A heart attack can occur without typical symptoms. Silent heart attack is also referred to medically as silent ischemia (lack of oxygen) to the heart muscle. Symptoms can be so mild that the heart attack goes unrecognized. There may be no symptoms at all. Heart damage is often discovered during a routine electrocardiogram (EKG) that records the electrical signals of the heart. The risk of advanced heart disease becomes greater because of lack of treatment and intervention. Symptoms of silent heart attack might include heart failure or heart rhythm disturbance after heart damage is already present.
Unrecognized or silent heart attack is a set up for future complications that can lead to more severe heart damage as coronary artery disease progresses. A second heart attack can cause more damage and noticeable symptoms, compounding the effects of suffering from loss of heart muscle that occurs with heart attack. Risk of premature death is high for individuals who experience undetected heart attacks.
According to the American Heart Association, 3 to 4 million Americans experience disruption of blood flow to the heart without experiencing symptoms (silent ischemia). When symptoms do occur, it is known as angina. Heart damage from silent heart attack can lead to sudden death from heart rhythm disturbance or heart failure from enlargement of the heart muscle.
Symptoms of a silent heart attack are often present but unrecognized. They can be very mild, but pinpointed with careful history taking by your physician. Episodes of mild indigestion, dizziness, weakness, sweating and sudden fatigue may be related to unrecognized heart attack. For others, especially diabetics, there may be no symptoms at all.
A routine electrocardiogram, stress test or echocardiogram (ultrasound of the heart) can reveal whether a silent heart attack has occurred. During an ultrasound of the heart, it is possible to see that the heart muscle is damaged. An electrocardiogram may reveal abnormalities in conduction of the electrical signals of the heart, leading to suspicion of undetected heart disease and unrecognized heart attack. A nuclear stress test that uses images to view the heart can show areas of damaged heart tissue.
Routine heart screening and annual exams for cholesterol, blood pressure and electrocardiogram tests can reduce the risk factors for silent heart attack. Heart screening tests are especially important for diabetics who need aggressive control of risk factors that can lead to heart attack. Silent heart attack can have no symptoms. Diabetics, anyone with a family history of heart disease and those at risk for heart attack from obesity, high blood pressure and inactivity should focus on lifestyle interventions guided by a physician. Routine screening for heart disease can lower the risk of having a silent heart attack.