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At least 739 records · Page 41Linked to original sources
PubMed1980

Exercise tolerance in patients on chronic hemodialysis.

Twenty-two patients on chronic hemodialysis were tested on a bicycle ergometer to determine their near-maximal physical work capacity. The patients were found to have low physical work capacity that averaged 51.6 +/- 3.8 (SE)% predialysis and 50.3 +/- 3.7% postdialysis, when compared with the physical work capacity of healthy control subjects. The exercise was stopped when patients complained of muscular fatigue, and the work load at this point was considered their subjective maximal work capacity. At this stage the patients had high blood lactic acid levels and an increased double product (systolic blood pressure x heart rate), the latter indicating a high stage of cardiac output. The oxygen consumption and oxygen pulse were similar to those obtained from control individuals at the same work load. This study suggests that limited physical work capacity of chronic hemodialysis patients is due to early muscular fatigue. This phenomenon is associated with the rapid onset of anaerobic metabolism and may thus be caused by limited maximal oxygen uptake.

Adult↗
PubMed1994

Effects of felodipine versus nifedipine on exercise tolerance in stable angina pectoris.

The effects of single doses of felodipine (5 and 10 mg) and nifedipine (10 and 20 mg) on chronic stable effort angina pectoris were assessed in a placebo-controlled, double-blind, crossover study of 24 patients receiving beta blockers and short-acting nitroglycerin. The effects were measured by repeated bicycle ergometer tests. The total work, and time until 1 mm of ST depression increased significantly by 9 to 31% after both active drugs at both dose levels in comparison with placebo. The differences were not significant between drugs or doses. At rest, blood pressure decreased (10 to 15%) and heart rate increased (5 to 10%) significantly after both active drugs. During exercise at the highest comparable work load, systolic blood pressure decreased significantly (23 to 26%), whereas heart rate was not affected after felodipine and nifedipine compared with placebo. The 2 drugs were well tolerated, and side effects were mild. Therefore, single doses of 5 and 10 mg of felodipine, and 10 and 20 mg of nifedipine have similar antianginal and anti-ischemic properties. However, felodipine has a longer duration of action, which may improve compliance.

Analysis of Variance↗
PubMed1986

Effects of a transdermal patch system containing nitroglycerin on exercise tolerance in patients with angina pectoris. Double-blind, placebo controlled, comparison with slow-release nifedipine and verapamil.

The antianginal efficacy of nitroglycerin (NTG), given in a new transdermal therapeutic system (TTS), was compared with that of nifedipine and verapamil, both in slow-release (SR) formulation, in a randomized, double-blind, placebo-controlled study, carried out in 8 patients with stable exercise-induced angina pectoris. TTS NTG 40 cm2 (releasing 20 mg of NTG over 24 hours), nifedipine 20 mg SR, verapamil 120 mg SR and placebo were given once on 4 consecutive days according to a 4 X 4 latin-square design, twice replicated. A cycloergometric symptom-limited exercise test was performed 4 and 8 hours after the administration of each drug. Four hours post-dosing, mean exercise duration was 407 sec. after placebo and 523 (+28%) and 485 (+ 19%) sec. after TTS NTG and nifedipine SR respectively, while at the 8th hour it was 375 sec. after placebo, and 515 (+ 37%) and 457 (+ 21%) sec. after TTS NTG and nifedipine SR. Exercise duration after verapamil was similar to that after placebo. In comparison with placebo maximal workload and total work performed were significantly higher on TTS NTG and on nifedipine at both times of observation, but no significant differences were seen after verapamil. Peak exercise systolic blood pressure was nearly identical after all the treatments tested. Peak exercise heart rate and pressure rate product were both significantly higher on TTS NTG, as well as on nifedipine, in comparison with placebo, while values after verapamil did not differ from those after placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1975

Effects of hyperoxic gas mixtures on exercise tolerance in man.

