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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The correlation between the three ischemia indicators angina pectoris (AP), ST-segment depression (ST) and excessive pulmonary wedge pressure rise (PCP) during exercise, and the coronary angiographic findings, were analysed in 293 patients without previous transmural myocardial infarction. This patient material consisted of 253 men and 40 women between the age of 20 and 65 years, the mean age being 48. The exercise tests were performed on a bicycle ergometer in supine position and in relatively steady state conditions. Pulmonary wedge pressure was measured by means of a Swan-Ganz floating catheter. The essential findings were: 1. If all three ischemia indicators were positive, the incidence of a positive angiographic finding i.e. a greater than or equal to 50% stenoses in at least one main coronary artery was 96.3%. 2. If only the two classic ischemia indicators were evaluated and positive, the incidence of a positive angiographic finding was only 86.1% (24). This difference is mainly due to false positive results of AP and ST in women. 3. If all three ischemia indicators were negative, the incidence of a negative angiographic finding was 89.2%. 4. If only the two classic ischemia indicators were evaluated and negative the incidence of a negative angiographic finding was as high (87,6% [24]). This lack of difference is due to the fact that patients with a previous intramural infarcion can be free not only of AP and ST but also of PCP during exercise. 5. The combination of AP and PCP, or ST and PCP, is equally reliable in predicting coronary morphology as the classic combination of AP and ST. It follows that PCP measurement is recommended, if one of the classic ischemia indicators cannot be properly evaluated.
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PMID:[Can predictability of coronary angiographic findings be improved by additional measurement of pulmonary wedge pressure during exercise? (author's transl)]. 91 74

We report 3 patients having a grade II milking effect of the proximal left anterior descending artery (LAD) and suffering from angina. Preoperative myocardial ischemia was demonstrated by stress ECG in all 3 and by pacing and lactates studies in 2. Surgical decompression of the systolically constricted artery has resulted in disappearance of angina, milking, and ischemia. Severe milking of the LAD is a rare entity, probably congenital in origin, capable of producing myocardial ischemia and possibly causing sudden death. More studies regarding its etiology and pathophysiology are necessary. Biopsy of the myocardium surrounding the artery could be useful.
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PMID:Successful course after supraarterial myotomy for myocardial bridging and milking effect of the left anterior descending artery. 92 75

Among 173 patients with typical effort angina (159 men and 14 women) which underwent exercise test and coronary angiography, significant stenosis (greater than or equal to 70%) of one or more of important coronary branches were present in 93,1% of the cases (96,3% among the males and 57% among the females). In the same group the exercise test sensitivity was 88,8%; when 3 coronary branches were involved the sensitivity rises to 94,3%. The 96,6% of patients with positive exercise test had coronary lesions too (true positives). We did not find any correspondence between the site of transient subendocardial ischemia occurred during the exercise test and coronary branch involved, when the stenosis was limited only one important coronary branch. Finally the researche of correlation between the entity of coronary disease (number of coronary vessels involved, entity of left ventricular contractility impairment) and behavior of patient during exercise test, evaluated with different parameters measured at the moment of stopping of exercise (heart rate and threshold work load, rate-pressure product, maximal downsloping of ST segment, different positivity criteria for exercise test) allowed us to show a good correlation only between the extent of coronary involvement and rate-pressure product or maximal downsloping of ST segment.
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PMID:[The effort test in the diagnosis of typical stable effort angina (author's transl)]. 92 65

The possible relationship between the cardiac volume, as determined radiologically in the supine position in 119 patients with angiographically proven coronary artery disease, and the results of ergometry and balloon catheterization was investigated. There was no relationship between the heart size on the one side and the maximum exercise tolerance and the maximum cardiac output on the other, except for the fact, that these parameters tended to decrease with increasing heart size. This was especially true in patients with angina. The maximum cardiac output of patients with angina was always below the value of patients without angina but comparable heart size. Reduced cardiac output under exercise (exertional cardiac insufficiency) was present in 50% of patients with enlarged hearts but already in 22% of patients with heart volumes in the lower range of normal. The diastolic pulmonary artery pressure, determined under exercise, was the only parameter with a significant relationship to the heart size: The larger the heart size, the higher the diastolic pulmonary artery pressure. On the other hand: the diastolic pulmonary artery pressure at rest was abnormal with significant frequency only, when the heart was enlarged. Our data suggest, that the hemodynamics are determined by 2 factors: Myocardial scarring secondary to infarction and coronary insufficiency (ischemia). Of these two factors only the former influences cardiac size. Therefore, determination of the heart volume helps evaluating the respective role of these two factors in individual cases.
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PMID:[Heart size and left ventricular function in coronary artery disease: I. Heart size, exercise tolerance, cardiac output and filling pressures (author's transl)]. 92 89

