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Biomedical subjects

J A Blumenthal

Publications and source records attributed to J A Blumenthal.

At least 19 recordsLinked to original sources
PubMed1992

Warming during cardiopulmonary bypass is associated with jugular bulb desaturation.

The objective of this study was to characterize cerebral venous effluent during normothermic nonpulsatile cardiopulmonary bypass. Thirty-one (23%) of 133 patients met desaturation criteria (defined as jugular bulb venous oxygen saturation less than or equal to 50% or jugular bulb venous oxygen tension less than or equal to 25 mm Hg) during normothermic cardiopulmonary bypass (after hypothermic cardiopulmonary bypass at 27 degrees to 28 degrees C). Cerebral blood flow, calculated using xenon 133 clearance methodology, was significantly (p less than 0.005) higher in the saturated group (33.7 +/- 10.3 mL.100 g-1.min-1) than in the desaturated group (26.2 +/- 6.9 mL.100 g-1.min-1), whereas the cerebral metabolic rate for oxygen was significantly lower (p less than 0.005) in the saturated group (1.28 +/- 0.39 mL.100 g-.min-1) than in the desaturated group (1.52 +/- 0.36 mL.100 g-1.min-1) at normothermia. The arteriovenous oxygen difference at normothermia was lower in the saturated group (3.92 +/- 1.12 mL/dL) than in the desaturated group (5.97 +/- 1.05 mL/dL). Neuropsychological testing was performed in 74 of the 133 patients preoperatively and on day 7 postoperatively. There was a general decline in mean scores of all tests postoperatively in both groups with no significant difference between the groups. We conclude that cerebral venous desaturation represents a global imbalance in cerebral oxygen supply-demand that occurs during normothermic cardiopulmonary bypass and may represent transient cerebral ischemia. These episodes, however, are not associated with impared neuropsychological test performance as compared with the performance of patients with no evidence of desaturation.

Aged↗
PubMed1992

Serum lipids, neuroendocrine and cardiovascular responses to stress in healthy Type A men.

This study examined the relationship between serum lipid activity in healthy Type A men and cardiovascular and neuroendocrine responses to a behavioral stressor, mental arithmetic. Assessment of blood lipids included measures of total cholesterol (TC), low density lipoprotein cholesterol (LDLC), high density lipoprotein cholesterol (HDLC), and serum triglycerides. Cardiovascular (blood pressure and heart rate) and neuroendocrine (epinephrine, norepinephrine and cortisol) responses were recorded before (rest), during (stress) and after (recovery) the mental arithmetic test. Diastolic blood pressure, mean arterial pressure and, to a lesser extent, systolic blood pressure levels at rest, during stress, and at recovery correlated positively with TC levels. In addition, both diastolic and mean arterial pressure were positively correlated with the ratio of TC to HDLC and with triglycerides during stress and recovery. Heart rate did not correlate with any lipid measure. Cardiovascular stress-reactivity calculated as change from rest to stress did not correlate significantly with any lipid measure. Plasma norepinephrine during stress correlated positively with triglycerides; a similar trend was observed for the TC/HDLC ratio. Plasma cortisol at rest and during stress correlated positively with the TC/HDLC ratio and serum triglycerides, and negatively with HDLC. Plasma norepinephrine reactivity calculated as change from rest to stress correlated negatively with HDLC and positively with triglycerides. In addition, cortisol reactivity was positively correlated with triglycerides. It is suggested that the mechanisms mediating Type A behavior and coronary heart disease may include increased cardiovascular and neuroendocrine responses as well as unfavorable lipid profiles.

Adult↗
PubMed1992

Exercise adherence or maintenance among older adults: 1-year follow-up study.

