Cardiac arrest is often preceded by symptoms lasting for more than an hour, and usually occurs in cases with a known history of heart disease or risk factors, German investigators report. These findings refute the theory that sudden cardiac death occurs at random in apparently healthy or low-risk patients, the authors say.
“These findings suggest that educating the public, patients, and relatives to recognize and respond to symptoms of heart disease holds promise for reducing mortality attributed to sudden death,” Dr. Dirk Muller and colleagues at the University of Berlin report in the journal Circulation.
Muller’s team evaluated data analyzed the circumstances surrounding 406 patients who suffered sudden cardiac arrest and obtained cardiac histories and the median duration of warning for 323.
Results showed that 22 percent of patients had experienced angina (chest pain) for 120 minutes. Dyspnea (difficulty breathing) was present in 15 percent of patients for 30 minutes, nausea or vomiting in 7 percent for 120 minutes, dizziness or fainting in 5 percent for 10 minutes, while other symptoms lasting 60 minutes were reported by 8 percent.
Only 25 percent had no warning symptoms at all.
The investigators report that in 90 percent of cases, symptoms had lasted for at least 5 minutes before the patient collapsed and in some cases much longer.
“These symptoms are misinterpreted, suppressed, or denied despite the presence of a preexisting cardiac disease or cardiac risk factors,” Muller and his associates write.
More than half of the patients had a history of heart disease, and many had other risk factors, such as diabetes, smoking, and chronic lung disease.
The researchers also observed that when arrests occurred in public places, bystanders often initiated CPR. However, most collapses occurred when patients were at home in the presence of relatives, who are unlikely to attempt CPR. Of the 57 patients for whom bystander CPR was performed, 23 percent were alive and discharged from the hospital. In contrast, only 4 percent of 349 without bystander CPR survived.
Muller’s group recommends that detailed information regarding warning symptoms and how to perform basic life support should be given to patients at risk and their relatives.
“Money invested in training and education instead of automated external defibrillator programs might well lead to earlier recognition more rapid contact of the emergency medical services, and a higher percentage of bystander CPR and thus to a higher probability of survival in patients with sudden cardiac deaths,” they conclude.
SOURCE: Circulation: Journal of the American Heart Association, September 12, 2006.