Emotional fainting and the psychophysiologic response to blood and injury: autonomic mechanisms and coping strategies

Respiratory and hemodynamic contributions to emotion-related pre-syncopal vasovagal symptoms

Vasovagal reactions are conventionally understood as resulting from systemic changes in cardiovascular activity; however, there exists a complementary perspective focused on specific changes in cerebral vasoconstriction associated with hyperventilation-induced hypocapnia. The present study investigated the role of cardiovascular and respiratory activity in self-reported pre-syncopal vasovagal reactions to a surgery video in a sample of 49 healthy women. Participants who indicated more previous real-life episodes of dizziness reported experiencing significantly more symptoms in the laboratory consistent with a vasovagal response. They also showed lower total peripheral resistance and higher pre-ejection period in general, suggesting lower sympathetic nervous system activity. Significant decreases in end-tidal carbon dioxide (P_ETCO₂) occurred during the surgery video among susceptible participants, without significant increases in respiration rate. Further, participants who experienced reductions from the neutral video in P_ETCO₂, systolic blood pressure, or both, reported vasovagal symptoms during the surgery video. The results suggest that patterns of respiration associated with decreases in P_ETCO₂ may contribute to vasovagal symptoms reported in non-clinical groups as well as those with blood-injection-injury phobia and are associated with susceptibility to dizziness.

PTSD symptom severity and sensitivity to blood, injury, and mutilation in U.S. army special operations soldiers

Sensitivity to blood, injury, and mutilation (SBIM) may increase risk for posttraumatic stress disorder (PTSD), given that traumatic events often involve actual or perceived threat of bodily harm to oneself and/or others, including exposure to blood and other mutilation-related stimuli. A self-report questionnaire was administered to male, active duty, U.S. Army Special Operations Command soldiers who had deployed to Iraq and Afghanistan (n =694 males). We first used exploratory factor analysis to examine whether the 30-item Mutilation Questionnaire (Klorman et al., 1974) comprised a unitary measure of SBIM, finding that 10 of the items form a cohesive SBIM factor. Summed, those 10 SBIM items had a significant bivariate correlation with PTSD symptom severity. In a multiple regression analysis that included demographic characteristics and lifetime trauma exposure, SBIM was positively associated with PTSD symptom severity. Other significant multivariate predictors were high lifetime trauma exposure and junior enlisted rank. When trait neuroticism was added to the model to test the robustness of these findings, the association of SBIM with PTSD symptom severity remained significant. The results suggest that SBIM may be a risk factor for PTSD in male soldiers. Further research is warranted to improve measurement and understanding of SBIM.

Disgust stimuli reduce heart rate but do not contribute to vasovagal symptoms

BACKGROUND AND OBJECTIVES

The vasovagal response demonstrates a unique form of stress response, common in medical settings yet provoked by a variety of blood-injury-injection stimuli. This study aimed to better understand the psychophysiological mechanisms of the vasovagal response..

METHODS

16 undergraduates with and 42 without a self-reported history of fainting watched five 3-5 min videos with different emotional content. One documentary clip (Neutral condition) described a campus environmental project while another (Blood/Injury) depicted portions of an open heart surgery. Three additional clips were also used, including Medical, Threat, and Contamination stimuli. Vasovagal symptoms and physiological variables were assessed during each video.

RESULTS

As predicted, while the disgust-related stimuli (Blood/Injury, Medical, Contamination) were associated with generally lower heart rate, the Blood/Injury video produced the highest symptoms and the only significant difference between previous fainters and non-fainters. The physiological measures also revealed that participants with a fainting history experienced higher stroke volume and lower systolic blood pressure throughout, as well as several main effects of video.

LIMITATIONS

An additional decrease in systolic blood pressure and respiration produced by watching the Blood/Injury video may have been sufficient to trigger symptoms in some, though results also suggest that systemic variables do not entirely explain susceptibility to symptoms. More careful evaluation of regional blood flow may be required.

CONCLUSIONS

Participants who had previously experienced strong vasovagal responses displayed what appeared to be an anticipatory response to the Blood/Injury video. Finally, disgust stimuli may reduce heart rate but do not appear to contribute to vasovagal symptoms.

Cardiovascular activity in blood-injection-injury phobia during exposure: evidence for diphasic response patterns?

