Exercise and ventricular ectopy: relationship to coronary artery disease.
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Coronary Disease↗
Biomedical subjects
G W Gleim
Publications and source records attributed to G W Gleim.
Increased levels of plasma renin, aldosterone, catecholamines and vasopressin in chronic ambulatory peritoneal dialysis (CAPD) patients.
Fluid excess can cause hyporeninemia and hypoaldosteronemia in hemodialysis patients. In six patients on CAPD, plasma renin activity (PRA) and plasma aldosterone (PA) were elevated to levels of : PRA 10.2 +/- 2.9 nl (1-5 ng/ml/h), and PA: 47.4 +/- 16.2 (normal 5-20 ng/dl). In 4 patients, data posthemodialysis and later during CAPD revealed that PRA increased from 0.9 +/- 0.3 to 14.1 +/- 4.6 and PA increased from 3.4 +/- 0.3 to 67.4 +/- 24.9 on CAPD (p less than 0.05). Mean arterial pressure was lower on CAPD and serum glucose was higher. No significant difference was seen in weight, hematocrit, BUN, or potassium, however. Plasma volume was not decreased in five CAPD patients: 3619 +/- 358 ml (predicted 3083 +/- 201 ml). Elevated catecholamine levels were seen in CAPD patients: norepinephrine 868.0 +/- 104.1 (normal 358.4 +/- 41.5 pg/ml), epinephrine 386.3 +/- 49.2 (normal 58.3 +/- 10.6 pg/ml). Plasma vasopressin levels were elevated to the range usually seen with hyperosmolality. In eight patients who lost or gained weight on CAPD, levels of PRA and PA changed as expected, but catecholamine levels did not correlate with weight changes. The data suggest that in CAPD patients, PRA and PA may be elevated in association with augmented sympathetic stimulation and elevated vasopressin levels. Serial observations demonstrated that PRA and PA can respond appropriately to changes in body weight, while catecholamine and vasopressin levels seem to be influenced by other factors.
Aldosterone↗
Using exercise respiratory measurements to compare methods of exercise prescription.
Exercise heart rate (HR) ranges based on peak HR, age-predicted maximal HR and peak oxygen consumption were compared to determine which method is most likely to result in an exercise prescription within guidelines determined from exercise respiratory measurements (upper limit--ventilatory threshold; lower limit--50% peak oxygen consumption). Exercise prescriptions based on either 80% peak HR or 70% peak measured oxygen consumption were significantly more likely to be within these guidelines (p less than 0.05) than other criteria tested; there was no significant difference between these 2 methods. Recommended exercise intensity based on 85% peak HR and 80% peak oxygen uptake resulted in a large percentage of patients with a heart rate above the ventilatory threshold (46% and 54%, respectively), whereas target HR derived from 75% peak HR and 60% peak oxygen consumption resulted in many patients with a heart rate below the lower limit (38% and 42%, respectively). Exercise prescription based on predicted maximal HR was of little value, regardless of the percentage used to determine target heart rate. The best methods identified in this study yielded an exercise intensity exceeding ventilatory threshold 15 to 20% of the time. Exercise prescription based on direct assessment of the ventilatory threshold is therefore preferred.
Adult↗
Principles of exercise prescription for patients with coronary artery disease.
Exercise performance is determined by the interaction of many systems. Cardiac disease, non-cardiovascular pathology, physical training, and the hemodynamic response to the type of exercise the patient wants to perform should all be considered when developing an exercise prescription. There are two stages for deriving a complete exercise prescription, determination of optimal exercise intensity from an exercise test and adoption of the recommendation to include other forms of exercise. The recommendation is usually based on a target oxygen consumption or a target heart rate derived from a treadmill test, but both of these methods may be of limited effectiveness. Ventilatory measurements during exercise, which reflect metabolic changes, are a useful adjunct. The exercise prescription must be individualized to the patient's needs, and may have to be modified so that exercise intensity remains within acceptable limits.
Cardiac Output↗
Acute cardiovascular response to exercise.
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Cardiovascular Physiological Phenomena↗
Pressure natriuresis and prostaglandin secretion by perfused rat kidney.