Follow-up evaluation was conducted of 101 older men and women (mean age = 67 +/- 5 years) who had participated in a randomized study of physiological and psychological effects of aerobic exercise. Eighty-five subjects completed the follow-up evaluation, and almost all of them (94%) reported continuing with physical activity, as assessed by a self-report measure. Total energy expenditure was calculated as an indicator of exercise maintenance, and energy expenditure at follow-up was predicted from measures of physiological functioning, psychological well-being, and cognitive functioning obtained at the conclusion of the structured exercise program. Greater cardiorespiratory endurance, faster psychomotor speed, and lower anxiety predicted exercise behavior at follow-up, accounting for 13% of the variance in exercise behavior. Gender was not a significant predictor of exercise behavior.

Aged↗
PubMed1991

Failure of exercise to reduce blood pressure in patients with mild hypertension. Results of a randomized controlled trial.

OBJECTIVE: --To assess the effects of physical exercise training on blood pressure in patients with mild hypertension. DESIGN: --Randomized controlled trial. SETTING: --Hospital-based cardiac rehabilitation program. PATIENTS: --Ninety-nine men and women with untreated mild hypertension (systolic blood pressure, 140 to 180 mm Hg; diastolic blood pressure, 90 to 105 mm Hg) were included in the volunteer sample. INTERVENTIONS: --Subjects were randomly assigned to a 4-month program of aerobic exercise training, strength and flexibility training, or to a waiting list control group. MAIN OUTCOME MEASURES: --The main outcome measures were systolic and diastolic blood pressures measured four times with a random zero sphygmomanometer on 3 separate days in a clinic setting. RESULTS: --After 4 months of exercise training, subjects in the aerobic exercise group did not exhibit greater reductions in blood pressure than subjects in the control group. We expected a differential decline of 5 mm Hg between the aerobic exercise and waiting list control groups and found a difference of -1.0 +/- 16 mm Hg and -1.2 +/- 10 mm Hg at alpha = .05 for systolic and diastolic blood pressure, respectively. CONCLUSIONS: --Moderate aerobic exercise alone should not be considered a replacement for pharmacologic therapy in nonobese patients with mild hypertension.

Adult↗
PubMed1991

Effects of exercise training on cardiorespiratory function in men and women older than 60 years of age.

This study reports the physiologic effects of up to 14 months of aerobic exercise in 101 older (greater than 60 years) men and women. After an extensive baseline physiologic assessment (Time 1), in which aerobic capacity and blood lipids were measured, subjects were randomized to an aerobic exercise condition (cycle ergometry, 3 times per week for 1 hour), nonaerobic yoga (2 times per week for 1 hour), or a waiting list nonexercise control group for 4 months, and then underwent a second (Time 2) assessment. At the completion of the second assessment, all remaining subjects completed 4 months of aerobic exercise and were reevaluated (Time 3). Subjects were given the option of participating in 6 additional months of supervised aerobic exercise, and all available subjects completed a fourth assessment (Time 4) 14 months after their initial baseline evaluation. Results indicated that subjects generally exhibited a 10 to 15% improvement in peak oxygen consumption after 4 months of aerobic exercise training, and a 1 to 6% improvement in aerobic power with additional aerobic exercise training. On the other hand, subjects, especially men, continued to have improvements in submaximal exercise performance (i.e., anaerobic threshold). In addition, aerobic exercise was associated with an improved lipid profile; subjects participating in aerobic exercise for up to 14 months exhibited increased levels of high-density lipoprotein cholesterol. Maintenance of regular aerobic exercise for an extended time interval is associated with greater cardiovascular benefits among older adults than has been reported previously.

Aged↗
PubMed1991

Stress reactivity and exercise training in premenopausal and postmenopausal women.