Exposure to feared stimuli in blood-injection-injury (BII)-phobia is thought to elicit a diphasic response pattern, with an initial fight-flight-like cardiovascular activation followed by a marked deactivation and possible fainting (vasovagal syncope). However, studies have remained equivocal on the importance of such patterns. We therefore sought to determine the prevalence and clinical relevance of diphasic responses using criteria that require a true diphasic response to exceed cardiovascular activation of an emotional episode of a negative valence and to exceed deactivation of an emotionally neutral episode. Sixty BII-phobia participants and 20 healthy controls were exposed to surgery, anger and neutral films while measuring heart rate, blood pressure, respiratory pattern, and end-tidal partial pressure of carbon dioxide (as indicator of hyperventilation). Diphasic response patterns were observed in up to 20% of BII-phobia participants and 26.6% of healthy controls for individual cardiovascular parameters. BII-phobia participants with diphasic patterns across multiple parameters showed more fear of injections and blood draws, reported the strongest physical symptoms during the surgery film, and showed the strongest tendency to hyperventilate. Thus, although only a minority of individuals with BII phobia shows diphasic responses, their occurrence indicates significant distress. Respiratory training may add to the treatment of BII phobia patients that show diphasic response patterns.

Does disgust increase parasympathetic activation in individuals with a history of fainting? A psychophysiological analysis of disgust stimuli with and without blood-injection-injury association

People with blood-injection-injury fear can faint when being confronted with blood, injections or injuries. Page (1994) holds that people with blood-injury phobia faint, because they are disgust sensitive and disgust facilitates fainting by eliciting parasympathetic activity. We tested the following two hypotheses: (1) Disgusting pictures elicit more disgust in blood-injection-injury-anxious people with a history of fainting than they do in controls. (2) Disgust causes parasympathetic activation. Subjects were 24 participants with high blood-injection-injury fear and a history of fainting in anxiety relevant situations and 24 subjects with average blood-injection-injury fear and no fainting history. We analyzed self-reported feelings of disgust, anxiety and faintness and reactions in heart rate, skin conductance, blood pressure and respiratory sinus arrhythmia during the confrontation with disgusting pictures with and without blood content. We did not find any evidence that the blood-injection-injury anxious subjects were more disgust sensitive than the control subjects and we also did not find any evidence that disgust elicits parasympathetic activation.

Cognitive-behavioural Treatment of Blood-Injury-Injection Phobia: A Case Study

This single case study examined the treatment of blood-injury-injection (BII) phobia in a 14-year-old female. Thirteen 1-hour sessions of cognitive behavioural therapy were conducted. The intervention included a combination of exposure, applied tension, and cognitive restructuring in an effort to produce clinically significant reductions in anxiety and fainting in response to BII stimuli. Results did indeed show dramatic reductions in subjective distress in BII situations from baseline to post-treatment. This was supported by small reductions in phobic anxiety and general anxiety on self-report measures. In contrast to baseline, fainting did not occur during treatment. The subject rated cognitive restructuring as the most effective treatment component for the latter half of therapy. It is suggested that, to date, the importance of cognitive therapy for the treatment of BII phobia has been overlooked.

Late cortical positivity and cardiac responsitivity in female dental phobics when exposed to phobia-relevant pictures

OBJECTIVES

Dental phobia is currently classified as a specific phobia of the blood-injection-injury (BII) subtype. In another subtype, animal phobia, enhanced amplitudes of late event-related potentials have consistently been identified for patients during passive viewing of disorder-relevant pictures. However, this has not been shown for BII phobics, and studies with dental phobics are lacking. Findings on cardiac responses in BII phobia during exposure are heterogeneous, as some studies showed a diphasic pattern of heart rate acceleration and deceleration, whereas others observed pure acceleration. In contrast, heart rate increase has consistently been shown for dental phobics, resembling the reaction of animal phobics. Moreover, the BII subtype is characterized by elevated disgust reactivity whereas the role of habitual disgust proneness in dental phobia is unclear.

METHODS

We recorded the electroencephalogram and the electrocardiogram from 18 dental phobic and 18 healthy women while they watched pictures depicting dental treatment, disgust, fear and neutral items.

RESULTS

Phobics relative to controls showed an enhanced late positive potential (300-700 ms) and heart rate acceleration towards phobic material, reflecting motivated attention and fear. Affective ratings revealed that dental phobics experienced significantly higher levels of fear than disgust during exposure to phobia-relevant material. Patients' elevated habitual disgust proneness was restricted to specific domains, such as the oral incorporation of offensive objects.

