Association of non-shockable initial rhythm and psychotropic medication in sudden cardiac arrest.

Background: Asystole (ASY) and pulseless electrical activity (PEA) have a poor outcome during sudden cardiac arrest (SCA). Psychotropic medication has been associated with a risk for sudden cardiac death (SCD). Our aim was to study the association of psychotropic medication with ASY/PEA during SCA.

Results: A total of 659 SCA subjects were derived from the emergency data of Oulu University Hospital (2007-2012). Subjects with non-cardiac origin of SCA and over 30-minute delay to rhythm recording were excluded. Population included 222 subjects after exclusions (mean age 64 ± 14 years, 78% males). Initial rhythm was ventricular fibrillation (VF) or ventricular tachycardia (VT) in 123 (55%), ASY in 67 (30%) and PEA in 32 (14%) subjects. The delay (collapse to rhythm recording) was similar in VF/VT and ASY/PEA subjects (median 8 min [1st-3rd quartile 3-12 min] versus 10 [0-14] minutes, p = 0.780). Among VF/VT subjects underlying cardiac disease was more often ischemic compared to ASY/PEA subjects (85% versus 68%, p = 0.003). Psychotropic medication was associated with ASY/PEA rhythm (OR 3.18, 95%CI 1.40-7.23, p = 0.006) after adjustment for gender, age and underlying cardiac disease. Subsequently, antipsychotics (OR 4.27, 95%CI 1.28-14.25, p = 0.018) were more common in the ASY/PEA group. Benzodiazepines and antidepressants were not associated with ASY/PEA.

Conclusions: Psychotropic medication and especially antipsychotics are associated with non-shockable rhythm during SCA and may lower the possibility of survival from the event. This might partly explain the risk of SCD related to psychotropic medication.