Carotid–cardiac baroreflex and training status: significance of initial responsiveness
| Autor: | M. J. Lundie, G. K. Savard |
|---|---|
| Rok vydání: | 1995 |
| Předmět: |
Adult
Male medicine.medical_specialty Sympathetic Nervous System Physiology Posture Population Blood Pressure Oxygen Consumption Heart Rate Physiology (medical) Internal medicine medicine Humans Aerobic exercise education Exercise Pharmacology education.field_of_study Cardiac baroreflex business.industry Heart General Medicine Baroreflex Low responder Carotid Sinus Physical Fitness Physical Endurance cardiovascular system Cardiology business |
| Zdroj: | Canadian Journal of Physiology and Pharmacology. 73:98-106 |
| ISSN: | 1205-7541 0008-4212 |
| DOI: | 10.1139/y95-014 |
| Popis: | The aim of this study was to demonstrate that within a population of healthy men (n = 15) of varying levels of aerobic fitness [Formula: see text], (i) there are high and low responders with respect to carotid–cardiac baroreflex responsiveness, despite similar baseline heart rates (HRs) both at rest and during dynamic exercise, and (ii) there is a weak association between this responsiveness and training status [Formula: see text] because of a large overlap in the responses between trained (endurance, ET) and untrained (UT) individuals. Baroreflex function curves were derived during supine rest for each subject by applying varying pressures around the neck in a beat-to-beat ramp (for 12 beats) of +40 to −60 mmHg (1 mmHg = 133.3 Pa). Subjects were divided into low (n = 8) and high (n = 7) responders on the basis of the magnitude of the maximal dynamic R–R interval (RRI) range of the baroreflex curve. Both bradycardic (percent slowing) and tachycardic (percent acceleration) components of the baroreflex curve, and peak sinus node responses (HR, RRI) to continuous neck suction (−60 mmHg) at rest and during exercise (cycling, 45% [Formula: see text]) were greater in high compared with low responders (p 2 = 0.497, p |
| Databáze: | OpenAIRE |
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