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Introduction: Falls can cause injury and may compromise function in spinal muscular atrophy (SMA) patients. Weakness and gait variability are associated with falls in other neurological disorders, and fatigue is well documented in SMA. The relationship of weakness, fatigue, and gait variability to falls has never been investigated., Methods: Seven ambulatory patients with SMA completed a falls history questionnaire, 6MWT, gait analysis, and strength testing. Pearson correlation coefficients were used to examine associations between these variables., Results: All 7 subjects reported falls in the previous year. Stride-length variability was significantly associated with falls, unlike strength, fatigue, or other gait variables., Conclusions: Stride-length variability was the key variable associated with falls. Preventive strategies to avoid falls should be incorporated into patient management plans. Gait analysis provides actionable information not revealed by standard assessments and should be included in clinical trials designed to address the prevention of falls in the SMA population., (Copyright © 2012 Wiley Periodicals, Inc.)

Background: Gait impairment is common in Parkinson's disease (PD) and may result in greater energy expenditure, poorer walking economy, and fatigue during activities of daily living. Auditory cueing is an effective technique to improve gait; but the effects on energy expenditure are unknown., Objective: To determine whether energy expenditure differs in individuals with PD compared with healthy controls and if auditory cueing improves walking economy in PD., Methods: Twenty participants (10 PD and 10 controls) came to the laboratory for three sessions. Participants performed two, 6-minute bouts of treadmill walking at two speeds (1.12 m·sec-1 and 0.67 m·sec-1). One session used cueing and the other without cueing. A metabolic cart measured energy expenditure and walking economy was calculated (energy expenditure/power)., Results: PD had worse walking economy and higher energy expenditure than control participants during cued and non-cued walking at the 0.67 m·sec-1 speed and during non-cued walking at the 1.12 m·sec-1. With auditory cueing, energy expenditure and walking economy worsened in both participant groups., Conclusions: People with PD use more energy and have worse walking economy than adults without PD. Walking economy declines further with auditory cuing in persons with PD.

Purpose: We investigated the relationship between physical activity and mental health and determined the optimal amount of physical activity associated with better mental health., Method: Self-reported data from a national random sample of 7674 adult respondents collected during the 2008 U.S. Health Information National Trends 2007 Survey (HINTS) were analyzed in 2012. Mental health was plotted against the number of hours of physical activity per week using a fractional 2-degree polynomial function. Demographic and physical health factors related to poorer mental health were examined. The optimal range of physical activity associated with poorer mental health was examined by age, gender, and physical health., Results: A curvilinear association was observed between physical activity and general mental health. The optimal threshold volume for mental health benefits was of 2.5 to 7.5h of weekly physical activity. The associations varied by gender, age, and physical health status. Individuals who engaged in the optimal amount of physical activity were more likely to have reported better mental health (odds ratio=1.39, p=0.006)., Conclusions: This study established a hyperbolic dose-response relationship between physical activity and general mental health, with an optimal range of 2.5 to 7.5h of physical activity per week., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Exercise performance during cardiopulmonary exercise testing (CPET) is a predictor of all-cause mortality in the general population and in patients with coronary heart disease. Mortality beyond one-year after lung transplantation (LTx) is due to multiple causes, is difficult to predict, and has not been fully evaluated in LTx recipients. We hypothesized that, similar to other populations, exercise performance after LTx may be associated with mortality. A retrospective review of all LTx recipients who underwent CPET between 2001 and 2009 was conducted. Chosen endpoint was re-transplantation or death. Survival analysis was performed using Cox proportional-hazard models in 183 patients. After adjusting for bronchiolitis obliterans syndrome (BOS) score, for every 10% increment in percent-predicted peak watts or percent-predicted peak oxygen uptake patients were approximately 23% less likely to experience an endpoint. We conclude that after adjusting for BOS score, lower exercise capacity one-year post LTx is independently associated with mortality. This may imply a protective role of exercise capacity in the LTx population., (Copyright © 2012 Elsevier B.V. All rights reserved.)

To determine how increased ventilatory demand impacts ventilatory kinematics, we compared the total chest wall volume variations (V(CW)) of male and female endurance-trained athletes (ET) to untrained individuals (UT) during exercise. We hypothesized that training and gender would have an effect on V(CW) and kinematics at maximal exercise. Gender and training significantly influenced chest wall kinematics. Female ET did not change chest wall end-expiratory volume (V(CW,ee)) or pulmonary ribcage (V(RCp,ee)) with exercise, while female UT significantly decreased V(CW,ee) and V(RCp,ee) with exercise (p<0.05). Female ET significantly increased pulmonary ribcage end-inspiratory volume (V(RCp,ei)) with exercise (p<0.05), while female UT did not change V(RCp,ei) with exercise. Male ET significantly increased V(RCp,ei) with exercise (p<0.05); male UT did not. Men and women had significantly different variation of V(CW) (p<0.05). Women demonstrated the greatest variation of V(CW) in the pulmonary ribcage compartment (V(RCp)). Men had even volumes variation of the V(RCp) and the abdomen (V(Ab)). In conclusion, gender and training had a significant impact on ventilatory kinematics., (Copyright © 2011 Elsevier B.V. All rights reserved.)

