Webster's New World Medical Dictionary

carcinoma of the breast, infiltrating ductal
One of several recognized specific patterns of can-
cer of the breast, so named because it begins in the
cells that form the ducts of the breast. It is the most
common form of breast cancer. On a mammogram,
invasive ductal carcinoma is usually visualized as a
mass with fine spikes radiating from the edges
(spiculation). It can sometimes be felt as a firm
lump in the breast. Treatment may include radia-
tion, chemotherapy, and surgery.
carcinoma of the breast, infiltrating lobular
The second most common type of invasive breast
cancer. Infiltrating lobular carcinoma starts in the
glands that secrete milk (lobules). On a mammo-
gram, a lobular carcinoma can look similar to a
ductal carcinoma, appearing as a mass with fine
spikes radiating from the edges (spiculation).
Infiltrating lobular carcinoma can cause a thicken-
ing of the breast tissue. Lobular carcinoma can
occur in more than one site in the breast or in both
breasts at the same time. Treatment may include
radiation, chemotherapy, and surgery.
cardiac
Having to do with the heart.
cardiac aneurysm
See 
aneurysm, cardiac.
cardiac arrest
A heart attack in which the heart
suddenly stops pumping sufficient blood. A cardiac
arrest that results in the death of heart muscle is
referred to as a myocardial infarction. See also
myocardial infarction, acute.
cardiac atrium
See atrium.
cardiac conduction system
The electrical con-
duction system that stimulates the heart to contract
and pump blood. This system generates electrical
impulses and conducts them throughout the muscle
of the heart. Among the major elements in the car-
diac conduction system are the sinoatrial node, the
atrioventricular (AV) node, and the autonomic nerv-
ous system. See also 
atrioventricular node; auto-
nomic nervous system; sinoatrial node.