Predictors of electromechanical dissociation during cardiac arrest

ECG patterns observed during cardiac arrest were analyzed in 261 comatose cardiac arrest survivors. Forty-seven patients (18%) exhibited electromechanical dissociation (EMD) at some point before restoration of stable spontaneous circulation. These patients had a higher mortality (P = .05) and a lower rate of cerebral recovery (P = .01) during the one-year follow-up than study patients who did not exhibit EMD. Patients who developed EMD subsequent to defibrillation had better outcome than patients presenting with EMD. Multivariate analysis revealed that age more than 70 years old (P = .007), pulmonary disease (P less than .001), diabetes (P = .013, in-hospital arrests only), and prearrest hypoxemia (P = .013, outside-hospital arrests only) were independently predictive of the occurrence of EMD. Although the generalizability of these findings is limited, they may offer new clues to the pathophysiology of EMD.