New advances in computer processing and imaging have allowed the development of innovative techniques to assess lung function. A promising methodology is optoelectronic plethysmography (OEP). OEP evaluates ventilatory kinematics through the use of infrared imaging. Markers are placed, and images read on the chest, back and abdomen of subjects. Currently, this system is used mainly in research settings, but in the future may have broad applicability to patient populations such as very young children, patients with neuromuscular disease and patients who cannot be tested with classical spirometry testing. This paper presents the history and development of OEP, along with a summary of the OEP methodology, a discussion of research findings and results to date, as well as application and limitations., (© 2011 The Authors. Clinical Physiology and Functional Imaging © 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine.)

The purpose of this Position Stand is to provide guidance to professionals who counsel and prescribe individualized exercise to apparently healthy adults of all ages. These recommendations also may apply to adults with certain chronic diseases or disabilities, when appropriately evaluated and advised by a health professional. This document supersedes the 1998 American College of Sports Medicine (ACSM) Position Stand, "The Recommended Quantity and Quality of Exercise for Developing and Maintaining Cardiorespiratory and Muscular Fitness, and Flexibility in Healthy Adults." The scientific evidence demonstrating the beneficial effects of exercise is indisputable, and the benefits of exercise far outweigh the risks in most adults. A program of regular exercise that includes cardiorespiratory, resistance, flexibility, and neuromotor exercise training beyond activities of daily living to improve and maintain physical fitness and health is essential for most adults. The ACSM recommends that most adults engage in moderate-intensity cardiorespiratory exercise training for ≥30 min·d on ≥5 d·wk for a total of ≥150 min·wk, vigorous-intensity cardiorespiratory exercise training for ≥20 min·d on ≥3 d·wk (≥75 min·wk), or a combination of moderate- and vigorous-intensity exercise to achieve a total energy expenditure of ≥500-1000 MET·min·wk. On 2-3 d·wk, adults should also perform resistance exercises for each of the major muscle groups, and neuromotor exercise involving balance, agility, and coordination. Crucial to maintaining joint range of movement, completing a series of flexibility exercises for each the major muscle-tendon groups (a total of 60 s per exercise) on ≥2 d·wk is recommended. The exercise program should be modified according to an individual's habitual physical activity, physical function, health status, exercise responses, and stated goals. Adults who are unable or unwilling to meet the exercise targets outlined here still can benefit from engaging in amounts of exercise less than recommended. In addition to exercising regularly, there are health benefits in concurrently reducing total time engaged in sedentary pursuits and also by interspersing frequent, short bouts of standing and physical activity between periods of sedentary activity, even in physically active adults. Behaviorally based exercise interventions, the use of behavior change strategies, supervision by an experienced fitness instructor, and exercise that is pleasant and enjoyable can improve adoption and adherence to prescribed exercise programs. Educating adults about and screening for signs and symptoms of CHD and gradual progression of exercise intensity and volume may reduce the risks of exercise. Consultations with a medical professional and diagnostic exercise testing for CHD are useful when clinically indicated but are not recommended for universal screening to enhance the safety of exercise.

Ultrasound may be a useful tool to assess abdominal adiposity, but it has not been validated in the spinal cord injury (SCI) population. This study evaluated associations between abdominal ultrasound and other methods to assess adiposity in 24 men with SCI and 20 able-bodied (AB) men. Waist (WC) and hip circumference (HC) and waist-to-hip ratio (WHR) were measured. Trunk (TRK%), android (A%) and waist fat (W%) were determined by dual energy x-ray absorptiometry (DXA); ultrasonography determined abdominal subcutaneous (SF) and visceral fat (VF). The SCI group had greater TRK% (40.0 ± 9.6 vs. 32.0 ± 10.3), W% (47.0 ± 9.7 vs. 40.6 ± 9.4), A% (43.0 ± 9.8 vs. 35.8 ± 10.6) and WHR (0.99 ± 0.1 vs. 0.92 ± 0.06) than the AB group. WC and WHR correlated with VF in the SCI group. These associations suggest that ultrasound may be a useful tool in clinical practice for the measurement of VF in weight loss programs and for the assessment of cardiometabolic disorders., (Published by Elsevier Inc.)

Background: Postprandial lipemia (PPL) is associated with vascular dysfunction and may be an etiologic factor in the progression of atherogenic cardiovascular disease., Objective: In 10 men with paraplegia and 10 able-bodied men, the magnitude of the PPL responses and the relationship of abdominal adiposity and the PPL responses were determined., Methods: Anthropometrics, dual energy x-ray absorptiometry, and abdominal ultrasonography were performed to determine visceral fat and total body fat. A fasting lipid profile was performed. A high-fat milkshake (1.3 g fat/kg body mass) was administered with serum collected at baseline and at 2, 4, and 6 hours after the test meal for subsequent measurement of triglyceride. The triglyceride response was determined by the area under the triglyceride curve., Results: No significant differences were noted between the groups in fasting lipid values or in measures of visceral fat. Total body fat tended to be higher in men with paraplegia than in able-bodied men (34.9 ± 10.0 vs. 27.3 ± 6.7%, p = 0.07). No significant difference between the groups was observed in triglyceride response. In men with paraplegia, visceral fat was strongly associated with the triglyceride (r = 0.8, p = 0.005), fasting low-density lipoprotein (r = 0.66, p = 0.04), and triglyceride responses (r = 0.80, p = 0.005); a significant relationship was not found between fasting high-density lipoprotein and any measure of adiposity. In men with paraplegia, triglyceride response was positively related to all measures of abdominal adiposity., Conclusion: Visceral abdominal fat was related to delayed triglyceride clearance after a fat load, which may contribute to coronary heart disease (CHD) risk and progression of vascular disease in men with paraplegia.

