Cardiovascular responses to sustained maximal isometric contractions of the finger flexors
| Autor: | D. K. Bloomfield, L. K. Essandoh, Denise L. Smith, James E. Misner |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Adult
medicine.medical_specialty Mean arterial pressure Physiology Hemodynamics Blood Pressure Isometric exercise Doppler echocardiography Cardiovascular Physiological Phenomena Fingers Heart Rate Isometric Contraction Physiology (medical) Internal medicine Heart rate medicine Humans Orthopedics and Sports Medicine Aorta End-systolic volume medicine.diagnostic_test business.industry Public Health Environmental and Occupational Health Stroke Volume General Medicine Stroke volume musculoskeletal system Echocardiography Doppler Surgery body regions Kinetics Blood pressure Cardiology Female business human activities |
| Zdroj: | European Journal of Applied Physiology and Occupational Physiology. 67:48-52 |
| ISSN: | 1439-6327 0301-5548 |
| DOI: | 10.1007/bf00377704 |
| Popis: | This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure (Pa), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and Pa increased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while Pa continued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, Pa, and SV during 20% and 100% MVC tasks. Unlike fc and Pa, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC. |
| Databáze: | OpenAIRE |
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