CONCLUSION

The psychophysiology of dental phobia resembles the fear-dominated subtypes of specific phobia reported in earlier studies. Future studies should continue to investigate whether the current classification of this disorder as BII phobia needs to be reconsidered.

The psychophysiology of blood-injection-injury phobia: looking beyond the diphasic response paradigm

Blood-injection-injury (BII) phobia is an anxiety disorder that may be accompanied by vasovagal fainting during confrontation with the feared stimuli. The underlying pattern of autonomic regulation has been characterized as a diphasic response, with initial increases in heart rate and blood pressure that are typical of a fight-flight response, and subsequent drops in blood pressure and/or heart rate that may precipitate vasovagal fainting. Tensing skeletal muscles of the arms, legs, and trunk (applied tension) has been proposed as a technique to cope with this dysregulation. This review critically examines the empirical basis for the diphasic response and its treatment by applied tension in BII phobia. An alternative perspective on the psychophysiology of BII phobia and vasovagal fainting is offered by focusing on hypocapnia that leads to cerebral blood flow reductions, a perspective supported by research on neurocardiogenic and orthostatically-induced syncope. The evidence may indicate a role for respiration-focused coping techniques in BII phobia.

Vulnerability to simple faints is predicted by regional differences in brain anatomy

Neurocardiogenic syncope (NCS, simple fainting) is a common and typically benign familial condition, which rarely may result in traumatic injury or hypoxic convulsions. NCS is associated with emotional triggers, anxiety states and stress. However, the etiology of NCS, as a psychophysiological process, is poorly understood. We therefore investigated the relationship between NCS and brain anatomy. We studied a non-clinical sample of eighteen individuals with histories characteristic of NCS, and nineteen matched controls who had never fainted. We recorded fainting frequency, resting heart rate variability measures and anxiety levels. Structural T1-weighted magnetic resonance images (MRI) were acquired at 1.5 T. Associations between brain morphometry (regional gray and white matter volumes) and NCS, resting physiology and anxiety were tested using voxel-based morphometry (VBM). Compared to controls, NCS participants had lower regional brain volume within medulla and midbrain (a priori regions of interest). Moreover, across NCS individuals, lower gray matter volume in contiguous regions of left caudate nucleus predicted enhanced parasympathetic cardiac tone, fainting frequency and anxiety levels. Our findings provide preliminary evidence for a hierarchical anatomical basis to NCS. First, differences in the volume of brainstem centers supporting cardiovascular homeostasis may relate to constitutional predisposition to NCS. Second, differences in the structural organization of the caudate nucleus in NCS individuals may relate to fainting frequency via interactions between emotional state and parasympathetic control of the heart. These observations highlight the application of VBM to the identification of neurovisceral mechanisms relevant to psychosomatic medicine and the neuroscience of emotion.

Do blood phobia patients hyperventilate during exposure by breathing faster, deeper, or both?

BACKGROUND

Recently we found that patients with blood-injection-injury (BII) phobia tend to hyperventilate when exposed to feared stimuli. Hyperventilation results from increases in minute ventilation above levels required by metabolic demand and can result from increases in either frequency or depth of breathing, or a combination of both.

METHOD

In order to determine which of these factors contributed most to hyperventilation in BII phobia we analyzed breathing patterns of BII phobia patients (N=12) and non-anxious controls (N=14), recorded with respiratory inductance plethysmography. Participants viewed ten film clips of either an emotionally positive, negative, or neutral quality, as well as surgery and asthma-relevant clips. During five film clips (one from each category) they also tensed their leg muscles.

RESULTS

Minute ventilation was markedly increased in blood phobia patients compared to other groups during surgery films. Also, tidal volume and irregularity of tidal volume showed strong increases, while respiration rate was not affected. Leg muscle tension increased ventilation in general but far below the extent brought about by hyperventilation in BII phobia. Patients who were breathing deeper during exposure reported stronger symptoms of dizziness, light-headedness and faintness. In general, patients showed a higher rate of spontaneous sighs throughout all film presentations, but not at baseline.

CONCLUSION

Thus, hyperventilation in blood phobia is produced by excessively deep and irregular breathing and may contribute to fainting responses. Behavioral interventions for BII phobia could benefit from attention to this aspect of dysfunctional breathing.

