Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We studied 12 patients with stable effort angina in a randomized, double-blind, cross-over and placebo-controlled trial to compare the different antianginal efficacy of "acute" and "chronic" (after reaching a steady-state level) gallopamil therapy. Efficacy was assessed using treadmill exercise testing (Bruce protocol) after a 50 mg single-dose and at the end of a nine-dose course of 50 mg of gallopamil (given three times a day). Three daily exercise tests were performed the first, second, fifth and eighth day of the study protocol at 8, 12 and 16 h. Four hours after a single-dose of gallopamil 50 mg both angina-free exercise time and time to 1 mm ST segment depression increased by a mean value of 78 s (p < 0.003) and 53 s (p < 0.03), respectively, with respect to placebo values. Under steady-state conditions exercise time and time to 1 mm ST segment depression increased by a mean value of 59 s (p < 0.009) and 46 s (p < 0.015), respectively, 4 h after the last dose. The duration of the anti-ischemic effects was no longer present after 8 h for both treatment schedules. Furthermore no significant differences were observed on parameters of ischemia after a single dose as compared to "chronic" therapy. The results of this study reveal that, in accordance with the pharmacodynamic properties of the drug, the anti-ischemic efficacy of 50 mg of gallopamil remains for approximately 4 h. Reaching a steady-state condition does not imply a prolongation of the anti-ischemic effect.
 ...
PMID:Comparison of acute and steady-state conditions of gallopamil therapy in stable angina pectoris. 142 94

The role of myocardial oxygen demand in the pathogenesis of silent ambulatory myocardial ischemia was evaluated by reviewing and assessing the methods and results of recent studies. The performance of simultaneous ambulatory electrocardiographic and blood pressure monitoring in 25 men with proven coronary artery disease (CAD) revealed significant increases in heart rate and blood pressure (p < 0.001) preceding most silent ischemic events. By plotting the mean heart rate obtained at 5-minute intervals during the 30 minutes before an ischemic event, the ischemic heart rate was shown to be significantly higher (95 +/- 15 vs 74 +/- 11 beats per minute [bpm]; p < 0.01) than the nonischemic heart rate. The evaluation of heart rate changes during ambulatory ischemia (in patients with CAD and ischemia induced by an exercise test using gradual work load increments) showed a significant heart rate increase (> 10 bpm) at 1-5 minutes preceding the onset of ST-segment depression. Heart rate increases during exercise testing according to the gradual work load increments of the National Institutes of Health protocol were compared with the heart rate preceding ischemic events during daily life monitored by ambulatory electrocardiography and were found to be closely related. In contrast, heart rate increases that occurred during exercise testing using the standard Bruce protocol were higher and correlated less with those preceding ischemia in daily life. Heart rate and blood pressure increased significantly in most silent ischemic episodes, indicating that increased myocardial oxygen demand plays a significant role in the pathogenesis of myocardial ischemia during daily life.
 ...
PMID:Role of myocardial oxygen demand in the pathogenesis of silent ischemia during daily life. 144 97

Myocardial ischemia may be defined as myocellular dysfunction resulting from hypoxia usually due to limited coronary blood flow. The methods commonly used to make a diagnosis of myocardial ischemia employ either clinical findings (e.g., angina, myocardial infarction) or signals from laboratory tests. Since ischemia is often clinically silent and since clinical events related to ischemia may be catastrophic (i.e., myocardial infarction and sudden death), physicians are dependent on tests using various targeted signals. These signals, however, do not actually provide quantitative measurements of the degree of ischemia or related myocardial dysfunction. Nevertheless, the functional abnormalities reflected by these signals can identify patients at high or low risk for adverse outcomes related to ischemia. So, in this sense, these signals can be used to support the diagnosis of ischemia as well as evaluate its importance in a given patient. The most commonly used signal is an ST-segment shift evident on the electrocardiogram (ECG). When this is horizontal or downsloping and > or = 10 mm, this is often, but not always, due to myocardial ischemia. Although assessment of the exercise-stress ECG offers several advantages over assessment of the resting ECG, the standard Bruce protocol is associated with notable shortcomings that become apparent when an attempt is made to assess the effects of a treatment on the ST-segment signal. These might be surmounted by use of a continuous ramp-type protocol. Ambulatory ECG monitoring is growing in importance in the wake of increasing awareness of the different daily life circumstances that are associated with ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:New insights in measurement of myocardial ischemia. 144 94

