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At least 649 records · Page 36Linked to original sources

PubMed2005

Functional-task exercise versus resistance strength exercise to improve daily function in older women: a randomized, controlled trial.

OBJECTIVES: To determine whether a functional-task exercise program and a resistance exercise program have different effects on the ability of community-living older people to perform daily tasks. DESIGN: A randomized, controlled, single-blind trial. SETTING: Community leisure center in Utrecht, the Netherlands. PARTICIPANTS: Ninety-eight healthy women aged 70 and older were randomly assigned to the functional-task exercise program (function group, n=33), a resistance exercise program (resistance group, n=34), or a control group (n=31). Participants attended exercise classes three times a week for 12 weeks. MEASUREMENTS: Functional task performance (Assessment of Daily Activity Performance (ADAP)), isometric knee extensor strength (IKES), handgrip strength, isometric elbow flexor strength (IEFS), and leg extension power were measured at baseline, at the end of training (at 3 months), and 6 months after the end of training (at 9 months). RESULTS: The ADAP total score of the function group (mean change 6.8, 95% confidence interval (CI)=5.2-8.4) increased significantly more than that of the resistance group (3.2, 95% CI=1.3-5.0; P=.007) or the control group (0.3, 95% CI=-1.3-1.9; P<.001). Moreover, the ADAP total score of the resistance group did not change significantly compared with that of the control group. In contrast, IKES and IEFS increased significantly in the resistance group (12.5%, 95% CI=3.8-21.3 and 8.6%, 95% CI=3.1-14.1, respectively) compared with the function group (-2.1%, 95% CI=-5.4-1.3; P=.003 and 0.3%, 95% CI=-3.6-4.2; P=.03, respectively) and the control group (-2.7%, 95% CI=-8.6-3.2, P=.003 and 0.6%, 95% CI=-3.4-4.6; P=.04, respectively). Six months after the end of training, the increase in ADAP scores was sustained in the function group (P=.002). CONCLUSION: Functional-task exercises are more effective than resistance exercises at improving functional task performance in healthy elderly women and may have an important role in helping them maintain an independent lifestyle.

Activities of Daily Living↗

PubMed2005

Prior heavy exercise eliminates VO2 slow component and reduces efficiency during submaximal exercise in humans.

We investigated the hypothesis that the pulmonary oxygen uptake (VO2) slow component is related to a progressive increase in muscle lactate concentration and that prior heavy exercise (PHE) with pronounced acidosis alters VO2 kinetics and reduces work efficiency. Subjects (n= 9) cycled at 75% of the peak VO2 (VO2peak) for 10 min before (CON) and after (AC) PHE. VO2 was measured continuously (breath-by-breath) and muscle biopsies were obtained prior to and after 3 and 10 min of exercise. Muscle lactate concentration was stable between 3 and 10 min of exercise but was 2- to 3-fold higher during AC (P < 0.05 versus CON). Acetylcarnitine (ACn) concentration was 6-fold higher prior to AC and remained higher during exercise. Phosphocreatine (PCr) concentration was similar prior to exercise but the decrease was 2-fold greater during AC than during CON. The time constant for the initial VO2 kinetics (phase II) was similar but the asymptote was 14% higher during AC. The slow increase in VO2 between 3 and 10 min of exercise during CON (+7.9 +/- 0.2%) was not correlated with muscle or blood lactate levels. PHE eliminated the slow increase in VO2 and reduced gross exercise efficiency during AC. It is concluded that the VO2 slow component cannot be explained by a progressive acidosis because both muscle and blood lactate levels remained stable during CON. We suggest that both the VO2 slow component during CON and the reduced gross efficiency during AC are related to impaired contractility of the working fibres and the necessity to recruit additional motor units. Despite a pronounced stockpiling of ACn during AC, initial VO2 kinetics were not affected by PHE and PCr concentration decreased to a lower plateau. The discrepancy with previous studies, where initial oxidative ATP generation appears to be limited by acetyl group availability, might relate to remaining fatiguing effects of PHE.

Adaptation, Physiological↗

PubMed2006

Prior heavy exercise elevates pyruvate dehydrogenase activity and speeds O2 uptake kinetics during subsequent moderate-intensity exercise in healthy young adults.

