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Results for “Exercise Tolerance”

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PubMed1994

Long-term iloprost infusion therapy for severe pulmonary hypertension in patients with connective tissue diseases.

OBJECTIVE: To determine the effects of short-term, maximum-tolerated-dose and long-term, optimum-dose iloprost treatment of severe pulmonary hypertension associated with systemic sclerosis (SSc) and the primary antiphospholipid syndrome (APS). METHODS: Three patients with SSc and 2 with APS who had failed to respond to oral vasodilator therapy for pulmonary hypertension were enrolled in a 32-week, open, prospective trial. Short-term infusion of maximum-tolerated doses and continuous infusion of optimum doses of iloprost were carried out following baseline cardiac catheterization. Catheterization was repeated at 2 and 32 weeks. All 5 patients completed the study and continued therapy for an average of 82 weeks (range 58-103). RESULTS: Acute infusion of maximum tolerated doses significantly ameliorated the cardiac index (0.92 liters/minute/m2; P < 0.01), pulmonary artery O2 saturation (10.6%; P < 0.05), and pulmonary resistance (-6.7 units; P < 0.05). After 2 weeks of continuous infusion of optimum doses, there was improvement in pulmonary resistance (> or = 16%) and pulmonary artery O2 saturation (> 30%) in the 2 patients with primary APS. After 2 and 32 weeks, the 3 SSc patients showed variable hemodynamic responses. New York Heart Association functional class and exercise tolerance improved in all patients. There was 1 episode of bacteremia, and 1 patient died after 72 weeks of study. CONCLUSION: Continuous iloprost infusion may improve exercise tolerance and quality of life in patients with severe pulmonary hypertension associated with SSc and primary APS.

Adolescent↗

PubMed2002

Beta blockers in older persons with heart failure: tolerability and impact on quality of life.

OBJECTIVE: To determine tolerability and symptom changes associated with the introduction of bisoprolol treatment in older patients with heart failure. DESIGN: Prospective observational cohort study. SETTING: Geriatric medicine outpatient department of a university hospital. PATIENTS: 51 patients (mean age 78 years, range 70-89 years) with stable symptomatic heart failure caused by left ventricular systolic dysfunction. INTERVENTIONS: Bisoprolol tablets, 1.25-10.0 mg. MAIN OUTCOME MEASURES: Tolerability; changes in symptoms and exercise tolerance. RESULTS: 69% of patients tolerated bisoprolol. Mean tolerated dose was 7.6 mg. There was no change in symptoms or exercise capacity in those who tolerated bisoprolol. Perceived health status and symptoms of anxiety and depression improved during the titration period. CONCLUSIONS: The rate of withdrawal from bisoprolol treatment in older patients with congestive heart failure was twice that previously reported in younger patients. The mean tolerated dose was similar to that found in trials reporting clinical efficacy. There was no evidence of a negative impact on symptoms or exercise capacity in patients who tolerated bisoprolol.

Adrenergic beta-Agonists↗

PubMed1990

[Possibilities of correction of mental disorders and dyslipoproteinemia in patients with neurocirculatory asthenia].

A total of 230 patients with neurocirculatory dystonia (NCD) were investigated. Different mental disorders associated with the atherogenic nature of dyslipoproteinemia were revealed in the majority of patients using the clinical scale and MMPI test. Psychotropic agents used for a period of 2-4 mos improved the mental status of these patients, increased exercise tolerance, and decreased blood levels of free fatty acids (FFA). A course of exercise training (graded walking) for 4-6 mos. helped to enhance exercise tolerance, to lower the blood levels of cholesterol, triglycerides, FFA, the total fraction of low- and very low-density lipoproteins, to reduce manifestations of hypochondriasis, depression, and neurasthenia . The results obtained can be used for developing programs of NCD patients' rehabilitation.

Adolescent↗

PubMed2000

Evaluation of the long-term functional outcome assessed by myocardial perfusion scintigraphy following excimer laser angioplasty compared to balloon angioplasty in longer coronary lesions.