Trends in body mass index (BMI) among 51,889 14- to 20-year-old Icelandic adolescents and young adults were examined using data from cross-sectional population surveys conducted from 1992 to 2007. Prevalence of overweight increased for both genders in all age groups, except for 14- and 20-year-old girls. Obesity prevalence increased among boys in all age groups, except for 16-year-olds, and among 15- and 20-year-old girls. The largest increase in obesity rates among both genders was found in the oldest age group. Moreover, not only has the prevalence of obesity increased, but also the extent of obesity has grown more severe among 15- and 17-year-olds boys and among girls in the oldest age group.

Background: Physical function is the ability to perform both basic and instrumental activities of daily living, and the ability of older adults to reside in the community depends to a large extent on their level of physical function. Multiple physical and health-related variables may differentially affect physical function, but they have not been well characterized. The purpose of this investigation was to identify and examine physical and mental health-related correlates of physical function in a sample of community-dwelling older adults., Methods: Nine hundred and four community dwelling older men (n = 263) and women (n = 641) with a mean (95% Confidence Interval) age of 76.6 (76.1, 77.1) years underwent tests of physical function (Timed Up and Go; TUG), Body Mass Index (BMI) was calculated from measured height and weight, and data were collected on self-reported health quality of life (SF-36), falls during the past 6 months, number of medications per day, depression (Geriatric Depression Scale; GDS), social support, and sociodemographic variables., Results: Subjects completed the TUG in 8.7 (8.2, 9.2) seconds and expended 6,976 (6,669, 7,284) Kcal.wk-1 in physical activity. The older persons had a mean BMI of 27. 6 (27.2, 28.0), 62% took 3 or more medications per day, and 14.4% had fallen one or more times over the last 6 months. Mean scores on the Mental Component Summary (MCS) was 50.6 (50.2, 51,0) and the Physical Component Summary (PCS) was 41.3 (40.8, 41.8).Multiple sequential regression analysis showed that, after adjustment for TUG floor surface correlates of physical function included age, sex, education, physical activity (weekly energy expenditure), general health, bodily pain, number of medications taken per day, depression and Body Mass Index. Further, there is a dose response relationship such that greater degree of physical function impairment is associated with poorer scores on physical health-related variables., Conclusions: Physical function in community-dwelling older adults is associated with several physical and mental health-related factors. Further study examining the nature of the relationships between these variables is needed.

Objective: This study investigated the relationship between overweight and obesity, age, and gender with physical activity and physical function in community-dwelling older men and women., Method: Multivariate analysis of covariance was used to analyze differences between normal weight, overweight, and obese adults (n = 821) above the age of 60 years., Results: Obesity but not overweight was associated with lower levels of physical activity and physical function. Within BMI groups, individuals who were physically active were less likely to have abnormal physical function scores compared to those who were sedentary. Compared to men, obese women had lower physical function scores, placing them at higher risk for future disability. Aging was associated with lower levels of physical activity and physical function., Discussion: The study illustrates the importance of avoiding obesity and participating in regular physical activity to prevent or slow down the loss of functioning in older age.

Objectives: We sought to identify variables associated with being in a particular stage of change for physical activity-a measure of behavioral intention to engage in regular physical activity. Understanding behavioral intentions can be useful in explaining why individuals are physically inactive or active., Methods: Data from the Rhode Island 2000 Behavioral Risk Factor Surveillance System were used to evaluate predictors of stage of change for physical activity. There were 3454 observations in the data set, representing a weighted population of 742636 people. Estimates were obtained from polytomous multiple logistic models., Results: Being a woman, Hispanic, non-Hispanic Black, and older than 55 years of age were associated with being in precontemplation and contemplation stages of change rather than maintenance. Self-perceived health status and rarely feeling healthy or full of energy were strongly predictive of stage of change. Having a health limitation was a dichotomous predictor, predicting being in action and precontemplation stages., Conclusions: Several sociodemographic and health variables were associated with varying patterns of stages of change for physical activity. The complexity of individual intentions for physical activity provides evidence for the potential existence of mediating, effect-modifying, and confounding variables that differ depending on individual characteristics.

Fatigue is a common problem in Parkinson's disease (PD), often the most troubling of all symptoms. It is poorly understood, generally under-recognized, and has no known treatment. This article reviews what is known about the symptom, putting it into the context of fatigue in other disorders, and outlines a program for developing better understanding and therapy.

Objective: To characterize physical activity and physical function by stage of change and age in older adults., Methods: One thousand two hundred thirty-four individuals completed The Yale physical activity survey (YPAS), stage of change for exercise, and the Up-and-Go physical function test., Results: Most subjects were in the maintenance (50.4%) or precontemplation stages (21/0%). YPAS scores were higher and Upand-Go scores were lower as exercise stage increased. Physical activity and physical function scores were lower in older age groups., Conclusion: Higher stages were positively associated with physical activity and physical function. Age was a significant moderator variable affecting stage, physical activity, and physical function.

