摘要:

The Effect of beta-adrenergic blockade on obtaining a trained exercise state was determined in a sample of 27 healthy adult males (mean age 24 years). For control purposes, subjects were given two maximal treadmill exercise tests, then were randomly assigned to either a placebo group or a beta-adrenergic blocking drug group (sotalol, 320 mg/day). A third maximal treadmill test was administered one week after the initiation of medication. Subjects then participated in a 13-week training program in which they exercised 45 minutes per day five days per week at a training heart rate equivalent to 75% of measured maximal oxygen uptake. Subjects underwent a fourth maximal treadmill test at the conclusion of the training program while under medication; seven days after cessation of medication subjects performed a fifth maximal treadmill test. Maximal oxygen uptake was increased following training in both groups; however, in the beta-blocked group this was manifest only when the subjects were no longer blocked, i.e., uptake did not change while the subjects were still taking beta-blocking drugs. This observation points to the importance of both stroke volume and heart rate in defining the adaptability of the oxygen transport system.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Adouble-blind, parallel-group, placebo-controlled study was conducted to determine the acute physiologic responses to maximal exercise consequent to chronic beta-adrenergic blockade. Twenty-eight healthy, male subjects were tested twice on a treadmill to the point of volitional fatigue using the Bruce protocol and were then randomly assigned to either the placebo (N = 14) or the beta-blockade group (N = 14). The beta-blocking agent sotalol was administered once daily (320 mg/day) for a period of seven days, after which subjects were given a third treadmill test to exhaustion. Oxygen uptake and heart rate were assessed each minute until the respiratory exchange ratio reached 0.95, at which point oxygen uptake was assessed at 30-second intervals. Beta blockade significantly reduced maximal heart rate (191 ± 8.8 versus 150 ± 13.2 beats/min, P < .05) but did not alter treadmill time to exhaustion (676 ± 44 versus 671 ± 57 sec). Maximal oxygen uptake was significantly reduced (43.6 ± 5.8 versus 42.0 ± 5.4 ml/kg/min, P < .05), but this small difference was not considered physiologically significant. No differences were identified in the placebo group for maximal heart rate (195 ± 7.2 versus 193 ± 7.2 beats/min), maximal oxygen uptake (43.9 ± 6.0 versus 43.7 ± 5.1 ml/kg/min), or treadmill time to exhaustion (701 ± 85 versus 705 ± 79 sec). Results indicate that beta-adrenergic blockade with the drug sotalol has little or no effect on physical work capacity and suggest that stroke volume and possibly peripheral oxygen extraction are enhanced at maximal exercise during beta blockade.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

The reproducibility and accuracy of measurements by the Beckman Metabolic Measurment Cart and by an established manual method of the ventilatory responses and aerobic requirements at rest and during symptom-limited exercise were evaluated in eight normal subjects. Each person performed four exercise tests. Both methods showed excellent reproducibility of minute ventilation, oxygen uptake (VO2), carbon dioxide production (VCO2), and respiratory exchange ratio (RER). The respective correlations for the metabolic measurement cart were r = .99, .99, .99, .93 and for the manual method r = .98, .99, .99, .93. Reproducibility of heart rate and blood pressure responses during exercise was good, with correlation coefficients of .95 and .91 for values obtained during tests with the metabolic measurement cart and .94 and .89 with the manual method. Each variable at maximal exercise showed good reproducibility with no significant difference for either method. Comparison between the pooled metabolic cart measurement and the pooled manual method measurements of variables during the third minute of each stage of exercise showed excellent agreement (r = .97, .98, .99, .93 for minute ventilation, VO2, VCO2, and RER, respectively). The means of differences observed between the two methods were small (.69, .04, .03 L/min and .00 for each variable, respectively), although VO2and VCO2showed significant differences (P < .05). Comparison of variables between the pooled results for the two methods at maximal exercise showed high agreement. We conclude that the metabolic measurement cart provides reproducible and accurate measurements of respiratory variables and on-line results that are an advantage over the manual method. It also saves technician time.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

Asurvey of smoking habits was conducted six months after myocardial infarction or coronary artery bypass surgery among 129 cardiac rehabilitation patients who smoked at the time of their cardiac event. Seventy-eight percent of the patients stopped smoking. Men were more successful in smoking termination than were women; men appeared to find family support more helpful than did women. The method of smoking termination (abrupt or gradual) was unimportant. Strategies to maintain abstinenc from smoking and to increase smoking termination in patients are discussed.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

In analyzing programs designed to facilitate the recovery of individuals from cardine events, return to work is frequently used as a measure of effectiveness. Such programs include medical and surgical treatment of coronary artery disease following cardiac events such as myocardial infarction, cardiac arrest, coronary artery bypass surgery, and other cardiac surgery.This paper examines the potential determinants of return to work, then summarizes their relative importance in a variety of clinical settings. Reports from the Second World Congress on Cardiac Rehabilitation, held in Jerusalem in late 1981, offer an international perspective to this aspect of the recovery process.1Cultural and national customs, as well as personal work status, satisfactions and autonomy on the job, and perception of medical risk, strongly influence individuals' decisions about returning to work. Specific advice by the therapeutic team can facilitate earlier return to work when appropriate. Finally, suggestions are made for further investigation into the medical, social, psychological, and economic facets of return to work.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

摘要:

QUESTIONS AND ANSWERS is a regular feature in which leading clinicians and researchers share with their colleagues their views on matters that are relevant to cardiac rehabilitation. The coeditors invite Journal of Cardiac Rehabilitation readers to suggest questions for discussion in this forum.

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID

ISSN:0275-1429    

出版商:OVID    

年代:1983

数据来源: OVID