OBJECTIVES: Evaluation of the long-term functional outcome assessed by exercise myocardial perfusion imaging following excimer laser angioplasty compared to balloon angioplasty in coronary lesions > 10 mm in length. BACKGROUND: Previous randomized studies evaluating the effect of coronary interventions mainly focused on the long-term clinical and angiographic outcome. The functional outcome, assessed by myocardial perfusion scintigraphy, has not been evaluated in a randomized setting. METHODS: A total of 308 patients with stable angina and a longer coronary lesion (> 10 mm) were randomized to excimer laser angioplasty or balloon angioplasty. A 99mTechnetium-2-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography (SPECT) study was performed in 139 patients before the initial angioplasty procedure and at 6 months follow-up (73 patients in the laser group versus 66 patients in the balloon group, respectively). Exercise tolerance at follow-up was compared to baseline values by means of exercise duration and double product at peak exercise. Myocardial perfusion of the randomized vascular bed was assessed semi-quantitatively on the MIBI SPECT images. The reversible defects were graded as mild, moderate or severe. Myocardial perfusion at follow-up was expressed as a percentage reduction in incidence and grading of the reversible defects compared to baseline values. RESULTS: Forty-four (61%) patients assigned to laser angioplasty were asymptomatic at 6 months follow-up compared to 34 (52%) patients assigned to balloon angioplasty (p = NS). Improvement in exercise duration and double product were 0.7 +/- 2.1 min and 4.3 +/- 6.2 min/mmHg/l,000, respectively, in the laser group, versus 0.3 +/- 2.5 min and 3.1 +/- 5.5 min/mmHg/1,000, respectively, in the balloon group (both p = NS). The percentage reduction of reversible defects was 23% in patients assigned to laser angioplasty vs. 29% in patients assigned to balloon angioplasty (Relative risk [RR]: 0.79, 95% confidence interval [CI]: 0.40-1.57; p = 0.50). The mild, moderate and severe reversible defects improved in 44.4, 63.6 and 66.6%, respectively, in the laser angioplasty group vs. 66.6, 53.8 and 90%, respectively, in the balloon angioplasty group. None of the comparisons were significantly different. CONCLUSION: Excimer laser angioplasty compared to balloon angioplasty in coronary lesions > 10 mm in length yields a similar long-term functional outcome assessed by anginal status, exercise tolerance and myocardial perfusion.

Adult↗

PubMed1990

Comparison of corridor and treadmill walking in patients with severe chronic obstructive pulmonary disease.

The maximal distance walked in a given time period is frequently used as a simple method to evaluate exercise tolerance in patients suffering from chronic obstructive pulmonary disease (COPD). Typically, patients walk on a treadmill or in a corridor at a self-paced speed. Little information is available about the differences between exercise performance in patients with COPD when using the two tests. Therefore, we compared 12-minute corridor walking and 12-minute self-paced treadmill walking in 11 patients with severe COPD. Distances covered in 2, 6, and 12 minutes and walking speeds were significantly higher during corridor walking than during treadmill walking. Heart rate values during the two procedures were not significantly different, and the same degree of breathlessness was found after both walking tests. The study illustrates that corridor walking is a simple and adequate form of exercise testing. Based on heart rate responses, corridor walking appears to be more efficient than treadmill walking, possibly because patients are more familiar with walking in a corridor than on a treadmill. Corridor walking is therefore a useful method to evaluate exercise tolerance and the effects of exercise training programs in patients with COPD.

Adult↗

PubMed2005

Myocardial hypoperfusion/reperfusion tolerance with exercise training in hypertension.

The purpose of this study was to examine whether exercise training, superimposed on compensated-concentric hypertrophy, could increase myocardial hypoperfusion-reperfusion (H/R) tolerance. Female Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) (age: 4 mo; N = 40) were placed into a sedentary (SED) or exercise training (TRD) group (treadmill running; 25 m/min, 1 h/day, 5 days/wk for 16 wk). Four groups were studied: WKY-SED (n = 10), WKY-TRD (n = 10), SHR-SED (n = 10), and SHR-TRD (n = 10). Blood pressure and heart rate were determined, and in vitro isolated heart performance was measured with a retrogradely perfused, Langendorff isovolumic preparation. The H/R protocol consisted of a 75% reduction in coronary flow for 17 min followed by 30 min of reperfusion. Although the rate-pressure product was significantly elevated in SHR relative to WKY, training-induced bradycardia reduced the rate-pressure product in SHR-TRD (P < 0.05) without an attenuation in systolic blood pressure. Heart-to-body weight ratio was greater in both groups of SHR vs. WKY-SED (P < 0.001). Absolute and relative myocardial tolerance to H/R was greater in WKY-TRD and both groups of SHR relative to WKY-SED (P < 0.05). Endurance training superimposed on hypertension-induced compensated hypertrophy conferred no further cardioprotection to H/R. Postreperfusion 72-kDa heat shock protein abundance was enhanced in WKY-TRD and both groups of SHR relative to WKY-SED (P < 0.05) and was highly correlated with absolute left ventricular functional recovery during reperfusion (R2= 0.86, P < 0.0001). These data suggest that both compensated hypertrophy associated with short-term hypertension and endurance training individually improved H/R and that increased postreperfusion 72-kDa heat shock protein abundance was, in part, associated with the cardioprotective phenotype observed in this study.