Cardiovascular dynamics in blood phobia: evidence for a key role of sympathetic activity in vulnerability to syncope

This study was aimed at clarifying the mechanism predisposing people with blood phobia to syncope by investigating the complete hemodynamic response pattern and the underlying autonomic control. Blood phobics and controls were shown 3 film-clips: phobia-related, phobia-unrelated, and neutral. Hemodynamic responses were recorded using impedance cardiography and Finapres. Preejection period and respiratory sinus arrhythmia were employed as indices of cardiac sympathetic and parasympathetic activity. Self-ratings of emotion were also collected. Blood phobics displayed global heart rate and cardiac output increases to the phobic film, mediated by augmented cardiac sympathetic activity. Systolic blood pressure and total peripheral resistance markedly declined, with no evidence of diphasic reaction or parasympathetic activation. An impaired vasomotor response under sympathetic control might be the key mechanism underlying the phobic dysfunctional response.

Watching emotional movies: affective reactions and gender differences

Previous studies have found that unpleasant film clips depicting mutilated bodies or injuries evoke a sustained heart rate deceleration which has been interpreted as reflecting a stimulus-specific aversive response or as increased orienting and attentional processing that varies with stimulus significance. Few studies, however, have examined cardiac changes during the viewing of high arousal pleasant films. To clarify this issue, the present study assessed evaluative, facial and autonomic reactions in both men and women during the viewing of highly arousing pleasant, as well as unpleasant, films. Results indicated a similar skin conductance increase and heart rate deceleration which were greater than those observed during the viewing of a neutral film. Compared to men, women rated both films as less pleasant and rated the unpleasant film as more arousing. The present findings suggest that sustained exposure to pleasant and unpleasant stimuli elicit similar cardiac orienting when stimuli are equated for subjective report of emotional arousal.

Blood-injury phobia with and without a history of fainting: disgust sensitivity does not explain the fainting response

OBJECTIVE

Individuals diagnosed with blood-injury phobia respond to venipuncture with strong psychophysiological responses. We investigated whether disgust sensitivity contributes to the fainting response and is associated with parasympathetic activation, as suggested by previous research.

METHODS

Twenty individuals diagnosed with blood-injury phobia (9 with a history of fainting to the sight of blood, 11 without such a fainting history) and 20 healthy controls were compared. Psychophysiological responses and self-report measures of anxiety, disgust, and embarrassment were monitored during rest, a paced breathing task, and venipuncture. In addition, trait disgust sensitivity and blood-injury fears were assessed.

RESULTS

Blood-injury phobics reported enhanced anxiety, disgust, and embarrassment during venipuncture. They also experienced heightened arousal, as indicated by heart rate, respiration rate, and minute ventilation. Blood-injury phobics without a fainting history tended toward higher anxiety and disgust scores. There was no evidence for increased parasympathetic activation in either blood-injury phobic subgroup or of an association of disgust and parasympathetic activation.

CONCLUSION

The tendency to faint when exposed to blood-injury stimuli may suffice as a conditioning event leading into phobia, without specific involvement of disgust sensitivity and parasympathetic activation.

End-tidal pCO2 in blood phobics during viewing of emotion- and disease-related films

OBJECTIVE

Many patients with blood, injection, and injury (BII) phobia respond to specific stimuli with vasovagal dysregulation and fainting. However, little is known about the role of hyperventilation in the distress of these patients. Hyperventilation, defined by subnormal arterial pCO2 levels, induces anxiety and may promote the development of fainting. We studied end-tidal pCO2 in 12 patients with BII phobia and 14 nonanxious controls during presentation of emotional films.

METHOD

Ten film clips were shown, two in each of 5 categories: pleasant, unpleasant, neutral, BII-related (surgery), and asthma-related (portraying labored breathing). For each subject, two subsets were created, each containing one clip from each category. For one subset, the instruction was simply to view the film, and for the other subset, to view the film while tensing the leg muscles. PCO2, heart rate, blood pressure, and leg electromyogram were recorded continuously during viewing, and self-report of symptoms and emotion was collected after each film.

RESULTS

Patients reported the greatest anxiety and disgust during surgery films. PCO2 was relatively stable throughout all categories except surgery films, during which minima were below 30 mm Hg, indicating significant hypocapnia. Cardiovascular variables suggested biphasic patterns in two patients with BII phobia. These patients, together with one additional patient and one control who were close to fainting after or during one surgery film, also showed a marked fall in pCO2) Leg muscle tension raised heart rate and systolic blood pressure for all films, but was not related to near-fainting or endurance in surgery film viewing.

