusion using rubidium-82 and positron tomography has shown that a decrease in myocardial perfusion (supply) is involved in the genesis of many episodes of ischemia during daily life. Clinical trials have shown that drugs that affect demand and supply are efficacious against both painful and painless ischemia and that combinations of agents can provide useful benefits. There is, however, marked natural variability in disease activity despite "stable" symptoms, which must be taken into account in individual patient assessment and the rational design of clinical trials. Ambulatory monitoring permits quantitation of previously unrecognized myocardial ischemia, and treatment can thus be assessed in terms of ischemic activity during everyday life rather than on data obtained during brief hospital visits. An active approach to the detection and monitoring of transient ischemia with and without pain will be necessary if prospective clinical research shows that treatment of silent myocardial ischemia can prevent myocardial damage and improve prognosis.
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PMID:Holter monitoring in assessment of angina pectoris. 382 27

To help characterize episodes of transient myocardial ischemia, 80 patients with chronic stable angina and evidence of obstructive coronary disease were studied by ambulatory electrocardiographic (ECG) monitoring outside the hospital to detect both symptomatic and asymptomatic episodes of ST-segment depression. In addition, patients were tested on an outpatient basis by means of positron emission tomography to assess regional coronary blood flow under different conditions. All patients showed ECG evidence of transient ischemia, with or without symptoms, while active outside the hospital. In-hospital testing showed that symptomatic and asymptomatic disturbances in regional coronary blood flow occurred with normal everyday activities and were not caused by physical exertion involving marked increases in heart rate and blood pressure. Most of these provocations were followed by a decrease in coronary blood flow in a poststenotic segment of myocardium and, like the ischemic events monitored out of hospital, the majority were silent. Many of these features characterizing the activity of ischemic heart disease may not be apparent from a patient's anginal history or results of hospital diagnostic testing.
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PMID:Transient ischemia in angina pectoris: frequent silent events with everyday activities. 405 Jul 16

Patients with angina and coronary artery disease (CAD) have many episodes of transient ST-segment depression during ordinary daily life, and these are often asymptomatic. To investigate this signal as a marker of myocardial ischemia, 30 patients with chronic stable angina and CAD underwent positron tomography, recording the regional myocardial uptake of rubidium-82, pain and ST-segment changes before, during and after 59 technically satisfactory exercise tests, 35 cold pressor tests and 22 episodes of unprovoked ST depression. Exercise resulted in 53 episodes of ST depression with angina and in 5 episodes without pain. After cold pressor tests, there were 3 episodes of ST depression and pain and 12 of painless ST depression. Only 9 episodes of unprovoked ST depression were accompanied by pain. Tomography showed independent evidence of ischemia in 63 (97%) of the total 65 episodes of ST depression with angina and in all 30 episodes of painless ST depression. In each patient perfusion defects occurred in the same myocardial segment during painful and painless ST depression and responses were significantly different from those in 16 normal subjects studied in the same way. These findings support the use of transient ST depression in continuous monitoring to assess the activity of CAD, but only in patients with typical angina pectoris, ST depression during exercise and proved CAD. They strengthen the evidence derived from ambulatory monitoring for a wider picture of the disease than is generally appreciated, with more frequent episodes of silent myocardial ischemia than of angina pectoris.
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PMID:Transient ST-segment depression as a marker of myocardial ischemia during daily life. 633 36


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