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PubMed1989

Exercise testing in women with chest pain. Are there additional exercise characteristics that predict true positive test results?

Women have a notoriously high rate of false positive exercise test results. Since the exercise ST segment response has low specificity in predicting CAD in women, we examined additional exercise parameters in 200 women with a history of chest pain compatible with angina and having ST segment depression greater than or equal to 1 mm recorded during a Bruce treadmill test. All subsequently had coronary arteriography. Two groups were compared: group A (n = 80) with CAD (greater than or equal to 70 percent stenosis of one or more coronary artery) and group B (n = 120) with angiographically confirmed normal coronary arteries (normal or minimal placquing). The exercise criteria analyzed included: (1) chest pain during exercise, (2) percent target heart rate, (3) extent of ST shift, (4) morphology of the ST segment slope, (5) time to normalization of the ST segment, and (6) total exercise duration. Multivariate analysis (using a stepwise logistic regression model) identified four independent exercise variables associated with the likelihood of CAD: (absence of MVP, p = .003; exercise duration less than 5 min, p = .02; ability to reach target heart rate, p = .027; time to ST normalization greater than or equal to 6 min, p less than .001). False positive exercise test results were more likely to occur when the following exercise test variables were present: ability to exercise to stage 3 of the Bruce protocol and a rapid (less than or equal to 4 minutes) normalization of ST shift after cessation of exercise. Attention to these additional exercise variables allows more careful selection of women requiring more definitive (and expensive) testing.

Angina Pectoris↗
PubMed1984

[Role of left ventricle angioscintigraphy during exercise in the diagnosis of coronary disease. Comparison of static and dynamic exercise].

The aim of this study was to compare the diagnostic value of exercise stress testing, Thallium 201 myocardial scintigraphy or after administration of dipyridamole and left ventricular angioscintigraphy performed either during a static (handgrip) or dynamic exercise (bicycle ergometry) for the positive diagnosis of stenosing coronary artery disease. The exercise angioscintigraphy was performed at equilibrium with 99m Tc red blood cell labelling. The global ejection fraction and that of seven radial segments of the left ventricle were measured, the data being recorded within a period of 2 minutes. The handgrip consisted in compressing a dynamometric ball at 1/3 maximal force for 3 minutes, with both hands; the ergometric exercise was increased by 30 Watt 2 minute increments until a positive ECG or 85% of the theoretical maximal heart rate for age was obtained. Normal subjects (n = 29) increased their global (+ 8%) and regional ejection fractions in each of the seven segments (p less than 0.05) during ergometric exercise: there was no significant change of global (-3% NS) or segmental ejection fractions during the handgrip exercise. In the coronary group (at least one greater than 70% stenosis) (n = 61) the fall in global ejection fraction was the same (-14%) with both forms of exercise; a similar fall in the segmental ejection fraction in the territory distal to the stenosis was observed with the handgrip (-22%) and bicycle ergometry (-28% NS). Dynamic exercise testing seemed superior to handgrip exercise. Therefore, the finding of an abnormal global ejection fraction on exercise (i.e. either a global ejection fraction less than the lower limit of normal on exercise, or lower than the global ejection fraction at rest), or of an abnormal regional ejection fraction (i.e. either a regional ejection fraction less than the lower limit of normal over at least 3 segments, or a regional ejection fraction on exercise lower than the regional ejection fraction at rest over at least 3 segments) detected coronary artery disease with a sensitivity of 94% and a specificity of 72%. Dynamic exercise angiography seemed to be more sensitive than maximal ECG stress testing (94% compared to 64%) more rapidly positive (p less than 0.05), as sensitive (94% compared to 83% NS) than Thallium myocardial scintigraphy, but less specific (72% compared to 90%, p less than 0.05), and as unspecific as ECG stress testing.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1997

Increased urinary excretion of LTE4 after exercise and attenuation of exercise-induced bronchospasm by montelukast, a cysteinyl leukotriene receptor antagonist.