CONCLUSION

Hyperventilation is part of the fear response of patients with BII phobia, but was transitory in experimental fear induction using surgery films. Its role in real-life exposure and fainting deserves further study.

Trauma Films, Information Processing, and Intrusive Memory Development

Three experiments indexed the effect of various concurrent tasks, while watching a traumatic film, on intrusive memory development. Hypotheses were based on the dual-representation theory of posttraumatic stress disorder (C. R. Brewin, T. Dalgleish, & S. Joseph, 1996). Nonclinical participants viewed a trauma film under various encoding conditions and recorded any spontaneous intrusive memories of the film over the following week in a diary. Changes in state dissociation, heart rate, and mood were also measured. As predicted, performing a visuospatial pattern tapping task at encoding significantly reduced the frequency of later intrusions, whereas a verbal distraction task increased them. Intrusive memories were largely unrelated to recall and recognition measures. Increases in dissociation and decreases in heart rate during the film were also associated with later intrusions.

Psychophysiologic effects of applied tension on the emotional fainting response to blood and injury

OBJECTIVE

The present study was designed to investigate the psychophysiologic effects of "Applied Tension" (AT) on the emotional fainting response to blood and injury in a controlled experiment.

METHOD

Twenty-two persons reporting to generally feel faint or to have fainted at the sight of blood or injury and 22 participants classified as Non-Fainters were randomly allocated to a treatment or control condition. Psychophysiologic responses were continuously monitored while individuals watched a video depicting open-heart surgery and a control film. Prior to the surgery film, participants in the treatment condition were instructed in the use of AT.

RESULTS

All participants classified as Fainters showed a diphasic response pattern while watching the surgery film. This response, however, was significantly attenuated in Fainters in the treatment condition.

CONCLUSIONS

These results suggest that AT provides an effective treatment strategy for the prevention of fainting responses in persons with a fear of blood and injury.

Blood phobia and spider phobia: two specific phobias with different autonomic cardiac modulations

Cardiac reactions to two fear-related and one control film were compared in individuals high in spider or blood/injury fear. Twelve subjects in each phobic group were selected on the basis of their scores in the Spider or Mutilation Questionnaires and a semi-structured interview. Cardiac responses and self-reported affective ratings to the films were investigated. Sympathetic and parasympathetic cardiac influences were indexed by T-wave amplitude and respiratory sinus arrhythmia measured during film viewing. Basal parasympathetic cardiac control was also assessed during a paced breathing task. Results indicate differential autonomic modulation of cardiac responses for blood and spider phobics. Although each group reacted with marked cardiac activation to its feared stimulus, a sympathetic increase followed by withdrawal over time was found in blood phobics. Greater vagal tone at rest was present in blood phobics compared with spider phobics.

Prevalence and prognostic significance of psychiatric disorders in patients evaluated for recurrent unexplained syncope

We aimed to assess the psychiatric profile and prognostic value of psychiatric disorders (PDs) in patients presenting with unexplained syncope. Forty patients with recurrent unexplained syncope referred for head-up tilt testing were compared with age- and sex-matched patients free of known chronic PDs referred for arrhythmia. All patients underwent a semistandardized psychiatry questionnaire (Mini-International Neuropsychiatric Interview) to assess their profile. Additional stress coping was performed to study adaptational processes to stressful situations. After tilt testing and psychiatric evaluation, a drug-free follow-up was performed in patients with syncope. Of the 80 patients who referred to the psychiatric interview, 40 had evidence of at least 1 psychiatric disorder. They were 26 patients (65%) in the syncope group and 14 patients (35%) in the control group (p = 0.01). Detailed analysis revealed a more frequent subprofile of anxiety and panic disorders in patients with syncope than in controls (30% vs 12% and 20% vs 10%, respectively), whereas the subprofile of depression was similar in both groups. Moreover, those with syncope were more likely to have a high anxiety index (25 +/- 5 vs 22 +/- 4, p = 0.004), and were more prone to avoidance-oriented coping strategies when experiencing undesirable life events than controls. Considering syncope patients, no difference could be found between the 25 with a positive tilt test and the 15 with a negative tilt test with respect to the number of syncopal episodes and psychiatric profile. After a 3-year drug-free follow-up, 15 patients (37.5%) had at least 1 recurrent syncope. The recurrence rate was similar in patients with positive and negative head-up tilt test results (9 of 25 vs 6 of 15, respectively). In contrast, the syncopal recurrence rate was higher in patients who fulfilled criteria for affective disorders (13 of 26 vs 2 of 14, 95% confidence interval 1.09 to 2.55, relative risk 1.7, p = 0.04). Thus, patients with recurrent unexplained syncope are more anxious and are more prone to panic disorders and avoidance-oriented coping strategies than control patients with arrhythmia. The presence of a psychiatric disorder is associated with an increased risk of recurrence. The outcome of such patients may be improved with recognition and treatment of PDs.

