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At least 775 records · Page 43Linked to original sources
PubMed1975

[Effect of stretching on the resting potential of isolated frog muscle fibers].

The resting potentials of single muscle fibers of the frog increased under a 30% stretching over the rest length (sarcomere length being about 3.2 microns). If the resting potential was increased during the resting state, no augmentation of the resting potential occurs under stretching. The stretching of fibres by 60% over the rest length (sacomere length about 3.9 microns) was accompanied, as a rule, by depolarization.

Animals↗
PubMed1999

Muscle sympathetic nerve activity (MSNA) after 120 days of 6 degrees head-down bed rest (HDBR).

The alterations in the sympathetic nervous system are commonly seen after spaceflight and its ground-based simulation model, 6 degrees head-down bed rest (HDBR). Several studies have examined the effect of HDBR for a few days or a weeks on the vasomotor sympathetic tone at rest. However, it remains unclear how a long-lasting (>50 days) HDBR affects resting vasomotor sympathetic nervous activity. Consequently, we measured muscle sympathetic nerve activity (MSNA) in six healthy male volunteers (range, 26-42 years) in a resting supine position before and after 60 and 120 days of HDBR. MSNA was measured directly from the tibial nerve using a microneurographic technique. Resting supine MSNA significantly increased after 60 (28.2 +/- 2.7 bursts/min) and 120 (29.4 +/- 4.2 bursts/min) days of HDBR compared with the pre-HDBR level (19.0 +/- 2.3 bursts/min). Heart rate was significantly higher after 60 (73 +/- 2 beats/min) and 120 (72 +/- 3 beats/min) days of HDBR than before (65 +/- 2 beats/min). In contrast, mean blood pressure remained unchanged during and after 120 days of HDBR. In conclusion, the resting vasomotor sympathetic tone increased after long-lasting simulated microgravity.

Adult↗
PubMed1975

Effect of 14 days of bed rest on urine metabolite excretion and plasma enzyme levels.

After one week of ambulatory baseline measurement, a group of eight men 19-26 years of age remained continuously recumbent for 14 days. Studies were continued for one week following the prolonged recumbency. Urine excretion rates for a number of constituents were determined 2 days before bed rest, on day 14 of bed rest, and day 6 after bed rest. Blood plasma samples were also obtained at these times, and analyzed for several enzymes. On day 14 of bed rest significant increases were observed in urine excretion of total osmotically active substances, magnesium, calcium, phosphate, creatinine, hydroxyproline, and 17-OH corticosteroids. A decrease occurred in urinary glucose excretion. Plasma levels of alkaline phosphatase and LDH-3 were depressed, while plasma GPT was elevated. Many of these changes persisted on day 6 after bed rest, and are interpreted as concomitants of the disuse atrophy of the musculoskeletal system that characterizes prolonged bed rest and weightlessness.

Adaptation, Physiological↗
PubMed2002

Maintaining oxygenation via demand oxygen delivery during rest and exercise.

BACKGROUND: Oxygen-conserving devices have been the foundation of highly portable oxygen systems that enable hypoxemic chronic lung disease patients to live active lives. Pulsing demand oxygen delivery systems (DODS) can adequately oxygenate most patients at rest and usually during exercise. However, some patients desaturate during exercise at DODS settings equivalent to continuous-flow oxygen. OBJECTIVE: Determine if design enhancements of the Oxymatic 401 DODS (including increased sensitivity, earlier inspiratory delivery, larger pulse volume, modified pulse contour, and higher settings) better maintain blood oxygen saturation (measured via pulse oximetry [S(pO2)]) in patients who severely desaturate during exercise. METHODS: We compared patients receiving DODS oxygen and patients receiving continuous-flow oxygen, during both rest and iso-exercise. SETTING: This study was conducted in the Pulmonary Rehabilitation Program at Mission Hospital, Regional Medical Center, Mission Viejo, California. SUBJECTS: We studied 10 patients with chronic lung disease and difficulty maintaining exercise S(pO2) with DODS. Nine patients had chronic obstructive pulmonary disease and one had restrictive lung disease. The group's (mean +/- SD) demographic and physiologic values included: age 67 +/- 7 y, forced expiratory volume in the first second 0.79 +/- 0.3 L, forced vital capacity 1.7 +/- 0.7 L, and S(pO2) 88%. INTERVENTIONS: Resting S(pO2) was measured during continuous oxygen flow and during DODS, at identical settings. S(pO2) was allowed to stabilize at each level before recording. During treadmill exercise at identical work loads we measured continuous flow and DODS S(pO2) at the same settings. If the DODS S(pO2) was less than during the equivalent continuous flow, the DODS setting was increased for another treadmill trial. RESULTS: At rest the DODS was equivalent to continuous flow: S(pO2) was 93.7 +/- 2.1% with DODS and 93.8 +/- 1.9% with continuous flow. During exercise at corresponding settings DODS S(pO2) was 90.5 +/- 3.8% and continuous-flow S(pO2) was 93.1 +/- 3.1%. Six subjects had S(pO2) > 90%, with 4 of them achieving equivalency. At higher DODS settings S(pO2) became equivalent: 92.5 +/- 2.8%. The DODS oxygen-use efficiency advantage was 6.7-fold at rest and 5.6-fold during exercise, except with subjects who required a higher exercise DODS setting, with whom the DODS advantage was 4.3-fold. CONCLUSIONS: The redesigned Oxymatic 401 DODS maintains adequate S(pO2) during rest and exercise, but some patients require the higher delivery settings. We recommend that all patients prescribed DODS undergo exercise evaluation with the prescribed DODS to ensure efficacy and determine the DODS settings required to maintain S(pO2) at the prescribed limits.

