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Autonomic cardiac control. II. Noninvasive indices and basal response as revealed by autonomic blockades
Author(s) -
CACIOPPO JOHN T.,
BERNTSON GARY G.,
BINKLEY PHILIP F.,
QUIGLEY KAREN S.,
UCHINO BERT N.,
FIELDSTONE ANNETTE
Publication year - 1994
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.1469-8986.1994.tb02351.x
Subject(s) - heart rate , atropine , metoprolol , heart rate variability , vagal tone , autonomic nervous system , medicine , atropine sulfate , anesthesia , saline , orthostatic vital signs , blood pressure , cardiology
Heart period, systolic time intervals, low and high frequency heart period variability, blood pressure, and respiration were measured in female subjects under three drug conditions (saline, atropine sulfate, metoprolol) while sitting and standing on three consecutive days. Following preinfusion baseline recordings, saline, metoprolol (14 mg), or atropine sulfate (2 mg) was infused for 15 min (by using a double‐blind procedure). Recordings were taken during a postinfusion baseline and in response to an orthostatic stressor (standing versus sitting postures). At the end of the metoprolol session, atropine sulfate was infused and responses were monitored during the post‐infusion (i.e., double blockade) baseline and during orthostatic stressor. Analyses of the blockade data revealed that the preejection period (PEP) reflected sympathetic but not vagal influences on the heart, and high frequency (HF, 0.12–0.40 Hz) heart rate variability (respiratory sinus arrhythmia) reflected vagal but not sympathetic influences on the heart. No other measure provided a specific index of the tonic sympathetic or vagal activation of the heart. Postinfusion PEP under saline predicted individual differences in postinfusion cardiac sympathetic activation, whereas postinfusion heart period (but not HF variability) under saline predicted individual differences in postinfusion cardiac vagal activation.