scholarly journals A Clinical Exercise Physiological Study Of The Effects Of Wearing A N95 Respirator Or Cloth Mask At Peak Exercise

2021 ◽  
Vol 53 (8S) ◽  
pp. 57-58
Author(s):  
Matthew Kampert
Keyword(s):  
Physiological Study ◽  
Peak Exercise

Effects of Rest and Exercise on Cardiac Blood Volume Determinations

1997 ◽  
Vol 36 (08) ◽  
pp. 259-264
Author(s):  
N. Topuzović
Keyword(s):  
Radionuclide Ventriculography ◽  
Left Ventricular ◽  
Peak Exercise ◽  
Volume Determination ◽  
Group I ◽  
Lv Volumes ◽  
Group Ii ◽  
Lv Volume

Summary Aim: The purpose of this study was to investigate the changes in blood activity during rest, exercise and recovery, and to assess its influence on left ventricular (LV) volume determination using the count-based method requiring blood sampling. Methods: Forty-four patients underwent rest-stress radionuclide ventriculography; Tc-99m-human serum albumin was used in 13 patients (Group I), red blood cells was labeled using Tc-99m in 17 patients (Group II) in vivo, and in 14 patients (Group III) by modified in vivo/in vitro method. LV volumes were determined by a count-based method using corrected count rate in blood samples obtained during rest, peak exercise and after recovery. Results: In group I at stress, the blood activity decreased by 12.6 ± 5.4%, p <0.05, as compared to the rest level, and increased by 25.1 ± 6.4%, p <0.001, and 12.8 ± 4.5%, p <0.05, above the resting level in group II and III, respectively. This had profound effects on LV volume determinations if only one rest blood aliquot was used: during exercise, the LV volumes significantly decreased by 22.1 ± 9.6%, p <0.05, in group I, whereas in groups II and III it was significantly overestimated by 32.1 ± 10.3%, p <0.001, and 10.7 ± 6.4%, p <0.05, respectively. The changes in blood activity between stress and recovery were not significantly different for any of the groups. Conclusion: The use of only a single blood sample as volume aliquot at rest in rest-stress studies leads to erroneous estimation of cardiac volumes due to significant changes in blood radioactivity during exercise and recovery.

Contribution of the peak exercise QT dispersion to the accuracy of an exercise test during the evaluation of coronary artery disease

2000 ◽  
Vol 55 (6) ◽  
pp. 335-339 ◽  
Author(s):  
Mehmet ÜLGEN ◽  
Aziz KARADEDE ◽  
Sait ALAN ◽  
A. Vahip TEMAMOĞULARI ◽  
Aziz KARABULUT ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Exercise Test ◽  
Qt Dispersion ◽  
Peak Exercise ◽  
Artery Disease

Clinical Physiological Study of the Action of BC 105 (Sandoz, Basle) in the Interval Therapy of Migraine

1974 ◽  
Vol 11 (6) ◽  
pp. 353-362 ◽  
Author(s):  
O. Starý ◽  
M. Janský ◽  
Š. Figar ◽  
J. Stein
Keyword(s):  
Physiological Study ◽  
Interval Therapy

Cardiopulmonary Exercise Testing in Combined Pulmonary Fibrosis and Emphysema

Respiration ◽  
2021 ◽  
pp. 369-377
Author(s):  
Michael Westhoff ◽  
Patric Litterst ◽  
Ralf Ewert
Keyword(s):  
Body Weight ◽  
Pulmonary Fibrosis ◽  
Sensitivity And Specificity ◽  
Exercise Testing ◽  
Cardiopulmonary Exercise Testing ◽  
Arterial Oxygen ◽  
Peak Exercise ◽  
Cutoff Value ◽  
Cardiopulmonary Exercise ◽  
Peak Vo2

