Published in the American Heart Association's journal Circulation, a new study has suggested that nearly half of all heart attacks could have no significant symptoms.
These 'silent' heart attacks, which don't have the classic warning signs - such as chest pain, shortness of breath and cold sweats, but blood flow is still restricted to the heart, causing an increase in the risk of death and other long-term problems like heart disease.
Any symptoms of silent heart attacks are so mild that they are usually not picked up on. They are normally detected later on, when patients have an ECG to check their heart's electrical activity.
Researchers at Wake Forest Baptist Medical Center looked at the records of nearly 9,500 middle-aged adults who were already enrolled in the Atherosclerosis Risk in Communities (ARIC), which analysed the causes of hardened arteries.
The team examined the data and found that more than 300 participants had silent heart attacks, while a further 386 had heart attacks with clinical symptoms. Analysis continued for more than 20 years to track any deaths from heart attacks or related diseases.
They found that silent heart attacks accounted for 45 per cent of all heart attacks and increased the risk of dying from heart disease by three times. In addition, the risk of dying from all causes was also raised by 34 per cent and it was found that silent heart attacks were more likely to cause death in women.
Dr Elsayed Z. Soliman, study senior author and director of the Epidemiological Cardiology Research Center at Wake Forest Baptist Medical Center, said the outcome from silent heart attacks are as bad as from those that display clinical symptoms.
However, because patients are often unaware that they are experiencing a heart attack, they may not receive the treatment they need to prevent another one, he explained.
The team took into consideration factors such as smoking, body weight, diabetes, high blood pressure and cholesterol and adjusted their findings accordingly.
Dr Soliman said that when silent heart attacks are discovered they should be treated as aggressively as ones that present symptoms.
"The modifiable risk factors are the same for both kinds of heart attacks," he said. "Doctors need to help patients who have had a silent heart attack quit smoking, reduce their weight, control cholesterol and blood pressure and get more exercise."
These findings could help improve care and better identify patients who may be at risk of suffering from further heart problems.
Find the nearest Barchester nursing home.