Aged↗
PubMed2002

[Hypotensive effects of telmisartan on blood pressure during rest and exercise in patients with mild and moderate arterial hypertension].

UNLABELLED: The aim of the study was to evaluate an antihypertensive effect of AT1-receptor blocker telmisartan on the rest and exercise blood pressure (BP) in patients suffering from mild and moderate arterial hypertension. Twenty males (mean age 50.9 +/- 6.9) following a 3-week placebo run-in phase were treated by telmisartan 80 mg q.d. Bicycle exercise test and echocardiography was performed at the end of placebo run-in phase and following 12 weeks of treatment. The workload on the bicycle exercise test has been increased by 25 watts every 2 min and stopped at systolic BP (SDP) 240 or diastolic BP (DBP) 130 mmHg. The maximal workload was the same, prior and after 12 weeks of the treatment. Antihypertensive therapy with telmisartan had a favorable effect, i.e. significantly decreased the rest BP--both SBP (152.5 +/- 11.4 mmHg vs. 139.2 +/- 12.3 mmHg, p < 0.001) and DBP (100.0 +/- 4.6 mmHg vs. 88.7 +/- 6.2 mmHg, p < 0.001). There were no significant changes in the heart rate (HR) at rest prior and after telmisartan treatment (71.4 +/- 9.1 b/min vs. 72.2 +/- 10.4 b/min). When repeating the exercise test after 12 weeks of telmisartan treatment we detected the significant decrease of BP at maximal workload, i.e. SBP decreased from 230.9 +/- 11.4 mmHg to 211.3 +/- 12.7 mmHg, p < 0.05 and DBP decreased from 124.6 +/- 7.5 mmHg to 109.7 +/- 9.7 mmHg, p < 0.05. There was a significant decrease in HR (140.6 +/- 13.2 b/min vs. 130.1 +/- 14.2 b/min, p < 0.05) and significant increase in JT interval at maximal workload after telmisartan treatment (0.193 +/- 0.014 sec vs. 0.201 +/- 0.014 sec, p < 0.05). Telmisartan decreased the double product at rest and maximal workload (diff. of 16 x 10(2) mmHg x b/min and 48 mmHg x 10(2) b/min, respectively, p < 0.05). CONCLUSIONS: Twelve weeks of the telmisartan treatment showed a significant decrease of blood pressure at rest and exercise with no effect on the heart rate at rest in patients with mild and moderate arterial hypertension. There was statistically significant decrease in HR at maximal workload after the treatment by telmisartan.

Adult↗
PubMed2004

Is bed rest an effective treatment modality for pressure ulcers?

Despite the well-documented medical, physical, and psychological complications associated with this care management option, bed rest remains a frequently prescribed treatment modality for conditions such as pressure ulcers. Cognitive and psychosocial complications of bed rest include depression, learned helplessness, perceptual changes, and fatigue. Physically, complications can include contractures, muscle atrophy, osteoporosis, pathologic fractures, urinary tract infections, decreased cardiac reserve, decreased stroke volume, resting and post-exercise tachycardia, orthostatic hypotension, pulmonary embolism, deep venous thrombosis, pneumonia, anorexia, constipation, and bowel impaction. Furthermore, the literature does not contain evidence supporting the use of bed rest to facilitate healing of pressure ulcers. More suitable approaches to pressure ulcer care include limiting bed rest, initiating occupational therapy, integrating meaningful tasks into daily activities, increasing outside stimulation, involving patients in care decisions and addressing their concerns, optimizing nutritional status, and managing pressure and shear throughout daily activities. Recommendations for implementing alternatives to bed rest are addressed.

