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Query: UMLS:C0015672 (fatigue)
 51,768 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intermittent claudication may occur in well-conditioned athletes because of an unusual form of popliteal artery entrapment that results from overtraining. These patients complain of calf muscle cramping, rapid limb fatigue, and occasional paresthesias on the plantar surface of the foot when running on inclines or when repetitive jumping is performed. Results of plethysmographic screening tests for popliteal entrapment are positive in these patients. Magnetic resonance angiography and intravenous digital subtraction angiography studies, however, do not demonstrate findings typical of anatomic popliteal entrapment. No evidence exists of aberrant positioning of the popliteal artery in foot neutral positioning, but with forced plantar flexion, the neurovascular bundle is deviated and compressed laterally. Surgical exploration of the popliteal fossa demonstrates no obvious musculotendinous abnormality. Symptoms of claudication and arterial compression are relieved by surgical release of the soleus muscle from its tibial attachments, resection of its fascial band, and resection of the plantaris muscle.
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PMID:Popliteal entrapment as a result of neurovascular compression by the soleus and plantaris muscles. 173 89

Ketanserin is a 5-HT2 receptor antagonist without partial agonist properties which also possesses weak alpha 1-adrenoceptor antagonistic activity, which may explain its antihypertensive mechanism of action in patients with essential hypertension. It also inhibits the effects of serotonin on platelets in cardiovascular disease, inhibits vasoconstriction caused by the amine, and when administered intravenously improves some haemorheological indices in patients with ischaemic diseases. The antihypertensive effect of oral ketanserin 40 mg twice daily is comparable with that of total daily doses of metoprolol 200 mg, propranolol 160 mg, captopril 100 mg, enalapril 20 mg, hydrochlorothiazide 50 mg, or alpha-methyldopa 1000 mg and is achieved without adverse effect on plasma lipoproteins or carbohydrate metabolism in patients with concomitant diabetes mellitus. Evidence from prospective studies suggests a greater antihypertensive efficacy in the elderly than in younger patients. In patients with intermittent claudication, results have been inconsistent in small studies, while a large study showed no improvement in pain-free walking distance but fewer amputations compared to placebo. In Raynaud's phenomenon symptomatic improvement relative to placebo was achieved in larger trials. Its role in preventing atherosclerotic complications requires further investigation. Ketanserin is reasonably well tolerated, the frequency of adverse effects being comparable with that of other antihypertensive drugs in controlled trials. Dizziness, tiredness, oedema, dry mouth and weight gain are the most commonly reported effects. Ketanserin prolongs QT interval in a dose-related manner, and when given in certain predisposing circumstances ventricular arrhythmias and syncope may occur. Administered intravenously, ketanserin 10mg followed by an infusion of 2 to 4 mg/h controls moderate to severe pre- and postoperative hypertension in most patients, acting as a balanced vasodilator, lowering cardiac pre- and afterload. Although the arrhythmogenic potential of ketanserin in patients receiving potassium-depleting diuretics requires suitable precautions, it appears that its antihypertensive activity is suited to the elderly provided plasma potassium concentrations are normal at the start of treatment and are maintained within the normal range.
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PMID:Ketanserin. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in hypertension and peripheral vascular disease. 207 1

The value of beta blockade after myocardial infarction is extremely well documented. Close to 50 randomized trials have been performed, involving about 40,000 patients with short- or long-term follow-up. Over 20,000 patients have been included in more than 20 placebo-controlled trials with a follow-up period of 3 months or more. In long-term follow-up studies, about 1 to 2 weeks to 1 year after myocardial infarction, mortality was reduced by 21% and reinfarction by 24% (about 20,000 patients in 24 trials). The trial medication was withdrawn in about 20% in both placebo and beta-blocker groups in the major trials. In addition to reduction of mortality and reinfarction rate, benefits have clearly been demonstrated on severity of chest pain, arrhythmias, and other thromboatherosclerotic complications, as well as on readmissions. Significantly more patients experienced congestive heart failure, hypotension, bradycardia, and cold hands with beta-blocker treatment, whereas no clear-cut difference was found for atrioventricular block, bronchial constriction, and intermittent claudication. Some studies have reported more tiredness, depression, and gastrointestinal disturbances. In the Stockholm metoprolol trial, analyses on quality of life have been performed. In this trial, 3 years of metoprolol treatment after myocardial infarction resulted in a prolongation of both survival and time spent completely asymptomatic, as well as in an optimal functional state. Furthermore, less time was spent disabled after serious atherosclerotic complications. Long-term beta blockade after myocardial infarction reduces mortality and morbidity but causes adverse reactions in some patients. With proper selection of patients and type and dosage of beta blocker, survival without atherosclerotic complications and side effects can be prolonged.
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PMID:Use of beta blockers in postinfarct prophylaxis: aspects on quality of life. 288 38

