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PubMed2006

Influence of acute plasma volume expansion on VO2 kinetics, VO2 peak, and performance during high-intensity cycle exercise.

The purpose of this study was to examine the influence of acute plasma volume expansion (APVE) on oxygen uptake (V(O2)) kinetics, V(O2peak), and time to exhaustion during severe-intensity exercise. Eight recreationally active men performed "step" cycle ergometer exercise tests at a work rate requiring 70% of the difference between the gas-exchange threshold and V(O2max) on three occasions: twice as a "control" (Con) and once after intravenous infusion of a plasma volume expander (Gelofusine; 7 ml/kg body mass). Pulmonary gas exchange was measured breath by breath. APVE resulted in a significant reduction in hemoglobin concentration (preinfusion: 16.0 +/- 1.0 vs. postinfusion: 14.7 +/- 0.8 g/dl; P < 0.001) and hematocrit (preinfusion: 44 +/- 2 vs. postinfusion: 41 +/- 3%; P < 0.01). Despite this reduction in arterial O(2) content, APVE had no effect on V(O2) kinetics (phase II time constant, Con: 33 +/- 15 vs. APVE: 34 +/- 12 s; P = 0.74), and actually resulted in an increased V(O2peak) (Con: 3.90 +/- 0.56 vs. APVE: 4.12 +/- 0.55 l/min; P = 0.006) and time to exhaustion (Con: 365 +/- 58 vs. APVE: 424 +/- 64 s; P = 0.04). The maximum O(2) pulse was also enhanced by the treatment (Con: 21.3 +/- 3.4 vs. APVE: 22.7 +/- 3.4 ml/beat; P = 0.04). In conclusion, APVE does not alter V(O2) kinetics but enhances V(O2peak) and exercise tolerance during high-intensity cycle exercise in young recreationally active subjects.

Adult↗

PubMed1993

[The relationship between the pathogenetic mechanisms of effort stenocardia and the pharmacodynamics of anti-anginal agents].

A single administration of nitroglycerin, corinfar, anapriline was studied for effects on exercise tolerance in 33 patients with exercise-induced angina with varying adrenergic vasoconstriction during exercise estimated by responses to pratsiol. The effect was found to be related to the degree of functional vasoconstriction. It is concluded that there is a pathogenetic heterogeneity of angina on effort in which in 57% of patients having high coronary reserve, adrenergic vasoconstriction along with organic changes in of great value in the genesis of myocardial ischemia during exercise. In 33% patients with low coronary reserve, the major role is played by organic changes in the coronary bed and vasoconstrictive responses are unassociated with adrenergic exposure. Only in 12% of patients the functional component of coronary vasoconstriction is lacking.

Adult↗

PubMed1986

[Predicting the effectiveness of nitrosorbide with regard to increasing tolerance to physical loads].

A study of the indices of spiroergometry, tetrapolar rheography, echocardiography at rest and during bicycle ergometry in 50 patients after myocardial infarction prior to and after the use of nitrosorbide showed that the use of this drug to raise exercise tolerance was recommended to patients after myocardial infarction with a considerable enlargement of the left ventricle. The invariability of heart rate after taking the drug at rest served as a prognostic criterion for the use of nitrosorbide to raise exercise tolerance. Increased cardiac rhythm at rest by 11% and upwards after the use of the drug was a sign of its inefficacy for the above purpose.

Adult↗

PubMed1989

Comparison of the antianginal efficacy of four calcium antagonists and propranolol in stable angina pectoris.

The antianginal effects of propranolol 160 mg/day, diltiazem 240 mg/day, nicardipine 80 mg/day, nifedipine 40 to 80 mg/day and verapamil 320 mg/day were compared in 12 patients with chronic stable angina pectoris using a symptom-limited exercise test. Compared to placebo propranolol and calcium antagonists similarly reduced (p less than 0.001) the frequency of antianginal attacks and nitroglycerin consumption, and increased exercise tolerance and time to greater than or equal to 1 mm S-T segment depression. After propranolol the pressure-rate product at submaximal and maximal exercise was significantly decreased. The calcium antagonists produced a significant reduction in the submaximal pressure-rate product, but no significant change in the peak pressure-rate product. Maximum ST depression was significantly lower after propranolol and was unchanged after the calcium antagonists. None of the drugs caused significant adverse effects. The results indicate that in patients with stable effort angina pectoris, diltiazem, nicardipine, nifedipine and verapamil were as effective as propranolol in improving exercise tolerance and time to ischaemia, and they did not alter the peak pressure-rate product. Different antianginal mechanisms may be operative for the various calcium antagonists.