Examined the influence of ovarian function on psychophysiological stress responses and determined if aerobic exercise reduced stress reactivity. Fifty premenopausal and postmenopausal women initially were subjected to a public speaking task and an ice-on-the-forehead procedure, during which time their blood pressure and heart rate were monitored and continuous blood samples were obtained. Subjects also underwent aerobic fitness evaluations with a maximum-exercise treadmill test. Subjects were then randomly assigned to a 12-week exercise program of either aerobic exercise (e.g., walking and jogging at a prescribed exercise intensity) or non-aerobic strength and flexibility training and were then reevaluated. Results indicated that postmenopausal women exhibited lower resting epinephrine levels but greater epinephrine reactivity to the speaking task compared to the premenopausal women. There were no differences between premenopausal and postmenopausal women with respect to cardiovascular or catecholamine responses during the cold challenge. Premenopausal and postmenopausal women also achieved comparable improvements in aerobic fitness. However, results of the mental stress testing were complex and provided only partial support for the role of aerobic exercise in reducing stress responses.

Arousal↗
PubMed1991

Long-term effects of exercise on psychological functioning in older men and women.

The purpose of this study was to determine the psychological, behavioral, and cognitive changes associated with up to 14 months of aerobic exercise training. For the first 4 months of the study, 101 older (greater than 60 years) men and women were randomly assigned to one of three conditions: Aerobic exercise, Yoga, or a Waiting List control group. Before and following the intervention, all subjects completed a comprehensive assessment battery, including measures of mood and cognitive functioning. A semi-crossover design was employed such that, following completion of the second assessment, all subjects completed 4 months of aerobic exercise and underwent a third assessment. Subjects were given the option of participating in 6 additional months of supervised aerobic exercise (14 months total), and all subjects, regardless of their exercise status, completed a fourth assessment. Results indicated that subjects experienced a 10-15% improvement in aerobic capacity. In general, there were relatively few improvements in cognitive performance associated with aerobic exercise, although subjects who maintained their exercise participation for 14 months experienced improvements in some psychiatric symptoms. However, the healthy subjects in this study were functioning at a relatively high level to begin with, and exercise training may produce greater improvements among elderly with concomitant physical or emotional impairments.

Affect↗
PubMed1991

Effects of exercise training on bone density in older men and women.

OBJECTIVES: To determine the effects of up to 14 months of aerobic exercise on measures of bone density in older adults. DESIGN: Randomized controlled trial with subjects assigned to either an aerobic exercise condition, non-aerobic yoga, or a wait list non-exercise control group for 4 months. Aerobic fitness and bone density were evaluated in all subjects at baseline (Time 1) and after 4 months (Time 2). A semi-crossover design was utilized with all subjects completing 4 months of aerobic exercise, followed by another evaluation (Time 3). All subjects were then given the option of 6 additional months of aerobic exercise, after which they had a fourth evaluation (Time 4). SETTING: An outpatient exercise rehabilitation facility at a large, major medical center. SUBJECTS: One-hundred-one healthy men (n = 50) and women (n = 51) over age 60 (Mean age = 67.0), recruited from the community. INTERVENTION: The exercise program included stretching, cycle ergometry, and walking three times per week for 60 minutes throughout the course of the study. OUTCOME MEASURES: Aerobic fitness (VO2max) as assessed by cycle ergometry, and bone density (bone mineral content) measured by single photon absorptiometry. RESULTS: Subjects achieved a 10%-15% increase in VO2max after 4 months of exercise training, and 1%-6% further improvement with additional training. Aerobic fitness was associated with significant increases in bone density in men, but not women, who maintained aerobic exercise for 14 months.

Aged↗
PubMed1991

A preliminary study of the effects of cardiac procedures on cognitive performance.

The effects of three commonly performed cardiac procedures on cognitive performance were evaluated in patients undergoing coronary artery bypass graft (CABG) surgery (N = 20), percutaneous transluminal coronary angioplasty (PTCA) procedure (N = 8), or cardiac valve repair (N = 11). Patients completed a neuropsychological test battery on the day prior to their surgery and at discharge. Results showed that valve and CABG patients exhibited declines in performance on the Digit Symbol subtest, while PTCA patients did not change. Reaction time performance improved for the PTCA patients but declined significantly for valve patients. These results suggest that common cardiac procedures may have measurable effects on cognitive performance, as assessed by a relatively brief test battery.