Animals↗

PubMedDate not supplied

Effects of long-term and ongoing cardiac rehabilitation in elderly patients with coronary heart disease.

The authors assessed the effect of very long-term cardiac rehabilitation (over 1 year) on exercise tolerance and coronary heart disease risk factors in patients older than 80 years with coronary heart disease relative to an elderly cohort without coronary heart disease. Included in this retrospective analysis were patients older than 80 at the time of their last evaluation who had completed at least 1 year of a cardiac prevention and exercise training program. A total of 43 coronary heart disease patients and 15 age-matched healthy subjects were included in this study. Long-term cardiac rehabilitation in very elderly coronary heart disease patients was shown to be feasible and effective in improving functional capacity (+5.4% after 1 year; P< .05) and risk factor control, and slowing the decline in exercise tolerance that occurs with normal aging.

Age Factors↗

PubMed1990

Nitrate tolerance. A problem during continuous nitrate administration.

The organic nitrates are effective agents in the management of patients with angina pectoris. They are the agents of choice in the treatment of acute episodes of angina pectoris and are useful in angina prophylaxis. While the organic nitrates are extremely effective in angina prophylaxis during acute therapy, there is increasing evidence that with many dosing regimens for oral and transdermal therapy, substantial attenuation of the antianginal effects develops. Thus, during acute therapy the organic nitrates improve exercise tolerance for many hours, but during sustained therapy designed to provide antianginal efficacy throughout the 24-h period there is significant attenuation of the beneficial effects. It has been documented that treatment regimens designed to provide a period of nitrate washout prevent or reverse nitrate tolerance, and such changes in dosing regimens have been shown to provide continued antianginal protection. It is clear that the objective of providing 24-h antianginal protection with the organic nitrates cannot be achieved. With appropriate dosing schedules, however, it is possible to improve exercise tolerance throughout the major portion of the 24-h dosing period.

Angina Pectoris↗

PubMed1979

[Correlations between effort tolerance and the severity of coronary disease. Influence of myocardial lesions].

The influence of coronary and myocardial lesions, defining the severity of the coronary artery disease on effort tolerance was studied in 51 patients. The appearances of the coronary arteriography and ventriculography were compared with the parameters of exercise tolerance: electrocardiographic changes, maximal charge (Cw), total work (TW), maximal systolic arterial pressure (SAP), maximal heart rate, percentage of the theoretical maximal heart rate, double product, exercise capacity index (CEI). The results showed that exercise tolerance (Cw, TW, ECI) and the exercise SAP are mainly affected by the myocardial lesions: patients with very reduced left ventricular ejection fractions and double or triple artery disease have very low indices: average Cw of 60 watts, TW less than 20,000 joules, ECI approximately 50. The SAP only rises slightly. On the other hand, patients with normal or subnormal ejection fractions have much higher indices whatever the state of their coronary arteries; Cw over 80 watts, TW over 30,000 joules, ECI over 80. In addition, major left ventricular dysfunction is associated with ST segment elevation during exercise.

Blood Pressure↗

PubMedDate not supplied

[Effect of aorto-coronary bypass on function of cardiac ventricles as evaluated by non-invasive techniques during a two year observation].

In 1989-1990, 892 patients with ischemic heart disease were treated at the III Department of Cardiology in Katowice-Ochojec. Aortocoronary bypass was performed in 51 (5.7%) of these patients. Thirty five out of these patients were followed-up for 24 months after surgery. They reported to the hospital for evaluation after 3, 6, 12 and 14 months following a discharge. Efficiency of revascularization was checked with physical examination, and non-invasive tests such as electrocardiography, echocardiography and exercise tolerance testing. Diastolic and symbolic functioning of left and right ventricle was assessed separately. All patients suffered from anginal pain before surgery whereas 85% of operated patients were free from pain. No correlation between incomplete revascularization and recurrence of the anginal pain was noted. Surgery produced an increase in exercise tolerance and maximal load. No significant improvement in the right ventricle was seen during a 2-year follow-up. In the group of patients without previous myocardial infarction measured parameters of cardiac ventricles functioning were better than those in patients who had myocardial infarction. Therefore, the former are better candidates to coronary vessels revascularization.