Isolated rat kidneys respond to elevations of perfusion pressure with an increase in glomerular filtration rate (GFR), filtration fraction (FF), and sodium excretion (UNaV) and a fall in fractional sodium reabsorption (FRNa). Significant linear correlations exist between each of these dependent variables and the renal artery pressure (P). In control kidneys, pressure natriuresis is seen to result both from an increase in filtered sodium load and a decrease in FRNa. In kidneys treated with indomethacin in doses which curtail the release into the perfusate of prostaglandin E2 (PGE2) and the prostacyclin metabolite, 6-keto-PGF1 alpha, the regression lines relating GFR, FF, and UNaV to P are shifted to the right. Thus, prostaglandin-inhibited kidneys require higher pressures than control kidneys to maintain comparable rates of filtration and sodium excretion. Total renal vascular resistance (RVR) is also higher in inhibited kidneys. These findings suggest that in the isolated perfused rat kidney, prostaglandins promote pressure natriuresis by maintaining afferent arteriolar dilation. Their inhibition leads to afferent constriction, which raises RVR, lowers FF and GFR, and reduces sodium excretion.
6-Ketoprostaglandin F1 alpha↗
Plasma osmolality, volume, and renin activity at the "anaerobic threshold".
Plasma renin activity (PRA), volume (PV), osmolality, and hemodynamic parameters were examined in relation to the anaerobic threshold (AT) during progressive cycle ergometry (PE) and repetitive bouts of unilateral isokinetic knee extension-flexion (LE) at 50% maximum voluntary contractions in eight normotensive males. During PE, the observed rise in PRA paralleled that of lactate with abrupt increases occurring at the AT. Correlation of % delta lactate (La), % delta osmolality, and % delta PV with % delta PRA were r = 0.65, 0.36, and -0.51, respectively (all P less than 0.01). In addition, when mean arterial pressure was plotted as a function of VO2, the rate of rise was greater below the AT than above the AT (11.5 vs. -2.4 mmHg X l-1 X min, P less than 0.001). A time control study (TC) exercising subjects for the same duration but at work rates maintained below the AT resulted in significantly lower values for both PRA and La (7.18 vs. 11.27 mg angiotensin I (ANG I) X ml-1 X min and 3.16 vs. 9.93 mM, P less than 0.05 for TC vs. PE) while producing a similar fall in % delta PV and rise in osmolality. During LE, a high correlation was obtained for % delta PRA and % delta La (r = 0.86, P less than 0.01) but not for % delta PRA with % delta PV or % delta osmolality. The data demonstrate that PRA parallels lactate during exercise and that mean arterial pressure rises more slowly beyond the AT despite a more rapid rise in PRA.
Adult↗
The profiling of professional football players.
We examined one professional football team over the course of the 1979 season in an attempt to divide the team into four basic positional categories of Line, TE-LB, OB, and DB-WR. Numerous significant differences could be found between these groups with regard to speed, anthropometric data, strength, and performance tests. This indicates a great deal of homogeneity by position within the professional football roster. We then employed a statistical treatment called "discriminant analysis," which, based upon combinations of four variables (two for size, one for fat, one for strength), could place each player into his position with a very high degree of accuracy. This has important implications for selection of players when they make the transition from college to professional football. Finally, we again employed discriminant analysis within the positions, adding variables of muscle deficits, injury history, and playing time and were able to rank players into either the injured or noninjured categories. These equations had a sensitivity of 93.7 per cent and specificity of 96.1 per cent, with the overall injury rate of 38 per cent. This indicates that some characteristics may abet injury. The discriminant analysis allows for selection of variables to statistically profile the football player. This technique addresses the multiple factors that contribute to the success or injury of the player and should be of use in profiling any sport, especially on the professional level.
Adult↗
Muscle strength and fiber typing.
The authors discuss fiber typing and morphologic changes resulting from training and how these affect athletic performance. Also considered is the concept of strength, its measurement and development, and how strength affects athletic performance, activity, and injury.
Athletic Injuries↗
Long-duration submaximal exercise conditioning in hemodialysis patients.
Objective changes in exercise tolerance were evaluated in five chronic hemodialysis patients (HD) following a ten week aerobic treadmill exercise conditioning program designed to exercise patients at a level approximating their anaerobic threshold (AT). This exercise conditioning program resulted in a 21% increase in peak oxygen consumption, an increase in test duration from 17.40 +/- 1.26 to 22.60 +/- 0.87 min (P less than 0.025), and an increase in AT from 0.81 +/- 0.08 to 0.97 +/- 0.08 1/min (P less than 0.05). These physiologic changes in exercise tolerance resulted in an overall increase in work capacity permitting the HD patient to perform a larger portion of the imposed work load aerobically.
