This
information has been prepared for individuals who will experience a
heart operation. Information is included for you and your family about
heart disease, the operation itself, postoperative care and recovery
at home.
Please note that there is an addendum at the end of the section "Your
Hospital Stay" as there have been some changes in hospital procedures
since the original text was written.
We hope this information will help to answer and address many of the
common questions and concerns most patients and their families have.
We encourage you to ask us everything you wish to discuss or cannot
understand.
The Heart
The heart is a four-chambered muscular organ that lies slightly to
the left in the center of the chest. Protected by the rib cage it is
situated be hind the breastbone (sternum) and between the lungs.
The upper two chambers of the heart are called atria and the bottom
two chambers ventricles. A thick, fibrous wall of tissue (septum) further
divides the heart into a right and left side. Four valves are present.
These valves act as doors to direct and regulate blood flow through
the heart and into the circulation.
Function of the Heart
The function of the heart is to pump, or circulate, blood through the
blood vessels to all parts of the body. The blood carries nutrients
and oxygen to nourish body cells. All cells require an oxygen supply
to sur vive. Blood vessels are divided into arteries and veins. Arteries
carry blood that is saturated with oxygen. The aorta is the largest
artery in the body. Arteries, like branches of a tree, originate from
the aorta and reach all areas of the body to provide oxygen-saturated
blood. Veins carry blood that has been used by the cells and is low
in oxygen or desaturated. Desaturated blood drains from small veins
into the largest venous vessels, the superior and inferior vena cavae.
The vena cavae return the desaturated blood to the right side of the
heart where it is circulated to the lungs to be replenished with oxygen.
The heart beats 60-100 times each minute throughout your life.
This contraction is stimulated and controlled by a natural pacemaker
within the heart cells. The electrical current is initiated and causes
the right and left atria to contract simultaneously followed immediately
by right and left ventricular contraction. This coordinated electrical
stimulation causes the heart to pump and circulate the blood. This flow
of blood can be felt as your pulse. The electrical activity of the heart
as it pumps can also be seen on an electrocardiogram (EKG).
Coronary Arteries
The heart requires a generous supply of oxygen and nutrients for nourishment.
This enables it to pump effectively and efficiently. The heart DOES
NOT "soak up" blood circulating through it. 
The coronary arteries provide the special network of blood vessels necessary
to feed the heart muscle food and oxygen. The coronary arteries are
the first branches of the aorta and lie on the surface of the heart.
Acknowledgements
Content: Jaelene K. Williams, RN, MS
Medical Illustrations: Kathleen Wagner
Illustrations: Catherine Gendron