Angioplasty, Balloon, Coronary↗
PubMed1990

Aerobic exercise reduces levels of cardiovascular and sympathoadrenal responses to mental stress in subjects without prior evidence of myocardial ischemia.

Thirty-seven healthy type A men (mean age 42 years) were randomly assigned to either an aerobic exercise training group or to a strength and flexibility training group. Before exercise, subjects underwent comprehensive physiologic and behavioral assessments, including graded exercise treadmill testing with direct measurement of oxygen consumption (VO2) and measurement of cardiovascular (heart rate, systolic and diastolic blood pressure and rate pressure product) and neuroendocrine (epinephrine and norepinephrine) responses to mental arithmetic. The aerobic exercise consisted of walking and jogging at an intensity of greater than or equal to 70% maximal heart rate reserve for 1 hour 3 times/week for 12 consecutive weeks. The strength training consisted of 1 hour of circuit Nautilus training 2 times/week for 12 weeks. At the completion of the exercise program, all subjects underwent repeat testing. For the aerobic group, peak VO2 increased significantly from 33.6 to 38.4 ml/kg/min (p less than 0.001), whereas the strength group only achieved a slight increase from 34.5 to 35.6 ml/kg/min (difference not significant). During the mental arithmetic, the aerobic group experienced a greater reduction in levels of heart rate, diastolic blood pressure and rate pressure product than the strength group (after completing the exercise training programs). The aerobic group also tended to secrete less epinephrine and to show a faster recovery than the strength group after the exercise program. In addition, the aerobic group tended to exhibit less cardiovascular reactivity to mental stress after exercise training. These data suggest that aerobic exercise reduces levels of cardiovascular and sympathoadrenal responses during and after mental stress.

Adrenal Medulla↗
PubMed1990

Temporal stability of the hemodynamics of cardiovascular reactivity.

Cardiovascular responses to a competitive reaction-time task were monitored in 13 male subjects tested twice, 3 months apart. The temporal stability of blood pressure responses was in line with previous reports. However, in this study impedance cardiography permitted the investigation of the hemodynamic adjustments underlying the observed blood pressure responses. Analyses revealed that cardiac output and total peripheral resistance responses displayed temporal stability, indicating that subjects' blood pressure responses on the two occasions were the result of similar hemodynamic responses. These data thus extend the literature by demonstrating that the hemodynamic response pattern itself represents a stable individual difference variable.

Adult↗
PubMed1990

Quality of life among hypertensive patients with a diuretic background who are taking atenolol and enalapril.

The cardioselective beta-blocker atenolol and the angiotensin-converting enzyme inhibitor enalapril were compared for efficacy, safety, and quality-of-life factors in 30 patients with hypertension whose hypertension was inadequately controlled with diuretic alone. Atenolol (50 to 100 mg once a day) and enalapril (2.5 to 40 mg once a day), combined with hydrochlorothiazide (25 mg once a day), had similar levels of efficacy and safety. A comprehensive battery of psychologic assessments for quality of life was administered, including measures of anxiety, depression, psychiatric symptoms, memory, and psychomotor function. These five conceptually based clusters were first analyzed by multivariate analysis of variance procedures, followed by univariate analyses of the individual variables composing each domain. In general, neither atenolol nor enalapril was associated with major changes in psychologic functioning. The only data cluster with a statistically significant change was memory function, primarily as a result of lower scores of the digit span (backward) test, for atenolol relative to enalapril. These preliminary findings suggest that atenolol and enalapril have comparable degrees of efficacy and safety, with no major disparities in quality-of-life effects, for hypertensive patients with a history of taking diuretics and this sort of quality-of-life assessment can be performed during trials of antihypertensive drugs.

Analysis of Variance↗
PubMed1990

Perceived change among participants in an exercise program for older adults.