Adult↗
Effect of exercise on lipid metabolism and dietary intake in hemodialysis patients.
In conclusion, a 10 wk exercise conditioning program in stable chronic hemodialysis patients resulted in improved exercise endurance without apparent adverse effects on nutritional status or lipid metabolism. Changes were observed suggesting a beneficial effect on carbohydrate and bone metabolism. The exercise-induced rise in serum creatinine may reflect an increase in muscle mass.
Adult↗
Quantification of posterior capsule tightness and motion loss in patients with shoulder impingement.
The relationship between posterior capsule tightness and dysfunction has long been recognized clinically but has not been biometrically quantified. The purpose of this study was to quantify changes in range of motion and posterior capsule tightness in patients with dominant or nondominant shoulder impingement. Measurements of posterior capsule tightness and external and internal rotation range of motion were made in 31 patients with shoulder impingement and in 33 controls without shoulder abnormality. Patients with impingement in the nondominant arm had increased posterior capsule tightness and decreased internal and external rotation range of motion compared with controls. Patients with impingement in their dominant arm had increased posterior capsule tightness and reduced internal rotation range of motion but no significant loss of external rotation range of motion compared with controls. Posterior capsule tightness in impingement patients showed a significant correlation with loss of internal rotation range of motion. Patients with shoulder impingement in their nondominant arm had a more global loss of range of motion compared with patients having impingement in their dominant arm. We believe we have described a valid clinical measurement for identifying posterior capsule tightness in patients with shoulder impingement.
Adult↗
Indirect assessment of cardiovascular "demands" using telemetry on professional football players.
Aerobic training is not a major component of th conditioning programs of professional football players. We used telemetric ECG monitoring to examine the cardiovascular "demands" of practice and game situations in six athletes who were selected to affect a variety of positions and aerobic capacities. Heart rates commonly considered high enough for an aerobic conditioning effect were rarely attained during a practice sessions. Maximum oxygen consumption testing confirmed that professional football players do not receive a sufficient amount of aerobic conditioning during practice. Telemetrically monitored heart rate response is much greater in a game situation than that experienced during practice. Telemetry results support injury statistics by indicating that aerobic conditioning should have a significant role in the training program of the professional football player.
Adult↗
The efficacy of manual assessment of muscle strength using a new device.
The purpose of this study was to compare the manual assessment of muscle strength with a small, handheld (by the examiner) force-measuring device developed by the Institute of Sports Medicine and Athletic Trauma (ISMAT). One hundred twenty-eight patients presented with a known lower extremity orthopaedic pathology. All patients were clinically evaluated for hip abductor and hip flexor weakness in standard positions using the "break test" technique. All 128 patients were then evaluated with the ISMAT Manual Muscle Tester, a small, hand-held device which recorded the peak force (kg) required to break a muscle contraction. Three bilateral measures of hip abduction and hip flexion were recorded, averaged, and compared to the subjective clinical evaluation using a chisquare analysis. Bilateral values which were within 5% of each other were not considered significant and therefore not included in the calculations. The average hip abduction and hip flexion scores measured by the ISMAT tester were consistent with the examiner's perception of muscle weakness (P less than 0.001). The results demonstrate consistent detection of muscle weakness by the ISMAT Manual Muscle tester over a broad range of testing conditions.
Humans↗
Hand and forearm strength and its relation to tennis.
Eight expert tennis players and 12 nontennis playing controls were studied to determine the relationship between dominant and minor extremities in regard to hand and forearm isometric strength. The results revealed that overall strength, including wrist extension, was significantly greater (P 0.01) in the dominant arm in both groups. The tennis players were distinguished from the controls by significantly increased strength of metacarpophalangeal joint extension of the fingers on the dominant side. Examination of a group of 16 "tennis elbow" sufferers demonstrated no significant extensor strength differential in the dominant arm, with no reports of pain during the testing procedure. The increased strength of hand extension in elite tennis players may be significant in explaining the observed rarity of "tennis elbow" in these individuals.
