Corresponding with a rise in sudden cardiac arrest cases presenting with pulseless electrical activity (PEA), researchers have found that PEA cases are associated with age, black race, female gender and pulmonary disease, as well as a higher prevalence of syncope in their lifetime, according to a study in the Nov. 23 Circulation.
Carmen Teodorescu, MD, PhD, from Cedars-Sinai Medical Center in Los Angeles, and colleagues noted the decreasing trend in ventricular fibrillation/ ventricular tachycardia (VF/VT) sudden cardiac arrest (SCA) cases, including a 56 percent drop in Seattle from 1980 to 2000.
Similarly, Goteborg, Sweden, saw a decrease from 39 percent in 1981 to 32 percent in 1997, and Helsinki, Finland, experienced a 48 percent drop in the prevalence of VF cases.
A corresponding increase in PEA cases has been similarly documented. In Goteborg, Sweden, for example, PEA increased from 6 to 26 percent between 1981 and 1997.
Survival from PEA is significantly lower compared with VF/VT. "Therefore, the rising prevalence of PEA has significant public health implications," researchers said.
To determine factors associated with PEA, Teodorescu and colleagues identified 1,277 cases of out-of-hospital sudden cardiac arrest who underwent attempted resuscitation in the Portland, Ore., metropolitan area between 2002 and 2007. The mean age was 65 years and 67 percent were male.
The presenting arrhythmia was VF/VT in 47.8 percent, PEA in 24.9 percent, asystole in 25 percent and bradycardia in 1.3 percent.
Researchers found that PEA cases were older, more likely to be female and less likely to survive to hospital discharge, compared with VF/VT cases. The differences were significant.
A history of syncope was strongly associated with PEA after adjustment for age, gender, response time and arrest circumstances. Black race was independently associated with PEA and pulmonary disease was a significant factor associated with PEA and asystole.
The higher prevalence of syncope during the lifetime of PEA cases was not explained by differences in the status of the cardiac conduction system as evaluated from the resting ECG, according to the study.
Whites were more likely to present with VF/VT and Asians were more likely to present with asystole. Cases that presented with VF/VT had a higher prevalence of documented coronary artery disease and hyperlipidemia.
"The present analysis found that 25 percent of VF/VT cases versus only 6 percent of PEA cases survived to hospital discharge. The combination of rising prevalence and low survival rates of PEA cases increases the urgency of enhancing the understanding of PEA mechanisms," especially its link with syncope, they concluded.