If you or someone you love has been diagnosed with a heart condition, you may feel as if you've come to a foreign country where you don't speak the language. Here are some brief definitions to help you and your doctor communicate more effectively:

• Angina pectoris: Pain in the chest and arms or jaw due to a lack of oxygen to the heart muscle. The pain usually occurs during exercise and at times of stress. The most common cause is coronary heart disease.
• Angiography: X-ray exam of the blood vessels or chambers of the heart.
• Arrhythmia: An abnormality in the rhythm or rate of the heartbeat. Arrhythmia is caused by a disturbance in the electrical impulses to the heart.
• Arteriosclerosis: A group of disorders that cause thickening and loss of elasticity of artery walls. Atherosclerosis is the most common type of arteriosclerosis.
• Balloon angioplasty: Procedure in which a catheter with a deflated balloon on its tip is passed into the narrowed part of an artery. The balloon is then inflated and the narrowed area widened.
• Cardiac arrest: Abrupt loss of heart function. This differs from myocardial infarction, or heart attack, in which the blood supply to the heart is reduced or blocked. However, myocardial infarction can cause cardiac arrest.
• Cardiac ischemia: Insufficient blood supply to the heart. The condition is often caused by a blood vessel disease such as atherosclerosis.
• Coronary arteries: The two arteries that provide blood to the heart.
• Coronary artery bypass graft: Surgical procedure in which blood is rerouted around clogged arteries. The procedure improves the blood supply to the heart.
• Echocardiography: Technique that uses ultrasound to examine the internal structure of the heart.
• Electrocardiography: Method of recording electrical impulses that precede contraction of the heart muscle. The resulting record, called an electrocardiogram (ECG or EKG) is used to diagnose disorders of the heart.
• Exercise stress test: Electrocardiography performed while the patient undertakes an activity such as walking on a treadmill. The test helps determine how well the heart works when demands are placed upon it.
• Heart failure: Condition in which the heart cannot pump enough blood to meet the body's needs.
• Myocardial infarction (heart attack): Event that occurs when the blood supply to the heart is drastically reduced or stopped, causing injury to the heart muscle. This differs from cardiac arrest, in which the heart stops beating.
• Stent: Tiny wire mesh tube permanently placed within an artery during angioplasty to help prevent the artery from narrowing again.
• Tissue plasminogen activator (TPA): Drug used to dissolve blood clots in an artery.