The adaptation of pulmonary oxygen uptake (.VO2) during the transition to moderate-intensity exercise (Mod) is faster following a prior bout of heavy-intensity exercise. In the present study we examined the activation of pyruvate dehydrogenase (PDHa) during Mod both with and without prior heavy-intensity exercise. Subjects (n = 9) performed a Mod(1)-heavy-intensity-Mod(2) exercise protocol preceded by 20 W baseline. Breath-by-breath .VO2 kinetics and near-infrared spectroscopy-derived muscle oxygenation were measured continuously, and muscle biopsy samples were taken at specific times during the transition to Mod. In Mod(1), PDHa increased from baseline (1.08 +/- 0.2 mmol min(-1) (kg wet wt)(-1)) to 30 s (2.05 +/- 0.2 mmol min(-1) (kg wet wt)(-1)), with no additional change at 6 min exercise (2.07 +/- 0.3 mmol min(-1) (kg wet wt)(-1)). In Mod(2), PDHa was already elevated at baseline (1.88 +/- 0.3 mmol min(-1) (kg wet wt)(-1)) and was greater than in Mod(1), and did not change at 30 s (1.96 +/- 0.2 mmol min(-1) (kg wet wt)(-1)) but increased at 6 min exercise (2.70 +/- 0.3 mmol min(-1) (kg wet wt)(-1)). The time constant of .VO2 was lower in Mod(2) (19 +/- 2 s) than Mod(1) (24 +/- 3 s). Phosphocreatine (PCr) breakdown from baseline to 30 s was greater (P < 0.05) in Mod(1) (13.6 +/- 6.7 mmol (kg dry wt)(-1)) than Mod(2) (6.5 +/- 6.2 mmol (kg dry wt)(-1)) but total PCr breakdown was similar between conditions (Mod(1), 14.8 +/- 7.4 mmol (kg dry wt)(-1); Mod(2), 20.1 +/- 8.0 mmol (kg dry wt)(-1)). Both oxyhaemoglobin and total haemoglobin were elevated prior to and throughout Mod(2) compared with Mod(1). In conclusion, the greater PDHa at baseline prior to Mod(2) compared with Mod(1) may have contributed in part to the faster .VO2 kinetics in Mod(2). That oxyhaemoglobin and total haemoglobin were elevated prior to Mod(2) suggests that greater muscle perfusion may also have contributed to the observed faster .VO2 kinetics. These findings are consistent with metabolic inertia, via delayed activation of PDH, in part limiting the adaptation of pulmonary .VO2 and muscle O2 consumption during the normal transition to exercise.

Adult↗

PubMed1989

Impaired blood pressure response to exercise in patients with coronary artery disease: possible contribution of attenuated reflex vasoconstriction in non-exercising muscles.

Eighteen patients with coronary artery disease were divided into two groups according to whether their blood pressure decreased (eight, group 1) or increased (10, group 2) in response to treadmill exercise testing. Age and the extent and distribution of coronary artery disease were similar in the two groups. At rest, blood pressure, pulmonary artery wedge pressure, cardiac index, forearm vascular resistance, and oxygen consumption were similar in the two groups. During supine leg exercise on a bicycle ergometer mean blood pressure increased in group 2 but did not change in group 1. Increases in cardiac index, pulmonary artery wedge pressure, and oxygen consumption during leg exercise were not significantly different in the two groups but forearm vascular resistance increased less in group 1 than in group 2. There was a positive correlation between the magnitude of the change in mean blood pressure and change in forearm vascular resistance during leg exercise. The impaired response of blood pressure to leg exercise in group 1 was not the result of a failure of the cardiac index to increase. The results suggest the possibility that attenuation of reflex vasoconstriction in non-exercising muscles may contribute to the impaired response of blood pressure to exercise in patients with coronary artery disease.

Adult↗

PubMed1991

A critical threshold of exercise capacity in the ventilatory response to exercise in heart failure.

