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Bradycardia during baroreflex stimulation and active or passive stressor tasks: Cardiorespiratory fitness and hostility
Author(s) -
GRAHAM RALPH E.,
ZEICHNER AMOS,
PEACOCK LELON J.,
DISHMAN ROD K.
Publication year - 1996
Publication title -
psychophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.661
H-Index - 156
eISSN - 1469-8986
pISSN - 0048-5772
DOI - 10.1111/j.1469-8986.1996.tb02433.x
Subject(s) - hostility , cardiorespiratory fitness , heart rate , bradycardia , baroreflex , psychology , stressor , type a and type b personality theory , vagal tone , blood pressure , stimulation , cardiology , medicine , autonomic nervous system , anesthesia , clinical psychology , neuroscience , personality , social psychology
We examined whether the resting bradycardia associated with cardiorespiratory fitness extends to lowered heart rate (HR) and mean arterial pressure during novel passive or active laboratory stressors and to a longer heart period during stimulation of the carotid‐cardiac vagal baroreflex, independently of the Type A behavior pattern (TABP) and hostility. Forty‐four normotensive Caucasian men (18–35 years of age) completed the Structured Interview for TABP, the Cook‐Medley Hostility Scale, and a peak oxygen uptake (Vo 2peak ) test. Vo 2peak was inversely related to HR prior to, during, and after each stressor and was positively related to heart period during baroreflex testing. Hostility was inversely related to heart period during baroreflex testing. TABP had no effects. Our findings indicate that cardiorespiratory fitness and low hostility are independently associated with a bradycardia during stimulation of the carotid‐cardiac baroreflex, consistent with a possible enhancement of cardiac vagal tone.