title: Psychophysiological correlates of peritraumatic dissociative responses in survivors of life-threatening cardiac events.
abstract: The psychophysiological startle response pattern associated with peritraumatic dissociation (DISS) was studied in 103 survivors of a life-threatening cardiac event (mean age 61.0 years, SD 13.95). Mean time period since the cardiac event was 37 (79 IQD) months. All patients underwent a psychodiagnostic evaluation (including the Peritraumatic Dissociative Experiences Questionnaire) and a psychophysiological startle experience which comprised the delivery of 15 acoustic startle trials. Magnitude and habituation to trials were measured by means of electromyogram (EMG) and skin conductance responses (SCR). Thirty-two (31%) subjects were indexed as patients with a clinically significant level of DISS symptoms. High-level DISS was associated with a higher magnitude of SCR (ANOVA for repeated measures p = 0.017) and EMG (p = 0.055) and an impaired habituation (SCR slope p = 0.064; EMG slope p = 0.005) in comparison to subjects with no or low DISS. In a subgroup analysis, high-level DISS patients with severe post-traumatic stress disorder (PTSD; n = 11) in comparison to high-level DISS patients without subsequent PTSD (n = 19) exhibited higher EMG amplitudes during all trials (repeated measures analysis of variance F = 5.511, p = 0.026). The results demonstrate exaggerated startle responses in SCR and EMG measures - an abnormal defensive response to high-intensity stimuli which indicates a steady state of increased arousal. DISS patients without PTSD exhibited balanced autonomic responses to the startle trials. DISS may, therefore, unfold malignant properties only in combination with persistent physiological hyperarousability.
authors.affiliation: Institut und Poliklinik für Psychosomatische Medizin, Medizinische Psychologie und Psychotherapie, Klinikum Rechts der Isar, Technische Universität München, Germany. kh.ladwig@lrz.tu-muenchen.de
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Ladwig
authors.forename: Birgitt
authors.initials: B
authors.lastname: Marten-Mittag
authors.forename: Isabel
authors.initials: I
authors.lastname: Deisenhofer
authors.forename: Birgit
authors.initials: B
authors.lastname: Hofmann
authors.forename: Johannes
authors.initials: J
authors.lastname: Schapperer
authors.forename: Sonja
authors.initials: S
authors.lastname: Weyerbrock
authors.forename: Natalia
authors.initials: N
authors.lastname: Erazo
authors.forename: Claus
authors.initials: C
authors.lastname: Schmitt
mesh_terms: D004213:Dissociative Disorders / Q000209:etiology / Q000523:psychology*; D004576:Electromyography; D006801:Humans; D011594:Psychometrics; D013216:Reflex, Startle / Q000502:physiology*; D012867:Skin; D013313:Stress Disorders, Post-Traumatic / Q000523:psychology*; D017741:Survivors / Q000523:psychology*