Angina Pectoris↗

PubMed1993

Captopril versus digoxin in patients with coronary artery disease and mild heart failure. A prospective, double-blind, placebo-controlled multicenter study. The CADS Study Group.

We conducted a prospective, double-blind, placebo-controlled multicenter trial in order to evaluate the long-term effects of captopril (50 mg/day), digoxin (0.25 mg/day) and placebo on quality of life, cardiovascular events, clinical symptoms and exercise tolerance in patients with documented myocardial infarction, resulting in regional wall motion abnormalities, and with mild heart failure (NYHA class II to III without treatment) and exercise not limited by angina. 222 patients were studied, 63 were randomized to captopril, 66 to digoxin, 67 to placebo. Follow-up was conducted for two years. Base line characteristics in the three treatment groups were similar. After one year of therapy, digoxin had significantly improved general well-being (p < 0.01 vs captopril), symptom score (p < 0.05 vs captopril and placebo), and vitality (p < 0.05 vs captopril). Digoxin improved NYHA class in 45% as compared to placebo (28%, p < 0.05). Worsening of angina was more frequent with captopril as compared to digoxin (p < 0.05). However, cardiovascular events during follow-up were lower in the captopril group as compared to placebo and digoxin (p < 0.01 captopril vs placebo). No differences between groups were observed in baseline and follow-up exercise tolerance between the three groups. Dizziness during upright tilt and cough were more frequent with captopril as compared to digoxin or placebo. After two years of follow-up (captopril n = 32, digoxin n = 29, placebo n = 27) general well-being was improved with both digoxin and captopril (p < 0.004 and p < 0.03 vs placebo).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

[Diagnosis of restenosis of the coronary artery following x-ray endovascular dilatation].

Altogether 40 patients with stable angina of effort were investigated in a long-term period after roentgenovascular dilatation of one or two coronary arteries. Control coronography was performed in 22 patients with lowered exercise tolerance. A reliable feature in the development of hemodynamically significant restenosis and/or "new" coronary stenosis in 11 patients was a combination of average and low exercise tolerance with its negative dynamics. For patients with I functional class, a sign of restenosis and/or "new" stenosis was the appearance of the ischemic shift of the CT-segment on ECG during bicycle testing. An efficient selection of patients resulted in increased sensitivity and specificity of noninvasive tests.

Adult↗

PubMedDate not supplied

The antiarrhythmic effect of the ACE inhibitor captopril in patients with congestive heart failure largely is due to its potassium sparing effects.

OBJECTIVE: To evaluate the mechanisms by which the angiotensin converting enzyme (ACE) inhibitor captopril may modify the presence of ventricular arrhythmias in patients with chronic heart failure. PATIENTS: Forty-seven patients with chronic stable congestive heart failure. METHODS: Twenty-four hour Holter monitoring was done prior to and after one month of therapy with the ACE inhibitor captopril. In a first group of 25 patients, changes in the incidence of ventricular arrhythmias were correlated with changes in cardiac hemodynamics (assessed invasively). In a second group of 22 patients, changes in ventricular arrhythmias were correlated with changes in echocardiographic measurements. In all patients serum potassium was kept constant, and changes in exercise tolerance and serum noradrenaline levels were assessed prior to and after captopril. RESULTS: One month of captopril therapy caused an improvement in cardiac hemodynamics and in exercise tolerance. It also led to a tendency for improved echocardiographic measurements and serum noradrenaline levels, similar to those already published by others. However, no change in the incidence or severity of ventricular arrhythmias was detected. No correlation could be found between changes in ventricular arrhythmias and any of the variables measured. CONCLUSIONS: As the only obvious difference between this and previous studies that documented a decrease in ventricular arrhythmias when ACE inhibitors were started in patients with congestive heart failure is a lack of change in serum potassium in this study, the current results suggest that the major antiarrhythmic effect of ACE inhibitors in patients with congestive hear failure is the result of their potassium sparing effects.

Adult↗

PubMed1979

Prevalence of asthma: a comparative study of urban and rural Xhosa children.

