Cardiac Pump Views
Cardiac pumps are most often used in heart surgery, so that a patient's heart can be disconnected from the body for longer than the twenty minutes or so it takes a prepared patient to die. Although unprepared patients get brain damage in three to four minutes, a patient can be prepared by cooling and drugs so that no damage will occur for twenty minutes or more.
Cardiac pumps are also sometimes used to keep babies with birth defects alive, or to aerate bodies with transplantable organs. Chronic use of cardiac pumps is contraindicated because the pressure profile of most practical pumps is believed to cause circulatory damage to the brain, especially in extended use. The pumps generate continuous pressure. When this pressure is set high enough to aerate tissues in the foot, it can easily damage tissue in the brain. Likewise, if set low enough to avoid damaging the brain, it often under-aerates some part of the body, such as the feet.
Cardiac pump theory refers to a proposed mechanism of how cardio-pulmonary resuscitation (CPR) works. Cardiac pump theory asserts that the action of chest compressions in CPR moves the heart to make it pump blood throughout the body. An alternative model, thoracic pump theory, suggests that compression of the chest area rather than the heart itself causes blood circulation. Both effects probably occur in CPR.
In CPR, the aid giver pushes down on the patient's chest, directly above the heart. Cardiac pump theory asserts that compressing the heart between the sternum (chest bone) and the spine pushes the blood in the heart to the rest of the body. Releasing the pressure allows the heart chambers and other blood vessels to refill. Rapidly repeating the compression and release causes the blood to move throughout the vital organs.
Cardiac Pump Images