Predisposition to vasovagal syncope in subjects with blood/injury phobia

BACKGROUND

Most subjects with blood/injury phobia experience syncope or presyncope as part of the phobic response. We tested the hypothesis that these subjects have a constitutional autonomic dysregulation that predisposes them to vasovagal syncope during head-up tilt.

METHODS AND RESULTS

We studied 11 subjects (9 females, 2 males) who had a history of syncope or presyncope only in response to a blood or injury stimulus and 11 healthy matched controls (10 females, 1 male) without a history of syncope. Blood pressure (BP) and heart rate (HR) were measured during a 15-minute baseline period with subjects in the supine position and then during 45 minutes of head-up tilt to 70 degrees. Measurements at rest did not differ between the blood phobic and control subjects. During tilt, 9 (82%) of the 11 blood phobic subjects experienced presyncope or syncope, leading to termination of the study after 22+/-17 minutes of tilt. Only 1 (9%) of the 11 control subjects experienced presyncope (chi(2)=11.7, P=0.001). Hemodynamic responses to tilt were consistent with a vasovagal mechanism in the blood phobic subjects, with simultaneous decreases in BP and HR during tilt. During tilt, systolic BP fell by 21+/-15 mm Hg (P=0.001), and HR fell by 22+/-25 bpm (P=0.01). By contrast, BP and HR were very stable in the control group.

CONCLUSIONS

Subjects with syncope related to blood/injury phobia have an underlying autonomic dysregulation predisposing them to neurally mediated syncope, even in the absence of any blood or injury stimulus. Fainting related to these stimuli may in large part be due to dysfunction in neural circulatory control, which may secondarily lead to the phobia because of repeated syncopal events.

Emotions and stress increase respiratory resistance in asthma

OBJECTIVES

Clinical reports suggest that various emotions and types of stress can precipitate asthmatic symptoms, but there is little experimental evidence to substantiate this claim. We studied the impact of different emotional states and stress on respiratory resistance in asthmatic and nonasthmatic individuals.

METHODS

Participants (24 asthmatic and 24 nonasthmatic patients) viewed short film sequences selected to induce anxiety, anger, depression, elation, happiness, contentment, or a neutral affective state and completed two stressful tasks, mental arithmetic to induce active coping efforts and viewing of medical slides to induce passive coping efforts. Oscillatory resistance, heart rate, blood pressure, baroreflex sensitivity, skin conductance level, respiration rate and volume, and self-reported affective state were measured throughout the session.

RESULTS

Uniform increases in oscillatory resistance were found in all emotional states compared with the neutral state and during mental arithmetic in both groups. Asthmatic patients showed stronger reactions to the medical slides than healthy control subjects, with significant increases in oscillatory resistance, blood pressure, skin conductance level, and minute volume, as well as higher levels of self-reported depression, arousal, and shortness of breath. Changes in oscillatory resistance were inconsistently correlated with other physiological indices.

CONCLUSIONS

Various emotional states and stress increase oscillatory resistance largely independently of concurrent increases in autonomic or ventilatory activity. The particular sensitivity of asthmatics to passive coping demand requires additional research.

Cardiac responses associated with affective processing of unpleasant film stimuli

The autonomic basis of cardiac reactions to unpleasant film stimuli was investigated. Film clips depicting major surgery, threats of violence, and neutral material were presented to 46 subjects. Self-report measures of emotion were obtained, as well as heart rate, respiration rate, respiratory sinus arrhythmia, T-wave amplitude and skin conductance level. Resting vagal tone was estimated in a paced breathing task prior to film viewing. Spontaneous blink rate was also taken as a measure of visual engagement during film viewing. Coherent increases in sympathetic activation accompanied the film containing violent threats, whereas the surgery film yielded greater electrodermal activation, as well as heart rate deceleration and T-wave increase. These data support the hypothesis of differential autonomic response patterns to specifically unpleasant material. As compared with threat and neutral films, greater blink rate inhibition was observed during the surgery film. Individual differences in parasympathetic cardiac control measured at rest were able to discriminate cardiac response patterns during film viewing.