Purpose: To examine whether the stages of change of exercise adoption appropriately address strenuous, moderate, and mild intensities of physical activity., Design and Setting: Secondary analysis of four data sets investigating transtheoretical model (TTM) constructs for exercise adoption., Subjects: Four samples of differing age groups (adolescents, n = 400; college students, n = 240; adults, n = 346; seniors, n = 504)., Measures: Stage of change algorithm for exercise adoption and self-reported physical activity., Results: Multivariate analysis of variance (MANOVA) results showed that stages of change were distinguished by strenuous and moderate but not mild exercise in the adolescent, college student, and adult sample. In the senior sample, stage differences were found in the frequency of exercising (equivalent for moderate to strenuous exercise) and the frequency of walking (equivalent for mild exercise). Bivariate correlation coefficients as well as sensitivity, specificity, and related quality indices decreased respectively from strenuous to moderate to mild exercise and from exercising to walking., Conclusions: Results provide additional support for the construct validity of the stages of change for strenuous and moderate intensities of physical activity. Development of a new stage assessment instrument for mild intensities of physical activity is recommended. Limitations include use of a different validation measure of exercise behavior in the senior sample.

Objectives: The effect of a community-based physical activity program in Pawtucket, RI, was evaluated relative to one in a comparison community., Methods: Cross-sectional surveys of 7529 residents of Pawtucket, RI, and 7732 residents of the comparison city were conducted at 2-year intervals during 7 years of intervention., Results: There were no differences in self-reported knowledge of the benefits of physical activity, attempts to increase exercise, or prevalence of physical inactivity between Pawtucket and the comparison community., Conclusions: Future community-based physical activity interventions should attempt to involve a wider range of individuals.

The hypothesis that health promotive diets associated with higher levels of habitual physical activity confound the relationship between regular physical activity and health has not been well explored in epidemiologic studies. We evaluated self-reported physical activity, Willett Food Frequency dietary data, sociodemographic and physiologic factors cross-sectionally for 2,004 household survey participants in two southeastern New England communities. We compared the dietary habits of sedentary participants (n = 964) to those of moderately active (n = 600) and very active (n = 440) participants after adjusting for age, gender, education, smoking status, year of survey, and total calories. Our results showed that moderately active and very active participants consumed more fiber, less total fat, and less saturated fat than sedentary participants (P < .01). They also consumed more vitamins (A, C, D, E), beta carotene, and calcium, (P < .01), and ate more fruits and vegetables (P < .001) than sedentary participants. We found these relationships in both New England communities studied. This association between regular physical activity and diet suggests that the relationship of habitual physical activity and chronic disease may be confounded by diet.

Objective: To determine if patients with acute myocardial infarction who receive thrombolytic therapy require more nursing care hours and a longer length of stay in the coronary care unit than those patients with acute myocardial infarction who do not receive thrombolytic therapy., Design: Retrospective cohort study using the coronary care unit data base and patient classification records., Setting: Northeastern university-affiliated, community-based, cardiovascular tertiary care center., Patients: All patients admitted to the coronary care unit with a diagnosis of acute myocardial infarction were screened. Of these, 20 patients who also had a patient classification form completed were included in the study. Ten of these patients had received thrombolytic therapy and 10 had not. The patients were grouped according to treatment with a thrombolytic agent or conventional treatment. There was no significant difference in age between the groups (64 +/- 19 years and 67 +/- 15 years)., Outcome Measures: Nursing care hours per patient per day and length of stay per patient in the coronary care unit., Results: On days 1 and 2 of hospitalization, there were no significant differences in total nursing care hours provided per patient per day. On days 3 and 4, those patients who received thrombolytic therapy received fewer nursing care hours compared with those who did not (11.1 and 9.2 vs 13.8 and 12.7 hours per patient day, respectively; p < or = 0.05). Patients who were treated with thrombolytic therapy also had a significantly shorter coronary care unit stay (3.1 vs 4.0 days; p < or = 0.05)., Conclusion: In this retrospective, observational pilot study, patients who received thrombolytic therapy for treatment of acute myocardial infarction had a significantly shorter coronary care unit stay and required significantly less nursing care on days 3 and 4.

Trends in patient morbidity and mortality, cost-effectiveness, and national recommendations mandate that we practice more preventive medicine. To address this need, we set out to develop a comprehensive curriculum in preventive medicine for medical schools. We constructed a competency-based (i.e., performance-based) curriculum with specific educational objectives defined by outcomes. Subject areas were subdivided by life stages, and learning objectives were created separately for epidemiology, assessment, and intervention. We hope that adoption of such an educational blueprint by medical schools will measurably enhance the attitudes, knowledge, and skills necessary for the incorporation of preventive principles into all aspects of clinical medicine.

To assess the prevalence of right ventricular perfusion defects after a recent inferior wall myocardial infarction, 33 patients were studied 6 to 14 days after infarction with low-level exercise testing and technetium 99m (99mTc) sestamibi (SPECT) imaging. Twenty-two control subjects with a < 5% likelihood of coronary artery disease undergoing exercise 99mTc sestamibi imaging were also studied. For each image the right ventricle was computer isolated from reconstructed transverse cardiac slices, followed by reorientation into oblique slices. Both right and left ventricular images were visually assessed for defects. A quantitative method of defect detection was also applied to the right ventricle. For the right ventricle, 100% of the stress images and 96% of the rest images were adequate for interpretation. Right ventricular stress perfusion defects were identified in 10 (30%) of 33 patients with recent inferior infarction, with 50% completely or partially normalizing on rest images, consistent with ischemia. Of 14 patients with left ventricular inferoseptal defects, eight (57%) had right ventricular defects compared with 2 (11%) of 19 without inferoseptal defects (p < 0.005). We concluded that the right ventricle can be adequately assessed for perfusion defects by means of exercise with 99mTc sestamibi SPECT imaging. Defects of the right ventricle after inferior myocardial infarction occur frequently, and many have evidence of ischemia. Right ventricular perfusion defects are closely associated with left ventricular inferoseptal defects.