During exercise patients with chronic left heart failure ventilate more than normal individuals at the same workload; the ratio of minute ventilation to minute production of carbon dioxide (VE/VCO2) is increased. The relation between increased VE/VCO2, severity of heart failure, and exercise capacity has not been defined. VE/VCO2 was measured in 47 patients with chronic left heart failure (New York Heart Association grades II and III) and in 1009 healthy controls. Exercise capacity was assessed by peak oxygen consumption (VO2max) during progressive exercise. In the controls VO2max ranged from 25 to 93 ml/kg/min; VE/VCO2 was 17-36 and did not correlate with VO2max. In chronic left heart failure the VO2max ranged from 9 to 29 ml/kg/min; VE/VCO2 was 22-42 and correlated strongly with VO2max. End tidal carbon dioxide and respiratory rate at peak exercise were similar in the controls and patients with chronic left heart failure. The increase in VE/VCO2 on exercise in chronic left heart failure indicates increased physiological dead space, presumably caused by a ventilation-perfusion mismatch. In the controls and patients with chronic left heart failure the relation of VE/VCO2 to VO2max was curvilinear with a threshold of VO2max below which VE/VCO2 started to rise above the normal range. This point of inflection may be explained by the existence of a critical level of cardiac function necessary to perfuse adequately all lung zones on exercise.

Adult↗

PubMed1994

Ten days of exercise training reduces glucose production and utilization during moderate-intensity exercise.

We have previously shown that 12 wk of endurance training reduces the rate of glucose appearance (Ra) during submaximal exercise (Coggan, A. R., W. M. Kohrt, R. J. Spina, D. M. Bier, and J. O. Holloszy. J. Appl. Physiol. 68: 990-996, 1990). The purpose of the present study was to examine the time course of and relationship between training-induced alterations in glucose kinetics and endocrine responses during prolonged exercise. Accordingly, seven men were studied during 2 h of cycle ergometer exercise at approximately 60% of pretraining peak oxygen uptake on three occasions: before, after 10 days, and after 12 wk of endurance training. Ra was determined using a primed, continuous infusion of [6,6-2H]glucose. Ten days of training reduced mean Ra during exercise from 36.9 +/- 3.3 (SE) to 28.5 +/- 3.4 mumol.min-1.kg-1 (P < 0.001). Exercise-induced changes in insulin, C-peptide, glucagon, norepinephrine, and epinephrine were also significantly blunted. After 12 wk of training, Ra during exercise was further reduced to 21.5 +/- 3.1 mumol.min-1.kg-1 (P < 0.001 vs. 10 days), but hormone concentrations were not significantly different from 10-day values. The lower glucose Ra during exercise after short-term (10 days) training is accompanied by, and may be due to, altered plasma concentrations of the major glucoregulatory hormones. However, other adaptations must be responsible for the further reduction in Ra with more prolonged training.

Adult↗

PubMed1996

CHO feeding before prolonged exercise: effect of glycemic index on muscle glycogenolysis and exercise performance.

This study examined the effect of preexercise carbohydrate (CHO) ingestion on muscle CHO metabolism and performance during prolonged exercise. Six endurance-trained men performed three exercise trials on a cycle ergometer after ingesting either a high glycemic index (HGI), low glycemic index (LGI), or placebo (Con) meal 45 min before exercise. During each trial, subjects cycled at a workload corresponding to 70% peak oxygen uptake for 120 min, followed by a 15-min performance cycle where total work (kJ) was measured. Ingestion of HGI resulted in an elevated (P < 0.01) blood glucose concentration 15 min after ingestion, compared with LGI and Con, but there were no differences in the glycemic responses to the meals thereafter, despite plasma insulin concentration being higher (P < 0.01) throughout the rest period after ingestion of HGI compared with LGI and Con. Plasma free fatty acid concentrations were lower (P < 0.05) throughout exercise in HGI compared with LGI and Con. In addition, concentrations of this metabolite were lower (P < 0.05) during the first hour of exercise in LGI compared with Con. Despite these results, no differences were observed in either the rate of muscle glycogen utilization during submaximal exercise or work output during the performance cycle when the three trials were compared. These results demonstrate that preexercise CHO ingestion has no effect on muscle glycogen utilization or exercise performance, irrespective of the glycemic or insulinemic responses to the ingested meals.

Adult↗

PubMed2006

Time required for the restoration of normal heavy exercise VO2 kinetics following prior heavy exercise.

