Etiology of out-of-hospital cardiac arrest in psychiatric patients: Chart review.

Aim: Although sudden cardiac deaths are more common in psychiatric patients than the general population, data on their causes are very limited. The aim of this study was to investigate initial rhythms and causes of out-of-hospital cardiac arrest (OHCA) in patients with psychiatric disorders.

Methods: We conducted a systematic chart review of patients resuscitated after OHCA and hospitalized in the Tertiary Emergency Medical Center of Tokyo Metropolitan Bokutoh Hospital in Japan between January 2010 and December 2017. The initial rhythms and causes of OHCA were compared between psychiatric patients and non-psychiatric patients. Parameters of interest were compared using chi-squared test, Fisher's exact test, or the Mann-Whitney U-test, as appropriate.

Results: A total of 49 psychiatric and 600 non-psychiatric patients were eligible for this study. Fatal but shockable arrhythmias (i.e. ventricular fibrillation and ventricular tachycardia) were less frequently observed as initial rhythms in patients with psychiatric disorders than the others (22.4% vs 49.7%, P < 0.001). Cardiac origin was less common as the cause of OHCA (26.5% vs 58.5%, P < 0.01), while airway obstruction and pulmonary embolism were more frequent in psychiatric versus non-psychiatric patients (24.5% vs 6.5%, P < 0.01; and 12.2% vs 1.5%, P < 0.01, respectively). The results were similar when psychiatric patients were compared with sex- and age-matched controls selected from the non-psychiatric patient group.

Conclusion: Although fatal arrhythmias may be less common, non-cardiac causes such as pulmonary embolism and airway obstruction need to be treated with high clinical suspicion in an event of sudden cardiac arrest in psychiatric patients.