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Your heart has four chambers. The lower-left chamber is called the left ven-
tricle, and it pumps oxygen-enriched blood out of the heart to the body
through an artery called the aorta. In this way, the left ventricle acts like a
circulation pump.
As a person gains weight, her body gets bigger, creating more area
through which the heart must circulate blood. To get blood through this
extra body mass, the left ventricle must pump harder and harder. The ven-
tricle enlarges from working so hard, much like any muscle would enlarge if
overly exercised. The ventricle’s walls thicken, making it more difficult for
46 / Health Issues Caused by Obesity
Frightening Facts
• Cardiovascular disease is responsible for one of
every four deaths in the United States each year.
• Cardiovascular disease is the leading cause of
death for both men and women.
• Someone in the United States has a stroke every
40 seconds.
• Cardiovascular disease causes more deaths than
cancer, chronic lower respiratory diseases, and
accidents combined.