This study was undertaken to determine the effects of O2-enriched gases on performance. Nine trained subjects ran to exhaustion on the treadmill on five different occasions breathing one of a range of hyperoxic gas mixtures--20%, 40%, 60%, 80%, or 100% O2. Each subject worked at a workload determined to be 110% of that necessary to elicit his maximum O2 uptake. The exercise bouts were scheduled one week apart to minimize the effects of training and fatigue. The subjects were given no cues as to the mixtures being breathed or to their running times. The parameters measured included running time, minute ventilation, and heart rate. The results indicate that the maximum performance time increases significantly as the O2 fraction of the gas is increased. Contrary to other published literature, 100% O2 increases performance significantly over 60% O2. Ventilation at any point in time is decreased when breathing hyperoxic mixtures. This decrease appears to be more a function of breathing frequency than of tidal volume. Terminal heart rates are not significantly different regardless of the O2 fraction of the inspired gas.

Adult↗
PubMed1984

[Exercise tolerance in evaluating the efficacy of continuous electrocardiostimulation in patients with atrioventricular block].

Fifty-three patients with brady-cardia were examined prior to and 1 year after the implantation of the cardiostimulator. It was found that the bicycle ergometric test was not contraindicated in examining the function of the respiration and circulation in patients with stable forms of bradyarrhythmia. Three types of the body's response to exercise were identified. It was shown that in patients with the third type of response the compensatory possibilities of the respiratory and cardiovascular systems were at the breaking point. The authors believe that electrocardiostimulation in them is of a doubtful value in terms of improving the quality of life and restoring the capacity for work. Implantation of cardiostimulators in such patients is mostly necessary in the presence of Morgagni-Edems-Stokes attacks.

Blood Pressure↗
PubMed1994

Exercise tolerance and work ability following aorto-coronary bypass surgery.

This investigation was performed to study the reasons for receiving disability pension after aortocoronary bypass surgery. During the period March 1983 to November 1985, 250 patients underwent aortocoronary bypass surgery. At a mean follow-up of 4.9 years (range 3.6-6.7) after the operation, 31 patients were dead. Of the 219 survivors, all except four underwent a follow-up examination including an exercise test. The mean physical work capacity had increased from 92.2 W preoperatively to 119.3 W at follow-up (p < 0.001). At follow-up, however, 72 patients had received disability pension. The percentage of positive ECG-tests were equal among those who were working and those who had received disability pension. We suggest that, among those who had received disability pension, about 50% were in sufficient physical condition to manage their previous jobs or another type of job. Reasons other than physical working capacity played an important part as criteria for receiving disability pension.

Adult↗
PubMed1999

Effects of lipid-lowering drugs on left ventricular function and exercise tolerance in dyslipidemic coronary patients.

Previous studies suggested that certain lipid-lowering drugs such as statins suppress ubiquinone, affect mitochondrial function, and may have deleterious effect on skeletal or cardiac muscles with potentially serious clinical consequences, especially in patients with established coronary heart disease and left ventricular dysfunction. In this double-blind study, we assessed the effects of 20 mg simvastatin (S, n = 32) or 200 mg micronized fenofibrate (F, n = 32, control group) on rest and exercise left ventricular function in hypercholesterolemic survivors of a previous Q-wave acute myocardial infarction. Left ventricular radionuclide imaging was performed at rest and during submaximal exercise and global and segmental (nine segment regional wall-motion score) ejection fractions were measured before treatment and 12 weeks later. Serum ubiquinone was reduced after treatment (p = 0.03) in the S but not the F group, whereas total and low-density lipoprotein (LDL) cholesterol were significantly reduced in both groups. Before treatment, mean global ejection fraction was 52.1+/-12.2% and 49.3+/-11.8% at rest in F and S patients, respectively, and increased (56.0+/-13.7% in F and 52.1+/-12.9% in S) at peak exercise (no difference between groups). After treatment, the increase in ejection fraction tended to be lower in S (0) than in F (+3.8%) but not significantly. However, ejection fraction at rest increased after treatment in S (p = 0.009) but not in F. Subgroup analyses indicated that the improvement in rest ejection fraction in S was essentially observed in patients with ejection fraction <40% (n = 8, +6%), whereas it was stable in patients with ejection fraction >40% (+1.8%). Finally, the numbers of akinetic or hypokinetic segments at rest and during exercise were not different in the two groups before and after treatment. Mean maximal exercise load (113+/-23 watts in F vs. 104+/-27 W in S before treatment) was not modified by the treatment (111+/-21 and 104+/-27 W). Thus a 12-week lipid-lowering treatment with either S or F did not negatively alter left ventricular function during exercise in dyslipidemic patients with established coronary heart disease and did not affect their ability to exercise. The improvement in left ventricular function at rest after simvastatin in patients with left ventricular dysfunction warrants confirmation in further studies with large sample size.