Prior heavy exercise markedly alters the O2 uptake (VO2) response to subsequent heavy exercise. However, the time required for VO2 to return to its normal profile following prior heavy exercise is not known. Therefore, we examined the VO2 responses to repeated bouts of heavy exercise separated by five different recovery durations. On separate occasions, nine male subjects completed two 6-min bouts of heavy cycle exercise separated by 10, 20, 30, 45, or 60 min of passive recovery. The second-by-second VO2 responses were modeled using nonlinear regression. Prior heavy exercise had no effect on the primary VO2 time constant (from 25.9 +/- 4.7 s to 23.9 +/- 8.8 s after 10 min of recovery; P = 0.338), but it increased the primary VO2 amplitude (from 2.42 +/- 0.39 to 2.53 +/- 0.41 l/min after 10 min of recovery; P = 0.001) and reduced the VO2 slow component (from 0.44 +/- 0.13 to 0.21 +/- 0.12 l/min after 10 min of recovery; P < 0.001). The increased primary amplitude was also evident after 20-45 min, but not after 60 min, of recovery. The increase in the primary VO2 amplitude was accompanied by an increased baseline blood lactate concentration (to 5.1 +/- 1.0 mM after 10 min of recovery; P < 0.001). Baseline blood lactate concentration was still elevated after 20-60 min of recovery. The priming effect of prior heavy exercise on the VO2 response persists for at least 45 min, although the mechanism underpinning the effect remains obscure.

Adult↗

PubMed2002

Invited review: Effects of acute exercise and exercise training on insulin resistance.

Insulin resistance of skeletal muscle glucose transport is a key defect in the development of impaired glucose tolerance and Type 2 diabetes. It is well established that both an acute bout of exercise and chronic endurance exercise training can have beneficial effects on insulin action in insulin-resistant states. This review summarizes the present state of knowledge regarding these effects in the obese Zucker rat, a widely used rodent model of obesity-associated insulin resistance, and in insulin-resistant humans with impaired glucose tolerance or Type 2 diabetes. A single bout of prolonged aerobic exercise (30-60 min at approximately 60-70% of maximal oxygen consumption) can significantly lower plasma glucose levels, owing to normal contraction-induced stimulation of GLUT-4 glucose transporter translocation and glucose transport activity in insulin-resistant skeletal muscle. However, little is currently known about the effects of acute exercise on muscle insulin signaling in the postexercise state in insulin-resistant individuals. A well-established adaptive response to exercise training in conditions of insulin resistance is improved glucose tolerance and enhanced skeletal muscle insulin sensitivity of glucose transport. This training-induced enhancement of insulin action is associated with upregulation of specific components of the glucose transport system in insulin-resistant muscle and includes increased protein expression of GLUT-4 and insulin receptor substrate-1. It is clear that further investigations are needed to further elucidate the specific molecular mechanisms underlying the beneficial effects of acute exercise and exercise training on the glucose transport system in insulin-resistant mammalian skeletal muscle.

Animals↗

PubMed2001

Effects of endurance exercise training on plasma HDL cholesterol levels depend on levels of triglycerides: evidence from men of the Health, Risk Factors, Exercise Training and Genetics (HERITAGE) Family Study.

High density lipoprotein (HDL) cholesterol concentrations have been shown to increase with regular endurance exercise and, therefore, can contribute to a lower risk of coronary heart disease in physically active individuals compared with sedentary subjects. Although low HDL cholesterol levels are frequently observed in combination with hypertriglyceridemia, some individuals may be characterized by isolated hypoalphalipoproteinemia, ie, low HDL cholesterol levels in the absence of elevated triglyceride (TG) concentrations. The present study compared the responses of numerous lipoprotein-lipid variables to a 20-week endurance exercise training program in men categorized on the basis of baseline TG and HDL cholesterol concentrations: (1) low TG and high HDL cholesterol (normolipidemia), (2) low TG and low HDL cholesterol (isolated low HDL cholesterol), (3) high TG and high HDL cholesterol (isolated high TGs), and (4) high TGs and low HDL cholesterol (high TG/low HDL cholesterol). A series of physical and metabolic variables was measured before and after the training program in a sample of 200 men enrolled in the Health, Risk Factors, Exercise Training and Genetics (HERITAGE) Family Study. At baseline, men with high TG/low HDL cholesterol had more visceral adipose tissue than did men with isolated low HDL cholesterol and men with normolipidemia. The 0.4% (not significant) exercise-induced increase in HDL cholesterol levels in men with isolated low HDL cholesterol suggests that they did not benefit from the "HDL-raising" effect of exercise. In contrast, men with high TG/low HDL cholesterol showed a significant increase in HDL cholesterol levels (4.9%, P<0.005). Whereas both subgroups of men with elevated TG levels showed reductions in plasma TGs ( approximately -15.0%, P<0.005), only those with high TG/low HDL cholesterol showed significantly reduced apolipoprotein B levels at the end of the study (-6.0%, P<0.005). Multiple regression analyses revealed that the exercise-induced change in abdominal subcutaneous adipose tissue (10.6%, P<0.01) was the only significant correlate of the increase in plasma HDL cholesterol with training in men with high TG/low HDL cholesterol. Results of the present study suggest that regular endurance exercise training may be particularly helpful in men with low HDL cholesterol, elevated TGs, and abdominal obesity.