Although multifocal atrial tachycardia (MAT) has been recognized since 1968, few data exist on its associated anatomic correlates. Using echocardiography, the authors describe the cardiac anatomy observed in hospitalized patients with MAT. Because MAT closely resembles atrial fibrillation (AF), these echocardiographic data are compared with those from an age- and sex-matched population with AF. There were 25 patients in each of the MAT and AF groups. Biatrial enlargement was present in both groups. However, the atrial enlargement was mild and significantly less in the MAT group. The MAT group had normal ventricular and aortic dimensions. Right ventricular dysfunction was rare in both groups. Moderate to severe global left ventricular dysfunction was present in 7 of 25 in the MAT group and in 9 of 25 in the AF group. Systolic wall-motion abnormalities were significantly less in the MAT group. Severe Doppler and structural abnormalities were not common in the MAT group. Based on these parameters, physiologic and not anatomic factors are probably more important in the genesis of MAT as compared with AF.

Studies using dobutamine thallium-201 myocardial perfusion imaging have suggested a high sensitivity and specificity for the detection of coronary artery disease. However, few data are available comparing dobutamine with exercise stress for the detection and localization of perfusion defects. This study compared the effects of dobutamine and exercise stress using technetium-99m sestamibi single-photon emission computed tomographic imaging in the same patients in a prospective crossover trial. Twenty-four patients with a high likelihood of coronary artery disease underwent tomographic myocardial imaging at rest, after symptom-limited treadmill exercise, and after intravenous dobutamine (maximum 30 micrograms/kg/min). Tomograms of the left ventricle were divided into 20 segments and were interpreted without knowledge of patient identity or stress protocol. Dobutamine was well tolerated by all patients. Segment-by-segment concordance between exercise and dobutamine images was highly significant (kappa = 0.56, p < 0.0001). Global first-order agreement (normal vs abnormal) between exercise and dobutamine studies was 96% (kappa = 0.65, p = 0.02); global second-order agreement (normal vs fixed vs ischemic defect) was 88% (kappa = 0.45, p = 0.02). Regional first- and second-order agreement were 96 and 93%, respectively (p < 0.001 for both). Twenty patients underwent coronary angiography. Comparisons between exercise and angiography and between dobutamine and angiography were similar for both global agreement (95 vs 100%, p = NS) and regional agreement (77 vs 72%, p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)

Background: Pharmacologic stress has been shown in animal studies to induce high degrees of myocardial hyperemia. At these levels of myocardial blood flow, the myocardial uptake of technetium 99m sestamibi may plateau and may affect the diagnostic accuracy. This study compared the effects of myocardial hyperemia induced by exercise, dipyridamole, and adenosine on 99mTc sestamibi tomographic imaging in normal subjects and patients with ischemic coronary artery disease., Methods and Results: Twenty subjects (group I, 10 normal subjects; group II, 10 patients with known coronary artery disease) underwent 99mTc sestamibi tomographic imaging after rest, exercise, dipyridamole infusion, and adenosine infusions on separate occasions. Total and background-corrected myocardial counts of the resulting images were calculated. Visual and computer-generated quantitative myocardial perfusion defect analysis was performed in subjects in group II. For subjects in both groups I and II, there were no significant differences in the background-corrected myocardial counts obtained with exercise, dipyridamole, and adenosine stress. There were no significant differences in the myocardial perfusion defects obtained after the three different modes of stress, including percentage defect size, stress deficit percentage, percentage of ischemia, count deficit index, and defect nadir., Conclusions: The myocardial uptake of 99mTc sestamibi in normal subjects and patients with coronary artery disease is comparable after exercise, dipyridamole, and adenosine stress. In addition, the defect sizes and intensities with 99mTc sestamibi after all forms of stress were equivalent. Thus 99mTc sestamibi, in combination with either adenosine or dipyridamole infusions, provides imaging data equivalent to those with exercise and may be considered an alternative in patients unable to undergo adequate exercise.

This study was designed to evaluate the effects of intravenous theophylline given before intravenous adenosine for thallium-201 imaging. Sixteen patients with known reversible thallium-201 defects were randomized to a double-blind crossover study of a 45-minute infusion of placebo or theophylline (given as the ethylenediamine salt, aminophylline, mean concentration 16.1 mg/L) before adenosine thallium-201 imaging. Adenosine was infused for 6 minutes at a rate of 140 micrograms/kg/min. Thallium-201 (2.5 to 3.0 mCi) was administered after 3 minutes of infusion. Blood pressure, heart rate, symptoms, and the electrocardiogram were monitored continuously. Planar thallium-201 imaging was obtained in three standard views and was interpreted using blinded segmental analysis and computerized quantitation. Systolic and diastolic blood pressure at baseline and during adenosine administration were similar following treatment with theophylline and placebo. The increase in heart rate observed during adenosine infusion was significantly reduced by theophylline pretreatment. Adenosine-induced symptoms (both cardiac and noncardiac) as well as ischemic electrocardiographic changes were significantly reduced after theophylline infusion (p < 0.05). In one patient, Mobitz type II heart block seen during adenosine infusion following placebo was absent with theophylline pretreatment. The size of adenosine-induced thallium-201 defects was unchanged by theophylline infusion using either segmental analysis (8 +/- 4 vs 9 +/- 5) or a computerized score (47 +/- 27 vs 45 +/- 21). Despite reduction in both symptoms and ischemic electrocardiographic changes, theophylline does not alter thallium-201 imaging following intravenous adenosine infusion.