Data regarding perceived change were collected as part of a study of the effects of aerobic exercise training on psychological, cognitive, and physiological functioning among 101 healthy older adults. Subjects were assigned randomly to an aerobic exercise group, a yoga control group, or a waiting list group for 16 weeks, after which all subjects participated in aerobic exercise for another 16 weeks. Exercise participants perceived positive changes in a wide range of significant life areas, and perceived improvement was more closely related to objective improvement for physiological indicators than for indicators of cognitive functioning or psychological well-being.

Aged↗
PubMed1990

Physiological, psychological, and behavioral factors and white coat hypertension.

Patients with hypertension in the clinic but not during daily activities ("white coat" hypertension) may be at lower risk of hypertensive morbidity and mortality than patients with hypertension in both settings ("persistent" hypertension). We hypothesized that the white coat phenomenon was due to greater blood pressure reactivity to the stress of a clinic visit and that, as a consequence, white coat hypertensive patients would display greater blood pressure reactivity to exercise and mental stress, as well as increased emotional reactivity and higher levels of anger, anxiety, or depression. We studied 89 patients with essential hypertension between 29 and 59 years old with ambulatory blood pressure monitoring, treadmill exercise testing with oxygen consumption measurement, mental stress testing (including mental arithmetic, public speaking, and video game tasks), and psychological testing (State-Trait Anxiety Scale, Cook-Medley Hostility Scale, Center for Epidemiologic Studies Depression Scale, emotional reactivity scale). We defined white coat hypertension as a mean ambulatory systolic blood pressure of 135 mm Hg or less and diastolic 85 mm Hg or less and persistent hypertension as a mean ambulatory systolic blood pressure of 140 mm Hg or more or diastolic 90 mm Hg or more. Forty-nine patients were classified as persistent hypertensives and 20 as white coat hypertensives. No significant differences were seen in demographic or clinical characteristics, fitness level, blood pressure response to exercise or mental stress, or psychological characteristics, except that white coat hypertensive patients had lower systolic blood pressures in the clinic and during exercise and greater variability of clinic diastolic blood pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Cardiovascular responses in the laboratory and in the natural environment: is blood pressure reactivity to laboratory-induced mental stress related to ambulatory blood pressure during everyday life?

Cardiovascular activity recorded at rest and during mental stress in the laboratory was studied in relation to ambulatory recorded cardiovascular activity at work and at home. Fifty-five Type A men (M = 42.4 years) underwent a standardized laboratory mental stress protocol in which systolic blood pressure, diastolic blood pressure, and heart rate were recorded at baseline and during a 15 min mental arithmetic task (MAT). On a subsequent day, ambulatory blood pressure and heart rate were recorded at 20 minute intervals for 12-14 hr during normal activities at home and at work. Subjects completed a behavioral diary concurrently with each cuff inflation. High and Low groups were identified based upon a median split of their cardiovascular response levels at baseline and during the MAT. Subjects with high systolic blood pressure levels during the MAT had high systolic blood pressure at home, at work, during physical activity, and when they reported being 'stressed'. Baseline systolic blood pressure in the laboratory was less consistently related to ambulatory systolic pressure across ambulatory conditions. Diastolic blood pressure at baseline was related to ambulatory diastolic blood pressure at work, at home, and when resting. Diastolic blood pressure during the MAT was associated with higher diastolic pressure at work and at home. Heart rate at baseline and during the MAT was related to heart rate at work and during physical activity. Change scores derived by subtracting mean values during the MAT from baseline resting levels were not associated with ambulatory blood pressures or heart rates under any daily conditions. In the best case, systolic blood pressure measured during the MAT was related to systolic blood pressure during physical activity, to systolic blood pressure and heart rate during mental stress, to systolic and diastolic blood pressure at rest, and to systolic blood pressure and heart rate at work but not at home. We conclude that levels of blood pressure and heart rate measured in the laboratory, but not reactivity (i.e, change scores) during the MAT, are related to blood pressure and heart rate levels recorded in the natural environment, especially in the work setting.

Activities of Daily Living↗