Adult↗

PubMed2000

The effects of oxitropium bromide on exercise performance in patients with stable chronic obstructive pulmonary disease. A comparison of three different exercise tests.

The purpose of the present study was to compare the characteristics of three different exercise tests in evaluating the effects of oxitropium bromide on exercise performance. Thirty-eight males with stable chronic obstructive pulmonary disease (COPD) (FEV(1) = 40.8 +/- 16.5% predicted; mean +/- SD) completed randomized, double-blind, placebo-controlled, crossover studies for each exercise test. The exercise tests were performed 60 min after the inhalation of either oxitropium bromide 400 microg or placebo. The patients performed 6-min walking tests (6MWT) on Days 1 and 2, progressive cycle ergometry (PCE) on Days 3 and 4, and cycle endurance tests at 80% of the maximal workload of PCE on Days 5 and 6. Spirometry was conducted before and at 45 and 90 min after the inhalation. Oxitropium bromide significantly increased FEV(1) as compared with placebo. Oxitropium bromide increased the endurance time significantly, by 19% (p < 0.001), and caused a small but significant increase in the 6-min walking distance by 1% (p < 0.05), but induced no significant increase in maximal oxygen consumption (V O(2)max) in PCE. The responses in these three exercise tests were different, and we conclude that the endurance test was the most sensitive in detecting the effects of inhaled anticholinergic agents on exercise performance in patients with stable COPD. An endurance procedure may be performed to detect clinical changes in evaluating the effects of oxitropium bromide on exercise performance.

Administration, Inhalation↗

PubMed2001

Children with asthma and physical exercise: effects of an exercise programme.

OBJECTIVE: To evaluate the effects of a physical exercise programme for children with asthma on an outpatient basis. DESIGN: Intervention study: a randomized pretest-post-test control group design. SETTING AND SUBJECTS: Forty-seven children with clinically diagnosed asthma participated in the intervention study, including 34 boys and 13 girls, from 8 to 13 years of age (mean age 10.6). INTERVENTIONS: The physical exercise programme consisted of regular group exercises and home exercises for a period of three months. It was based on a theoretical model describing the relationships between physical competence (condition), perceived physical competence, self-esteem and coping behaviour. MAIN OUTCOME MEASURES: Maximum incremental exercise test, endurance test, the Self-Perception Profile for Children (CBSK), the Asthma Coping Test (ACBT), lung function and exercise-induced bronchoconstriction. RESULTS: The results showed significant effects of the intervention programme on physical condition. There was a significant improvement of 15 W on the maximal workload (Wmax) (p < 0.001), of 7% on VO2max (oxygen uptake) (p = 0.002) and a significant decrease on heart rate submaximal of 6% (p = 0.001). There was also a significant improvement of 50% in running time measured with the endurance test (p = 0.021). Furthermore, a significant effect of the intervention was seen on coping with asthma (p = 0.003). CONCLUSION: It was concluded that participation in the physical exercise programme not only enhanced physical fitness, but also improved coping behaviour with asthma.

Activities of Daily Living↗

PubMed1995

Increase in respiratory resistance after exercise in conscious guinea pigs. As a model for exercise-induced asthma.