Objectives: The effects of varying concentrations of theophylline on exercise-induced myocardial ischemia were evaluated in patients with stable coronary artery disease., Background: Theophylline is a competitive antagonist of adenosine and may have potential as an anti-ischemic medication. It is not known whether these effects on myocardial ischemia are concentration dependent., Methods: In a double-blind, randomized, crossover manner, 11 patients received, at 1-week intervals, placebo and each of three theophylline doses by intravenous infusion for 45 min. Graded exercise testing was performed before randomization and immediately after each infusion. Concurrent anti-ischemic medications were withheld for 24 h before each exercise test. Serum theophylline concentrations achieved were 3.9 +/- 1.0 mg/liter (low), 8.2 +/- 1.8 mg/liter (medium) and 13.2 +/- 2.3 mg/liter (high)., Results: Compared with placebo, none of the three theophylline infusions produced a significant alteration in rest heart rate, blood pressure, mean frequency or severity of ventricular ectopic activity or noncardiac symptoms. The time to onset of ischemia was progressively increased, with medium and high concentrations achieving statistical significance. Similar patterns were observed for oxygen uptake and the heart rate-systolic blood pressure product at the onset of ischemia. Total exercise duration was significantly prolonged with the medium and high concentrations., Conclusions: It is concluded that administration of varying doses of theophylline before exercise produces a clinically significant and concentration-dependent improvement in the indicators of myocardial ischemia in patients with chronic stable coronary artery disease.

Objectives: Theophylline has been shown to delay the onset of myocardial ischemia and to prolong exercise duration. The present study was done to evaluate the mechanisms and actions of intravenous theophylline on the onset of ischemia and exercise duration., Background: The ischemic threshold may be altered by the differential coronary vasodilation induced by endogenous adenosine. Theophylline is a competitive receptor antagonist of adenosine and may have a potential as an anti-ischemic medication., Methods: A double-blind, placebo-controlled crossover trial using an infusion of intravenous theophylline (8.0 +/- 2.0 mg/liter) or placebo before exercise in 12 patients was done. Oxygen uptake, heart rate, blood pressure and heart rate-blood pressure product were determined at the onset of > or = 0.1-mV ST segment depression and angina pectoris, as well as at peak exercise. The extent of myocardial ischemia was evaluated by electrocardiographic criteria and quantitation of thallium-201 images at peak exercise., Results: When compared with placebo, theophylline significantly delayed time to the onset of exercise-induced ischemia. Ischemia occurred at a higher heart rate-blood pressure product and oxygen uptake. Exercise duration was prolonged but was not associated with greater ischemia, as determined by oxygen uptake, ST segment depression, angina pectoris and size of thallium-201 defect., Conclusions: It is concluded that theophylline favorably alters myocardial ischemia not only by delaying its onset but also by enabling it to occur at a higher threshold without causing deleterious effects during exercise. The mechanism for the increased ischemic threshold may be through the inhibition of adenosine and the coronary steal phenomenon.

Validation of the London School of Hygiene (Rose) Questionnaire with objective measures of myocardial ischemia is incomplete. Therefore, we compared the Rose Questionnaire with exercise thallium-201 myocardial scintigraphy in 147 male and 97 female patients with chest pain referred for clinical exercise testing. Of those with "Rose Questionnaire angina", 26% of the females and 73% of the males had positive thallium-201 scans. Negative results on both the Rose Questionnaire and thallium-201 scintigraphy were observed in 71% of the females and 47% of the males. The sensitivity of the Rose Questionnaire was similar in females (41%) and males (44%). The specificity was 77% in males, while in females it was significantly lower at 56%. The specificity values reflect the higher (p less than 0.05) prevalence of "false positive" Rose Questionnaire results in females (75%) compared with males (27%). In addition, males had a greater (p less than 0.05) number of "false negative" results (53%) than females (29%). The accuracy of the Rose Questionnaire for myocardial ischemia was 0.19 in females, 0.48 in males, and 0.29 overall when including both males and females. Our results indicate a generally poor relationship between Rose Questionnaire angina and thallium-201 scintigraphy, an objective measure of myocardial ischemia in patients with chest pain referred to clinical exercise testing. Further, there are gender-specific differences in this relationship between the questionnaire and exercise thallium-201 imaging.

In order to compare the physiological effects of an 8 week aerobic dance program to those of a walk-jog exercise training program, 60 male and female University employees ages 24-48 years were randomly assigned to an aerobic dance program (N = 22), a walk-jog program (N = 24), or a sedentary control group (N = 15). Subjects who had an exercise compliance rate less than or equal to 85% were dropped from the study, as were control subjects who had scheduling conflicts or illnesses precluding post-treatment testing. Thirty-five subjects completed the 8 week period with a compliance rate greater than or equal to 85%, leaving 14 in the aerobics group, 11 in the walk-jog group and 10 in the control group. Significant increases (p less than 0.001) in maximal oxygen uptake occurred in both the aerobics (+3.9 ml/kg-1/min-1) and walk-jog group (+3.4 ml/kg-1/min-1), while no significant change was observed in the control group. Peak heart rate decreased significantly (p less than 0.05) in the aerobics (-4 b/min-1) and walk-jog groups (-3 b/min-1 but was unchanged in the control group (-1 b/min-1) following the treatment period. Body weight, peak respiratory exchange ratio and peak minute ventilation remained the same in the aerobics, walk-jog and control groups throughout the treatment period. It is concluded that aerobic dance programs can result in similar improvements in aerobic power as a walk-jog program. Thus, an aerobic dance program is an effective alternative to a traditional walk-jog training regime.

