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

We studied the effect of propranolol administration on risk assessment based on submaximal exercise testing performed early after myocardial infarction. A total of 70 patients with recent infarction underwent modified Bruce treadmill testing with simultaneous measurement of expired gases in the absence of antianginal agents including beta-antagonists. Among these, 31 patients who had at least one of the following abnormalities--ST depression greater than or equal to 1 mm (22 patients), chest pain (four patients), or treadmill time less than 360 seconds (12 patients)--were studied in a randomized double-blind fashion and received either placebo or 240 mg of propranolol/day. A total of 28 patients completed the randomized phase and were able to undergo repeat exercise testing an average of 3.4 +/- 1.8 days later. Randomized groups were equivalent at baseline except for a higher peak oxygen consumption and carbon dioxide production (p less than 0.05) in the propranolol compared with the placebo group; these differences were taken into account in statistical analyses of the study data. Resting heart rate (59 +/- 1.2 versus 82 +/- 4.2 beats/min) and peak heart rate x systolic blood pressure (14,208 +/- 496 versus 20,075 +/- 1,062) were both significantly less (p less than 0.01) after propranolol than after placebo. Eight of nine patients treated with placebo maintained ST depression greater than or equal to 1 mm from the initial to the randomized exercise test, compared with only 4 of 13 receiving propranolol (p less than 0.01). In those with continued ST depression, time to positivity was significantly longer in those receiving propranolol compared with those taking placebo (538 +/- 73 versus 318 +/- 44 seconds, p less than 0.05). In contrast, the peak ratio between carbon dioxide production and oxygen consumption was higher in those receiving propranolol compared with those receiving placebo (0.93 +/- 0.04 versus 0.81 +/- 0.03, p less than 0.05). We conclude that propranolol therapy reduces evidence of ischemia and changes traditional estimates of potential cardiac risk derived from submaximal postinfarction exercise testing.
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PMID:Propranolol therapy alters estimation of potential cardiovascular risk derived from submaximal postinfarction exercise testing. 203 80

Evidence suggests that physical activity is related to lower coronary risk factors in middle-aged subjects, but to date data are lacking for older persons. A total of 32 healthy male subjects in their seventh decade (64 +/- 3 years) were divided into 2 groups based on maximal exercise tests (Bruce protocol). Group I consisted of 14 individuals who showed "excellent" work capacity (exercise duration of greater than or equal to 10 min, 11 +/- 1 min), and Group II 18 individuals with "fair" work capacity (7.5 +/- 1 min). None of them showed ECG evidence of ischemia in these tests. As compared with Group II, Group I showed lower casual and 24 hour ambulatory blood pressure (136 +/- 21 vs 114 +/- 11 mmHg for the average daily systolic pressure respectively), higher apo A-I levels (116 +/- 36 vs 139 +/- 20 mg/dl) and lower apo B/A-I ratios. There was no significant difference in triglycerides, total and HDL cholesterol or apo-B levels between these two groups. Body mass index and smoking habits were similar in Groups I and II. These results suggest that even in older persons, excellent physical fitness is related to lower cardiovascular risk factors.
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PMID:[Relationship between exercise endurance capacity and cardiovascular risk factors in seventh decade subjects]. 204 60

To determine the relation between myocardial ischemic indexes on exercise testing and on ambulatory Holter recording, 60 patients with stable coronary artery disease who exhibited an ischemic response to both testing procedures were studied. All patients performed a Bruce protocol exercise test and underwent 24-hour Holter recording within 2 weeks without antianginal medications. Mean exercise duration was 7.4 +/- 2.8 minutes, mean heart rate at 1-mm ST depression was 118 +/- 20 beats/min and mean maximal ST depression during exercise was 2.2 +/- 1 mm. During Holter recording the average number of ischemic episodes was 4.7 +/- 2.6 per patient, mean duration of daily ischemia was 62 +/- 54 minutes, mean maximal ST depression was 3.2 +/- 1.3 mm and average heart rate at 1-mm ST depression was 93 +/- 17 beats/min. Overall, the correlations between ischemic indexes on both testing procedures were very weak (mean r2 = 0.054). The only exercise variable that had a significant correlation (p less than 0.05) with all Holter variables was heart rate at 1-mm ST depression, yet it correlated very weakly (0.064 less than or equal to r2 less than or equal to 0.125) with most Holter covariates and had a better correlation (r2 = 0.256) only with average heart rate at 1-mm ST depression during Holter. Thus, ischemic indexes on exercise testing cannot accurately predict ischemic indexes on ambulatory Holter recording in patients with stable coronary artery disease who exhibit ischemic changes on both tests.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Usefulness of severity of myocardial ischemia on exercise testing in predicting the severity of myocardial ischemia during daily activities. 206 78

