Dr. Comilla Sasson, who conducted the study while at the University of Michigan, found cardiac arrest rates in some neighborhoods were two to three times higher than in other neighborhoods in the same county.
The neighborhoods with high cardiac arrest rates also tended to have lower median household incomes, more African-American residents and lower education levels, the study found.
Sasson and colleagues analyzed emergency medical services and 911 call data. U.S. Census information was used to approximate neighborhoods.
The study, published in the Annals of Internal Medicine, found that year after year, residents of the neighborhoods with the highest risk for a cardiac arrest had the lowest rates of bystander CPR.
"These findings have national public health indications. They show that it is time to change our thinking on how and where we conduct CPR training if we are ever going to change the dismal rate of survival from cardiac arrest," Sasson, the lead author, said in a statement. "Nine out of 10 people die from a cardiac arrest event. This number can and must change."