The image of a man clutching his chest before hitting the ground in pain is quite possibly the quintessential image of someone having a heart attack.

However, that’s more of a theatrical version of a heart attack than a realistic one.

New research suggests that nearly half of all heart attacks show no symptoms, yet they can still increase a person’s chance of heart failure.

These “silent” heart attacks represent 45 percent of all heart attacks, yet affect different groups of people in different ways, according to a study appearing in the latest issue of Circulation, the journal of the American Heart Association.

Dr. Elsayed Soliman, the senior author of the study and director of the epidemiological cardiology research center at Wake Forest Baptist Medical Center in North Carolina, says these heart attacks that show no symptoms are just as common as those that do.

“Silent heart attacks are still heart attacks,” he told Healthline.

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The Silent Killer

While silent heart attacks don’t give the typical warnings of a clinical heart attack, their lingering effects are still detectible by an electrocardiogram (EKG or ECG), which tests the electrical activity in the heart.

To determine how common silent heart attacks are, researchers examined 9,498 participants in the Atherosclerosis Risk in Communities (ARIC) study.

Of those, 703 had a heart attack—either silent or with symptoms—within nine years.

African-Americans had a slightly higher rate of silent heart attacks than whites, but whites had a higher rate of clinical heart attacks.

The rate of silent and clinical heart attacks was more than twice as high in men, but women died from both kinds of heart attacks more often than men.

The differences between genders and races, Soliman said, warrants further research.

“We need to give this a more careful look,” he said.

While silent heart attacks don’t have the normal warning signs, as Soliman’s team’s research suggests, they still have the same life-altering—or ending—capabilities as one that can bring you to your knees.

However, preventing a silent heart attack works the same as preventing one that would show symptoms. This includes keeping blood pressure and cholesterol within desirable levels, not smoking, getting daily cardiovascular exercise, and eating a balanced diet.

Those who don’t take preventative measures may need to get their hearts checked, especially if heart disease runs in their families.

“Those people may benefit from an EKG screening at one point or another,” Soliman said.

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Heart Attack First, Heart Failure Second

One out of every four people who suffer a heart attack will eventually develop heart failure, according to a new study from a research team led by Dr. Johannes Gho, a cardiology resident at the University Medical Center Utrecht, in Utrecht, the Netherlands.

The research was presented at the World Congress on Acute Heart Failure.

Using data from 24,745 adults who experienced their first heart attack between 1998 and 2010, researchers found just under 25 percent of those patients had developed heart failure within four years.

Overall, researchers found for every 10 years in age a patient was, their risk of heart failure increased by 45 percent. Those in lower socioeconomic brackets also had a 27 percent higher risk factor for heart failure following a heart attack.

Some co-existing health conditions greatly increased a person’s risk of heart failure, namely atrial fibrillation and diabetes.

“Identifying these prognostic factors in heart attack patients could help us predict their risk of developing heart failure and allow us to give treatments to reduce that risk,” Dr. Gho said in a press release.

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