Current approaches to etiology and pathophysiology of specific phobia

Specific phobia is a common, heterogeneous disorder whose central feature is persistent, unreasonable fear of a circumscribed object or situation. This article reviews current etiological theories and empirical data that seem likely to be important in investigating the pathophysiology of this disorder. These include conditioning, modified conditioning, and nonassociative models of phobia development, physiological response to the phobic stimulus, neuroimaging, primate, and biological challenge studies. Pathophysiological hypotheses suggested by recent research on the neurocircuitry of conditioned fear are also discussed. Though specific phobias have been of less public health and clinical interest than other anxiety disorders, their circumscribed nature and possible relationship to conditioned fear may make them a productive subject for research into basic pathophysiology.

An historical and critical review of the articles on blood pressure published in Psychosomatic Medicine between 1939 and 1997

Between 1939 and 1997, there have been 59 volumes of Psychosomatic Medicine. Over this period there were 200 articles dealing with blood pressure. About 90% of these were concerned with high blood pressure. This article reviews all of these papers both from an historical perspective and critically. Although there has been a significant growth in the rate of articles published since 1939, there has always been a strong interest in the nature of hypertension, particularly the roles of affects and emotions in the natural history of the disease. For example, volume 1, number 1 of the Journal includes a symposium on high blood pressure in which Franz Alexander stated his well-known hypothesis that the chronic inhibition of rage plays a causal role in the production of hypertension. In various forms, the notion that anger is an important mediator of hypertension has neither been proved nor abandoned. One major conclusion drawn from this review is that the current research on high blood pressure is drifting somewhat aimlessly. It has become preoccupied with demonstrations that various stimuli or situations (usually characterized as stresses) can acutely raise blood pressure. Despite this focus, neither the necessary nor the sufficient conditions for labeling a stimulus as stress has ever been agreed upon. Likewise, there have been many demonstrations of an iatrogenic effect on blood pressure, but neither the behavioral mechanisms underlying this effect nor the strategies for eliminating it have been explicated. Finally, this article identifies several areas where it would be useful to review and integrate current knowledge. Hopefully, such integrations could play a significant role in focusing and shaping future research and clinical practice.

Psychiatric illness and syncope

Studies have reported a high prevalence of psychiatric illness in patients with syncope, particularly among those with syncope of unknown etiology. Although mortality rates for patients with syncope and psychiatric disorders tend to be lower than for patients with cardiac cause for syncope, treatment of these psychiatric illnesses appears to result in lower rates of recurrence of the symptoms. The authors recommend an assessment for psychiatric illness in those patients in whom the initial evaluation does not suggest an organic cause for syncope. Further studies are needed to elucidate the pathophysiologic mechanisms for syncope and the effects of treatment of psychiatric illness on recurrence of syncope.

Respiratory sinus arrhythmia in blood phobic subjects

12 blood-phobic subjects, selected according to the Fear Survey Schedule and the Mutilation Questionnaire, and 50 control subjects performed a paced respiration task during which heart rate and respiration were recorded. Respiratory Sinus Arrhythmia (RSA) was analyzed as an autonomic index of vagal influence on the heart. Analysis showed a larger RSA in the blood-phobic group than the controls and points to a difference in vagal activity at rest between the groups.

Animal phobias versus claustrophobias: exteroceptive versus interoceptive cues

The overall purpose of this investigation was to examine heterogeneity among specific phobias. In particular, the goals were to compare features of fear responding between individuals fearful of claustrophobic situations and individuals fearful of spiders/snakes, and to compare their response to hyperventilation challenges. By so doing, specific predictions were tested in relation to a conceptual model of exteroceptive and interoceptive fear cues. Using a nonclinical sample, 19 subjects with spider/snake phobias, 18 nonphobics, and 9 subjects with claustrophobias were exposed on two separate occasions to a live tarantula or python, a small closet, and a hyperventilation challenge. Dependent measures included subjective anxiety, panic attacks, physical symptoms, cognitive symptoms (or, fear of symptoms) and heart rate. In addition, subjects completed a standardized self-report scale that measures fear of bodily symptoms of arousal. It was found that subjects with claustrophobia reported more physical symptoms and cognitive symptoms than did subjects with snake/spider phobias, in response to their fear-relevant stimulus. In addition, claustrophobic subjects were more fearful of hyperventilation challenges and reported more fear of bodily symptoms, than did snake/spider phobic subjects. Finally, subjects with claustrophobia were as fearful of hyperventilation as they were of their fear-relevant stimulus. Theoretical and empirical implications of these findings are discussed.

