A heart attack or myocardial infarction (MI) occurs when a coronary artery becomes partially or completely blocked, stopping oxygenated blood from reaching the heart muscle. The muscle becomes starved for oxygen and is damaged or in some cases dies. The term 'myocardial' refers to the heart muscle, while 'infarction' refers to tissue death caused by lack of oxygenated blood. Seeking immediate treatment for a heart attack is critical to minimizing the damage and surviving.

A heart attack generally falls into one of the following three causal categories:

• A buildup of plaque on the coronary artery wall that blocks passage of blood
• A blood clot that catches on the plaque on the coronary artery wall and blocks passage of blood
• A spasm in the coronary artery that causes the artery to temporarily contract (Rare form of MI and the cause of the spasm is unknown)

Heart attack warning signs
If you experience any of these symptoms, seek IMMEDIATE medical attention:

• Angina symptoms that lasts more than 20 minutes
• An indigestion-like burning pain or feeling of fullness
• Pain, pressure, tightness or heaviness of the chest, back, arms, neck and/or shoulders
• Shortness of breath
• Burning or aching pain in the chest, throat and/or jaw
• Tingling or numbness
• Irregular or rapid heart beat
• Weakness, faintness or dizziness
• Sweating (cold, clammy, etc.)
• Vomiting
• Gray or pale skin

Heart attack treatment
If you have a heart attack and seek immediate medical attention, your treatment may include:

• Thrombolytics (clot busting medications)
• Medications to help the heart pump more efficiently and improve blood flow (aspirin)
• Medication to correct an arrhythmia or an irregular heartbeat
• Diagnostic cardiac catheterization*
• Percutaneous coronary intervention (PCI) (also know as angioplasty) and stenting*
• Coronary artery bypass graft (CABG) surgery (open-heart surgery)*
• Cardiac rehabilitation therapy program