Arrhythmias
Abnormal heart rhythms. Can cause the heart to pump less effectively.

Atherosclerosis
Build-up of fatty substances, cholesterol, cellular waste products, calcium and other substances in the inner lining of an artery. Also used as a general term for the thickening and hardening of arteries.

Atrial fibrillation
A disorder in which the two small upper chambers of the heart, the atria, quiver instead of beating effectively. Blood isn't pumped completely out of them when the heart beats, so it may pool and clot. About 15 percent of strokes are caused by atrial fibrillation.

Angina
The medical term for chest pain due to coronary heart disease.

- B -

Bradycardia
A heart rhythm that's too slow; can cause fatigue, dizziness, lightheadedness, fainting or near-fainting spells.

- C -

CABG or "Cabbage"
Coronary Artery Bypass Graft Surgery

CHD
Abbreviation for congenital heart disease and coronary heart disease.

Cardiomyopathy
Disease in which the heart muscle doesn't work as well as it should. There may be multiple causes, including viral infections.

- H -

HDL cholesterol
High-density lipoprotein. Medical experts think HDL tends to carry cholesterol away from the arteries and back to the liver, where it's passed from the body. Some experts believe HDL removes excess cholesterol from atherosclerotic plaques and thus slows their growth. Also referred to as "good" cholesterol.

Hyperlipidemia
An elevation of lipids (fats) in the bloodstream. These lipids include cholesterol, cholesterol esters (compounds), phospholipids and triglycerides. They're transported in the blood as part of large molecules called lipoproteins.

- I -

Ischemia
Lack of blood flow to the heart.

- L -

LDL cholesterol
Low-density lipoprotein is the major cholesterol carrier in the blood. If too much LDL cholesterol circulates in the blood, it can slowly build up in the walls of the arteries feeding the heart and brain. Also referred to as "bad" cholesterol.

- M -

Myocardial infarction or "M.I."
A heart attack.

- P -

PTCA (Percutaneous transluminal coronary angioplasty )
Coronary artery balloon dilation or balloon angioplasty.

- S -

Syncope
A temporary loss of consciousness usually related to temporary insufficient blood flow to the brain.

- T -

Tachycardia
Rapid heart beating; can produce symptoms of palpitations, rapid heart action, dizziness, lightheadedness, fainting or near fainting.

- V -

Ventricular fibrillation
A condition in which disordered electrical activity causes the ventricles to contract in a rapid, unsynchronized, uncoordinated fashion. When this occurs, little or no blood is pumped from the heart.