Blood phobics and nonphobics: Psychological differences and affect during exposure

This study compared psychological dimensions of blood phobics and nonphobic controls, examined affect in response to phobic and neutral stimuli, and investigated the relationship between reported feelings of faintness and blood pressure. Blood phobics (24 adults with extreme Mutilation Questionnaire scores) and 24 nonphobics completed several psychological measures and viewed one of two 60 sec surgery scenes and a 60 sec neutral scene in counterbalanced order. Subjective, psychophysiologic, and motoric measures of affect were assessed. On questionnaires, phobics reported greater anxiety sensitivity, empathic distress, fear and insecurity, and nightmares, but no difference in autonomic arousal, muscle tension, motion sickness, or other empathy domains. During surgery scenes, phobics had more negative affect than controls; however, phobics were more anxious during only one of the two surgeries, and often only when the surgery was presented prior to the neutral scene. Fainting did not occur, and self-reported feelings of faintness were unrelated to blood pressure changes. The findings highlight the lack of information on blood phobic stimulus properties, fainting's relationship to self-reports and blood pressure, and the specific emotion experienced in blood phobia.

Psychophysiological response patterns to positive and negative film stimuli

The aim of the present study was to investigate differential emotional response patterns to film stimuli by multimodal assessment of mood ratings, perception of bodily sensations, salivary cortisol, autonomic variables and facial electromyogram (EMG). Film stimuli, chosen to elicit positive and negative emotional states, were presented to 12 subjects with general anxiety disorder and 12 controls. Changes in mood, bodily sensations, autonomic activity (heart rate, respiration rate and skin conductance), facial EMG activity (corrugator and zygomatic muscle region) and salivary cortisol were measured. Analyses revealed differential changes in all response systems except for respiration rate and salivary cortisol. Although high-anxious subjects did not differ from controls in their average responses to the negative film stimuli, there is a tendency of a greater coherence of emotional response components in generalized anxiety subjects. However, spontaneous facial expressions to positive and negative film stimuli were associated with augmented electrodermal activity within both groups. Results are interpreted in light of directional response fractionation, dimensional approaches of emotion, and the facial feedback literature.

The effects of muscle tension on cerebral circulation in blood-phobic and non-phobic subjects

This study aimed to assess whether (1) a muscle tensing procedure which has been found to be useful in the treatment of blood-phobic patients produces an increase in heart rate and cerebral blood flow and (2) whether this increase is greater than that produced by mental effort alone. Subjects were 17 volunteers with a history of fainting in response to blood-injury stimuli, (12 were phobic) and 8 volunteers with no fainting history. They were required to (a) rest, (b) do mental arithmetic, and (c) repeatedly tense and release their arm and leg muscles. It was found that Ss, heart rate and cerebral blood flow velocity were significantly greater during the muscle tensing procedure than during mental arithmetic or resting conditions. The increased cerebral blood flow produced by muscle tensing may enable blood phobic patients to prevent fainting during exposure treatment.

Blood/injury fear, fainting and avoidance of medically-related situations: a family correspondence study

The relationship of mutilation fear and fainting was examined in 204 students, (103 fainters and 101 non-fainters) by administering a series of questionnaires and a structured interview concerning the history, effects and circumstances of their fear and fainting. Two hundred and sixty of their parents completed the same scales along with a self-report version of the structured interview. Subjects were classified according to their fainting status and level of fear based on Mutilation Questionnaire scores, as phobic, fearful, and non-fearful fainters, and fearful non-fainters. Phobic and fearful fainters avoided significantly more medical and related situations due to their fear and fainting than fearful non-fainters and non-fearful fainters. Medical avoidance was best predicted by a linear combination of subjects' estimated probability of future fainting and number of past faint episodes. More females reported fainting and females reported greater fear, but they did not differ from males in fear-motivated avoidance of medical situations. A significant parent-child correspondence was found for fainting, but not for fear nor for avoidances. Implications of these findings for fear and fainting acquisition and its relation to avoidance were discussed.