Cardiodynamic and hemodynamic reactions to emotion-eliciting film sequences were investigated. Thirty-two healthy subjects (12 women, 20 men) were randomly assigned to one of two groups. In the first group, anger was induced using selected scenes of the film “Ragtime.” In the second group, scenes of the film “The Shining” were chosen to elicit fear. A documentary film was used as a baseline stimulus in both groups. EKG, impedance cardiography, and blood pressure were continuously monitored. The two emotional conditions elicited significant differential changes in subjective ratings and cardiovascular indices. Fear was associated with decreased cardiac output, increased total peripheral resistance, and a reduction in stroke volume and myocardial contractility. Anger was associated with an increase of cardiac output and small changes in total peripheral resistance. These results support the hypothesis that discrete emotions such as fear and anger elicit differential patterns of physiological responses.

Summary

Background and objective: Increased inspired oxygen fractions (FiO2) have significant haemodynamic effects in awake volunteers. We sought to establish whether these effects are also present in anaesthetized patients.

Methods: We prospectively studied 30 ASA I–II patients, 15 in each of a propofol and sevoflurane group. Their haemodynamic responses, awake and anaesthetized, when the FiO2 was changed between 0.3 and 1.0 were measured with a non-invasive transthoracic bio-impedance monitor.

Results: While preoxygenating awake patients in both groups the FiO2 was increased from 0.21 to 1.0. This reduced the mean cardiac index (3.38 ± 0.5 to 3.03 ± 0.5 L min−1 m−2; P < 0.001); reduced the heart rate (HR) (68.1 ± 10.4 to 62.8 ± 9.4 beats per minute (bpm); P < 0.001); and reduced the stroke index (50.4 ± 9.6 to 48.5 ± 8.6; P = 0.02). It increased the systemic vascular resistance index (2060 ± 319 to 2220 ± 382 dyn s−1 cm−5 m−2; P = 0.002); but did not change mean arterial pressure. In the anaesthetized patients, when decreasing the FiO2 from 1.0 to 0.3, mean cardiac index (L min−1 m−2) increased (3.06 ± 0.57 to 3.25 ± 0.56, P = 0.008 for sevoflurane; 2.76 ± 0.46 to 2.89 ± 0.42, P = 0.002 for propofol). The mean HR (bpm) increased (65.1 ± 7.8 to 69.1 ± 7.5, P < 0.001 for sevoflurane; 67.5 ± 11.8 to 72.7 ± 11.6, P = 0.001 for propofol). The mean systemic vascular resistance (dyn s−1 cm−5 m−2) decreased (1883 ± 329 to 1735 ± 388, P = 0.008 for sevoflurane; 2015 ± 369 to 1771 ± 259, P = 0.003 for propofol). Mean arterial pressure (mmHg) decreased (74.8 ± 8.7 to 71.4 ± 8.7, P < 0.001 for sevoflurane; 72.1 ± 8 to 66.5 ± 6.8, P = 0.002 for propofol).

Conclusion: O2 has haemodynamic effects in awake and anaesthetized patients. These effects were of overall similar magnitude for patients anaesthetized with propofol and sevoflurane.

We examined whether responder type groups reflecting patterns of hemodynamic reactivity might also differ in recovery responses. Cardiac output (CO), total peripheral resistance (TPR), systolic and diastolic blood pressure, heart rate, and Heather index were assessed at rest and during speech and cold pressor tasks in young adults. Participants (n = 152) were classified as myocardial, vascular, or mixed-mild responders based on CO and TPR responses to speech presentation. Vascular responders exhibited slower CO and TPR speech recovery than the myocardial and/or mixed-mild groups. Responder type differences in reactivity showed limited task-generalizability. The sustained vascular response pattern of the vascular group is consistent with that seen in hypertension. In light of associations of heightened TPR with markers of disease risk, this suggests potentially negative health implications for vascular responders.

This report evaluated (a) the temporal stability of hemodynamic responses to three tasks using impedance cardiography, and (b) the influence of aging on stress responses in a multi-ethnic pediatric sample. One hundred children 8 to 10 years old and 49 adolescents 15 to 17 years old were tested at study entry and on average 3 years later. Results showed that the composite task-induced changes in stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR), and pre-ejection period (PEP) were moderately stable across 3 years (rs = .36 to .51), with children showing greater stability in task-induced CO change than did adolescents. However, the magnitude of the participant's stress responses changed over time, varied by task, age group, and gender. These results suggest that hemodynamic responses to stress change with aging during childhood and adolescence and that they can be measured reliably.

