heart attack
heart attackReuters

Some routine feelings of uneasiness, such as indigestion, pain in the jaw, upper back or arms, and fatigue, which are often ignored, could actually point to a silent heart attack (SHA). The symptoms of an SHA are so mild that the patient doesn't even know he is having a heart attack. A study in the journal Circulation of the American Heart Association said SHAs accounted for nearly 45 percent of all heart attacks and are often associated with poor diagnosis.

The study said having an SHA increased the chances of dying from coronary heart disease three times, and increased the incidence of death from any cause by 34 percent.

Men are more prone to heart attacks than women, but women are likelier to die from heart attacks, the study found.

The study involved analysis of 9,489 participants who were at an increased risk of suffering a heart attack during 1987-2010.

The study found that 317 (3.3 percent) participants had an SHA while 386 (4.1) had clinically diagnosed heart attacks during an average period of 8.9 years.

SHA is defined as the Electrocardiogram (ECG)-based evidence of heart attacks without clinical documentation of the subject.

Although SHA can happen to anyone, people likeliest to experience these are those who have had a prior heart attack, diabetics, and people above the age of 65 years, or those who are on continuous medication, according to silentheartattack.org.

The best way to identify an SHA is through careful study of medical history, ECG that measures heart activity and testing blood for cardiac enzymes. The most important treatment in such cases is restoring blood flow to the heart.

Some of the most obvious symptoms of a heart attack are tightness or pain in the chest, neck, back or arms, as well as fatigue, lightheadedness, abnormal heartbeat and anxiety. Women are more likely to have atypical symptoms than men.

The treatment varies from lifestyle changes and cardiac rehabilitation to medications, stents and bypass surgery.