We have developed an experimental model for exercise-induced asthma (EIA) using conscious guinea pigs. Respiratory resistance (Rrs) was measured before and after exercise (running). When a 0.05% lipopolysaccharide (LPS) was inhaled by guinea pigs which had been pretreated with a corticosteroid biosynthesis inhibitor metyrapone (50 mg/kg, i.v.), Rrs significantly increased 24 h after exercise. Metyrapone had no effect, however, on the LPS-induced increase in the numbers of macrophages, eosinophils, neutrophils and lymphocytes in bronchoalveolar lavage fluid (BALF). In order to examine the role of airway inflammation, the effects of murine recombinant interleukin-5 (mrIL-5) and platelet activating factor (PAF) were investigated in guinea pigs. The exercise-elicited increase in Rrs was observed 24 h later than the treatment with mrIL-5 in metyrapone-treated animals. The number of macrophages, eosinophils and neutrophils increased in the BALF of mrIL-5-treated animals. In contrast, a 0.05% PAF aerosol caused an increased number of eosinophils in BALF, but did not affect Rrs after exercise in either metyrapone-treated or non-treated animals. Moreover, to evaluate the value of this model as a pharmacological tool, the effect of ketotifen and prednisolone on the exercise-induced increase in Rrs was investigated. Prior administration of ketotifen and prednisolone showed a tendency to prevent, or clearly inhibited, the exercise-induced increase in Rrs in animals treated with the combination with LPS and metopyrone.

Airway Resistance↗

PubMed1997

Clinical application of cardiac output during ramp exercise calculated using the Fick equation--comparison with the 2-stage bicycle ergometer exercise protocol in the supine position.

The purpose of this study was to clarify whether the direct Fick method is applicable to the measurement of cardiac output (Q) during ramp exercise. Twelve patients with chronic health failure underwent both a ramp exercise test and a steady-state exercise test. Oxygen intake (VO2), arterial oxygen saturation and mixed venous oxygen saturation were continuously measured using a pulse oximeter and a fiberoptic catheter, and the arteriovenous oxygen difference (a-v O2 diff) and Q were calculated. Both VO2 and a-v O2 diff were significantly lower in the ramp protocol than in the steady-state protocol when they were compared at the same workload. However, the VO2 vs Q relationship and the VO2 vs a-v O2 diff relationship were very similar in the 2 protocols. The difference between Q measured during steady-state exercise and Q calculated at the matched VO2 during ramp exercise was small (3.7 +/- 7.0% and 5.6 +/- 6.6%). The results indicate that, clinically, Q measured by the direct Fick method with simultaneous measurement of VO2 and a-v O2 diff during ramp exercise is a good substitute for the true Q measured by the steady-state protocol. We conclude that Fick Q is applicable to ramp exercise.

Adult↗

PubMed1994

Exercise echocardiographic correlates of transient dilatation of the left ventricular cavity on exercise thallium-201 SPECT imaging.

Transient dilatation of the left ventricular cavity on exercise thallium perfusion imaging is recognized as a marker of significant coronary disease, but the mechanisms that produce this finding are not fully understood. We studied 32 patients who underwent exercise thallium imaging and exercise echocardiography to determine the changes in left ventricular cavity size that underlie transient dilatation. Left ventricular area from the apical four-chamber view was used to approximate left ventricular cavity size. There were 24 patients who did not have transient dilatation (group 1) and 8 patients who did have transient dilatation (group 2) on thallium imaging. Systolic area decreased from rest to exercise in group 1 patients but not in group 2 patients. There was no significant change in diastolic area from rest to exercise in either group 1 or group 2 patients. Thus, exercise-induced systolic dysfunction, manifested as a failure to decrease left ventricular systolic cavity size in exercise, may be an important mechanism in producing scintigraphic transient dilatation.

Echocardiography↗

PubMed1988

Physiologic pacing in the elderly. Effects on exercise capacity and exercise-induced arrhythmias.