Hemodynamic responses to an anger interview and cognitive and physical stressors were compared, and the stability of associated hemodynamic reactions examined. Participants experienced control, handgrip, counting, and mental arithmetic tests and an anger interview on two occasions. Systolic and diastolic blood pressure, heart rate, stroke volume, and cardiac output were measured. Total peripheral resistance was also derived. The anger interview produced larger, more sustained changes in blood pressure in both sessions than the other stressors. These changes were largely a consequence of increased peripheral resistance. Consistent with previous findings, handgrip was associated with a resistance-type reaction whereas arithmetic was associated with a cardiac output-type reaction. There was low-to-modest stability of hemodynamic reactions to the interview. Further research is necessary to optimize its utility in studies of cardiovascular function. Nevertheless, the findings underscore the ability of ecologically relevant stressors to provoke unique configurations of cardiovascular activity.

We evaluated the effects of two laboratory stressors (speech preparation and isometric handgrip) on gastric myoelectrical and autonomic cardiac activity, and the extent to which autonomic responses to these stressors and somatization predict reports of motion sickness during exposure to a rotating optokinetic drum. Both stressors prompted a decrease in preejection period (PEP) and respiratory sinus arrhythmia (RSA), and an increase in a dysrhythmic pattern of gastric myoelectrical activity, termed gastric tachyarrhythmia. Stressor-induced decreases in RSA and higher somatization scores predicted increased reports of motion sickness during drum rotation. These results demonstrate that laboratory stressors concurrently affect gastric myoelectrical activity and autonomic control of the heart, and that stressor-induced decreases in RSA and higher levels of somatization predict motion sickness susceptibility.

The validity and reliability of a new ambulatory impedance cardiograph (AZCG) was tested against the Minnesota Impedance Cardiograph (ZCG) during rest, orthostasis, and mental stress. Impedance cardiography allows noninvasive assessment of stroke volume, cardiac output, and systolic time intervals. A reliable ambulatory device would allow studies outside the lab. The devices were compared at two sites in healthy subjects. In both studies, the AZCG tracked changes across conditions closely with the ZCG (all Period × Device interactions were nonsignificant). Pearson rs, were .65 to .93, random intraclass correlation coefficients ranged from .80 to .98, indicating high degrees of shared measurement variance, and Cronbach's alpha indicated very good internal reliabilities (.91 to .99). Relative to the ZCG, the new AZCG appears to provide valid and reliable estimates of cardiac function at rest and during behavioral challenges in the lab.

The pathogenic processes responsible for cardiovascular disease have their origins in childhood. Although children's measures of heart rate and blood pressure have been found to be reliable, the reliability of impedance cardiography derived measures have not been evaluated. Thirty-three children, ages 8–11 participated in two sessions. Stressors included serial subtraction, isometric handgrip, and mirror-image tracing. Results indicated the impedance measures showed moderately high temporal stability (average scores ravg = .74; difference scores ravg = .53) and intertask consistency (average scores ravg = .78; difference scores ravg = .53). Blood pressure demonstrated the lowest reliability; Heather index, preejection period, and stroke volume demonstrated the highest. These findings suggest children's cardiovascular reactivity to laboratory stressors can be reliably and consistently assessed using impedance cardiography.

This study provides the first psychophysiological analysis of narcissism by measuring autonomic responses during active and passive anticipatory coping in 40 undergraduate men who scored high or low on the Narcissistic Personality Inventory (NPI). Compared to the low NPI group, the high NPI group showed greater preejection period (PEP) shortening, cardiac deceleration, and skin conductance response (SCR) habituation during anticipation of an aversive stimulus (p < .02). As expected, SCR and PEP reactivity were greater during active than passive coping. In the case of PEP, this effect emerged only in the low NPI group; the high NPI group showed the greatest PEP reactivity during the first task, regardless of coping demands. These data support hypothesized relationships among narcissism, psychopathy, and psychological predictors of cardiovascular disease, and suggest that a psychobiological dimension may underlie important features of narcissism.

We hypothesized that patterns of sympathetic and parasympathetic reactivity observed in adults would be apparent in a sample of children and adolescents and that these patterns would be consistent across tasks. We explored the relationship between these patterns and psychosocial risk factors for cardiovascular disease. We measured preejection period (PEP) and an index of respiratory sinus arrhythmia (mean successive difference [MSD] statistic) during three reactivity tasks. We classified participants into four groups based on increases or decreases in PEP and MSD. Ninety percent of the sample exhibited the same pattern during at least two of the tasks. PEP and MSD demonstrated consistency, suggesting individual response stereotypy. Exhibiting a consistent pattern of decreased PEP and increased MSD was associated with less child- and parent-reported family conflict. These results are discussed in the context of vagal regulation of environmental demands.

