BALANCED PERIOD VARIABILITY EFFECT VERSUS SUSTAINABLE RESERVOIR MANAGEMENT IN RESERVE CAPACITY RATIO APPLICATION TO THE CONSTANT PRODUCTION STRATEGY

Effects of Fear Induction on Heart Period Variability

Journal of Psychophysiology ◽

10.1027//0269-8803.13.1.18 ◽

1999 ◽

Vol 13 (1) ◽

pp. 18-26 ◽

Cited By ~ 3

Author(s):

Rudolf Stark ◽

Alfons Hamm ◽

Anne Schienle ◽

Bertram Walter ◽

Dieter Vaitl

Keyword(s):

Blood Pressure ◽

Trait Anxiety ◽

State Anxiety ◽

Self Report ◽

Emotional States ◽

Heart Period ◽

Experimental Conditions ◽

Heart Period Variability ◽

Physiological Variables ◽

Period Variability

Abstract The present study investigated the influence of contextual fear in comparison to relaxation on heart period variability (HPV), and analyzed differences in HPV between low and high anxious, nonclinical subjects. Fifty-three women participated in the study. Each subject underwent four experimental conditions (control, fear, relaxation, and a combined fear-relaxation condition), lasting 10 min each. Fear was provoked by an unpredictable aversive human scream. Relaxation should be induced with the aid of verbal instructions. To control for respiratory effects on HPV, breathing was paced at 0.2 Hz using an indirect light source. Besides physiological measures (HPV measures, ECG, respiration, forearm EMG, blood pressure), emotional states (pleasure, arousal, dominance, state anxiety) were assessed by subjects' self-reports. Since relaxation instructions did not have any effect neither on the subjective nor on the physiological variables, the present paper focuses on the comparison of the control and the fear condition. The scream reliably induced changes in both physiological and self-report measures. During the fear condition, subjects reported more arousal and state anxiety as well as less pleasure and dominance. Heart period decreased, while EMG and diastolic blood pressure showed a tendency to increase. HPV remained largely unaltered with the exception of the LF component, which slightly decreased under fear induction. Replicating previous findings, trait anxiety was negatively associated with HPV, but there were no treatment-specific differences between subjects with low and high trait anxiety.

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133Xe-DSPECT: Normalwerte von zerebraler Ruhedurchblutung und Reservekapazität

Nuklearmedizin ◽

10.1055/s-0038-1628887 ◽

1987 ◽

Vol 26 (05) ◽

pp. 192-197 ◽

Cited By ~ 8

Author(s):

T. Kreisig ◽

P. Schmiedek ◽

G. Leinsinger ◽

K. Einhäupl ◽

E. Moser

Keyword(s):

Blood Flow ◽

Cerebral Blood Flow ◽

Cerebrovascular Disease ◽

Correlation Coefficient ◽

Regional Cerebral Blood Flow ◽

Regression Line ◽

Reserve Capacity ◽

Regional Cerebral Blood ◽

Quantitative Measurements ◽

Before And After

Using the 133Xe-DSPECT technique, quantitative measurements of regional cerebral blood flow (rCBF) were performed before and after provocation with acetazolamide (Diamox) i. v. in 32 patients without evidence of brain disease (normals). In 6 cases, additional studies were carried out to establish the time of maximal rCBF increase which was found to be approximately 15 min p. i. 1 g of Diamox increases the rCBF from 58 ±8 at rest to 73±5 ml/100 g/min. A Diamox dose of 2 g (9 cases) causes no further rCBF increase. After plotting the rCBF before provocation (rCBFR) and the Diamox-induced rCBF increase (reserve capacity, Δ rCBF) the regression line was Δ rCBF = −0,6 x rCBFR +50 (correlation coefficient: r = −0,77). In normals with relatively low rCBF values at rest, Diamox increases the reserve capacity much more than in normals with high rCBF values before provocation. It can be expected that this concept of measuring rCBF at rest and the reserve capacity will increase the sensitivity of distinguishing patients with reversible cerebrovascular disease (even bilateral) from normals.

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