New research from the Cedars-Sinai Heart Institute suggests that people who experience "sudden" cardiac arrest may begin to exhibit symptoms up to four weeks before their heart suddenly stops.

For their study, researchers examined the medical records of 567 men ages 35 to 65 who experienced out-of-hospital cardiac arrests between 2002 and 2012. Paramedics responding to the cases had asked family members about signs and symptoms of heart problems in the weeks preceding the arrest.

The preliminary findings of the study were presented this week at the American Heart Association's (AHA) Scientific Sessions in Dallas.

Researchers found that 53% of the men in the study had exhibited symptoms in the month preceding. Of those men:

• 80% experienced symptoms four weeks to one hour before the cardiac arrest;
• 56% experienced chest pain;
• 13% had shortness of breath; and
• 4% reported dizziness, fainting, or palpitations.

"The findings were entirely unexpected," says lead author Sumeet Chugh, adding that the researchers "never thought more than half of these middle-aged men would have had warning signs so long before their cardiac arrests. Previously we thought most people don't have symptoms so we can't do anything about it."

According to AHA, less than 10% of U.S. patients who experience such a cardiac arrest survive. Although most men had coronary artery disease at the time of the attack, just half had been tested for it before it occurred, according to the study.

"The message here is, if you have these signs or symptoms, please don't ignore them: seek health care," Chugh says (Pierson/Berkrot, Reuters, 11/19; Hellmich, USA Today, 11/19).