Background: Combined pulmonary fibrosis and emphysema (CPFE) is a distinct entity among fibrosing lung diseases with a high risk for lung cancer and pulmonary hypertension (PH). Notably, concomitant PH was identified as a negative prognostic indicator that could help with early diagnosis to provide important information regarding prognosis. Objectives: The current study aimed to determine whether cardiopulmonary exercise testing (CPET) can be helpful in differentiating patients having CPFE with and without PH. Methods: Patients diagnosed with CPFE in 2 German cities (Hemer and Greifswald) over a period of 10 years were included herein. CPET parameters, such as peak oxygen uptake (peak VO2), functional dead space ventilation (VDf/VT), alveolar-arterial oxygen difference (AaDO2), arterial-end-tidal CO2 difference [P(a-ET)CO2] at peak exercise, and the minute ventilation-carbon dioxide production relationship (VE/VCO2 slope), were compared between patients with and without PH. Results: A total of 41 patients with CPET (22 with PH, 19 without PH) were analyzed. Right heart catheterization was performed in 15 of 41 patients without clinically relevant complications. Significant differences in peak VO2 (861 ± 190 vs. 1,397 ± 439 mL), VO2/kg body weight/min (10.8 ± 2.6 vs. 17.4 ± 5.2 mL), peak AaDO2 (72.3 ± 7.3 vs. 46.3 ± 14.2 mm Hg), VE/VCO2 slope (70.1 ± 31.5 vs. 39.6 ± 9.6), and peak P(a-ET)tCO2 (13.9 ± 3.5 vs. 8.1 ± 3.6 mm Hg) were observed between patients with and without PH (p < 0.001). Patients with PH had significantly higher VDf/VT at rest, VT1, and at peak exercise (65.6 ± 16.8% vs. 47.2 ± 11.6%; p < 0.001) than those without PH. A cutoff value of 44 for VE/VCO2 slope had a sensitivity and specificity of 94.7 and 72.7%, while a cutoff value of 11 mm Hg for P(a-ET)CO2 in combination with peak AaDO2 >60 mm Hg had a specificity and sensitivity of 95.5 and 84.2%, respectively. Combining peak AaDO2 >60 mm Hg with peak VO2/body weight/min <16.5 mL/kg/min provided a sensitivity and specificity of 100 and 95.5%, respectively. Conclusion: This study provided initial data on CPET among patients having CPFE with and without PH. CPET can help noninvasively detect PH and identify patients at risk. AaDO2 at peak exercise, VE/VCO2 slope, peak P(a-ET)CO2, and peak VO2 were parameters that had high sensitivity and, when combined, high specificity.

Dietary effects on exercising muscle metabolism and performance by 31P-MRS

1994 ◽  
Vol 77 (3) ◽  
pp. 1108-1115 ◽  
Author(s):  
D. E. Larson ◽  
R. L. Hesslink ◽  
M. I. Hrovat ◽  
R. S. Fishman ◽  
D. M. Systrom
Keyword(s):  
Minute Ventilation ◽  
Muscle Metabolism ◽  
Exercise Duration ◽  
Quadriceps Muscle ◽  
Peak Exercise ◽  
Crossover Fashion ◽  
Resonance Spectroscopy ◽  
Phosphorylation Potential ◽  
Beneficial Effects ◽  
Muscle Ph

To determine how diet modulates short-term exercise capacity, skeletal muscle pH and bioenergetic state were examined by 31P-magnetic resonance spectroscopy in nine healthy volunteers. Subjects performed incremental quadriceps exercise to exhaustion after 5 days of high-carbohydrate (HCHO) or high-fat (HFAT) diet randomly assigned in crossover fashion and separated by a 2.5-day period of ad libitum mixed diet. Simultaneous measurements were made of pulmonary gas exchange, minute ventilation, and quadriceps muscle pH and phosphorylation potential. At rest and peak exercise, respiratory exchange ratio and minute ventilation were higher after HCHO than after HFAT (P < 0.05), reflecting greater CHO utilization. Peak O2 consumption (VO2) was not increased after HCHO (P > 0.05), but exercise duration was (339 +/- 34 s for HCHO vs. 308 +/- 25 s for HFAT; P < 0.05). HCHO was associated with a blunted early fall of phosphocreatine (PCr)/Pi vs. VO2 (-4.1 +/- 0.7 x 10(-2) min/ml for HCHO vs. -5.6 +/- 1.2 x 10(-2) min/ml for HFAT; P < 0.05). On both study days, the slope of PCr/Pi vs. VO2, before and after the PCr threshold, was correlated with exercise time. The results suggest that a diet rich in CHO improves exercise efficiency through beneficial effects on intracellular phosphorylation potential.

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