BACKGROUND: A study was undertaken to determine whether montelukast, a new potent cysteinyl leukotriene receptor antagonist, attenuates exercise-induced bronchoconstriction. The relationship between the urinary excretion of LTE4 and exercise-induced bronchoconstriction was also investigated. METHODS: Nineteen non-smoking asthmatic patients with a forced expiratory volume in one second (FEV1) of > or = 65% of the predicted value and a reproducible fall in FEV1 after exercise of at least 20% were enrolled. Subjects received placebo and montelukast 100 mg once daily in the evening or 50 mg twice daily, each for two days, in a three-period, randomised, double blind, crossover design. In the evening, approximately 20-24 hours after the once daily dose or 12 hours after the twice daily dose, a standardised exercise challenge was performed. Data from 14 patients were available for complete analysis. RESULTS: The mean (SD) maximal percentage decrease in FEV1 after exercise was 29.6 (16.0), 17.1 (8.2), and 14.0 (9.4) for placebo, once daily, and twice daily regimens, respectively. The mean (95% CI) percentage protection was 37 (15 to 59) for the group who received 50 mg twice daily and 50 (31 to 69) for those who received 100 mg once daily. Active treatments were not different from each other. The mean (SD) plasma concentrations of montelukast were higher after the twice daily regimen (1.27 (0.81) microgram/ml) than after the once daily regimen (0.12 (0.09) microgram/ml); there was no correlation between the percentage protection against exercise-induced bronchoconstriction and plasma concentrations. After exercise urinary excretion of LTE4 increased significantly during placebo treatment (from 34.3 to 73.7 pg/mg creatinine; p < 0.05) but did not correlate with the extent of exercise-induced bronchoconstriction. CONCLUSIONS: Montelukast protects similarly against exercise-induced bronchoconstriction between plasma concentrations of 0.12 and 1.27 micrograms/ml. The increase in the urinary excretion of LTE4 after exercise and the protection from exercise-induced bronchoconstriction with a cysteinyl leukotriene receptor antagonist provide further evidence of the role of leukotrienes in the pathogenesis of exercise-induced bronchoconstriction.

Acetates↗
PubMed1985

Effect of isotonic exercise training on left ventricular volume during upright exercise.

To determine the changes in left ventricular volume and their time course during exercise we studied 30 runners. Left ventricular end-diastolic and end-systolic volumes were measured from biapical two-dimensional echocardiograms recorded during graded upright bicycle exercise. The validity of this echocardiographic technique was assessed by comparing measurements at rest and exercise with results obtained by gated equilibrium radionuclide angiography in 10 patients with coronary artery disease. Although the absolute volume measurements were lower by echocardiography, ejection fraction was not significantly different and the directional changes in volume during exercise were comparable. In the runners, resting left ventricular end-diastolic volume measurements by echocardiography correlated with their maximum bicycle exercise endurance times (r = .80). Left ventricular end-diastolic volume, stroke volume, and ejection fraction increased during exercise with the most marked changes occurring in the first half of exercise. Systolic blood pressure/end-systolic volume (SBP/ESV) also increased during exercise, but the largest change occurred during the second half of exercise. Left ventricular volumes were larger in the 12 competitive marathon runners (maximum exercise duration greater than or equal to 27 min) as compared with the 18 noncompetitive runners (exercise duration less than or equal to 23 min): resting end-diastolic volume 130 +/- 29 (SD) ml vs 87 +/- 20 ml (p less than .001), respectively. During exercise the competitive runners exhibited a larger increase in end-diastolic volume and the noncompetitive athletes showed a greater increase in SBP/ESV. Therefore, highly trained competitive marathon runners make greater use of the less energy-consuming Frank-Starling mechanism to accomplish high levels of isotonic exercise performance as compared with less well-trained runners.

Blood Pressure↗
PubMed1983

Role of exercise echocardiography as a predictor of coronary artery disease. Detection of exercise-induced asynergy by M-mode echocardiography.

