Posttraumatic stress disorder as a consequence of myocardial infarction: A study of contributing factors

Ruth Woods McPhearson


A study designed to assess the nature of veteran responses to a diagnosis of posttraumatic stress disorder (PTSD), the occurrence of a myocardial infarction (MI), or both was conducted. Pre-existing patterns of behavioral and emotional functioning were assessed, as were changes in coping ability after an identified stressor. For the purposes of this study, emotional processing was defined as a veteran's tendency to experience affect at a certain intensity, and the level of ambivalence he felt regarding the expression of emotion. The study involved male veterans between the ages of 45 and 64. Participants were separated into four groups on the basis of ever having experienced a heart attack, or ever having been diagnosed with PTSD. They were administered the Posttraumatic Stress Disorder Checklist (PCL), the Affect Intensity Measure (AIM), and the Ambivalence Over the Expression of Emotion Questionnaire (AEQ). A general questionnaire, designed for this study, assessed the degree of behavioral and attitudinal change between the time before and after a major stressor. Results indicated that veterans with pre-existing PTSD experienced more PTSD symptoms, greater changes in attitudes and behaviors since the occurrence of an identified stressor, and greater ambivalence regarding the expression of emotion. All group scores on the PCL-S were strongly correlated with guilt, vulnerability, loneliness and fatigue, intrusive thoughts, and re-experiencing phenomena. Veterans who had experienced heart attack identified it as a significant stressor more than other events. Veterans with past MI who experienced strong PTSD symptoms also experienced strong ambivalence over emotional expression. No evidence supported the existence of a significantly large group of veterans with sub-clinical PTSD. This study has contributed to the currently limited literature on the manifestation of PTSD post-MI by examining the rate with which PTSD may be diagnosed post-MI in a veteran sample, and by considering the contribution emotional and behavioral patterns make to traumatic responses.