Antipsychotic drugs are associated with pulseless electrical activity: the Oregon Sudden Unexpected Death Study.

BACKGROUND: There has been a paradigm shift in the manifestation of sudden cardiac arrest (SCA), with steadily decreasing rates of ventricular fibrillation/tachycardia (VF/VT) and a significant increase in the proportion of pulseless electrical activity (PEA) and asystole.

OBJECTIVE: Since PEA is marked by failure of myocardial contractility, we evaluated the potential role of drugs that affect cardiac contractility in the pathophysiology of human PEA.

METHODS: Subjects with out-of-hospital SCA (aged≥18 years) who underwent attempted resuscitation were evaluated in the ongoing Oregon Sudden Unexpected Death Study (2002-2009). Specific classes of medications with either negative or positive cardiac inotropic effects were evaluated for association with occurrence of PEA vs VF/VT by using Pearson χ(2) tests and logistic regression.

RESULTS: PEA cases (n = 309) were older than VF/VT cases (n = 509; 68±14 years vs 64±15 years; P<.0001) and were more likely to be women (39% vs 25%; P<.0001). In a logistic regression model adjusting for age, sex, comorbidities, disease burden, and resuscitation variables, antipsychotic drugs (odds ratio 2.40; 95% confidence interval 1.26-4.53) were significant predictors of PEA vs VF/VT. Conversely, use of digoxin was associated with the occurrence of VF/VT (P<.0001).

CONCLUSIONS: When drugs modifying myocardial contractility were evaluated in a comprehensive analysis of patients who suffered SCA, use of antipsychotic agents was a significant and independent predictor of manifestation with PEA.