Left ventricular asynergy has been shown to occur commonly in patients with coronary artery disease (CAD) and to be induced or exaggerated by exercise. The purpose of this study is to report on a method to detect asynergy and estimate its severity by M-mode echocardiographic analysis of left ventricular wall motion at rest and during supine ergometric exercise. Sixteen patients with CAD underwent graded supine ergometric exercise until anginal pain occurred or apparent ischemic changes were noted on ECG. This study was done using the following criteria: 1) Asynergy at rest was defined as occurring when the amplitudes of the interventricular septum and/or the posterior left ventricular wall were below normal values at rest. 2) Asynergy during exercise was defined as occurring when one or both of the two amplitudes were more than 2 mm below the values at rest (severe) or were unchanged in spite of sufficient exercise load (mild). The results were as follows: 1) In the normal subjects, the septal and posterior wall amplitudes increased during exercise (ranging from 7 mm to 9 mm for the septum, and from 13 mm to 16 for the posterior wall). In patients with CAD, asynergy at rest was demonstrated in only 3 cases (19%), whereas septal and/or posterior wall asynergy during exercise was noted in 75% of cases. 2) The location of exercise-induced asynergy detected by echocardiography showed a good correlation with that of coronary artery lesions (greater than or equal to 75% stenosis) recognized by angiography. 3) Significant differences were observed between changes in left ventricular dimensions in patients with CAD and those of normals during exercise. In the normal subjects, left ventricular end-systolic dimension (ESD) decreased without significant change in end-diastolic dimension (EDD) during exercise. On the other hand, both ESD and EDD increased during exercise in patients with CAD. Although echocardiographic analysis of left ventricular wall motion during exercise has some limitations, this study suggests that asynergy induced or exaggerated by ergometric exercise can be successfully detected by M-mode echocardiography.

Adult↗
PubMed1984

Symptoms, exercise capacity and exercise hemodynamics: interrelationships and their role in quantification of the valvular lesion.

To compare the symptoms with the objectively-determined exercise capacity, the symptoms as well as the exercise capacity with the exercise hemodynamics and the symptoms, exercise capacity and exercise hemodynamics with the severity of the valvular lesion, in 154 patients with aortic regurgitation, mitral regurgitation, aortic stenosis or mitral stenosis, the symptoms were classified according to the New York Heart Association and the exercise capacity was determined by means of bicycle ergometry with simultaneous measurement of heart rate, blood pressure, pulmonary artery pressure, cardiac output and the left ventricular ejection fraction. Among the parameters studied, no relationships could be established; to a certain degree, the exercise hemodynamics correlated with the severity of the valvular lesion in that a markedly pathologic response was associated with the presence of a high-grade valvular lesion. Since the symptoms were not indicative of the exercise capacity, nor the symptoms or the exercise capacity of either the exercise hemodynamics, the exercise ejection fraction or the severity of the valvular lesion, the symptoms and the exercise capacity should be evaluated on the basis of the exercise hemodynamics before they are taken into consideration for meaningful decision-making processes such as establishment of the indication for surgery.

Adolescent↗
PubMed1994

Patients with high baseline exercise capacity benefit from cardiac rehabilitation and exercise training programs.

Despite the well-proven benefits of cardiac rehabilitation and exercise training, no data are available on the benefits of this therapy in patients with preserved baseline exercise capacity. Therefore we assessed data before and after phase II cardiac rehabilitation and exercise programs at two large teaching institutions to determine the benefits in 163 patients with high baseline exercise capacity (> or = 6 estimated [mean 8.8 +/- 2.4] metabolic equivalents [METs]) compared with 125 patients with low baseline functional capacity (< 6 estimated [mean 4.6 +/- 0.8] METs). After cardiac rehabilitation and exercise training, patients with high baseline exercise capacity had significant improvements in triglyceride (-10%; p < 0.05), high-density lipoprotein cholesterol (+7%; p < 0.001), and low-density lipoprotein cholesterol (-4%; p = 0.09) levels; low-density lipoprotein/high-density lipoprotein ratio (-10%; p < 0.01); body mass index (-1.5%; (p < 0.001); percent body fat (-6%; p < 0.0001); and exercise capacity (+22%; p < 0.0001). Patients with high baseline exercise capacity had less relative improvement in exercise capacity (p < 0.0001) after cardiac rehabilitation but had greater relative improvement in low-density lipoprotein cholesterol level (p < 0.05) and low-density lipoprotein/high-density lipoprotein ratio (p < 0.05) than did patients with low baseline exercise capacity. These data demonstrate the benefits of cardiac rehabilitation and exercise training in patients with preserved exercise capacity and support routine referral of these patients to these programs after major cardiac events.

