Contrary to popular belief, sudden cardiac arrest rarely occurs “out of the blue” with no warning, say German researchers.

Scientists at the University of Berlin analyzed data on 406 patients who suffered sudden cardiac arrest and found that the majority had symptoms that lasted at least five minutes and often several hours before they collapsed. The study showed that 22 percent had had chest pain for two hours, 15 percent had shortness of breath for a half hour, 7 percent had nausea or vomiting for two hours, and 5 percent experienced dizziness or fainting for 10 minutes prior to collapse. Only a quarter of the patients had no warning symptoms at all.

Furthermore, the investigators found, two-thirds of the patients had a history of heart disease, and many others had significant risk factors for heart disease, such as high blood pressure, diabetes, or a history of smoking. The researchers concluded that although warning symptoms preceding sudden cardiac death “are present for a surprisingly long time in many patients, these symptoms are misinterpreted, suppressed, or denied despite the presence of a preexisting cardiac disease or cardiac risk factors.”

The study also found that 72 percent of collapses occurred at home, and 67 percent occurred in the presence of eyewitnesses, but patients were more likely to survive when the arrest happened in a public place, where bystanders were more likely to begin CPR. It is “of the utmost importance” that both patients at risk and their relatives know how to recognize the warning symptoms of cardiac arrest and how to react accordingly, the researchers say. While much attention is focused on providing defibrillators in public places, “relatives are the most probable witnesses and should therefore learn to perform basic life support,” they conclude.

According to the American Heart Association, more than 330,000 heart patients die, primarily from sudden cardiac arrest, before reaching the hospital or while in the emergency room. “If more people performed effective CPR when someone suffers cardiac arrest, thousands more lives could be saved,” the association notes. For more information, log onto www.cpranytime.org.

Source: Circulation