RESUMO
Objective:To observe the effects of static 70° head-up tilted standing and of repeated body repositioning on hemodynamics in healthy young and middle-aged persons.Methods:The hemodynamics of 24 middle-aged and 23 younger persons were studied. Both groups were requested to perform static 70° head-up tilted standing and to repeatedly change their body position from 0° to 70° of tilt at a velocity of 1°/second for ten minutes in a random order. Before, between and after each test the subjects rested supine for ten minutes. Hemodynamic variables and blood pressure were recorded non-invasively.Results:The average heart rate (HR) increased significantly in both groups when rising from supine to the testing positions. In 70° tilted standing the average HR of the youth group, 84.0±9.5bpm, was significantly higher than that in the other position and that of the middle-aged group in the same position. The average HR of the middle-aged group in 70° tilted standing was also significantly higher than in the other position. Among the middle-aged group, the average stroke volume (SV) in the testing positions was significantly lower than when resting. Significant differences were observed in the average diastolic blood pressure (DBP) between the testing and rest positions for both groups, with the average DBP of the middle-aged group significantly higher than that of the youth group in all three positions. Among the youth group, the average SV, CO and systolic blood pressure (SBP) of the males were significantly higher than among the females in all of the different body positions.Conclusions:Young persons mainly rely on an increased heart rate to maintain cardiac output while middle-aged participants appear to achieve this through increased peripheral resistance. Repeated position changes have less impact on hemodynamics than 70° inclined standing, making it a safer and more stable training method. However, the long-term effects of such intervention need to be confirmed in further studies.
RESUMO
Objective: To study therapeutic effect of personalized aerobic exercise based on exercise load test assessment on heart function and psychological state in patients with acute myocardial infarction (AMI). Methods: According to random number table, a total of 80 AMI patients during recovery period were randomly and equally divided into routine treatment group (n=40, received routine drug therapy) and exercise group (n=40, received personalized aerobic exercise based on exercise load test assessment on the basis of routine treatment group). Serum levels of high-sensitivity cardiac troponin I (hs-cTnI) and creatine kinase isoenzyme MB (CK-MB), and left ventricular ejection fraction (LVEF), stroke volume (SV), left ventricular fractional shortening (LVFS), ventricular wall thickening rate (△T), motion amplitude of interventricular septum (AIS), and scores of self-rating anxiety scale (SAS) and self-rating depression scale (SDS) were compared between two groups before and after 12-week intervention. Results: Compared with before intervention, there were significant reductions in serum levels of hs-cTnI and CK-MB, and scores of SAS and SDS; and significant rise in LVEF, SV, LVFS, △T and AIS in both groups after 12-week intervention (except LVEF of routine treatment group), P<0.05 or <0.01; compared with routine treatment group, there were significant reductions in serum levels of hs-cTnI [(9.31±1.04) ng/L vs. (5.89±0.72) ng/L] and CK-MB [(11.34±1.25) U/L vs. (8.41±1.01) U/L],in scores of SAS [(51.34±6.54) scores vs. (42.32±5.29) scores] and SDS [(50.23±6.92) scores vs. (43.86±6.03) scores];and significant rise in LVEF [(57.12±6.67)% vs. (62.32±7.34)%], SV [(62.45±7.13) ml vs. (69.18±7.84) ml], LVFS [(23.93±2.96)% vs. (28.45±3.12)%], △T [(28.51±3.41)% vs. (34.52±4.87)%] and AIS [(9.56±1.02) mm vs. (12.45±1.46) mm] in exercise group, P<0.05 or <0.01. Conclusion: Personalized aerobic exercise based on exercise load test assessment can reduce myocardial cell injury, improve cardiac function, relieve negative emotions and promote patients’ rehabilitation rapidly.