Illustration of a healthy blood pressure reading, blood vessel and heart (left) and those of a patient with hypertensive heart disease (right). The righthand blood vessel has atherosclerosis. Atherosclerosis is a condition in which an artery wall thickens as a result of accumulations (atheromas) of fatty materials such as cholesterol. Such narrowing of blood vessels raises blood pressure, which puts strain on the heart and can lead to an enlarged heart (cardiomegaly, right).