Adult↗

PubMed2004

Are hematinic deficiencies the cause of anemia in chronic heart failure?

BACKGROUND: Anemia in chronic heart failure (CHF) is common, varying in prevalence between 14.4% and 55%, and is more frequent in patients with more severe heart failure. Patients with CHF who have anemia have a poorer quality of life, higher hospital admission rates, and reduced exercise tolerance. We explored the relation between hematinic levels and hemoglobin (Hb) levels and exercise tolerance in a group of patients with CHF. METHODS: We analyzed data from 173 patients with left ventricular systolic dysfunction (LVSD), 123 patients with symptoms of heart failure, but preserved left ventricular (LV) systolic function ("diastolic dysfunction"), and 58 control subjects of similar age. Each underwent echocardiography, a 6-minute walk test, and blood tests for renal function and Hb and hematinic levels (vitamin B12, iron, and folate). We classified patients as having no anemia (Hb level >12.5 g/dL), mild anemia (Hb level from 11.5-12.5 g/dL), or moderate anemia (Hb level <11.5 g/dL). RESULTS: Of patients with LVSD, 16% had moderate anemia and 19% had mild anemia. Of patients with preserved LV function, 16% had moderate anemia and 17% had mild anemia. Four control subjects had a Hb level <12.5 g/dL. Of all patients, 6% were vitamin B12 deficient, 13% were iron deficient, and 8% were folate deficient. There was no difference between patients with LVSD and the diastolic dysfunction group. In patients with LVSDS, the average Hb level was lower in New York Heart Association class III than classes II and I. The distance walked in 6 minutes correlated with Hb level in both groups of patients with CHF (r = 0.29; P <.0001). Patients with anemia achieved a lower pVO2 (15.0 [2.3] vs 19.5 [4.4], P <.05). Peak oxygen consumption correlated with Hb level (r = 0.21, P <.05) in the patients, but not in the control subjects. In patients with anemia, the mean creatinine level was higher than in patients with a Hb level >12.5 g/dL, but there was no clear relationship with simple regression. Hematocrit level and mean corpuscular volume were not different in the patients with diastolic dysfunction, patients with LV dysfunction, or the control subjects. Hematocrit levels were not influenced by diuretic dose. Patients with anemia were not more likely to be hematinic deficient than patients without anemia. CONCLUSIONS: Patients with symptoms and signs of CHF have a high prevalence of anemia (34%) whether they have LV dysfunction or diastolic dysfunction, but few patients have hematinic deficiency. Hemoglobin levels correlate with subjective and objective measures of severity and renal function.

Aged↗

PubMed1990

Sudden cardiac death associated with exercise: the risk-benefit issue.

Although there is an overall increased risk of sudden cardiac death associated with physical exertion, the risk is small. Yet it warrants consideration by physicians and their adult patients who pursue exercise because, in any individual patient, the risk may be high. To advise patients properly on the risks and benefits of exercise, physicians should have an understanding of the risks of exercise, a strategy for patient evaluation that effectively identifies patients at risk, and a knowledge of appropriate exercise procedures that minimize risk. Patients should also know proper exercise procedures, be aware that there is some degree of risk in exercise, know their exercise tolerance, understand self-monitoring procedures, and be sensitive to prodromal symptoms. The essential feature of prudent exercise is a gradual progression during which an individual remains well within the limits of his/her exercise tolerance.

Death, Sudden↗

PubMed1982

Physiological response to "pressure-demand" respirator wear.

