Background: Programs for research and practice in resuscitation have focused on identification and reversal of ventricular fibrillation (VF). While substantial progress has been achieved, evidence is accumulating that clinical death is less likely to be caused by fibrillation now than in the 1960s and 1970s. Pulseless electrical activity (PEA) has emerged as the most common rhythm found in arrests in the hospital and is rapidly rising in pre-hospital reports.
Purpose: To identify the magnitude of changes occurring, search for potential explanations from population and clinical epidemiology and present the data available regarding etiology and treatment of PEA.
Data sources: Synthesis of material from population epidemiology, clinical epidemiology, animal and human research on VF and PEA.
Conclusions: VF is a manifestation of severe, undiagnosed coronary artery disease (CAD). Rates of death from CAD increased from rare in 1930 to become the most common cause of death in the US. CAD death rates peaked in the early 1960s and had declined over 50% by the late 1990s. Primary and secondary prevention, early diagnosis and aggressive, successful treatment have contributed to this decline. PEA is a brief phase in clinical death that occurs after losses in consciousness, ventilatory drive and circulation but before decay to asystole; survival rates are poor. PEA is a common stage in clinical death from any of a variety of tissue hypoxic/anoxic insults. Research on PEA is needed; 50 years of attention to CAD and VF have resulted in improved survival and changed the disease spectrum. Similar attention to animal and clinical research on PEA may have the potential to improve survival.