Blood Pressure↗
PubMed1983

Sustained improvement in exercise tolerance following physiological cardiac pacing.

Fifty-three patients have received 'physiological' pacemakers, 37 with atrioventricular (AV) block having atrial synchronous units (VAT or VDD) implanted and the remaining 16 patients with both AV block and sick sinus syndrome having 'universal' (DDD) pacemakers. Effort tolerance was assessed by serial bicycle ergometry and in 16 patients direct comparisons between ventricular pacing and atrial synchronous pacing could be made acutely. Physiological pacemakers were found to increase maximum effort tolerance by 43% compared to pre-pacing values (P less than 0.01). The increase was sustained over a mean of 33 months post pacing. The atrial synchronous mode increased maximum effort tolerance by 34% acutely compared to ventricular inhibited pacing. Dual chambered 'physiological' pacemakers represent a significant therapeutic advance over standard ventricular inhibited pacemakers.

Adult↗
PubMed1976

Venous pressure and exercise tolerance.

Compared to the number of contractions obtained when a blood pressure cuff on the upper arm was at zero pressure, inflation of the cuff to pressures ranging between 5 and 40 mm Hg resulted in an augmentation of the number of hand contractions that could be performed prior to the development of ipsilateral severe fatigue or intolerable pain. Cuff pressures of 60 mm Hg reduced the number of contractions below the control level. These results are consistent with the concept that exercise during venous congestion facilitates the washout of the toxic catabolite presumed to be produced during muscular contraction.

Adolescent↗
PubMed1992

Effects of a new metabolic modulator, ranolazine, on exercise tolerance in angina pectoris patients treated with beta-blocker or diltiazem.

Ranolazine (RS 43285) is a new piperazine derivative with anti-ischemic properties attributed to a modulation of myocardial metabolism. Its antianginal action was assessed in 104 patients recruited in a double-blind, crossover, randomized study comparing placebo with a single dose of ranolazine (10, 60, 120, and 240 mg). All patients had chronic stable angina pectoris and remained symptomatic (at least 0.1 mV ST-segment depression and angina during prestudy exercise testing) despite treatment with a beta-blocker or with diltiazem. No significant effects of ranolazine on exercise duration or time to angina were observed after the dose of 10, 60, and 120 mg. After the 240 mg dose, however, significant improvement in exercise duration (+13.1% in the combined group, two-tailed p = 0.002; +14.3% in the beta-blocker group, p = 0.009; +11.9% in the diltiazem group, p = 0.06), in time to angina (+56.8 s, p = 0.008), and in time to 1 mm ST-segment depression was observed. The cumulative proportion of patients who improved their time to angina by at least 30 s above placebo were 25, 42, 50, and 72% with the doses of 10, 60, 120, and 240 mg, respectively. Sixty-seven percent of the patients with ranolazine plasma levels above 500 ng/ml improved their time to angina against 40% at plasma levels below 500 ng/ml and summed ST-segment depression during exercise and recovery was also significantly reduced at these plasma concentrations. Both heart rate and arterial pressure at rest and at peak exercise were unchanged after ranolazine, 240 mg.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetanilides↗