During pregnancy significant cardiovascular changes occur. To study these anatomic and physiologic changes we performed two-dimensional and Doppler echocardiography in 28 women during the third trimester (34.4 +/- 1.9 weeks) of pregnancy and then again after delivery (7.8 +/- 2.2 weeks). Fourteen nonpregnant age- and sex-matched subjects served as controls. Left ventricular diastolic and systolic dimensions were similar among pregnant, postpartum, and control subjects. Left atrial area as determined by two-dimensional echocardiography was significantly larger during pregnancy (16.7 +/- 4.0 cm2) compared with measurements postpartum (13.8 +/- 3.1 cm2) and with controls (15.5 +/- 3.5 cm2) (p less than 0.01). Doppler study showed that the ratio of early diastolic flow velocity to late diastolic flow velocity (E/A max) and E/A integral were lower among pregnant subjects (1.3 +/- 0.3, 2.0 +/- 0.5) compared with postpartum subjects (1.6 +/- 0.4, 2.5 +/- 1.5) and controls (1.9 +/- 0.5, 3.0 +/- 0.8) (p less than 0.05). Heart rate was higher among pregnant subjects (84 +/- 10 beats/min) compared with postpartum subjects (70 +/- 16) and controls (69 +/- 13) (p less than 0.05). In summary, in pregnant subjects during late third trimester left ventricular chamber dimensions were similar to these postpartum measurements in control subjects; however, the left atrium is dilated during pregnancy. Although there are significant alterations in Doppler-derived left ventricular diastolic parameters during the third trimester, increased heart rate and a dilated left atrium may explain these findings.

The effects of two levels of exercise intensity on the size and location of thallium-201 defects were compared in 22 patients with known ischemic coronary artery disease. A symptom-limited incremental exercise test was performed followed (greater than 48 hours) by submaximal steady-state exercise at 70% of the peak heart rate achieved during the incremental test. Planar thallium-201 myocardial scans obtained after each protocol were analyzed by means of both visual qualitative and computerized quantitative methods. After incremental exercise all patients exhibited reversible thallium-201 defects, and submaximal exercise still resulted in reversible defects in 20 (91%) patients. However, the size of the ischemic area and the degree of ischemia were significantly reduced by both qualitative and quantitative criteria after submaximal exercise. Therefore interpretation of thallium-201 scans with regard to severity of disease and prognosis should take into account exercise intensity.

The effects of oral dipyridamole on exercise performance and anginal symptoms were evaluated in 15 men with stable angina pectoris. In a double-blind, randomized, crossover design, patients received 75 mg of dipyridamole or placebo every 8 hours for 2 weeks in addition to their previously prescribed cardiac medications. Graded exercise tolerance testing was performed twice before randomization, at the end of each treatment period, and after single-blind placebo washout. When compared with baseline tests, the time to onset of 0.1 mV ST-segment depression was similar between dipyridamole and placebo treatments (316 +/- 89 vs 345 +/- 102 seconds, respectively, p = not significant). No significant differences existed between treatments in the peak systolic blood pressure-heart rate product or in the duration of exercise. Angina pectoris occurred during all 3 baseline exercise tests in 7 of the 15 subjects; the time to onset of angina was unchanged by either treatment. Analysis of symptom diaries conducted in 13 patients revealed no significant alteration in reported anginal symptoms during dipyridamole treatment compared with placebo treatment (0.6 +/- 0.9 vs 0.3 +/- 0.4 episodes per week). Ambulatory electrocardiographic monitoring in 12 patients revealed few episodes of ischemia during daily activities with no alteration in frequency of episodes during treatment periods. Plasma concentrations of dipyridamole did not correspond with the outcomes of exercise testing. It is concluded that chronic oral dipyridamole therapy given in its usual clinical dose does not adversely affect exercise performance, daily anginal episodes or ambulatory ischemia in patients receiving concurrent anti-ischemic medication.

This study was performed to evaluate the presence of angina pectoris, electrocardiographic changes and reversible thallium-201 defects resulting from 2 different levels of exercise in 19 patients with known coronary artery disease and evidence of exercise-induced ischemia. The exercise protocols consisted of a symptom-limited incremental exercise test (Bruce protocol) followed within 3 to 14 days by a submaximal, steady-state exercise test performed at 70% of the maximal heart rate achieved during the Bruce protocol. The presence and time of onset of angina and electrocardiographic changes (greater than or equal to 0.1 mV ST-segment depression) as well as oxygen uptake, exercise duration and pressure-rate product were recorded. Thallium-201 (2.5 to 3.0 mCi) was injected during the last minute of exercise during both protocols, and the images were analyzed using both computer-assisted quantitation and visual interpretations. Incremental exercise resulted in anginal symptoms in 84% of patients, and electrocardiographic changes and reversible thallium-201 defects in all patients. In contrast, submaximal exercise produced anginal symptoms in only 26% (p less than 0.01) and electrocardiographic changes in only 47% (p less than 0.05), but resulted in thallium-201 defects in 89% of patients (p = not significant). The locations of the thallium-201 defects, when present, were not different between the 2 exercise protocols. These findings confirm the sequence of the ischemic cascade using 2 levels of exercise and demonstrate that the cascade theory is applicable during varying ischemic intensities in the same patient.