Adverse effects of beta-adrenergic receptor blocking drugs can be divided into two categories: 1) those that result from known pharmacological consequences of beta-adrenergic receptor blockade; and 2) other reactions that do not appear to result from beta-adrenergic receptor blockade. Adverse effects of the first type include bronchospasm, heart failure, prolonged hypoglycemia, bradycardia, heart block, intermittent claudication, and Raynaud's phenomenon. Neurological reactions include depression, fatigue, and nightmares. It is not yet proven whether the beta 1-selective adrenergic blockers or those with partial agonist activity reduce the overall frequency of adverse reactions seen with propranolol. Patient age does not appear, in itself, to be associated with more beta-blocker side effects. Side effects of the second category are rare. They include an unusual oculomucocutaneous reaction and the possibility of oncogenesis. There are also many drugs that interact with beta-blockers, which may increase toxicity. Finally, there are specific patient characteristics where one beta-blocker may be more effective and safer than another.
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PMID:Beta-adrenergic receptor blockers. Adverse effects and drug interactions. 289 72

Sixty-eight medical, social, and occupational history variables were analyzed in a general population of 442 men and 478 women, aged 30, 40, 50, and 60 years to identify possible indicators for first-time experience and recurrence or persistence of low-back trouble (LBT) during a 1-year follow-up. Variables that in univariate analyses showed statistically significant indications for future LBT were subjected to stepwise logistic regression analyses. The most important indicators for recurrence or persistence of LBT thus identified were, for men, intermittent claudication, restlessness, or other discomfort in the lower limbs, frequent headache, and living alone. For women, the corresponding indicators were rumbling of "the stomach" and feeling of fatigue. For first-time experience of LBT, the indicators identified by the regression analyses were frequent pain in the top of the stomach, previous hospitalizations and operations, daily smoking, and a long distance from home to work. The result suggests that the population likely to experience future LBT does not enjoy good general health even prior to its first LBT episode, and this, in turn, may be due to greater psychosocial pressure.
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PMID:Medical, social and occupational history as risk indicators for low-back trouble in a general population. 294 36

Fourteen patients with degenerative spondylolisthesis and three patients with degenerative scoliosis, all of whom experienced low-back pain, lumbar radiculopathy, and/or intermittent claudication were treated with posterolateral fusion and correction of deformities using a new instrumentation system. This new spinal fixation system combines the advantages of a rod for scoliotic deformities and a plate for sagittal plane disorders. The combination rod-plates can apply multiple forces to facilitate correction of complex deformities as well as enable indirect neurologic decompression. The system allows segmental rigid fixation via transpedicular screws that is limited only to the abnormal vertebral levels to preserve the maximum number of uninvolved lumbar motion segments. The physiologic lumbar lordotic curvature is also preserved. The minimum follow-up period was 1 year. Satisfactory results were obtained in 15 patients (88%). No intraoperative complications occurred. Screw fatigue occurred in two patients at 1-year follow-up examination with no sequelae. The scoliotic and spondylolisthetic deformities were reduced significantly in all patients. This method appears to assist in reducing pathologic motion and deformities that contribute to low-back pain. Compression on neural structures is relieved by thorough decompression and distraction; spinal canal anatomy is also restored.
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PMID:Degenerative spondylolisthesis and degenerative scoliosis treated with a combination segmental rod-plate and transpedicular screw instrumentation system: a preliminary report. 298 Feb 52

The effect of short-term (1 day-1 week) and long-term (6-12 weeks) femoral artery ligation on the oxygen tension (pO2), blood flow, metabolism and function of rat gastrocnemius muscle has been examined. Femoral artery ligation reduced resting blood flow, pO2 and pH. Concomitantly, the concentration of high energy phosphates was reduced and the muscle lactate concentration increased. The fatigue developed by the gastrocnemius/plantaris muscle, during a 10 min period of isometric exercise, was increased and the associated hyperaemia was attenuated. The surgery, performed to ligate the artery, induced an increase in the plasma fibrinogen concentration and whole blood viscosity. As the time interval increased after the femoral artery ligation there was a progressive reduction of the magnitude of the effects. Ten weeks after ligation resting muscle concentrations of high energy phosphates and lactate, whole blood viscosity and muscle pH had normalized. However, resting muscle blood flow, pO2, ability to sustained isometric exercise and the exercise induced hyperaemia were still reduced compared to intact animals. Comparison with literature data reveals that the changes produced by chronic femoral artery ligation in rat calf muscle mimic those seen in man with intermittent claudication.
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PMID:The effect of short-term and long-term femoral artery ligation on rat calf muscle oxygen tension, blood flow, metabolism and function. 335 Jun 22

