Mediastinitis is a condition market by inflammation of the mid-chest (mediastinum) which includes the heart, large blood vessels, trachea, esophagus, thymus gland and connective tissues. It can be acute or chronic. Acute cases are generally caused by bacterial infections which break apart organs in the mid-chest. These cases can progress very quickly or gradually over time. Chronic cases are due to longstanding inflammation of the mid-chest. Both forms are usually an unwelcome result of open chest surgery. Cases are treated with antibiotics and or surgery to remove the infection.