Activities of Daily Living↗
PubMed2002

[Effect of smoking on PaO2 at rest and during moderate exercise].

The most data on smoker's arterial oxygen tension (PaO2) were carried out at rest and from non arterial blood sample. The aim of this retrospective study was to compare smokers and nonsmoker's arterial oxygen tension (PaO2) at rest and during a moderate exercise. 98 male smokers between 23 and 69 years old and 98 male nonsmokers with the same age bracket were recruited among subjects submitted to arterial blood gas analysis according to the following protocol: 2 arterial blood samples were taken at rest, with an interval of 5 minutes, followed by a third one taken at the end of a moderate effort (50 watts during 5 minutes) on a bicycle in the supine position. Wilcoxon's test was used to compare the measured biological parameters between smokers and nonsmokers. Unlike nonsmokers, smoker's PaO2 increased meaning fully during moderate exercise. However, like at rest, it remained lower than nonsmoker's PaO2.: 87.6 +/- 15.8 mmHg Versus 94.1 +/- 10.4 mmHg (p < 0.0001). These beneficial effects of exercise on smoker's PaO2, although limited among heavy smokers group, suggested that hypoxia observed at rest must be due to troubles in ventilation/perfusion ratio in the lungs. In comparison to nonsmokers, the most significantly hypoxia was founded in smokers between 40 and 59 years old. The variation of PaO2 in nonsmokers was normal in comparison with age, but strongly disturbed in smokers at rest as well as during a moderate exercise, despite the lack of correlation between PaO2 and the intensity of tobacco consumption (expressed as number of pack-years). Thus, the smokers' PaO2 deterioration concerned together its value and its variation in comparison with age.

Adult↗
PubMed2005

Intensive cycle training with artificial gravity maintains muscle size during bed rest.

INTRODUCTION: The present study aimed to investigate the effect of intensive cycle training with short-arm centrifuge-induced hypergravity during bed rest on muscle size and function. METHODS: This study involved 10 healthy men who were divided into 2 groups: a countermeasure group, BR-CM (n = 5); and a control group, BR-Cont (n = 5). The BR-CM subjects partook in intensive cycle training (to 90% of maximum HR) with short-arm centrifuge-induced artificial gravity on alternate days during 20-d bed rest. Muscle volume of the thigh and maximum voluntary contraction (MVC) during isometric knee extensions was measured before and after bed rest. Muscle functional magnetic resonance imaging (mfMRI) and electromyogram (EMG) of the quadriceps femoris were obtained during submaximal knee extension exercises at a load of 30% MVC. RESULTS: The volume of the total thigh muscles was maintained in the BR-CM group (-1%), whereas it was not in the BR-Cont group (-9%, p < 0.05). MVC decreased in the BR-CM (7%) and BR-Cont groups (23%). EMG activity in the BR-CM group after bed rest was significantly lower than that of before; however, no significant change was found in the BR-Cont group. There were no significant changes in the resting and exercised mfMRI signals in either the BR-CM or BR-Cont groups. CONCLUSION: These results suggest that intensive cycle training with hypergravity maintained the size of human skeletal muscles during bed rest.

Adult↗
PubMed2005

Rest versus stress ejection fraction on gated myocardial perfusion SPECT.