It is generally accepted that angina pectoris and, presumably, myocardial ischemia occur at a fixed heart rate-systolic blood pressure product in a given patient. This concept of a fixed threshold has recently been challenged. To evaluate the effects of varying exercise intensity on the ischemic threshold, 33 patients with coronary artery disease and provokable myocardial ischemia, documented by thallium-201 myocardial perfusion imaging, underwent two exercise tests 2 to 7 days apart. A symptom-limited incremental treadmill exercise test was followed by a 20 min submaximal treadmill test at an intensity approximating 70% of the peak heart rate attained during the incremental test. During the incremental exercise test, angina pectoris developed in 16 patients and 17 patients were asymptomatic. At least 0.1 mV of ST segment depression developed in all subjects during the incremental exercise test at a mean exercise duration of 5.3 +/- 2.6 min, a rate-pressure product of 19,130 +/- 5,735 and oxygen uptake of 19.6 +/- 7.0 ml/kg per min. During the submaximal exercise test, 28 (85%) of the 33 patients had significant ST segment depression. Of these patients, 24 (86%) were asymptomatic, including 10 patients who had previously reported anginal symptoms during the incremental test. The average time to onset of 0.1 mV ST segment depression during the submaximal test was 8.1 +/- 4.5 min. These changes occurred at a rate-pressure product of 15,250 +/- 3,705 and an oxygen uptake of 14.3 +/- 5.9 ml/kg per min, and were significantly (p less than 0.001) lower than values observed during the graded exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors' modification of the Astrand-Rhyming Cycle Ergometer Test is of short duration, has low initial and peak work rates and was in an earlier study applied for population fitness testing (N = 587) at a survey center after other cardiovascular risk factor measures were obtained in the home. To add fitness testing in the home, the authors have designed a safe, brief 10 inch (25.4 cm) high step test for estimating maximal oxygen uptake (VO2max). Measured maximal oxygen uptake for step tests has been shown to be approximately 10% higher than that reported for cycle tests. All test instructions and stepping rates were included on a cassette tape; heart rates were monitored by a digital tachograph during the last 30 seconds of stepping. Maximal oxygen uptake was measured directly on a bicycle, estimated by the step test, and measured by the authors' bike test in 48 men and women aged 19-70 years who took part in a community fitness program in Pawtucket, Rhode Island in January-February 1983. No significant differences in maximal oxygen uptake were found between the bicycle protocols. The step test estimate of maximal oxygen uptake (VO2max) was significantly higher (12%) than directly measured VO2max, reflecting the expected difference between stepping and cycling. The correlation between direct and both estimates was 0.92. The cross-validation correlation between the estimates was 0.98. The authors' protocol provides accurate estimates of maximal oxygen uptake and is safe and suitable for in-the-home assessment of fitness of people aged 19-70 years for epidemiologic studies.

We examined the effects of mental stress during steady-state exercise on heart rate, blood pressure, pressure-rate product, and oxygen uptake in 10 coronary artery disease patients. Subjects walked at three mph with grade increases of 4% every two minutes until the target heart rate (60% peak heart rate from a previous symptom-limited exercise test) was reached. A computerized Stroop-Color-Word Test (mental stress) was added one minute after the subject reached steady-state exercise and lasted 11 +/- 4 minutes. When mental stress was added to steady-state exercise it significantly (p less than 0.01) increased the heart rate (101 +/- 15 to 108 +/- 19 beats per min), systolic (154 +/- 26 to 170 +/- 26 mmHg) and diastolic (86 +/- 10 to 92 +/- 13 mmHg) blood pressure, and pressure-rate product (158 +/- 42 to 179 +/- 48 x 10(-2)). This increase in the mean response during exercise and mental stress was not observed for oxygen uptake (17 +/- 6 to 18 +/- 5 ml/kg/min). The circulatory changes probably reflect increased sympathetic activity with both centrally mediated cardioacceleratory (and probably cardiac output) and vasoconstrictor effects during the combination of mental stress and steady-state exercise. The altered hemodynamics without concomitant changes in oxygen uptake has major implications concerning the safety of competitive exercise for people with coronary artery disease.

Although silent myocardial ischemia is a well recognized phenomenon, the reasons for the lack of symptoms in patients with coronary artery disease (CAD) is unclear. Because the endogenous opioid beta-endorphin has been related to pain modulation, plasma beta-endorphin levels were studied before, during and after exercise-induced ischemia in symptomatic and asymptomatic men. Because beta-endorphin responses have been closely linked to adrenocorticotropic hormone (ACTH) and cortisol responses, these hormones also were measured. Nine symptomatic and 12 asymptomatic patients with a high probability (at least 95%) of CAD and 8 apparently healthy men completed a Bruce protocol treadmill test. Blood samples were drawn before, during and 10 minutes after exercise. During exercise the measured hormones showed no significant increases from basal levels. However, plasma beta-endorphin, ACTH and cortisol levels were significantly elevated (p less than or equal to 0.01) 10 minutes after exercise in all 3 groups. There was no significant difference in plasma beta-endorphin levels during or after exercise between the symptomatic and asymptomatic patients with CAD. Thus, differences in circulating levels of beta-endorphin, ACTH and cortisol are not associated with the presence or absence of pain during exercise-induced myocardial ischemia.