The aim of the study was to assess clinical/prognostic significance of exercise-induced ischemia in patients with healed myocardial infarction. From May 1988 to January 1991, 777 consecutive patients underwent a symptom-limited (Bruce protocol) treadmill test at least 1 year after myocardial infarction. Clinical and ergometric data were entered in a prospective way in our data base. The exercise-test was positive in 231 out of 777 patients and 2 different subgroups were retrospectively identified depending on criteria of interruption: 156 patients with painless exercise-ST depression; 75 patients with painful exercise-ST depression. The main results (mean +/- SD) were analyzed with Student t test and chi 2 test. Patients with silent ischemia had longer exercise duration (547 +/- 153 s versus 395 +/- 173 s; p < 0.001) and higher double product (22.98 +/- 0.5 versus 19.71 +/- 0.4; p < 0.001) than symptomatic patients. Ischemic threshold was lower (double product: 17.98 +/- 0.4 versus 21.22 +/- 0.4; p < 0.001 with onset of ST depression at 297 +/- 148 s versus 448 +/- 147 s; p < 0.001) and time to ST normalization was longer (368 +/- 155 s versus 234 +/- 212 s; p < 0.001) in patients with painful ischemia. Patients with angina and ST depression had significantly higher prevalence of downsloping ST depression in the recovery phase (68% versus 37%; p < 0.001) and a higher prevalence of treadmill exercise score indicating high risk (49% versus 3.2%; p < 0.001). The 2 groups when compared with 99 patients with negative test post-AMI were significantly different.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[The clinical and prognostic significance of symptomatic and silent ischemia on the exercise test in patients with a prior myocardial infarct]. 148 74

To evaluate both the safety and clinical use of predischarge symptom-limited exercise testing after successful uncomplicated percutaneous transluminal coronary angioplasty (PTCA), 100 patients were randomized to undergo exercise testing (n = 50) or no exercise testing (n = 50). There were no differences in clinical or angiographic characteristics between the groups. Exercise testing was performed 38 +/- 14 hours after PTCA. Patients who exercised achieved 71 +/- 12% of predicted maximal heart rate, with 38% reaching greater than or equal to stage III of the Bruce protocol. No patient in either group developed cardiac complications during 48-hour follow-up. Of the 11 patients with a positive test result, 92% had angiographically incomplete revascularization. Attending physicians (n = 16) were questioned both before and after exercise testing about when, after discharge, they would allow their patient to perform each of 11 specific activities of daily living. Questionnaires were administered to physicians at similar time frames for patients in the no-exercise group. Comparison of the responses between initial and repeat questionnaires showed that patients in the exercise group (with a test result negative for ischemia) were allowed to perform 7 of 11 activities, including return to work, earlier (p less than 0.05) than the no-exercise patients. These data indicate that in this well-defined group of patients, symptom-limited exercise testing early after PTCA appears to be safe, and alters physician management in allowing patients with a negative test result to return to various activities at an earlier date. Such testing may be useful in counseling patients after PTCA.
 ...
PMID:Safety and clinical use of exercise testing one to three days after percutaneous transluminal coronary angioplasty. 158 56

Successful transluminal coronary angioplasty (PTCA) should improve left ventricular systolic function. To assess the effect of this procedure 25 patients with coronary heart disease were examined before and 3-to 5 days after successful PTCA with electrocardiographic treadmill exercise test, and exercise two-dimensional echocardiography (modified Bruce protocol). Echocardiographic examination was obtained prior to and immediately following exercise. Left ventricular ejection fraction and segmental wall motion at the baseline and immediately after exercise were assessed. Electrocardiographic evidence of ischemia was found in 16 of 25 patients prior to PTCA and in 9 patients after PTCA. Following angioplasty, exercise duration was increased and the exercise-induced angina rate was significantly decreased. Ejection fraction did not change significantly in patients prior and after PTCA (52 +/- 10% versus 55 +/- 16%, p = NS). Following angioplasty, ejection fraction increased from 55 +/- 10% (rest) to 64 +/- 11% (exercise) (p less than 0.001). New exercise-induced echocardiographic segmental wall motion abnormalities were found in 16 of 25 patients prior to PTCA and in only one patient following PTCA. Significant improvement of ejection fraction and segmental wall motion were also observed in 11 patients with old myocardial infarction subjected to successful angioplasty of infarct-related coronary artery. Opposite to post-exercise results, the resting mean values of these echocardiographic parameters did not differ significantly between pre and post-PTCA examinations. These data demonstrate an improvement in systolic left ventricular function and better exercise tolerance following successful PTCA. This occurs also in patients with old myocardial infarction after angioplasty of infarct-related coronary artery. Two-dimensional exercise echocardiography may be helpful in assessing the early results of successful angioplasty.
 ...
PMID:[PTCA and left ventricular systolic function (evaluation by exercise two-dimensional echocardiography)]. 162 8

A comparison of the respiratory responses of jogging in place, an alternative exercise test we recently proposed, was made with those of the Bruce exercise test. We obtained on-line measurements of heart rate, ventilation, oxygen uptake, and carbon dioxide production from 9 healthy subjects of mean age 25 years. There was a higher heart rate and ventilatory response with jogging than with the Bruce test, but by 10 minutes the responses of the two tests were similar. Oxygen consumption, while higher with jogging, rose in parallel with that of the Bruce test from the second to the seventh min, and the change of the ratio of minute ventilation to oxygen consumption indicated that the anaerobic threshold occurred earlier during jogging. These results show that jogging in place is more vigorous than the graded exercise test and may produce ischemia earlier.
 ...
PMID:Comparison of respiratory response of jogging in place and Bruce treadmill exercise test. 176 28