OBJECTIVES: It is widely accepted that exercise-induced stunning has an impact on left ventricular ejection fraction (EF); yet, despite the recommendations of the American Society of Nuclear Cardiology, many departments only perform gated SPECT on stress studies. The aim of this investigation was to determine the relationship between rest EF and stress EF in myocardial perfusion studies and to identify possible predictors of variability. METHODS: This study was a retrospective cross-sectional study of 133 patients (266 studies) undergoing myocardial perfusion SPECT. Automated computer-generated functional data (end-diastolic volume, end-systolic volume [ESV], and EF) for rest and stress studies were correlated as matched pairs and analyzed with respect to the following variables: age, sex, stress method, time between stress and scanning, and presence or absence of pathology scintigraphically. Differences in matched EF pairs (DeltaEF) and transient dilatation were also determined. RESULTS: Matched pairs of rest EF and stress EF demonstrated excellent correlation (0.90) with no significant difference noted (P=0.15). Bland-Altman analysis demonstrated a mean DeltaEF of -0.65% (95% confidence interval [CI], -1.54% to 0.23%) with 94% of data points within the 95% limits of agreement. No statistically significant difference was determined between the mean DeltaEF and the hypothetic mean of 0 (P=0.15). A time between stress and scanning of <45 min was shown to be predictive of a negative DeltaEF (P=0.04). Transient dilatation was shown to be predictive of a negative DeltaEF (P=0.01). Resting ESVs between 25 and 50 mL were shown to be predictive of a negative DeltaEF (P=0.02). A stress EF of <50% was also shown to be predictive of a negative DeltaEF (P=0.003). CONCLUSION: No statistically significant difference between stress and rest EF was demonstrated and no trend was identified toward either under- or overestimation of the stress EF with a DeltaEF. A negative DeltaEF was, however, predicted by transient dilatation of >1.0, a time between stress and scanning of <45 min, a stress EF of <50, and an ESV between 25 and 50 mL. Gated SPECT performed on both stress and rest studies may provide a mechanism to predict exercise-induced stunning and transient dilatation.

Adult↗
PubMed1990

[Assessment of myocardial viability by resting 201Tl SPECT image].

The aim of this study was to assess whether resting 201Tl scintigraphy is superior in detecting viable myocardium than previous conventional methods. We performed not only stress 201Tl SPECT but also resting 201Tl SPECT within one month in 65 patients with coronary artery disease. Resting 201Tl images were quantitatively compared with 4 hour late images of stress study using a polar map. In stress study, redistribution was recognized on 83% (25/30) of non-MI SEGs with perfusion defect in the stress 201Tl image, and on 39% (18/46) of infarcted SEGs. The agreement of resting 201Tl study with 4 hour late images of stress study was shown on 93% (28/30) of non-MI SEGs and on 52% (24/46) of MI SEGs. The increased uptake of 201Tl in resting study, however, was found on 13 (46%) of 28 MI SEGs showing fixed defects in stress study. In stress delayed image with fixed defect, the %Tl uptake of improved SEGs was higher than that of unchanged SEGs (59 +/- 10% vs 48 +/- 11%; p greater than 0.05). There was no viable myocardium which had %Tl uptake less than 40% at stress delayed image. In conclusion, the resting 201Tl imaging will give an important information as for the myocardial viability showing fixed defects, if more than 40% Tl uptake is observed.

Aged↗
PubMed1985

Rest and exercise hemodynamic and adrenergic responses to enalapril, hydrochlorothiazide, and combination treatment in patients with systemic hypertension.

The effects of enalapril (10-20 mg twice daily), hydrochlorothiazide (25-50 mg twice daily), and combination enalapril-hydrochlorothiazide therapy (10-20 mg enalapril/25-50 mg hydrochlorothiazide in combination tablet twice daily) were evaluated and compared to no therapy (control) in eight patients with mild to moderate hypertension at rest and during treadmill exercise. All active treatments reduced standing blood pressure in patients at rest compared to the control group (p less than 0.05); however, none produced significant reductions of standing blood pressure in patients at peak exercise. Standing heart rates of patients at rest and at peak exercise were not changed with active therapy. However, standing heart rate in patients at rest was lower with enalapril than with hydrochlorothiazide and combination therapy (p less than 0.05). Heart rate of patients on hydrochlorothiazide was higher than with control and other therapies at Stage I of exercise (p less than 0.01). Supine norepinephrine levels in patients at rest were elevated with both hydrochlorothiazide and combination therapy when compared to that in patients with enalapril and control (p less than 0.05). Treatment with enalapril alone produced no changes in plasma catecholamine levels compared to control. There were no differences between control and all treatment regimens in peak exercise levels of catecholamines. Thus, enalapril, hydrochlorothiazide, and combination therapy, although effective in lowering resting blood pressure, may not be effective in blunting the blood-pressure response to exercise. The drugs do not appear to have any significant effects on catecholamine levels in patients at peak exercise.

Adult↗
PubMed1988

Bed rest effect on extremity muscle torque in healthy men.