Adult↗
PubMed1990

Attenuation of exercise-induced ST depression during combined isometric and dynamic exercise in coronary artery disease.

ST-segment depression was measured during submaximal dynamic (treadmill) and combined isometric-dynamic (isodynamic) exercise at comparable rate-pressure products in 11 patients (mean age 63 years) with stable coronary artery disease who were participating in an exercise training program. Each patient completed 3 separate trials. Trial 1 (baseline) was a submaximal treadmill exercise test to determine the threshold heart rate-systolic blood pressure (rate-pressure product) for ST-segment depression (greater than or equal to 1.0 mm). During trials 2 and 3, patients performed (in random order) dynamic treadmill exercise and isodynamic exercise (treadmill walking 1.5 to 2.0 mph carrying 15 to 25 kg) until threshold rate-pressure product was achieved. During trial 1, each patient showed significant ST depression (mean 1.7 mm) at target rate-pressure product (mean 18,200). Subsequent dynamic exercise trials 2 and 3 showed similar mean ST depression (1.5 mm) and rate-pressure product (18,000). During isodynamic exercise trials 2 and 3, subjects showed only minimal ST depression (mean 0.4 mm) at a rate-pressure product similar to dynamic exercise (mean 18,590). Heart rates were significantly lower (-10/min) and systolic (+20 mm Hg) and diastolic (+25 mm Hg) pressure was higher during isodynamic exercise (p less than 0.05). The rate-pressure product is not a valid index of ST response during isodynamic exercise in stable exercise-trained cardiac patients. Attenuation of ST depression during isodynamic exercise may be attributed to a combination of increased diastolic perfusion pressure, decreased heart rate and possibly to reductions in venous return and ventricular diastolic wall tension due to increased intrathoracic and abdominal pressure.

Aged↗
PubMedDate not supplied

Exercise: Part II. Translating the exercise prescription.

Exercise comes in many forms and uses different substrates (fuels) for adenosine triphosphate (energy) production. The greater the intensity of exercise, the greater the relative contribution of carbohydrate as a fuel source. However, as intensity exceeds the anaerobic threshold, anaerobic glycolysis is inhibited, forcing a decrease in exercise intensity. Proper manipulation of the exercise prescription components can create the desired health and fitness benefits, provide a high level of carbohydrate utilization, and control exercise risks while maintaining exercise intensity at aerobic levels. The calculation of target heart rate zones and proper monitoring of exercise heart rates allows for greater compliance to exercise prescriptions. Individual responses to various exercise intensities and modalities require regular assessments. Monitoring blood glucose levels before and after exercise assists in prescribing exercise duration and exercise times in relation to the medication and dietary regimen.

Blood Glucose Self-Monitoring↗
PubMed1989

Exercise-related changes in serum catecholamines and potassium: effect of sustained exercise above and below lactate threshold.

Plasma potassium and catecholamines exhibit rapid shifts during exercise testing, particularly when exercise intensity exceeds lactate threshold. To assess changes that may occur during sustained exercise, we studied 10 healthy men to determine the effect of 20 minutes of exercise at 25 W above lactate threshold (ALT) and 20 minutes of exercise at 25 W below lactate threshold (BLT). Both conditions showed elevation of catecholamines at end exercise compared to baseline, but catecholamine levels ALT were significantly higher than the levels BLT (2270 +/- 190 versus 900 +/- 230 pg/ml norepinephrine, p less than 0.001; 509 +/- 69 versus 150 +/- 18 pg/ml epinephrine, p less than 0.001). This difference persisted at 2 minutes of recovery (1620 +/- 130 versus 590 +/- 60 pg/ml norepinephrine, p less than 0.001; 216 +/- 31 versus 98 +/- 16 pg/ml epinephrine, p less than 0.001). Both conditions resulted in a significant elevation in potassium at end exercise compared to baseline, but the potassium levels ALT were significantly higher than the levels BLT (1.1 +/- 0.1 mEq/L versus 0.5 +/- 0.1 mEq/L, p less than 0.001. The fall in potassium in the immediate post-exercise period was significantly greater following exercise ALT (-0.8 +/- 0.1 mEq/L versus -0.2 +/- 0.1 mEq/L, p less than 0.001). Thus sustained exercise slightly ALT resulted in a significant potassium flux and very elevated catecholamine levels. Avoiding these metabolic stresses by exercising BLT may decrease chances for exercise-related arrhythmia or other cardiac dysfunction in susceptible patients.