The impact of evaluative observation on cardiovascular reactivity and adaptation to recurrent psychological stress was evaluated in 162 undergraduate men and women. All participants performed three mental arithmetic tasks with or without evaluative observation. Impedance cardiographic, blood pressure, task performance, and stress appraisal measures were recorded for each task. Evaluative observation moderated the effects of task repetition on cardiac reactivity but not vascular reactivity. The introduction of evaluative observation disrupted cardiac adaptation, resulting in a resurgence of β-adrenergic cardiac reactivity (p < .005), whereas the removal of evaluative observation promoted cardiac adaptation. Evaluative observation also increased stress appraisals and slowed task performance. The results support the dual process theory of habituation, rather than stimulus comparator theory, but only partially support cognitive appraisal theory.

The effects of prior task exposure on cardiovascular reactivity to stress were examined in two experiments by randomly assigning participants to repeated exposure groups that performed mental arithmetic pretest and test tasks versus delayed exposure groups that performed only the test task after prolonged rest. Impedance cardiographic and blood pressure measures were recorded continuously from 60 undergraduate men in Experiment 1 and 112 undergraduate men and women in Experiment 2. Task repetition attenuated cardiovascular reactivity and improved task performance in repeated exposure groups (p < .001), suggesting an integrated process of behavioral adaptation. During the test task, delayed exposure groups showed greater cardiac reactivity (p < .01), but not vascular reactivity, than repeated exposure groups. Thus, cardiac reactivity varied as a specific function of prior task exposure, whereas vascular reactivity varied as a general function of time.

Baroreflex (BR) testing with phenylephrine (PE) and amyl nitrite (AN) provided an opportunity to evaluate the ability of impedance cardiography (IC) to track the rapid hemodynamic (HD) changes elicited by these drugs. The AN response was measured after inhalation and the PE response was measured after a bolus injection in 19 subjects on two occasions. High reliability was observed for all of the HD measures. Blood pressure (BP), peripheral resistance (PR), and preejection period (PEP) decreased significantly after administration of AN, whereas heart rate (HR) and cardiac output (dotted Q) increased. BP and total PR increased significantly after administration of PE; HR and dotted Q decreased and PEP did not change significantly. Stroke volume did not change significantly with either drug. The BR slope was reliably elicited with AN and PE. The IC and Finapres BP consistently detected short-term changes in HD responses to AN and PE. The pharmacological interventions demonstrated that IC measures followed the course predicted by the actions of the drugs. Change in PEP and dZ/dt reflected increased contractility. The BR sensitivity was also reproducible.

The interrater reliability and concurrent validity of two methods of scoring the ensemble-averaged impedance cardiogram were evaluated. Impedance cardiographic and electrocardiographic signals were recorded from 40 undergraduate men and women during a baseline rest period and a vocal mental arithmetic task period. Recordings were scored by four raters using a conventional method, involving ensemble averaging after careful editing of beat-to-beat waveforms, and a streamlined method, involving ensemble averaging without beat-to-beat editing. Intraclass correlations for interrater reliability exceeded .92, whereas intraclass correlations for concurrent validity exceeded .97, indicating excellent agreement between raters and scoring methods for all cardiac measures. The streamlined method was significantly faster than the conventional method. The results indicate that variations in beat-to-beat editing do not constitute a serious source of error in the ensemble-averaged impedance cardiogram and support the interrater reliability and concurrent validity of the two scoring methods.

Persons at risk for hypertension may show elevated blood pressure (BP) at rest and during mental stress; however, the hemodynamics underlying the BP of those persons at high risk are not well characterized. We chose 21 high risk and 21 low risk men using their parental hypertension history and resting systolic blood pressures on two screenings. Then, on a day of extended rest versus a day with prolonged mental arithmetic and reaction time tasks, we examined whether high risk BP elevations reflected greater vascular resistance or cardiac output. High risk men had raised systolic/diastolic pressures (Fs = 74/15, ps < .0001/.0001) and higher vascular resistance (F = 6.6, p < .02) with minimal differences in heart rate and cardiac output. This finding implicates vascular resistance as the altered element in BP control in these high risk men tested in a familiar environment with minimal task-related threat.