In previous studies we demonstrated that variant angina could not be attributed to increased myocardial demands. In order to investigate whether a reduction of regional myocardial blood supply could be responsible for these ischemic episodes, we studied regional myocardial perfusion in six patients admitted to our coronary care unit. Myocardial scintigrams, obtained 5-7 min following i.v. injection of 1 mCi of thallium-201, performed during an episode of ST-segment elevation, showed transmural deficits of tracer uptake in the heart wall corresponding to the leads showing ST-segment elevation. These regional deficits ahd disappeared by 2 hours because of late uptake in previously ischemic myocardium. One week later, following injections performed in the absence of acute ischemia, no deficit was apparent. Tracer uptake in ischemic areas was 60% to 85% of that observed a week later. After adjusting for thallium-201 kinetics and counting geometry promblems., these scintigrams actually represent large underestimations of actual flow reduction. Thus variant angina appears to be caused by massive transmural reduction of myocardial blood supply.
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PMID:Transient transmural reduction of myocardial blood flow demonstrated by thallium-201 scintigraphy, as a cause of variant angina. 93 25

In order to assess the relative significance of precordial ST-segment elevations and depressions, 32 patients with anterior transmural myocardial infarction were studied utilizing serial 49-lead precordial maps. Theoretically, zones of ST-segment depression adjacent to major zones of ST-segment elevation might represent border areas of mild ischemia, and hence could be more readily amenable to intervention therapy. As expected, an extensive zone of ST-segment elevation was observed precordially in each of these patients. However, zones of ST-segment depression in adjacent areas were noted to occur inconsistently, were limited in distribution and magnitude, and bore no fixed relationship to zones of ST-segment elevation. Thus, mapping of precordial ST-segment depression in anterior transmural infarction probably has a limited role in assessing evolution of ischemic injury or therapy in these patients. This finding does not, however, vitiate the significance of ST-segment depressions in angina, intermediate coronary syndrome, or non-transmural infarction, conditions which may deserve further study using mapping techniques.
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PMID:Precordial ST-segment mapping. 4. Experience with mapping of ST-segment depression in anterior transmural myocardial infarction. 97 82

We compared patients with variant angina (ST-segment elevation during pain) who had normal or near normal coronary arteriograms (Group 1) with 20 in whom variant angina occurred in the presence of obstructive coronary lesions (Group 2). A long history of nonexertional angina without angina of effort or previous infarction was the rule in Group 1, whereas recent-onset unstable angina preceded by effort angina and infarction predominated in Group 2 (P less than 0.001). Normal electrocardiograms at rest, with ischemic ST-segment elevation in the inferior leads, and ischemia-induced heart block and bradycardia, characterized Group 1, whereas abnormal electrocardiograms, ischemic involvement or fibrillation were more common in Group 2 (P less than 0.001). Variant angina with normal coronary arteriogram generally has a benign course and is probably unrelated to atherosclerosis.
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PMID:Clinical syndrome of variant angina with normal coronary arteriogram. 98 80

Studies of the pulmonary circulation in normal man, performed with external radiation detectors, have shown that pulmonary blood volume is about 10% of total blood volume. Pulmonary blood volume was unchanged in patients with acute or chronic left atrial hypertension and in normal persons during expansion of total blood volume in spite of marked increases in pulmonary vascular pressures. However, pulmonary blood volume was greatly increased in patients with polycythemia rubra vera and a large total blood volume and in patients with a left to right shunt but normal pulmonary intravascular pressure. Studies of regional myocardial perfusion with injection of xenon-133 solution into the left coronary artery revealed localized areas of ischemia distal to stenotic lesions even when the patient was at rest. During angina produced by pacing, more severe ischemia occurred, thus suggesting that functional factors reduce local perfusion below resting levels. In patients with "variant" angina, intravenous injection of thallium-201 chloride during spontaneous attacks has revealed large cold areas in myocardial scintigrams not present under control conditions, thus suggesting severe transmural reduction of perfusion in heart muscle corresponding to S-T segment elevation in the electrocardiogram.
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PMID:Pathophysiologic studies of the pulmonary and coronary circulations in man. 99 14

Our series (30 cases) of variant angina as well as the reports from literature, were reviewed, to investigate the consequences of an acute regional ischemia on seno-atrial, atrio-ventricular and intraventricular conduction. Sinoatrial conduction was never affected independently from the anterior or posterior localization of the ischemia. A junctional impairment of atrio-ventricular conduction was rather frequent in cases of variant angina affecting the inferior wall, ranging in different series from 8% to 25%. Only one case of bundle branch block was observed. Hemiblocks were found to be extremely rare, while a deviation of the main axis of the QRS on the frontal plane, especially to the left in cases with anterior localization of the ischemia, was observed quite frequently. This axis deviation, in the absence of changes of the initial vector of the QRS compatible with the diagnosis of hemiblocks, were considered to be depending on a parietal block.
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PMID:[Prinzmental's angina and disturbances of the stimulus conduction (author's transl)]. 101 Jan 72

A hemodynamic study was conducted in 11 patients with myocardial bridging and milking effect (ME) of the left anterior descending artery (LADA), but with otherwise normal coronary arteries. During pacing, patients with grade III ME (over 75% narrowing of arterial size during systole) showed anterior wall ischemia, lactate production and severe angina. Thus, grade III ME observed on coronary arteriography may result in significant obstruction of the LADA with typical angina. Surgical treatment is worth considering in symptomatic patients with this rare anomaly.
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PMID:[Hemodynamic significance of myocardial bridging and milking effect of the anterior interventricular artery: a mild variant or source of angina?]. 101 74


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