The human heart functions to pump oxygen-rich blood through the body. The heart is divided into four chambers, the two upper chambers called the atria and two lower chambers called the ventricles. The heart muscle continually pumps, propelling over 2,000 gallons of blood through the body each day. The lining of the heart is divided into three layers--the pericardium, myocardium and endocardium--which work together to protect the heart and aid in efficient pumping.
Myocarditis
Myocarditis is inflammation of the middle layer of the heart wall, known as the myocardium. As the muscular portion of the heart wall, the myocardium functions to pump blood out of the heart. An infection such as from a virus, bacteria, fungus or parasite usually causes the inflammation. Inflammation of the myocardium can also be a result of an allergic reaction to a medication or another disease, such as lupus.
The most common symptoms of myocarditis include chest pain, an abnormal heartbeat and shortness of breath. Myocarditis often also causes fatigue, as the inflammation interferes with the heart's ability to pump sufficient blood throughout the body, therefore depriving the cells of oxygen. Fluid retention, known as edema, in the legs, ankles or feet may also occur.
Myocarditis can become serious, permanently damaging the heart. The damage can lead to heart failure--the inability of the heart to meet the needs of the body--as well as blood clots, heart attack or stroke.
Pericarditis
The heart is surrounded by a thin sac-like membrane which consists of an outer layer and an inner layer, known as the pericardium. A thin layer of fluid lies between the layers of the pericardium. A viral, bacterial or fungal infection can affect the pericardium, causing inflammation of the membrane, a condition known as pericarditis. Other causes of pericarditis include heart attack, cancer, radiation treatments and injury or surgery. Inflammation of the membrane increases the volume of fluid between the layers, which squeezes the heart and interferes with its normal functions.
Pericarditis causes sharp, piercing chest pain that can spread to the neck and left shoulder. Some also experience a fever and general feeling of illness. Treatment includes anti-inflammatory medications and analgesics to treat the pain as well as antibiotics if a bacterial infection is suspected. Pericarditis recurs in approximately 20 percent of patients, according to the American Heart Association.
Endocarditis
Endocarditis is the inflammation of the endocardium, the inner lining of the heart. Endocarditis is often caused by a bacterial infection, known as infective endocarditis. Endocarditis often affects the heart valves and is most common in those with damaged heart valves, according to MayoClinic.com.
Symptoms of endocarditis include fever, chills, fatigue, muscle or joint aches, night sweats, shortness of breath, paleness, persistent cough, edema, unexplained weight loss and the presence of a new or changes in a heart murmur. Endocarditis can lead to more serious conditions, including organ damage, stroke and heart failure.