The purpose of this study was to assess the effect of bed rest on appendicular muscle torque. Fifteen healthy male volunteers between the ages of 21 and 54 participated in the study. The subjects were put on five weeks of strict horizontal bed rest. They were allowed to sit up for bowel movements only; however, no lower extremity weight-bearing was allowed. During bed rest, the subjects were required to ingest a fixed nutritionally adequate diet. Data for muscle torque were obtained using a Cybex II dynamometer, Upper Body Exercise Table (UBXT), and a data analysis computer (HUMAC). The subjects were tested on Cybex at the speed of 60 degrees/sec during the week before starting bed rest and the day after starting reambulation. The muscle groups tested were soleus, gastrocnemius-soleus, dorsiflexors, knee flexors, knee extensors, elbow flexors, and elbow extensors. The torque in all groups but elbow extensors was reduced by 24%, 26%, 8%, 8%, 19%, and 7%, respectively. Student's t-test for paired means demonstrated significant loss of torque in all muscle groups except elbow extensors (p less than 0.05). The results of this study suggest that a strengthening exercise program should be administered to these patients while they are on bed rest, and that the earliest possible attempt should be made to ambulate patients after prolonged bed rest to minimize the loss of muscle torque.

Adult↗
PubMed1987

Influence of exercise and quiet rest on state anxiety and blood pressure.

A series of investigations was performed in which Ss rested quietly for 40-min and performed aerobic exercise on separate occasions. Blood pressure (BP) and state anxiety were assessed prior to and following the conditions. In the first experiment, 15 normotensive Ss were assessed during the 3-h following the treatments. The results revealed that state anxiety and BP were reduced following both conditions. The exercise-induced BP reductions remained significant for 2 to 3 h (P less than 0.05), whereas the BP reductions returned to baseline within 20-min following cessation of quiet rest. The second experiment involved an evaluation of the effects of exercise and quiet rest on 15 pharmacologically controlled hypertensive Ss. A significant reduction in systolic BP (P less than 0.05) was observed following exercise and quiet rest. State anxiety was reduced following quiet rest and exercise (P less than 0.05). It is concluded that exercise and quiet rest have similar effects on state anxiety, and both conditions are followed by a transitory reduction in blood pressure. These anti-anxiety effects, however, are sustained for a longer period following exercise.

Adult↗
PubMed1986

[Metabolic response in the acute stage of cerebral infarction--with special reference to oxygen consumption and resting metabolic expenditure].

Oxygen consumption, carbon dioxide production, respiratory quotients, and resting metabolic expenditure were measured in 23 patients with cerebral infarction in their acute stage. Metabolic measurement were carried out with the technique of indirect calorimetry on their admission within two days from the onsets. At the same time, urine was collected twenty-four hours to measure urinary catecholamine excretion. Mean value of resting metabolic expenditure was 115.1% and this positively correlated with urinary catecholamine, especially noradrenaline excretion. Maximum value of resting metabolic expenditure was up to 187.1% of that expected for an uninjured resting person of equivalent age, sex, and body surface area. Oxygen consumption and carbon dioxide production also positively correlated to urinary catecholamine excretion. On the other hand, respiratory quotients did not have any significant correlation with oxygen consumption, carbon dioxide production, resting metabolic expenditure, or urinary catecholamine excretion. From those facts, it was implied that overactivity of sympathetic nervous system existed in their acute stage of cerebral infarction, and the overflow might directly influence oxygen consumption, carbon dioxide production, and resting metabolic expenditure, and moreover we had to take into consideration of hyper-metabolic state to manage patients with ischemic cerebrovascular diseases as malnutrition might cause weight loss and immune incompetence.

Adult↗
PubMed1983

Evaluation of a Reverse Gradient Garment for prevention of bed-rest deconditioning.

A Reverse Gradient Garment (RGG) was used to intermittently induce venous pooling in the extremities of a magnitude similar to that seen in going from a lying to standing position during the course of a 15-d period of horizontal bed rest. Venous pooling failed to improve bed-rest-induced losses in +2.5 Gz and +3.0 Gz centrifugation tolerance or to prevent increased heart-rate responses to lower-body negative pressure (LBNP). Four subjects served as controls, four were treated. Tests during the 7-d recovery period showed fluid/electrolyte and body composition values to have returned to pre-bed-rest levels with continued depression of acceleration tolerance times (56% decreased at +2.5 Gz and 74% decreased at +3.0 Gz compared to pre-bed-rest levels) and exaggerated blood insulin response on glucose tolerance testing (blood insulin for treated group increased 95% at 1 h before bed rest and 465% during recovery). This study demonstrates that the physiologic changes after bed rest persist for significant periods of time. Acceleration tolerance time proved to be a sensitive test for the deconditioning process.

Acceleration↗
PubMed1984

[Diagnosis of myocardial ischemia in Kawasaki disease: thallium-201 myocardial imagings at rest, with exercise and with dipyridamole administration].

