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The History of EECP
The history of EECP began in the early
1950s, when researchers discovered that the heart
was doing two different kinds of work. The first type of work occurred during the pumping part of the heartbeat (systole), during which the heart needed to overcome the blood pressure in the aorta in order to pump blood through it. The second type of work occurred during the relaxed part of the heartbeat (diastole), during which the heart received blood via backflow from the aorta. This was described as the difference between pressure work and flow work, respectively. Counterpulsation was introduced as a strategy by which the blood flow from the aorta back to the heart could be increased during diastole, so the heart would not have to work so hard during systole. The increased blood flow to the heart would provide the heart with more oxygen, to improve circulation and strengthen the cardiopulmonary system. In 1958, Harvard researchers documented positive results from counterpulsation in laboratory studies, and animal studies in the early 1960s supported these results. From this research, American researchers began to develop a device that could be surgically implanted in the chest to produce counterpulsation (an intra-aortic balloon pump [IABP]). While most American physicians were pursuing invasive techniques such as the IABP, Chinese physicians were developing one of the other findings that came from Harvard in the 1960s. The Harvard researchers had discovered that counterpulsation could be achieved without inserting a device into the aorta. Instead, cuffs were applied to the lower legs and timed to alternately fill and empty of water, in the same rhythm as the patient's heartbeat.
By gently compressing the blood vessels
in the legs, this increased the blood flow to the
heart during the diastole phase of the heartbeat. Chinese physicians pursued this painless, noninvasive technique for achieving counterpulsation and have been developing and refining it over the last 40 years. Today the technique of enhanced external counterpulsation uses a pressure suit that sends counterpulsation waves through computer-controlled pneumatic cuffs located at three points on the leg. Precisely timed by the computer, these modern cuffs inflate and deflate rapidly between heart beats. The modern cuffs used today fill with air instead of water, for the greater comfort of the patient and the greater ease of the physician. The three cuffs also fill sequentially, one at a time, rather than suddenly filling all at once. In 1989, researchers from the State University of New York at Stony Brook determined that enhanced external counterpulsation continued to show helpful effects on patients even three years after treatment. There are no reported risks of complication, and as of this time, centers are opening up across the country to provide this service.
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