The hypothesis that endogenous opioids may be involved in reduced exercise-induced ischemic pain or in silent ischemia was tested. Fifteen male patients with coronary artery disease were tested in a randomized, double-blind crossover study. After a preliminary screening effort test they were divided into two groups: the first group of nine patients received an i.m. injection of naloxone 0.4 mg, or saline as placebo, and the second group, comprising six patients, received 4 mg naloxone or saline i.v. Effort testing was performed at weekly intervals on an ergometric bicycle, following the Bruce protocol. ECG, heart rate, blood pressure and pain perception were monitored continually. Blood was sampled through an indwelling venous catheter for beta-endorphin determination before, at the peak of, and 10-20 min following exercise. ST depression, heart rate, blood pressure and the double product were similar after naloxone and following saline administration. Beta-endorphin concentrations in plasma were significantly increased following exercise in the second group of patients. The increase in beta-endorphin concentration was larger when the patients were pretreated with naloxone (4 mg) than with placebo. However, chest pain was not significantly altered by either dose of naloxone.
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PMID:Asymptomatic or mildly symptomatic effort-induced myocardial ischemia: plasma beta-endorphin and effect of naloxone. 213 95

Today silent myocardial ischemia (SMI) is a well-recognized phenomenon. However, in the absence of clinical signs suggesting coronary artery disease (CAD), a streamlined diagnostic approach for precise clarification has proved to be difficult. Sensitivity and specificity of ergometric results are rather poor in symptom-free patients. Thus the question arises, whether the necessity of coronary angiography can be established more precisely by 201Tl myocardial SPECT in these patients. Treadmill exercise according to the Bruce protocol, 201Tl myocardial SPECT and coronary angiography were performed in a total of 106 patients with suspected SMI. In group I (high probability of ischemia; n = 46), reversible defects detected by SPECT correlated well with significant stenoses and irreversible defects with subtotal stenoses or complete occlusions. SPECT sensitivity in the detection of ischemia was 91%, its specificity 96%. In group II (low probability of ischemia; n = 60), SPECT sensitivity was as high as in group I (94%) but due to a high number of false-positive results (e.g. cardiomyopathy) specificity was only 75%. However, SPECT was superior to exercise ECG (sensitivity 70%; specificity 56%) in the detection of SMI. In addition, beta-endorphin levels were determined in 180 healthy subjects, 37 patients with symptomatic CAD and in 34 patients with SMI before and during maximum exercise. Exercise values in patients with SMI were significantly higher than in healthy subjects or in patients with symptomatic CAD.
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PMID:201Tl myocardial SPECT and beta-endorphin levels in patients with suspected silent ischemia. 221 10

To clarify the central effects of physical training on patients with coronary heart disease, 81 subjects were selected for the present study. Evaluations of the oxygen transport system function were performed according to the definition proposed by Bruce and others in terms of FAI (functional aerobic impairment), LVI (left ventricular impairment) or MRI (myocardial reserve impairment), CRI (chronotropic reserve impairment) and PCI (peripheral circulatory impairment). Remarkable improvement in left ventricular impairment was found in those patients with single vessel disease or those who experienced disappearance of chest pain after the completion of the program. In another series of study on myocardial perfusion performed on 11 patients with coronary heart disease, improvement in ischemia was also demonstrated in 7 of 8 patients who revealed redistribution pattern in 201TL exercise stress images specifying myocardial ischemia. In conclusion, exercise training could induce improvements not only the left ventricular functions characterized by increased maximal pressure rate product and maximal heart rate, but also in myocardial ischemia. Further studies are needed to specify its effects, since natural progression or regression of the disease process itself may influence the results.
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PMID:Physical training of the patients with coronary heart disease: noninvasive strategies for the evaluation of its effects on the oxygentransport system and myocardial ischemia. 228 45