Adult↗
PubMed1989

Reduced exercise capacity of chronic obstructive pulmonary disease patients exercising with noseclip/mouthpiece.

A noseclip and low resistance mouthpiece are often used to monitor exhaled gases during exercise. Because otolaryngologic studies suggest that 50% of airway resistance is in the nose and mouth, it was hypothesized that patients with advanced chronic obstructive pulmonary disease might be artifactually limited by exercise testing with a noseclip and mouthpiece. Accordingly, 12 patients with stable chronic obstructive pulmonary disease performed identical symptom-limited supine bicycle exercise tests with and without noseclip and mouthpiece. Right-sided cardiac hemodynamic measurements, radionuclide ventriculography and arterial and mixed venous gas sampling were performed during each exercise test. Exhaled gases were analyzed during the noseclip/mouthpiece exercise. The order of exercise tests was alternated. Comparing exercises with and without a noseclip, there were significant reductions in exercise duration (397 +/- 270 vs 300 +/- 230 seconds, p less than 0.01), exercise oxygen consumption (780 +/- 279 vs 638 +/- 200 ml/min, p less than 0.01) and exercise cardiac output (8.4 +/- 2.7 vs 7.3 +/- 2.0 liters/min, p less than 0.05), an increase in right ventricular ejection fraction (0.39 +/- 0.08 vs 0.43 +/- 0.08, p less than 0.01) and no change in exercise heart rate (106 +/- 14 vs 106 +/- 14), right-sided cardiac pressures or arterial and mixed venous blood gases. These data suggest that a noseclip/mouthpiece can limit exercise tolerance in advanced chronic obstructive pulmonary disease patients. This limitation may result from decreased right-sided cardiac preload (venous return).

Adult↗
PubMed1998

Pre-exercise carbohydrate ingestion: effect of the glycemic index on endurance exercise performance.

PURPOSE: This study aimed to examine the effect of glycemic index of pre-exercise carbohydrate (CHO) ingestion on exercise metabolism and performance. METHODS: Eight endurance trained men ingested a high glycemic index (HGI), low glycemic index (LGI), or a placebo (CON) meal 45 min before exercise and then cycled for 50 min at 67% VO2max. Subjects subsequently performed a 15-min self-paced performance ride in which total work (kJ) was recorded. RESULTS: Plasma glucose concentrations were higher (P < 0.01) after ingestion in HGI compared with LGI and CON (7.53 +/- 0.64 vs 5.55 +/- 0.21 and 4.65 +/- 0.14 mmol.L-1 for HGI, LGI, and CON, respectively, 30 min postprandial; mean +/- SE) but declined at the onset of exercise and were lower (P < 0.01) compared with LGI and CON (4.03 +/- 0.31 vs 4.64 +/- 0.24 and 5.09 +/- 0.16 mmol.L-1 for HGI, LGI, and CON respectively; mean +/- SE) at 10 min of exercise. Plasma glucose remained depressed (P < 0.01) until 30 min into exercise in HGI compared with other trials. Plasma insulin concentrations were higher (P < 0.01) following ingestion during rest and exercise in HGI compared with LGI and CON. Plasma FFA concentrations were lower (P < 0.05) following ingestion in HGI and LGI compared with CON and higher (P < 0.05) in LGI compared with HGI at the start and end of exercise. RER and CHO oxidation was higher (P < 0.01) in HGI compared with LGI and CON during submaximal exercise. There were no differences in work output during the performance cycle. CONCLUSIONS: These data indicate that pre-exercise CHO feedings with varying glycemic indexes do not affect exercise performance following short term submaximal exercise despite alterations in metabolism.

Adult↗
PubMedDate not supplied

Exercise habits and exercise relapse in persons with non-insulin-dependent diabetes mellitus.