An epidemiological study was undertaken to determine the prevalence of asthma in young urban and rural black (Xhosa) children. One thousand three hundred and seventy five children were studied, 694 from a Cape Town african township and 671 from a rural area in Transkei. The exercise tolerance test which required free range running at maximum effort for 6 min was used to identify asthmatic subjects. A fall of 15% or more in the post-exercise FEV1 and PEFR values was regarded as a positive result. Twenty-three children were found to be asthmatic, twenty-two from the city area, but only one from the country, giving a prevalence figure for asthma of 3.17% in the first group and 0.14% for the second. Possible reasons for these differences are discussed. The exercise tolerance test was found to be a useful tool for epidemiological studies of asthma.

Asthma↗

PubMed2000

Pathophysiology of cardiac transplantation and the challenge of exercise.

Heart transplantation is now currently performed in adult (A-HTR) as well as in pediatric cardiac patients (P-HTR). In A-HTR, heart denervation results in a delayed, blunted heart rate (HR) response to exercise onset, mainly sustained by the level of circulating catecholamines. At the offset of exercise HR resumes the pre-exercise level in 5-25 min, depending on the absolute work intensity. Peak HR is approximately 140 beats/min. Maximal aerobic power is 19 O2/kg x min, i.e., approximately 60% than that of healthy age-matched sedentary subjects and exercise tolerance is therefore reduced. A functional impairment at the muscle level may also be present, as suggested by the slow kinetics of the VO2 readjustment (phase II) at the onset of submaximal aerobic exercise. P-HTR generally behave as A-HTR. However, recently, in a few P-HTR a fast HR response to exercise and greater peak HR values (172 +/- 22 beats/min) were demonstrated. Maximal aerobic power of P-HTR was 32 +/- 7 ml O2/kg x min, greater than that of A-HTR, but yet approximately 60% of that of healthy age-matched controls. It may be concluded that occasionally P-HTR may resume an almost normal cardiovascular response to exercise; nevertheless, their exercise tolerance is limited, likely by functional impairment at the muscle level, whose origin is still unknown.

Child↗

PubMed2000

[The effect of cardiovascular rehabilitation on the variability of the RR cycle after a first uncomplicated acute myocardial infarct].

BACKGROUND: The aim of this study was to verify the changes in the autonomic balance by means of heart rate variability assessment in patients with myocardial infarction referred for cardiac rehabilitation. METHODS: We studied 122 patients (79 males, 43 females, mean age 56 +/- 5 years), with a first uncomplicated myocardial infarction (anterior 48, thrombolysis 72), Killip class 1, preserved left ventricular function (ejection fraction 49 +/- 6%). All patients were free of inducible residual ischemia. Four weeks after myocardial infarction, patients were randomized into two groups; Group 1 (n = 58) referred for an 8 week cardiac rehabilitation program (scheduled: 24 sessions); Group 2 (n = 64): normal daily physical activity. During a 24-hour Holter ECG monitoring the following parameters were calculated in pharmacological wash-out at randomization (T0) and at the end of cardiac rehabilitation/control period (T1): mean value of RR intervals (RR), its standard deviation (SDNN), pNN50, rMSSD in the time domain; low frequency (LF) and high frequency (HF) value and the LF/HF ratio in the frequency domain. T1-T0 changes in percent values (delta %) were considered and compared between the two groups. RESULTS: Thirty-one patients were excluded from the study either for insufficient adhesion to the cardiac rehabilitation program (< 13 sessions, 22 patients) or recurrent ischemia (3 Group 1 patients and 3 Group 2 patients) and non-assessable 24-hour Holter ECG monitoring (3 patients). Thirty-one Group 1 patients and 60 Group 2 patients completed the study with a first and a second 24-hour Holter ECG monitoring performed at 30 +/- 3 days and 60 +/- 4 days respectively. At the same time an ergospirometric test was performed to evaluate cardiopulmonary function by means of exercise time, maximum oxygen consumption, anaerobic threshold, exercise time at the anaerobic threshold, and maximum oxygen consumption at the anaerobic threshold. Twenty-eight Group 1 patients and 44 Group 2 patients completed the study with a first and a second ergospirometric test. Baseline heart rate variability parameters were comparable in the two groups. During the observation period only in Group 1 patients heart rate variability parameters changed significantly: RR (Group 1 = +18.3 +/- 21.3; Group 2 = +4.2 +/- 5.2, p = 0.000), pNN50 (Group 1 = 45.0 +/- 38.9; Group 2 = +24.2 +/- 34.7, p = 0.011), HF (Group 1 = +81.6 +/- 124; Group 2 = -28.7 +/- 75.4, p = 0.014) and LF/HF ratio (Group 1 = -26.0 +/- 16.1; Group 2 = -4.9 +/- 6.1, p = 0.062). There were no significant differences in SDNN, rMSSD and LF. A linear correlation between delta LF/HF ratio and baseline LF/HF ratio values was found in Group 1 (r = 0.489, p = 0.006), whereas no correlation was found between this parameter and age, ejection fraction, creatine phosphokinase, and infarct localization. Group 1 patients had a significant improvement in exercise tolerance compared to Group 2 patients. CONCLUSIONS: A cardiac rehabilitation program positively modifies the sympatho-vagal balance in patients with uncomplicated myocardial infarction, increasing the parasympathetic tone and exercise tolerance.

