Thoratec - Patients & Families: Glossary

Angiogram - A series of x-rays of the blood vessels in the heart taken in rapid sequence following the injection of a contrast substance into the blood stream.

Arteries - The thick, muscular tubes that carry blood away from the heart.

Asynchronous mode - In this mode used with the Thoratec VAD, the VAD pumping rate is determined and fixed by the operator. The volume of blood pumped with each beat (called the stoke volume) may vary.

Auto Rate Mode - The Auto rate mode allows the HeartMate system to change pumping rate depending on the patient's body's needs. The more the patient exercises, for instance, the more oxygen-carrying blood is demanded by the muscles.

Bi-VAD - Bi-Ventricular Assist Device.

Blood clots - The conversion of blood into a semisolid gel.

Blood thinner - Medication used to prevent blood clots or keep the blood in a liquid form. (for example, Coumadin®)

Blood vessels - An extensive network of flexible tubes that carries blood to and from the heart and throughout the body. The blood vessels are the transportation system of the body. The blood vessels include arteries, capillaries, and veins.

CABG - (pronounced "Cabbage") Coronary Artery Bypass Grafting. A heart surgery procedure that treats the symptoms of coronary artery disease. CABG surgery reroutes (or 'bypasses') the blood flow around the blockages in the coronary arteries, restoring blood flow to the heart muscle itself.

Cannulae - tubes that connect the heart and blood vessels to the pump. These tubes are made of Thoratec Corporation's material called Thoralon®. This material is designed to be strong, durable and resistant to blood clots.

Cardioflex® Polyurethane - The elastic, plastic material used in the diaphragm of the HeartMate LVAD.

Coronary Heart Disease (CHD) - A disease in which plaque deposits containing cholesterol atherosclerosis and fat globules are deposited within the intima and inner media of large and medium-sized arteries.

Diaphragm - The HeartMate LVAD has two chambers: the blood chamber and the air chamber. The flexible membrane that separates these two chambers is the diaphragm. The membrane moves up and down with pulses of air.

Ejection fraction - The efficiency with which blood is moved from the ventricles to the body expressed in a percentage.

Fixed Rate Mode - This is the same as the asynchronous mode but in the HeartMate system, it is referred to as the Fixed Rate Mode.

Graft - A tube created by using portions of another artery or vein from the patient's body or synthetic materials to reroute blood around a blockage.

Heart chambers - The four sections of the heart through which blood is pumped. The two upper chambers are called the left atrium and right atrium. The two lower chambers are the left and right ventricles. Oxygen-rich blood from the lungs enters the left atrium, while oxygen-depleted blood from the rest of the body flows into the right atrium. Both atria simultaneously pump blood into the ventricles. The ventricles then pump the blood to the lungs (from right ventricle) and to the rest of the body (from the left ventricle).

Heartbeat - A heartbeat consists of the contraction of the atria, quickly followed by the contraction of the ventricles. The rate of the heartbeat varies according to different levels of activity: the higher the level of activity or emotional excitement, the faster the heart will beat.

Intravenous lines - The tubing going into the vein in order to administer fluids or medications, or both, into the blood circulation through a vein.

IP - Implantable Pneumatic; the pump is surgically placed inside your body and functions with pulses of air.

Ischemic - Not receiving adequate blood flow.

LVAD - Left Ventricular Assist Device.

LVAS - Left Ventricle Assist System which includes the LVAD (blood pump), drive line, System Controller, Batteries, PBU and Display Module.

Myocardial infarction - Damage or death of myocardial tissue (heart muscle) of blood flow to the area.

Myocardial revascularization - Returning/improving blood flow to the myocardium (heart muscle).

Paracorporeal - Refers to "outside the body" and describes the location of the Thoratec VAD lying on top of the abdomen.

Perfusion scan - A test to determine blood flow through the vessels to the heart.

RVAD - Right Ventricular Assist Device.

Thoralon® Polyurethane - The elastic, plastic material used in the diaphragm of the Thoratec VAD pump and Vectra® and Aria™ grafts.

VAD - Ventricular Assist Device.

Valves - Flap-like structures that maintain blood flow in one direction only, through the heart and pump.

VE - Vented Electric; the implanted pump contains an electric motor but is vented to outside air through the driveline.

Volume Mode - In this mode, the Thoratec VAD pumping rate is determined by the volume of blood circulating within one's body. The VAD will pump blood out as often as it completely fills. In other words, as soon as the blood sac is totally filled, it provided a signal to the console to send a burst of air (positive pressure) up through the driveline into the back of the VAD causing ejection of blood out of the pump (emptying). This mode is sometimes referred to as the "fill to empty mode".