What occurs during a silent heart attack is exactly the same as a regular heart attack; they are described as “silent” merely because their symptoms lack the intensity of a classic heart attack.

Silent heart attacks increase the chance of a subsequent heart attack, heart disease complications, and even death. But people who suffer a silent heart attack may never even discover that they have heart disease, and therefore miss the opportunity to take lifesaving drugs, undergo a procedure to restore blood flow to the heart, or get the motivation they need to make lifestyle changes and reverse their heart disease. These measures could add years to such a person’s life.

There is an alarming link between silent heart attacks and cardiac arrest, also called sudden cardiac death, which occurs when the heart’s electrical system decompensates, often due to a heart attack.

According to a study in JAMA Cardiology, 42.4 percent of people who had no knowledge of heart disease prior to their death from cardiac arrest actually had suffered a silent heart attack, according to evidence that was found during autopsies.

Another study that was published in the Journal of the American Medical Association looked at almost 2,000 men and women ages 45 to 84 who were free of heart disease. After 10 years, 8 percent had myocardial scars — evidence of a heart attack.

Overall, the prevalence of myocardial scars was five times higher in men than it was in women.

Most surprising was the fact that 80 percent of those with myocardial scars were unaware that they had heart disease.