Aged↗

PubMed2004

[A case of food-dependent exercise-induced anaphylaxis caused by various foods which contained flour for thirty years].

The patient was a 65-year-old man with chief complaints of flare, swelling, itching and loss of consciousness. He had a history of diabetes diagnosed at the age of 34 years and was receiving medication from a local doctor. He had experienced systemic flare, swelling and loss of consciousness 20 minutes after drinking beer at a party at the age of 34 years. Since that time, he had frequently experienced urticaria and loss of consciousness while taking a walk after eating various foods (all of which contained flour). In February 2001, he experienced systemic flare, swelling and loss of consciousness when he returned home from a walk after eating a meal that included meat dumplings. Laboratory tests on admission showed a serum IgE level of 253 IU/ml, and the IgE level for flour in a RAST was 2.13 UA/ml (class 2). The results of exercise tolerance tests were normal during fasting, after ingestion of food that did not include allergens (wheat, shrimps and crab) and after ingestion of half of a thick slice of white bread, but systemic wheal and flare reactions appeared during an exercise tolerance test after ingestion of one thick slice of white bread. A diagnosis of food-dependent exercise-induced anaphylaxis caused by flour was made on the basis of the results.

Aged↗

PubMed1996

Usefulness of the transcendental meditation program in the treatment of patients with coronary artery disease.

Twenty-one patients with documented coronary artery disease were tested at baseline by exercise tolerance testing, and assigned to either stress reduction using the Transcendental Meditation (TM) program or to a wait-list control, After 8 months, the TM group had a 14.7% increase in exercise tolerance, an 11.7% increase in maximal workload, an 18% delay in onset of ST-segment depression, and significant reductions in rate-pressure product at 3 and 6 minutes, and at maximal exercise compared with the control group.

Angina Pectoris↗

PubMed1995

Dose-ranging study of a new, once-daily diltiazem formulation for patients with stable angina.

A double-blind safety and efficacy dose-ranging study was conducted with a new, once-daily, extended-release (XR) diltiazem hydrochloride formulation (Dilacor XR, Rhône-Poulenc Rorer, Collegeville, PA) in 189 patients with chronic stable angina pectoris. After a 2-week placebo lead-in phase, the patients were randomly assigned to 1 of 4 once-daily, fixed-dose treatment groups: placebo, XR diltiazem 120 mg, 240 mg, or 480 mg. Extended-release diltiazem, at 240-mg and 480-mg once-daily doses, significantly improved (P < .05) total exercise time during treadmill exercise tolerance testing after 2 weeks of treatment when assessed 24 hours after the previous dose. These increasing doses of XR diltiazem were associated with incremental improvements in exercise tolerance. Outpatient function, as assessed by frequency of anginal attacks, nitroglycerin use, and ambulatory electrocardiogram (Holter, Scole Engineering Culver City, CA) monitoring of ischemic events, was also improved by XR diltiazem. This extended-release diltiazem formulation can be clinically titrated within the 120- to 480-mg dosing range, permitting effective once-daily administration for treating chronic stable angina.

Adult↗

PubMed1986

Twelve-minute walking test in a group of Dutch patients with chronic obstructive pulmonary diseases; relationship with functional capacity.

Limitations in exercise tolerance are characteristic for patients with chronic obstructive pulmonary disease. The twelve-minute walking test has been proposed as a simple, reproducible test to assess exercise tolerance in these patients. We investigated factors, that predicted the twelve-minute walking distance in a group of fifty patients with COPD, who had a maximal reversibility in the FEV1 of 20% after inhaled salbutamol. There was a strong correlation between walking distance and IVC (%pred) (p less than 0.001), RV% TLC (%pred) (p less than 0.001), FEV1 (ml) (p less than 0.001), FEV1 (%pred) (p less than 0.001) and PaO2 (mm Hg) (p less than 0.01). It is concluded that pathophysiological factors are the main determinants of the twelve-minute walking distance.

