There are blood tests which can be done to attempt to identify damage to the heart. One of these tests measures the levels of a number of different proteins that can be present in higher quantities when the heart muscle has been damaged. Elevation of cardiac enzymes is usually an indicator that some damage to the heart has occurred, though other conditions, such as kidney disease, can also lead to elevations in the cardiac enzyme levels.
Heart Attack
Elevated cardiac enzymes are most commonly associated with a heart attack, the American Heart Association explains. After a heart attack, portions of the heart muscle die or become damaged due to the loss of blood flow. This results in the destruction of some of the cells in the heart muscle, causing their contents to spill out into the blood. There are a number of cardiac enzymes that can be used to attempt to diagnose a heart attack. One of the most common ones is creatine kinase; sometimes a sub-type of creatine kinase, CK-MB is also measured. In addition to creatine kinase levels, doctors may also check for the levels of troponins, another protein which is found in heart cells. Elevated cardiac enzymes coupled with symptoms of a heart attack can be used to definitely diagnose an acute myocardial infarction, which allows doctors to try and limit the damage done to the heart.
Malignant Hypertention
Malignant hypertension, which is defined as a sudden and rapid elevation in blood pressure, can also result in elevated cardiac enzyme levels, Medline Plus explains. Malignant hypertension often occurs if there is significant kidney damage and can hurt heart muscle cells due to the extra strain placed on the heart. Patients may also have swelling in their feet and lower extremities as well as the buildup of fluid in the lungs due to poor circulation as the heart struggles to keep up with the increased workload.
Renal Disease
Many patients with significant renal and kidney disease may also have elevated cardiac enzymes, UptoDate.com explains. This may be due to the fact that patients with significant kidney disease also suffer from coronary artery disease. Kidney disease may also result in damage to muscle tissue throughout the body as well as problems with vitamin D deficiency, which can also affect the heart. In many cases patients with kidney problems will have elevated cardiac enzyme levels in the absence of any signs of heart damage, which can make this diagnostic less useful in detecting heart attacks in patients who are also on dialysis or have significant renal dysfunction.
Polymyositis
Polymyositis, which is a disorder that causes inflammation of muscles throughout the body, can also lead to elevated cardiac enzymes, "Wheeless' Textbook of Orthopedics" reports. This condition, which can be triggered by a viral infection, results in damage to muscles throughout the body and may affect the heart. It causes tenderness of muscles and joints and progressive weakness which begins with the muscles in the abdomen and trunk.