Isonitrile-technetium, a Thallium 201 analog, was used for myocardial perfusion imaging in 12 patients with known coronary heart disease. 10-40 mCu of the isotope were injected at maximal effort during a Bruce stress test. Imaging was performed using 3 projections immediately after exercise and 24 hr later, using a gamma camera attached to a computer. Myocardial necrosis was detected with a sensitivity of 89% and specificity of 63%. Corresponding figures for stress induced ischemia were 89% and 100%. Accurate localization of ischemia or necrosis was obtained in 70% of all cases, improving to 100% in cases of total artery occlusion. These results, similar to those reported in the literature, encourage the use of Tc labeled isonitrile for myocardial perfusion imaging whenever Thallium 201 is difficult to obtain.
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PMID:[Myocardial perfusion during exercise and rest in coronary patients. Evaluation with a thallium 201 analog (isonitrile-technetium 99 m)]. 251 96

Type A patients with coronary artery disease (CAD) tend to ignore or underreport symptoms, especially during challenging tasks such as the treadmill exercise test. To determine whether type A CAD patients might be more likely than type B patients to have silent ischemia during exercise and consequently a worse prognosis, 403 patients with stable CAD who had significant coronary disease on angiography, a positive Bruce protocol treadmill test and a structured interview to assess type A behavior were studied. Median follow-up time was 6 years. Type A patients were more likely to experience silent ischemia during exercise than were type B patients (35 vs 25%, p = 0.05). Patients with silent ischemia during exercise had a history of fewer anginal episodes/week, and type A patients with silent ischemia were less likely to have had a history of typical angina. However, using the Cox model, there were no significant differences in survival between type A patients and B patients with silent ischemia (4-year survival 86 vs 79%, p = 0.44) and no significant differences in survival between type A patients with silent ischemia and type A patients with symptomatic ischemia (6-year survival 86 vs 80%, p = 0.59). Similar results were obtained for infarction-free survival. Type A patients are more likely than type B patients to have silent ischemia during exercise, but long-term survival is not affected.
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PMID:Clinical correlates and prognostic significance of type A behavior and silent myocardial ischemia on the treadmill. 258 93

We tried to establish the incidence of silent myocardial ischemia (SMI) in the general population and also in patients with recognised ischemic heart disease. For this, purpose 2, 375 stress tests (ST) with Bruce protocol were reviewed, 364 were positive and those patients were divided in two groups: group I with SMI during the ST and group II with myocardial ischemia and angina during the ST. Coronary risk factors ergometric behaviour and angiographic factors were analysed. Group I had 263 patients with SMI (71%). Group II had 111 patients with ischemia and angina (29%) P less than 0.05; 90 patients had diabetes mellitus in group I and 19 in group II P less than 0.05. A previous myocardial infarction was registered in 157 patients from group I and 55 from group II P less than 0.05. The remaining coronary risks factors, ergometrics variables and significance and number of diseased coronary vessels were similar in both groups. We conclude that SMI is a frequent event in patients with ischemic heart disease. It represents probably the most frequent event in this disease. Previous myocardial infarction and diabetes mellitus may play an important role in the pathogenesis of SMI. The ST and Holter monitoring are dependable procedures for the identification of SMI and should be always performed specially in patients with high coronary risk factors. Once detecting SMI a therapeutic plan should be considered for medical, angioplastic or surgical procedures even in asymptomatic patients.
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PMID:[Silent myocardial ischemia: a problem in diagnosis and treatment]. 262 2

There is a number of factors in favor of a different effect between the two main calcium-blockers causing bradycardia. The effects of 3 doses of verapamil 120 mg and 3 doses of diltiazem 60 mg, were compared in a double-blind study with cross-over, in 12 patients with coronary insufficiency diagnosed by coronary angiography. Four stress tests were performed in each patient, two with placebo before each treatment period and two after treatment, according to the Bruce protocol, using a computerized ECG reading system. As compared with the placebo, the two products decrease the myocardial oxygen needs, increase the duration of the stress and improve the baseline offset of the ST segment. The ischemia, demonstrated by the baseline offset of the ST segment, appears significantly less with verapamil than with diltiazem.
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PMID:[Cross-over double-blind study of verapamil versus diltiazem in effort myocardial ischemia]. 273 40


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