Thallium-201 myocardial imaging was performed at rest in 131 children with coronary arterial lesions due to Kawasaki disease. The coronary arterial lesions were assessed by selective coronary angiography within a few days of the isotope study. Twenty-one children had occlusive lesions, and segmental stenotic lesions were seen in 16 children. Perfusion defects of the myocardial images were detected in nine of the former and in three of the latter. The locations of the perfusion defects coincided with the perfusion areas of the affected vessels on coronary angiography. Twelve patients with initial perfusion defects at rest had a follow-up study and the defects disappeared in five. These patients had re-establishment of coronary blood flow in the initially affected areas by either development of collateral vessels or recanalization. Myocardial imaging with exercise was performed in 27 patients including four with coronary arterial occlusion and two with segmental stenosis on coronary angiography. All with coronary artery lesions showed perfusion defects on the imaging with exercise, while the resting study showed the defects only in one patient, in whom more extensive perfusion defects were observed after exercise. Myocardial imaging following intravenous injection of dipyridamole was carried out in 43 patients. Perfusion defects after the injection were noted in 15 of 17 patients with coronary occlusion and in nine of 13 patients with segmental stenosis. In four patients with perfusion defects at rest, additional or more extensive defects were revealed by this drug in the areas of additional coronary arterial involvements. In 20 patients with perfusion defects only after dipyridamole injection, the perfusion defects coincided with the angiographic findings very well. A perfusion defect was documented following dipyridamole injection in one exceptional patient who had no stenotic lesions, but had three giant coronary aneurysms of the right coronary artery. Thus the dilated coronary lesions seemed to give a perfusion defect. In some of the patients whose perfusion defects disappeared at rest on a follow-up study, the defects were disclosed by exercise and/or dipyridamole administration. Thus, thallium-201 myocardial imagings combining resting and exercise or dipyridamole studies were valuable for the detection and assessment of coronary arterial lesions of Kawasaki disease.

Adolescent↗
PubMed1983

Nuclear left ventriculography at rest and during atrial pacing in the evaluation of coronary artery disease.

This study was undertaken to examine the value of rapid atrial pacing (RAP) combined with left-ventricular nuclear (LVN) angiography in the diagnosis of ischemic heart disease. It included 32 patients: 12 normal subjects and 20 with clinical coronary artery disease (CAD) and greater than 50% narrowing of a coronary artery (significant CAD). The ECG and an LVN angiogram (LVNA) were recorded at rest and during graded RAP. In the normal subjects, left-ventricular wall motion was normal at rest and during atrial pacing, but a wall motion abnormality (WMA) appeared in one subject. Left-ventricular ejection fraction (EF) did not change significantly. In the 20 patients with significant CAD, the diagnostic sensitivity of the ECG during RAP was 100% and 90% for the nuclear angiogram (presence or appearance of WMA at rest and during RAP). The mean EF in this group decreased from 0.38 to 0.31. WMA on the LVNA was present in 79% of patients with significant left-anterior descending, in 44% of those with right, and in 33% of those with circumflex coronary artery disease. WMA (at rest or on pacing) occurred in 17% of patients with 50 to 89% narrowing of an artery, in 50% with 90 to 99% narrowing and in 68% with total obstructions. The LVNA (rest and/or RAP) identified patients with significant single-vessel disease, but underestimated the extent of double-and triple-vessel disease. The LVNA at rest and during atrial pacing was an excellent method of evaluating significant coronary artery disease.

Adult↗
PubMed1983

Variation in left ventricular ejection fraction determination at rest and during exercise.

The results of multi-gated blood pool imaging (MBPI) for determination of left ventricular ejection fraction (LVEF) in 48 patients at rest and during exercise were analysed in order to evaluate observer variance and interstudy variance. Twenty-three MBPI studies carried out with the patient at rest and 37 studies carried out during graded ergometer exercise were analysed by two independent observers in order to determine intra- and inter-observer variance. On the intra-observer level regression analysis yielded excellent correlation between rest and exercise studies (r = 0,998 at rest, r = 0,964 during exercise), and showed no statistically significant difference (P less than 0,01); this was also true of the inter-observer measurements (r = 0,999 at rest, r = 0,988 during exercise). In order to evaluate interstudy variance, MBPI was repeated in 15 patients at rest. Interstudy variation of the LVEF was minimal as indicated by regression analysis (r = 0,98), and showed no statistically significant difference (P less than 0,01). During the repeat study a mean increase in the LVEF of 2,1% was obtained, but this difference was not statistically significant.

Adolescent↗