Even though chest pain is not always caused by the heart or lungs, doctors in the emergency department will first want to check these organs. Conditions affecting the heart and lungs can be life-threatening and must be treated quickly. A doctor can perform a thorough exam and ask you about your symptoms and medical history. Then several tests can be done to find out if your chest pain involves your heart or lungs.

Noninvasive Tests

• Electrocardiogram (ECG)
• Chest x-ray
• Echocardiogram
• Computerized tomography (CT scan)
• Magnetic resonance imaging (MRI)
• Blood tests (cardiac enzymes, including troponin, creatine kinase, c-reactive protein, fibrinogen, homocysteine, lipoproteins, triglycerides, brain natriuretic peptide, and prothrombin)
• Stress testing (with or without exercise and with or without nuclear or echocardiographic imaging) assesses the heart's ability to tolerate exercise or simulated stress. It is the most common screening for CAD.

Invasive Tests

• Cardiac catheterization and coronary angiography is performed by injecting dye into the arteries of the heart and assessing the arteries for blockages
• Intravascular ultrasound (IVUS) can be performed with cardiac catheterization to assess the lining of an artery for blockages.
• Optical Coherence Tomography (OCT) is a new technique performed with cardiac catheterization to assess the lining of an artery for blockages at very high resolution
• Fractional Flow Reserve (FFR) is a technique to assess the significance of a blockage in a heart artery by measuring the pressures before and after the blockage.