It is not clear whether hemodynamic and other benefits from dual-chamber pacing also exist in elderly patients. We studied a group of 18 elderly patients (mean age 74 +/- 4 yrs) with exercise testing in DDD and VVI modes in a randomized way to compare the effects of these pacing modes on exercise capacity, atrial rate and exercise-induced arrhythmias. Patients were selected when complete heart block was present without clinical evidence of sinus node dysfunction. Significant differences were observed: atrial rate was lower during exercise in DDD-mode (p less than 0.01); exercise time and cumulative load increased (p less than 0.05); maximal oxygen uptake was improved (p less than 0.05). Some of these differences were less clear in a subgroup with replacement of a VVI-device by DDD-stimulation. No differences could be observed in severity of exercise-induced arrhythmias. No evidence of sinus node dysfunction was found during exercise. Reprogramming of atrial sensitivity was required in 3 patients, with reprogramming to DVI because of paroxysmal atrial fibrillation once. Two patients died within a mean follow-up period of 13 months. Sinus rhythm was present at the most recent evaluation in all patients, including the patient stimulated in the DVI mode. Physiologic stimulation is of value for elderly patients with an active life style and complete heart block. Reprogramming to another pacing mode is only seldom necessary.

Aged↗

PubMed2001

[Silent myocardial ischemia and exercise-induced arrhythmia detected by the exercise test in the total health promotion plan (THP)].

We investigated the prevalence and characteristics of ischemic heart disease especially silent myocardial ischemia (SMI) and arrhythmia in need of careful observation in the exercise stress tests in the Total Health Promotion Plan (THP), which was conducted between 1994-96 for the purpose of measuring cardiopulmonary function. All workers (n = 4,918, 4,426 males) aged 18-60 yr old in an occupational field were studied. Exercise tests with an ergometer were performed by the LOPS protocol, in which the maximal workload was set up as a presumed 70-80% maximal oxygen intake, or STEP (original multistage protocol). ECG changes were evaluated with a CC5 lead. Two hundred and fifteen people refused the study because of a common cold, lumbago and so on. Of 4,703 subjects, 17 with abnormal rest ECG and 19 with probable anginal pain were excluded from the exercise tests. Of 4,667 who underwent the exercise test, 37 (0.79%) had ischemic ECG change, and 155 (3.32%) had striking arrhythmia. These 228 subjects then did a treadmill exercise test with Bruce protocol. Twenty-two (0.47% of 4,703) showed positive ECG change, 9 (0.19%) of 22 had abnormal findings on a 201Tl scan. 8 (0.17%) were diagnosed as SMI (Cohn I), in which the prevalence of hypertension, hyperlipidemia, diabetes mellitus, smoker and positive familial history of ischemic heart disease was greater than that of all subjects. In a 15-30 month follow up, none has developed cardiac accidents. Exercise-induced arrhythmia was detected in 11 (0.23%) subjects. Four were non-sustained ventricular tachycardia without any organic disease, 4 were ventricular arrhythmia based on cardiomyopathy detected by echocardiography, 2 were atrial fibrillation and another was WPW syndrome. It is therefore likely that the ergometer exercise test in THP was effective in preventing sudden death caused by ischemic heart disease or striking arrhythmia.

Adolescent↗

PubMed2004

Exercise-related time course of pulsatility index in brachial artery following forearm exercise assessed by Doppler ultrasound.

At rest, vascular reactivity assessed by the changes in pulsatility index (PI) is one indicator of vessel stenosis in some clinical/basic science research. However, all types of vessel stenosis do not show an alteration in the PI, because flow perfusion may be maintained by the development of collateral vessels such as in severe arterial stenosis or non-severe arterial stenosis. Therefore at rest, changes in the PI may not always be a precise indicator of vessel stenosis. However, a few studies have used the PI following exercise, which may provide additional information on hemodynamics. The purpose of the present study was to examine the exercise-related time course of the PI in the brachial artery after ischemic or non-ischemic isometric handgrip exercise (IHE) using Doppler ultrasound, and to determine the potential use of this parameter as an indicator of vascular disease. Ten healthy young male subjects performed IHE at 10% and 30% of maximum voluntary contraction (MVC) for 2-minutes (min) with or without arterial occlusion (AO), or 2-min of AO alone. Following each 2-min session, PI was determined during the 5-min recovery period. A significant difference in the recovery PI was observed between IHE, ischemic IHE, as well as AO alone. Exercise with AO significantly increased the reduction in the PI compared to exercise alone, or AO alone, at both 10% and 30%MVC. These results suggest, exercise-induced changes in the time course of the PI during recovery may potentially be a useful diagnostic tool. Exercise-induced ischemic state may potentially be a useful indicator for detecting arteriovascular disease, even if it is not detected by AO alone.

Adult↗