A Glossary of Heart Disease Terms
Homocysteine: An amino acid in the body. High levels of homocysteine are a risk factor for coronary artery disease.
Hydrogenation: A process used to harden unsaturated liquid vegetable oils into saturated fats.
Hyperlipidemia: High levels of fat in the blood, such as cholesterol and triglycerides.
Hypertension: High blood pressure.
Hypertrophic Obstructive Cardiomyopathy (HOCM): See IHSS below.
Hypertrophy: An abnormal enlargement of an organ or thickening of its tissue. Ventricular hypertrophy is the name given to a thickened ventricle.
Hypotension: Low blood pressure.
Idiopathic: When the cause of a disease or process is not known.
IHSS: Idiopathic Hypertrophic Subaortic Stenosis is another term used synonymously with hypertrophic obstructive cardiomyopathy (HOCM). It is an inherited disease that causes thickening of the heart muscle and other changes to the heart that significantly impair its function. Although the disease is rare, IHSS is the single most common cause of sudden cardiac arrest in seemingly healthy young people.
Immunosuppressants: Drugs that are used to keep the body's immune system from rejecting a transplanted organ, such as the heart, or to slow down the destructive processes of autoimmune disease (where the body's immune system goes awry and kills normal cells and tissue.)
Implantable Cardioverter Defibrillator (ICD): A surgically inserted electronic device that constantly monitors your heart rate and rhythm. When it detects a very fast, abnormal heart rhythm, it delivers electrical energy to the heart muscle to help the heart to beat in a normal rhythm again.
Infarction: Tissue death due to lack of oxygen-rich blood.
Inotrope Medication: A medication used to strengthen the heart's contractions and improve blood circulation.
Insulin: A hormone produced by the pancreas that helps the body use sugar.
Intra-aortic Balloon Pump Assist Device (IABP): A machine that can help the pumping function of the heart. It is usually inserted through an artery in the groin area and threaded backwards into the descending thoracic aorta in the chest. In this location, the balloon inflates and deflates in synchrony with the heart in order to aid the blood pumping function of the heart in people with cardiac disease.
Intracardiac Tumor: An intracardiac tumor can be any tumor of the heart, either malignant or benign. The most common tumor of the heart is a benign atrial myxoma.
Intravascular: Inside a blood vessel.
Intravascular Ultrasound (IVUS): An invasive procedure, performed along with cardiac catheterization. A miniature sound probe (transducer) on the tip of a catheter is threaded through the coronary arteries and, using high-frequency sound waves, produces detailed images of the interior walls of the arteries.
Ischemia: Condition in which there is not enough oxygen-rich blood supplied to the heart muscle to meet the heart's needs.
Lead Extraction: A lead is a special wire that delivers energy from a pacemaker or implantable cardioverter defibrillator (ICD) to the heart muscle. A lead extraction is the removal of one or more leads from inside the heart.