This investigation determined cardiorespiratory responses of subjects with normal lung function and exercise tolerance and compared them with subjects with moderate impairment of lung function and exercise tolerance. The respirator was an air-line full-face mask (MSA-Ultravue) "pressure-demand" breathing type equipped with an inspiratory resistance of 85 mmH2O at 85 L/min air flow. This resistance was operable in conjunction with the fixed 25 mmH2O inspiratory and expiratory resistance required to pressurize the face piece. Physiologically and subjectively the response of the normal and moderately impaired subjects to respirator wear during rest, 35%, 50% and 80% of their maximal aerobic capacity (VO2max) were not different. However, the pressure swings inside the face piece exceeded 24 cmH2O and resulted in 50% of the subjects being unable to finish 10 minutes of work at 80% VO2max. The greater the ventilatory demand placed upon the respirator due to increasing workload, the more like a "demand" system pressure-flow response the "pressure-demand" system produced. Hence, the concept of increased protection and reduced inspiratory resistance as a result of pressurizing the facepiece during heavy work is seriously questioned.

Adult↗

PubMed2002

Skeletal muscle apoptosis and weight loss in chronic obstructive pulmonary disease.

Patients with chronic obstructive pulmonary disease (COPD) often lose weight during the course of their disease. We hypothesized that this may be due to skeletal muscle apoptosis. To investigate this possibility, we obtained quadriceps femoris biopsies in 15 patients with COPD (8 with normal body mass index [BMI] and 7 with low [< 20 kg/m(2)] BMI), 8 healthy volunteers, and 6 sedentary subjects undergoing orthopedic surgery (both groups with normal BMI). Skeletal muscle apoptosis was assessed by the transferase-mediated dUTP nick end labeling (TUNEL) technique and the immunodetection of poly-(ADP-ribose)-polymerase proteolytic fragments. Exercise tolerance on a cycloergometer was also determined in patients with COPD. We found that skeletal muscle apoptosis (by both techniques) was increased in patients with COPD and low BMI as compared with the other three groups (p < 0.005). In patients with COPD, BMI was inversely related to skeletal muscle apoptosis (TUNEL, p = 0.009), and it was better correlated with exercise capacity (p = 0.006) than with the degree of airflow obstruction present (p = 0.02). Markers of skeletal muscle apoptosis were not related to any of the measured lung function variables. This study shows that skeletal muscle apoptosis (1) is increased in patients with COPD having low BMI; and (2) is associated with a lower exercise tolerance despite a similar degree of lung function impairment.

Aged↗

PubMed2005

Effect of beta-blocker therapy on functional status in patients with heart failure--a meta-analysis.

BACKGROUND: The results of randomised control trials (RCTs) evaluating the effect of beta-blockers on functional status in patients with chronic heart failure are conflicting. AIM: To perform a systematic review and meta-analysis of RCTs evaluating the effect of beta-blockers on New York Heart Association (NYHA) classification and exercise tolerance in chronic heart failure. METHODS AND RESULTS: We selected 28 RCTs evaluating beta-blocker versus placebo in addition to ACE inhibitor therapy. Combined results of 23 RCTs showed that beta-blockers improved NYHA class by at least one class with odds ratio (OR) 1.80 (1.33-2.43) p<0.0001. Meta-analysis of 10 RCTs showed a significant prolongation of exercise time by 44.19 (6.62-81.75) s p=0.021. Combining 8 RCTs evaluating the maximal peak oxygen uptake and 9 RCTs evaluating 6-min walk distance showed that beta-blockers had no significant effect compared with placebo, p=0.484, and p=0.730, respectively. Combined results of the 23 RCTs showed significant reducing effect on all cause mortality with OR=0.69 (0.59-0.82) p<0.0001. CONCLUSION: Chronic use of a beta-blocker in conjunction with ACE inhibitor therapy improves dyspnoea and prolongs exercise tolerance time, but has no significant effect on 6-min walk test or maximal oxygen uptake in patients with heart failure.

Adrenergic beta-Antagonists↗

PubMed1995

Alar fold resection in horses: 24 cases (1979-1992).

Between 1979 and 1992, the alar folds were resected bilaterally in 22 horses and unilaterally in 2 horses. Abnormal respiratory tract noise and exercise intolerance were the primary complaints prior to surgery. Significantly (P = 0.01) more Standardbreds underwent resection of the alar folds, compared with the number of Standardbreds in the hospital population during the same period. The alar folds palpated abnormally thick in 13 horses and normal in 11 horses. Temporary dilatation of the nares with mattress sutures or clips lessened the respiratory tract noise and improved exercise tolerance in all 8 horses in which the diagnostic test was performed. Manual elevation of the alar folds reduced respiratory noise in the 11 horses evaluated. Long-term follow-up evaluation by telephone was available for 14 horses. All surgical incisions had healed cosmetically. Respiratory tract noise was decreased, and exercise tolerance improved in 10 of 14 (71%) horses. Complete charted racing information was obtained for 16 horses. Fourteen horses started their first race a mean of 118 days (range, 13 to 321 days) after surgery. The mean number of starts after surgery was 51, with 14 of 16 (88%) horses starting more than 6 times after surgery. Of the 16 horses, 8 horses raced at least 3 times before and after surgery; 4 had improved racing performance, 2 had similar performance, and 2 had decreased performance. Five Standardbreds never raced, and 1 Standardbred raced once before surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2004