Adult↗

PubMed1977

A noninvasive study of the response of ischemic heart to exercise.

The response to exercise during increasing workloads (supine bicycling), was studied in 105 men, of whom 70 had ischemic heart disease and 35 did not, clinically classed into 6 groups. Heart rates, blood pressures and systolic time intervals (STI) were measured in relation to exercise tolerance and capacity. The ischemic heart disease (IHD) subjects differed from the nonischemic by an increased PEP/LVET ratio at rest and by a tendency of the diastolic blood pressure to increase upon exercise. Two main types of abnormal reaction of STI to workload were ascertained: (1) prolonged LVETc with respect to controls (prevailing in angina pectoris), and (2) prolonged PEPEc together with shorter LVETc (typical for left ventricular failure). The dominant feature appears to be the depressed contractility in the latter and a decreased compliance (or rate of relaxation) in the former. Estimation of STI may contribute to the evaluation of the exercise tolerance test in long-term examination of ischemic patients.

Adult↗

PubMed1984

Beta-adrenergic stimulation of the failing ventricle: a double-blind, randomized trial of sustained oral therapy with prenalterol.

Eleven patients with severe left ventricular impairment (mean ejection fraction 24%) and moderate impairment of exercise tolerance underwent a double-blind, placebo-controlled, cross-over trial of the orally administered beta-agonist prenalterol. Exercise hemodynamics and tolerance were measured during bicycle and treadmill exercise after 2 weeks of therapy with placebo or prenalterol. Cardiac index, ejection fraction, and stroke work index were not improved and exercise duration and peak oxygen consumption were not significantly different during the two treatments. During prenalterol treatment heart rate during exercise was consistently reduced. These results show that prolonged therapy with prenalterol does not improve hemodynamics or exercise tolerance and is associated with a diminished heart rate response to exercise.

Administration, Oral↗

PubMed1979

[Continuous ambulatory electrocardiographic recordings using the Holter system in the late phase of hospitalization for recent myocardial infarct. Value and limitations studied in a series of 100 patients].

Repeated continuous ambulatory electrocardiography by Holter monitoring was performed after early mobilisation post-myocardial infarction in 100 patients, without ventricular extrasystoles on classical ECG. Frequent ventricular arrhythmias were recorded in 58 p. 100 cases, unrelated to the localisation of the infarct. The observation of ventricular arrhythmias in the Coronary Care Unit (CCU) was not related to the occurrence of VEs during Holter monitoring. On the other hand, VEs were less frequent (38 p. 100 compared to 68 p. 100) in patients taking amiodarone or betablockers on transfer from the CCU. The reduced activity of patients during Holter monitoring minimises the frequency of arrhythmias, and 10 p. 100 patients were observed to have VEs only after exercise tolerance testing. These VEs seem to be a bad prognostic factor; the 9 patients who died in this series all presented VEs on ambulatory monitoring (7) or during exercise tolerance testing (2). However the number of patients with triple vessel disease was greater in the group with VEs on ambulatory monitoring (57 p. 100 compared with 13 p. 100). It is difficult to assess the precise role of the VEs amongst the other risk factors of sudden death. This is not a randomised study, but it would appear that long=term amiodarone or betablockers therapy may influence the medium-term prognosis.

Adrenergic beta-Antagonists↗

PubMed1996

Behavioral adjustment of children with surgically palliated complex congenital heart disease.

Examined the behavioral adjustment at school age of 26 children with surgically treated complex congenital heart disease compared to that of 26 children who had been diagnosed as having an innocent murmur. The children with complex heart disease were rated by their parents as more withdrawn, having more social problems, and engaging in fewer activities, and by their teachers as more withdrawn. The families of the children with complex heart disease reported experiencing more stress. Two variables, family strain and exercise tolerance, were strong predictors of teacher-rated school adjustment in the children with complex heart disease, with family strain accounting for 33% of the variance, and exercise tolerance 24%. The impact of the child's chronic condition on the family thus seems to be a critical factor in the school adjustment of these children, more so even than the physical limitations imposed on the child by the chronic condition.

Activities of Daily Living↗