Isokinetic plantar flexor peak torques (PT) and contractional work (CW) of the triceps surae muscle have been measured in 24 patients with peripheral arterial insufficiency and intermittent claudication and in 15 controls. Tests were performed both during non-fatiguing (30-180 degrees/s) and fatiguing (200 repeated plantar flexions at 60 degrees/s) conditions. The electromyographic signals (iEMG) from all three heads of the triceps surae were measured. The patients were significantly weaker (PT) and produced significantly less contractional work (CW) than the controls. In contrast, similar iEMGs of the triceps surae heads indicated similar levels of activation. At 40 contractions the majority of the patients had already given up and the remainder showed significantly greater declines in PT (50%) and CW (55%) than did the controls (13% and 18%, respectively). The decline in muscular excitations was similar in both groups. The ratio CW/iEMG showed a dramatic decline in the patients but was virtually constant in the controls. These results indicate a fatigue of low-frequency type in the patient group. There were close correlations between maximum walking tolerance and total work production.
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PMID:Isokinetic strength and endurance in peripheral arterial insufficiency with intermittent claudication. 371 29

The potential for physical training to enhance collateral-dependent blood flow (BF) to the hindlimbs of aged male rats (Fischer 344) was evaluated following bilateral femoral artery ligation at 20.5 mo of age. Rats were either limited to cage activity (sedentary, n = 11) or trained by a mild-intensity treadmill program (trained, n = 14), which involved walking twice a day at 15 m/min (15% grade) to fatigue, 5 days/wk for 8-11 wk. Exercise tolerance of the trained rats increased from approximately 5 to approximately 25 min/bout by week 7, whereas exercise tolerance of the sedentary group changed little (to approximately 8 min/bout) during the training period. At approximately 23 mo age, animals were surgically prepared for hindquarter perfusion (aortic pressure = 100 +/- 1.3 mmHg) and force measurement of the left gastrocnemius-plantaris-soleus (GPS) muscle group during isometric contractions at 4, 8, 15, 30, and 45 tetani/min via sciatic nerve stimulation (approximately 6 V, 0.1-ms square waves at 100 Hz for 100 ms). Although initial force development was similar between groups (12.9 N/g), trained rats maintained tension better at 8, 15, 30, and 45 tetani/min (P < 0.01). BF to the entire hindlimb of the trained group, determined with 85Sr 15-microns microspheres, was 43% greater (P < 0.05) than in the sedentary group. Thus collateral-dependent BF was improved by physical training. The greatest increase in BF was to the distal limb muscles (approximately 78%), the tissues most at risk during intermittent claudication.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Training increases collateral-dependent muscle blood flow in aged rats. 790 Aug 71

There is currently no established treatment for intermittent claudication with proven long term benefit. Exercise classes have been shown to improve walking distance. Chronic electromyostimulation (CEMS) a method of stimulating skeletal muscle has effects on normal muscle which may also benefit claudicants. We investigated the effects of one month of CEMS on claudicants in a single blind placebo controlled study. Patients were randomised to either CEMS (treatment) or transcutaneous nerve stimulation (TENS) placebo. The effects of the two modalities were assessed using the conventional measures of claudicating distance (CD), maximum walking distance (MWD), ankle-brachial pressure index (ABPI) and pressure recovery time (PRT). Muscle performance was assessed by the fatigue index (FI) a technique determining the decrease in ischaemic muscle response to repeated contraction. After 4 weeks treatment the CEMS group showed significant improvements in their median CD (88 to 111) and MWD (118 to 158); this was not seen in the control group. Muscle performance also increased significantly during the 4 weeks of treatment in the CEMS group but not in the control group. These changes were not maintained after CEMS was stopped. This pilot study suggests that CEMS may well have a role to play in the treatment of intermittent claudication though a number of further studies need to be undertaken.
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PMID:Chronic muscle stimulation improves ischaemic muscle performance in patients with peripheral vascular disease. 808 92


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