Adenoviral-mediated transfer of vascular endothelial growth factor 121 cDNA enhances myocardial perfusion and exercise performance in the nonischemic state.

BACKGROUND: Angiogenic gene therapy has been demonstrated to enhance perfusion to ischemic tissues, but it is unknown whether the administration of angiogenic growth factors will increase blood flow to nonischemic tissues. This study investigates whether enhanced myocardial perfusion can be mediated by adenovirus-mediated transfer of vascular endothelial growth factor 121 cDNA to nonischemic myocardium. METHODS: New Zealand White rabbits received adenovirus (5 x 10(10) particle units) encoding for vascular endothelial growth factor 121 (n = 14) or a control vector without a transgene (n = 13) or saline solution (n = 9) via direct myocardial injection. Fluorescent microsphere perfusion studies and histologic analyses were performed 4 weeks later. In a parallel study, exercise treadmill testing was performed to assess the functional effects of this therapy in Sprague-Dawley rats. RESULTS: Microsphere assessment of myocardial perfusion in rabbits 4 weeks after adenovirus-encoding vascular endothelial growth factor administration was greater than that for rats injected with control vector without a transgene or saline solution (3.2 +/- 0.5 vs 2.7 +/- 0.7 and 2.4 +/- 0.4, respectively; P <.03). The endothelial cell count per high power field was increased in animals injected with adenovirus-encoding vascular endothelial growth factor versus animals injected with control vector without a transgene or saline solution (147 +/- 27 vs 123 +/- 14 and 125 +/- 16 cells, respectively), although this did not reach statistical significance (P =.12). Rats treated with adenovirus-encoding vascular endothelial growth factor also demonstrated prolonged exercise tolerance compared with rats injected with control vector without a transgene or saline solution (exhaustion time: 26 +/- 5 minutes vs 19 +/- 2 minutes and 20 +/- 3 minutes, respectively; P =.006). CONCLUSIONS: Adenovirus encoding-mediated transfer of vascular endothelial growth factor 121 induces an enhancement in regional perfusion in nonischemic myocardium that corresponds to changes in exercise tolerance. Adenovirus-encoding vascular endothelial growth factor therapy may be useful for inducing angiogenesis in the nonischemic state, such as for prophylactic therapy of early coronary artery disease.

Adenoviridae↗

PubMed2006

Oxygen exchange in muscle of young and old rats: muscle-vascular-pulmonary coupling.

Sustained performance of muscular exercise is contingent upon increasing muscle O(2) delivery (Qo2; the product of blood flow and arterial O(2) content, i.e. Q X Cao2) and utilization (Vo2m ) rapidly at exercise onset and sustaining necessary conductive and diffusive O(2) fluxes throughout exercise. A tight co-ordination of pulmonary, cardiovascular and muscle system responses is therefore required to prevent muscle microvascular O(2) pressures (P(mvO(2))) from falling to levels that impair blood-muscle O(2) exchange and/or impact metabolic control and reduce exercise tolerance. Microvascular O(2) pressures are determined by the balance between and Qo2 and Vo2m, and emerging evidence indicates that this balance is regulated differently across muscle fibre types and also in aged muscle. Moreover, disease states such as diabetes (type I and II) and chronic heart failure (CHF) also impact P(mvO(2)). This brief review primarily examines evidence obtained in animals that ageing: (1) redistributes exercising away from highly oxidative muscles and muscle fibres; (2) alters muscle capillary haemodynamics; and (3) reduces the O(2) pressure head within the microcirculation (P(mvO(2))) that serves to facilitate blood-muscle O(2) transfer. In many respects, these alterations found in healthy ageing animals bear a striking resemblance to those present in some chronic diseases (e.g. diabetes, CHF) and may help explain the compromised exercise tolerance present in aged individuals. Putative mechanistic insights are explored within the context of current knowledge and future investigative approaches.

Aging↗