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

BackgroundThere 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.ObjectiveSince 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.MethodsSubjects 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 χ2 tests and logistic regression.ResultsPEA 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).ConclusionsWhen 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.