Psychological Stress Preceding Idiopathic Ventricular Fibrillation

Objective: Emotional stress is well established as a trigger of sudden death in the context of coronary heart disease (CHD), but its role in patients experiencing cardiac arrest with apparently normal hearts is unknown. This study sought to determine the role of psychosocial stress as a precipitant of cardiac arrest in patients with apparently normal hearts, so-called idiopathic ventricular fibrillation (IVF). Methods: We interviewed 25 IVF survivors (12 men, 13 women) and 25 matched comparison patients regarding life events during the 6 months and 24 hours preceding the cardiac event. The comparison group consisted of patients with an acute myocardial infarction or angina pectoris requiring angioplasty but without cardiac arrest. Judges independently rated written summaries of these interviews for psychosocial stress at each time point on a three-point scale (low, moderate, severe). Results: During the 6 months before the cardiac event, 20 patients sustaining IVF had severe/moderate stress and five had low stress, whereas 10 comparison patients had severe/moderate stress and 15 had low stress (Fisher exact p = .008). During the preceding 24 hours, nine patients with IVF had severe/moderate stress and 16 had low stress, whereas two comparison patients had severe/moderate stress and 22 had low stress (Fisher exact p = .04) (one silent myocardial infarction could not be precisely dated). Conclusion: These data suggest that psychosocial stress is playing a role in otherwise unexplained cardiac arrest. CHD = coronary heart disease; DSM-IV = Diagnostic and Statistical Manual, Fourth Edition; ICD = implantable cardioverter defibrillator; IVF = idiopathic ventricular fibrillation; IVF-US = Idiopathic Ventricular Fibrillation Registry of the United States; UCARE = Unexplained Cardiac Arrest Registry of Europe.