Exercise is widely recognized as a crucial component in the management of non-insulin-dependent diabetes mellitus (NIDDM), but little is known about actual exercise practices in this group. This study investigated exercise habits in 60 persons with NIDDM and 60 nondiabetic significant others. Despite the importance of exercise, most of the persons with NIDDM in our study were not exercising regularly, and the percent of persons exercising regularly was no greater in the diabetic group than in the group of significant others. Although those with NIDDM reported more frequent discussion about exercise with health care professionals, only 25% reported receiving specific guidelines for exercise. Diabetic respondents reported a greater number of relapse or dropout episodes than did the nondiabetic significant others, and relapse was associated with increased guilt. Persons with NIDDM appear to receive recommendations to exercise without instruction on exercise maintenance strategies, resulting in more failed attempts to exercise, and increased guilt. Interventions shown to be effective for increasing exercise maintenance need to be incorporated into the diabetic regimen.

Diabetes Mellitus, Type 2↗
PubMed1998

[Effect of exercise duration on the magnitude and duration of post-exercise hypotension].

PURPOSE: Considering that exercise duration may play a role in post-exercise hypotension, we tested the hypothesis that a prolonged submaximal exercise would lead to a greater and longer blood pressure fall after exercise than a shorter exercise bout. METHODS: Experimental protocol-10 subjects were submitted to two cycle ergometer exercise trials (25 and 45 min) at 50% of VO2 peak. Control protocol-12 subjects rested in the sitting position for 45 min. Blood pressure (BP) was measured before (20 min) and after (90 min) rest or exercise bouts. RESULTS: Systolic BP decreased significantly after exercise and this reduction was greater and lasted longer after 45 min of exercise. Mean and diastolic BP decreased after exercise and they were significantly lower during the 45 min session. Control protocol--no change in BP was observed after resting condition. CONCLUSION: A longer exercise bout leads to a greater and longer post-exercise hypotension.

Adult↗
PubMed1992

[Hypertensive reaction to exercise. Retrospective studies of 1363 consecutive exercise tests].

OBJECTIVE: To study exercise hypertensive reaction and its relation with rest blood pressure, hypertension type and hypertensive cardiac disease. DESIGN: Retrospective study of treadmill exercise testes (ET) performed from January/89 to June/91: (n: 1703). SETTING: Stress tests Laboratory of Cardiology Service of a Military Hospital. METHODS: 1363 consecutive ET of male subjects, performing at least the 3rd stage of the Bruce protocol, were studied. From each ET record were obtained general data, including the reason for test, medication and the rest and exercise blood pressure. Exercise hypertensive reaction was defined as a Bruce protocol 3rd stage systolic blood pressure above 187 mmHg, which corresponds to mean +2SD of 130 normal male subjects previously studied. The Echocardiograms of non-treated hypertensives, obtained less than a month from ET, were reviewed. The diagnosis of borderline or moderate hypertension was base on the clinical records. RESULTS: 1) The 1363 ET included 132 (9.7%) ET to study hypertensive subjects, and 68 of these had hypertensive reaction. 86 ET were performed by non-treated hypertensive subjects, of whom 73 had Echocardiogram. 43 (3.5%) from 1231 ET performed by non-hypertensive subjects also had exercise hypertensive reaction. 2) The left ventricular (LV) mass index of non-treated hypertensive patients had a positive correlation with exercise systolic pressure (r: 0.45; p < 0.001), more important than with rest blood pressure or exercise systolic pressure response; there was a relation with LV wall thickness, but not with internal ventricular dimensions, that was only observed in hypertensive subjects that also had hypertensive reaction to exercise. 3) Exercise systolic blood pressure was usually normal in borderline and elevated in moderate hypertensives (Qui2: 27.249; p < 0.001). 4) Subjects with exercise hypertensive reaction, but not previously diagnosed as hypertensives, were usually true hypertensives. CONCLUSIONS: 1) Hypertensive peaks seem to be an important determinant factor in LV hypertrophy of hypertension, but its influence is felt only above a certain blood pressure threshold; it results on LV concentric type hypertrophy. 2) Exercise systolic blood pressure had a discrimination power of about 80% to separate borderline and moderate hypertensive subjects. 3) All subjects having an exercise hypertensive reaction must be carefully observed, even if their blood pressure at rest is normal, because most of them are true hypertensive patients.

Adult↗