According to a new US study, the heart attack treatment is the most effective when it is given within an hour after the symptoms occur, but many people with heart disease do not know the symptoms of a heart attack.

Kathleen Dracup and colleagues at the University of California, San Francisco, School of Nursing studied 3,522 patients, who had previously suffered a heart attack or had undergone a procedure, such as angioplasty, for heart disease, in the United States, Australia and New Zealand.

The researchers found that 44 percent of them had poor knowledge about the symptoms of heart attack. They said, the lack of knowledge about the range of heart attack symptoms as measured in the study, is shocking.

According to researchers, those who suffer a heart attack have a better chance of surviving if treatment begins within one hour, but most patients are admitted to the hospital 2-1/2 hours to three hours after symptoms begin.

The study concluded that shorter hospital stays and a move to outpatient treatment have decreased the amount of patient’s knowledge about heart attack symptoms, which include nausea and pain in the jaw, chest or left arm.mood disorders