BACKGROUND AND PURPOSE: Previous studies have demonstrated that cardiac rehabilitation (CR) improves exercise tolerance and muscle strength in patients with myocardial infarction (MI) and in patients after cardiac surgery. However, the association between exercise tolerance and muscular strength following CR and the comparison of relationships among various disease categories has not been fully examined. The purpose of the present study was to assess the relationship between exercise tolerance and muscle strength following CR in patients after cardiac surgery and patients with MI. METHODS AND RESULTS: One hundred and four patients who participated in CR for 6 months were enrolled [post-cardiac valve surgery (VALVE), n=28; post-coronary artery bypass grafting (CABG), n=42; post-acute MI, n=34]. The exercise tolerance, thigh/calf circumferences, and muscle strength were measured before and after CR. At the baseline, the thigh circumference was significantly smaller in the VALVE group than in the MI group. There were significant positive correlations between peak VO(2) and muscle torques of the lower muscles in all groups. After 6 months, peak VO(2) and muscle torque were significantly increased in all groups (p<0.001). A positive significant correlation between percent increases in peak VO(2) and muscular strength was observed in the VALVE group (r=0.51, p<0.01), but not in the other groups. In addition, the changes in peak VO(2) and calf circumference after CR were significantly higher in the VALVE group than in the MI group. CONCLUSIONS: These data suggest that exercise intolerance in patients after heart valve surgery may in part depend on decreased muscular strength. Further studies are needed to assess whether the strategy of increasing muscular strength of lower limb by programmed resistance training could be effective for improving exercise intolerance in patients after heart valve surgery and symptomatic patients with heart failure.
BACKGROUND AND PURPOSE: Previous studies have demonstrated that cardiac rehabilitation (CR) improves exercise tolerance and muscle strength in patients with myocardial infarction (MI) and in patients after cardiac surgery. However, the association between exercise tolerance and muscular strength following CR and the comparison of relationships among various disease categories has not been fully examined. The purpose of the present study was to assess the relationship between exercise tolerance and muscle strength following CR in patients after cardiac surgery and patients with MI. METHODS AND RESULTS: One hundred and four patients who participated in CR for 6 months were enrolled [post-cardiac valve surgery (VALVE), n=28; post-coronary artery bypass grafting (CABG), n=42; post-acute MI, n=34]. The exercise tolerance, thigh/calf circumferences, and muscle strength were measured before and after CR. At the baseline, the thigh circumference was significantly smaller in the VALVE group than in the MI group. There were significant positive correlations between peak VO(2) and muscle torques of the lower muscles in all groups. After 6 months, peak VO(2) and muscle torque were significantly increased in all groups (p<0.001). A positive significant correlation between percent increases in peak VO(2) and muscular strength was observed in the VALVE group (r=0.51, p<0.01), but not in the other groups. In addition, the changes in peak VO(2) and calf circumference after CR were significantly higher in the VALVE group than in the MI group. CONCLUSIONS: These data suggest that exercise intolerance in patients after heart valve surgery may in part depend on decreased muscular strength. Further studies are needed to assess whether the strategy of increasing muscular strength of lower limb by programmed resistance training could be effective for improving exercise intolerance in patients after heart valve surgery and symptomatic patients with heart failure.
Authors: Lizette N Abraham; Kirstine L Sibilitz; Selina K Berg; Lars H Tang; Signe S Risom; Jane Lindschou; Rod S Taylor; Britt Borregaard; Ann-Dorthe Zwisler Journal: Cochrane Database Syst Rev Date: 2021-05-07
Authors: Kirstine Laerum Sibilitz; Selina Kikkenborg Berg; Tina Birgitte Hansen; Signe Stelling Risom; Trine Bernholdt Rasmussen; Christian Hassager; Lars Køber; Daniel Steinbrüchel; Christian Gluud; Per Winkel; Lau Caspar Thygesen; Jane Lindschou Hansen; Jean Paul Schmid; Viviane Conraads; Barbara Christina Brocki; Ann-Dorthe Zwisler Journal: Trials Date: 2013-04-22 Impact factor: 2.279
Authors: Sandra Mandic; Claire Hodge; Emily Stevens; Robert Walker; Edwin R Nye; Dianne Body; Leanne Barclay; Michael J A Williams Journal: Biomed Res Int Date: 2013-07-07 Impact factor: 3.411
Authors: Andrea Avila; Jomme Claes; Kaatje Goetschalckx; Roselien Buys; May Azzawi; Luc Vanhees; Véronique Cornelissen Journal: J Med Internet Res Date: 2018-06-22 Impact factor: 5.428