Call emergency medical services immediately (in the United States,
dial 911). Treating a myocardial infarction quickly is important to limit heart muscle damage and prevent complications. Oxygen, aspirin (taken immediately), and pain relief with morphine (or a similar medication)
are usually used in the immediate evaluation period. An electrocardiogram (electrical tracing of the heartbeats) is part of early assessment, as are blood tests looking for heart muscle damage. Other tests may be prescribed, such as an echocardiogram (using sound waves to evaluate heart function), chest x-ray,
and coronary angiography (a test using dye studies of the heart's blood vessels). During coronary angiography,
the cardiologist may be able to treat the diseased blood vessel using percutaneous coronary interventions, such as a balloon (to open the artery for better blood flow) or a stent. If cardiac bypass graft surgery is recommended, the cardiac surgeon uses the angiographic images to guide the surgical approach.