Diagnosis (and treatment) of a heart attack can begin when emergency medical personnel arrive after you call 9-1-1. Don’t put off calling 9-1-1 because you are not sure that you are having a heart attack.

At the hospital emergency room, doctors will work fast to find out if you are having or have had a heart attack. They will consider your symptoms, medical and family history, and test results. Initial tests will be quickly followed by treatment if you are having a Heart Attack.

Tests used include:

 
• Electrocardiogram (ECG or EKG) (also called cardiac echo). This test is used to measure the rate and regularity of your heartbeat. A 12-lead EKG is used in diagnosing a heart attack. Echocardiogram is an ultrasound examination of the heart that produces detailed images of the organ. It uses a microphone-like device (transducer) to transmit and receive sound waves that travel through the chest wall to the heart, and then are reflected back. The reflected sound waves are translated into images of the heart, including the aortic valve, chambers, and walls. Echocardiogram is used to detect abnormalities in the structure of the heart, to assess thickening of the walls, to measure the pressure change (gradient) between the left ventricle and the aorta, to measure the amount of dilation (increased diameter) of the left ventricle, and to measure the ejection fraction (the percentage of blood ejected from the left ventricle with each heart beat). Echocardiogram may be used in the diagnosis of aortic stenosis, atrial fibrillation, congestive heart failure, Endocarditis, Heart Attack, and pericarditis.  
• Blood tests. When cells in the heart die, they release enzymes into the blood. They are called markers or biomarkers. Measuring the amount of these markers in the blood can show how much damage was done to your heart. These tests are often repeated at intervals to check for changes. The specific blood tests are:       o Troponin test. This test checks the troponin levels in the blood. It is considered the most accurate blood test to see if a heart attack has occurred and how much damage was done to the heart.       o CK or CK-MB. These tests check for the amount of the different forms of creatine kinase in the blood.       o Myoglobin test. This test checks for the presence of myoglobin in the blood. Myoglobin is released when the heart or other muscle is injured.  
• Nuclear heart scan. This test uses radioactive tracers (technetium or thallium) to outline heart chambers and major blood vessels leading to and from the heart. A Nuclear heart scan shows any damage to your heart muscle.  
• Cardiac catheterization. A thin flexible tube (catheter) is passed through an artery in the groin or arm to reach the coronary arteries. Your doctor can determine pressure and blood flow in the heart’s chambers, collect blood samples from the heart, and examine the arteries of the heart by x-ray.  
• Coronary angiography. This test is usually performed along with cardiac catheterization. A dye that can be seen using x-ray is injected through the catheter into the coronary arteries. Your doctor can see the flow of blood through the heart and see where there are blockages. A coronary angiogram is obtained by injecting an iodine-based dye or other contrast agent into the bloodstream and taking x-rays of the coronary arteries. This enables the physician to see blockages, malformations, and stenosis in the vessels.  
• Chest x-ray. Chest x-rays may be performed to detect abnormalities in the size and shape of the heart (e.g., an enlarged heart), to detect fluid around the heart (pericardial effusion), and to detect heart failure. They also may be used to detect abnormalities of the major artery (aorta).