The effects of exercise training on myocardial perfusion during the first 3 months after acute myocardial infarction (AMI) were assessed by exercise myocardial scintigraphy and fibrinolytic examinations. Symptom-limited treadmill exercise with thallium-201 myocardial single photon emission CT (SPECT) and fibrinolytic examinations (tissue plasminogen activator antigen: tPA, plasminogen activator inhibitor-1 antigen : PAI-1) were performed 2 and 14 weeks after AMI in 13 patients with exercise training and in 12 patients without exercise training. For quantitative analysis, counts of region of interest in the infarct area and normal reference area were calculated on a polar map obtained from myocardial SPECT. Severity of the hypoperfused myocardium was determined as an initial percent uptake (%IU) and a delayed percent uptake (%DU). The difference (%DU-%IU) was defined as a parameter of residual ischemia in the infarct area (%redistribution : %RD). Total treadmill exercise duration according to the Bruce protocol increased significantly in the training group (351 +/- 89 to 431 +/- 118 sec, p < 0.01); whereas, there was no significant change in the non-training group (340 +/- 95 to 356 +/- 123 sec). In the training group the pressure-rate product and %DU increased significantly (225 +/- 55 to 259 +/- 58 mmHg.beats/min x 100, 59 +/- 19 to 65 +/- 20%, p < 0.01, respectively), and %RD decreased significantly (8.8 +/- 6.7 to 4.8 +/- 4.5%, p < 0.01), but there was no significant change in the non-training group (231 +/- 89 to 240 +/- 86 mmHg.beats/min x 100, 56 +/- 17 to 57 +/- 12% and 7.4 +/- 5.5 to 6.2 +/- 6.5%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:[Cardiac rehabilitation in patients with acute myocardial infarction: assessments with T1-201 myocardial scintigraphy]. 184 44

It has recently been demonstrated that treadmill capacity and collateral circulation improve as a result of exercise with heparin pretreatment in patients with effort angina. In the present study, we assessed whether heparin alone is effective in increasing treadmill capacity in 14 patients with effort angina. Patients were randomly assigned to one of two treatment arms: (1) group A--20 treadmill exercise periods with standard Bruce protocol twice a day for 10 days with heparin (5000 IU intravenously) pretreatment (seven patients) or (2) group B--10 injections of heparin calcium (10,000 IU subcutaneously) once a day for 10 days (seven patients). In group A, total exercise time was increased from 6.9 +/- 1.2 (SD) to 9.9 +/- 1.9 minutes (p less than 0.0005), as was the maximal double product, from 21,700 +/- 3,500 to 27,000 +/- 4,800 mm Hg/min (p less than 0.05). The double product at the onset of angina was also increased by 34% (p less than 0.05), and the double product at which ST depression (0.1 mV) first appeared was 22% (p less than 0.05) greater after treatment. In contrast, in group B, all of the above-mentioned parameters of treadmill capacity remained unchanged. These data indicate that heparin does not serve as an angiogenic factor by itself, but that it potentiates the ischemia-derived angiogenic factor.
 ...
PMID:Comparative effect of heparin treatment with and without strenuous exercise on treadmill capacity in patients with stable effort angina. 185 25

This study was performed to evaluate the presence of angina pectoris, electrocardiographic changes and reversible thallium-201 defects resulting from 2 different levels of exercise in 19 patients with known coronary artery disease and evidence of exercise-induced ischemia. The exercise protocols consisted of a symptom-limited incremental exercise test (Bruce protocol) followed within 3 to 14 days by a submaximal, steady-state exercise test performed at 70% of the maximal heart rate achieved during the Bruce protocol. The presence and time of onset of angina and electrocardiographic changes (greater than or equal to 0.1 mV ST-segment depression) as well as oxygen uptake, exercise duration and pressure-rate product were recorded. Thallium-201 (2.5 to 3.0 mCi) was injected during the last minute of exercise during both protocols, and the images were analyzed using both computer-assisted quantitation and visual interpretations. Incremental exercise resulted in anginal symptoms in 84% of patients, and electrocardiographic changes and reversible thallium-201 defects in all patients. In contrast, submaximal exercise produced anginal symptoms in only 26% (p less than 0.01) and electrocardiographic changes in only 47% (p less than 0.05), but resulted in thallium-201 defects in 89% of patients (p = not significant). The locations of the thallium-201 defects, when present, were not different between the 2 exercise protocols. These findings confirm the sequence of the ischemic cascade using 2 levels of exercise and demonstrate that the cascade theory is applicable during varying ischemic intensities in the same patient.
 ...
PMID:Comparison of chest pain, electrocardiographic changes and thallium-201 scintigraphy during varying exercise intensities in men with stable angina pectoris. 187 74


1 2 3 4 5 6 7 Next >>