If you encounter someone who is unconscious from a presumed heart attack, call for emergency medical help. If you have received training in emergency procedures, begin cardiopulmonary resuscitation (CPR). This helps deliver oxygen to the body and brain.
According to guidelines by the American Heart Association, regardless of whether you’ve been trained, you should begin CPR with chest compressions. Press down about 2 inches (5 centimeters) on the person’s chest for each compression at a rate of about 100 a minute. If you’ve been trained in CPR, check the person’s airway and deliver rescue breaths after every 30 compressions. If you haven’t been trained, continue doing only compressions until help arrives.
Sudden cardiac arrest during a heart attack is commonly caused by a deadly heart rhythm in which the heart quivers uselessly (ventricular fibrillation). Without immediate treatment, ventricular fibrillation leads to death. The timely use of an automated external defibrillator (AED), which shocks the heart back into a normal rhythm, can provide emergency treatment before a person having a heart attack reaches the hospital. But, if you’re alone, it’s important to continue chest compressions. If there’s a second person present, that person can look for a nearby AED.


Ischemia is a condition where the flow of oxygen-rich blood to a part of the body is restricted. Cardiac ischemia refers to lack of blood flow and oxygen to the heart muscle. It occurs when an artery becomes narrowed or blocked for a short time, preventing oxygen-rich blood from reaching the heart. If ischemia is severe or lasts too long, it can cause a heart attack (myocardial infarction) and can lead to heart tissue death. In most cases, a temporary blood shortage to the heart causes the tremendous pain of angina pectoris. Patients with silent ischemia have pain-free ischemia. It is dangerous because it may cause a heart attack with no prior warning.
How Common is Silent Ischemia and Who is at Risk?
The American Heart Association estimates that 3 to 4 million Americans have episodes of silent ischemia. People who have had previous heart attacks or those who have diabetes are especially at risk for developing silent ischemia. Heart muscle disease (cardiomyopathy) caused by silent ischemia is among the more common causes of heart failure in the United States.
Major risk factors include:
• Previous heart attack
• Coronary artery disease
• Diabetes
• High blood pressure (hypertension)
• Cardiomyopathy
• Obesity
• Smoking
• Alcohol and drug abuse

Symptoms- Silent ischemia has no symptoms. Researchers have found that patients who have noticeable chest pain may also have episodes of silent ischemia.