Descriptions of cardiac biomarkers and their use require the knowledge of several terms. These terms and their definitions are below:
Acute Coronary Syndrome (ACS):
Includes all the ischemic events that can occur in the heart. Ischemia is defined simply as inadequate blood supply to an organ (in this case, the heart). These ischemic events range from angina (where there is no cell death or reversible cell injury) to an AMI with large areas of cell necrosis (dead cardiac myocytes). A continuum of events that are involved in ACS is illustrated on the page that follows this glossary of terms.
Angina:
Chest pain caused by inadequate supply of oxygen to heart myocardium. It is synonymous with angina pectoris (pectoris refers to the chest).
Acute Myocardial Infarction (AMI):
Commonly referred to as a heart attack, this is a sudden loss of circulating blood and oxygen that causes necrosis of myocardial tissue. It is most often caused by the narrowing of coronary arteries by atherosclerosis, a thrombus, or dislodged plaque material.
Congestive Heart Failure (CHF):
CHF is usually, a left ventricular dysfunction resulting from aging, hypertension, atherosclerosis or muscle damage from an AMI or repeated AMIs. In CHF, the heart is not able to effectively pump blood through its chambers and to the rest of the body. Fluid accumulates in the lungs and tissues causing edema because less blood leaves through the arteries than what entered the heart from the veins.
Electrocardiogram (ECG or EKG):
These terms refer to the tracings of the electrical current that passes through the myocardium. The heart contractions are stimulated by this current. In areas of myocyte necrosis, the current does not pass through normally and the tracings will reflect this with abnormal patterns.
Infarction:
An area of tissue death that occurs due to lack of oxygen. Clogging of an artery will cause dead muscle tissue or infarction. Infarctions are localized areas of necrosis.
