| Full text | |
| Author(s): |
Leite, Poliana H.
[1]
;
Melo, Ruth C.
[2]
;
Mello, Marcelo F.
[1]
;
da Silva, Ester
[3]
;
Borghi-Silva, Audrey
[1]
;
Catai, Aparecida M.
[1]
Total Authors: 6
|
| Affiliation: | [1] Univ Fed Sao Carlos UFSCar, Nucleus Res Phys Exercise NUPEF, Lab Cardiovasc Phys Therapy, Phys Therapy Dept, BR-13565905 Sao Carlos, SP - Brazil
[2] Univ Sao Paulo, Sch Arts Sci & Humanities EACH, Sao Paulo - Brazil
[3] Univ Metodista Piracicaba UNIMEP, Fac Hlth Sci, Piracicaba, SP - Brazil
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | BRAZILIAN JOURNAL OF PHYSICAL THERAPY; v. 14, n. 5, p. 383-389, SEP-OCT 2010. |
| Web of Science Citations: | 6 |
| Abstract | |
BACKGROUND: The magnitude of cardiovascular responses is dependent on the static and dynamic components as well as the duration and intensity of the contraction performed. OBJECTIVE: To evaluate the heart rate responses to different percentages of isometric contractions in 12 patients (63±11.6 years) with coronary artery disease and/or risk factors for coronary artery disease that were participating in a phase III cardiac rehabilitation program. METHODS: Heart rate variation (ΔHR) was evaluated during maximum (MVC, five and ten seconds in duration) and submaximal (SMVC, 30 and 60% of MVC-5, until muscle exhaustion) voluntary contraction, using a handgrip dynamometer. Additionally, the representative index of cardiac vagal modulation (RMSSD index) was calculated at rest (pre-contraction), at the final 30 seconds of SMVC and during recovery (post-contraction). RESULTS: ΔHR showed higher values in MVC-10 versus MVC-5 (17±5.5 vs 12±4.2 bpm, p<0.05) and the SMVC-60 vs SMVC-30 (19±5.8 vs 15±5.1 bpm, p<0.05). However, results for CVM-10 showed similar ΔHR compared to results for CVSM (p> 0.05). RICVM at rest decreased (p<0.05) during SMVC-30 (30% = 27.9±17.1 vs 12.9±8.5 ms) and SMVC-60 (60% =25.8±18.2 vs 9.96±4.2 ms), but returned to the baseline values when the contraction was interrupted. CONCLUSIONS: In patients with coronary artery disease and/or risk factors for coronary heart disease, low intensity isometric contraction, maintained over long periods of time, presents the same effect on the responses of HR, compared to a high intensity or maximal isometric contraction of briefly duration. (AU) | |