Forearm↗
Metabolic costs and heart rate responses to treadmill walking in water at different depths and temperatures.
Treadmill walking/jogging in water is a potentially useful therapeutic modality. Since energy costs of this activity are unknown, we compared oxygen consumption (VO2) of treadmill walking/jogging in water to a dry treadmill at speeds of 40.23 to 160.9 meters/min (m/m) in 13.4 m/m increments in 11 subjects. At speeds greater than or equal to 53.6 m/m, ankle depth, below knee, midthigh, and waist depth walking/jogging in water significantly elevated VO2 and heart rate (HR) above dry treadmill walking (P less than 0.05). At speeds greater than or equal to 134.1 m/m, VO2 of waist depth jogging was not significantly greater than dry jogging. These findings showed no gender specificity. Treadmill walking/jogging in waist depth water at temperatures of 30.5 degrees C and 36.1 degrees C was compared to dry treadmill walking in five subjects. The rate of increase of HR compared to VO2 was significantly greater at 30.5 degrees C than dry walking, and greater at 36.1 degrees C than 30.5 degrees C (P less than 0.05). Treadmill walking in water can double the oxygen cost of movement depending on the depth and speed, and the response to increasing speed is nonlinear. Water temperature affects the relationship of HR to VO2 at waist depth, suggesting that water temperature can add a significant thermal load to the cardiovascular system. Metabolic and cardiovascular demands of treadmill walking/jogging in water must be considered when using this modality since greater external work results at much lower speeds than on land.
Adult↗
Subject variability of shoulder abduction strength testing.
To quantify normal biological variability of shoulder abduction strength testing with an isokinetic and a hand-held dynamometer, we tested nine healthy subjects over a clinically relevant period. One side was tested with a Cybex at 60 deg/sec and the other with a hand-held dynamometer. Six maximal trials, following warmup, were conducted on each of 5 days, separated by 1 to 2 weeks. Intraday correlations of individual trials ranged from 0.82 to 0.995 for hand-held dynamometer, and 0.88 to 0.996 for Cybex. Interday correlations ranged from 0.94 to 0.98 for hand-held dynamometer, and 0.88 to 0.97 for Cybex. The best values to use for Cybex interday variability were the average of the first three repetitions, and yielded standard errors of 8.6% to 19.2% of the sample mean. The average of the last three repetitions were the best for hand-held dynamometers, and yielded standard errors of 5.5% to 10.8%. There was a significant decline (P less than 0.05) in strength of the mean of the last three versus the mean of the first three daily repetitions on Day 1 and 4 for hand-held dynamometers, and a trend toward this on the other days, that was not seen with Cybex. Regression of average Day 1 values for Cybex and hand-held dynamometer yielded r = 0.86 (P less than 0.01) with a slope of 1.07 indicating good agreement between modalities. In conclusion, intraday/interday correlations were high for Cybex and hand-held dynamometer. Interday variability was minimized by using the mean score of the first three and last three repetitions for Cybex and hand-held dynamometer, respectively. Changes in Cybex and hand-held dynamometer strength of less than 19% and 11%, respectively, are within the area of "measurement error" and should therefore not be considered clinically significant.
Adult↗
Strength profiles and performance in Masters' level swimmers.
The purpose of this study was to profile shoulder, trunk, and thigh strength and shoulder range of motion in competitive Masters' level swimmers and to see if these variables were related to swimming performance. Twenty-four Masters' level swimmers (13 men and 11 women) were tested for isometric trunk flexion and extension, isokinetic knee extension and flexion, shoulder abduction, internal rotation, external rotation, and supraspinatus muscle strength; shoulder internal and external rotation range of motion; and 50-yard swimming time. Strength scores were adjusted for weight. The men were significantly stronger than the women in trunk extension and flexion. Shoulder range of motion, shoulder abduction strength, and thigh strength were equal for both the men and the women. The men were stronger than the women in internal and external shoulder rotation. Conversely, the women tested were significantly stronger than the men in the supraspinatus muscle test. The men were significantly faster than the women in the 50-yard swim. Inverse relationships existed between swimming time and trunk flexion, trunk extension, and shoulder internal rotation strength. Trunk flexion strength remained the only significant predictive variable of swimming time in a multiple regression analysis.
Adult↗