Assisted Circulation
نویسندگان
چکیده
A NUMBER of methods utilizing extracorporeal devices to assist the circulation have been described and tested experimentally during the past five years.'-' The two categories into which these methods may be divided are synchronous and asynchronous assistance. Both of these approaches attempt to relieve the work of the heart and to provide an adequate arterial perfusion pressure. Asynchronous partial bypass has the theoretical disadvantage that during cardiac systole the pump creates an increased pressure against which the left ventricle must contract. Dennis et al.,6 however, report that full or near-full bypass effectively reduces myocardial oxygen consumption. Diastolic augmentation, a form of synchronous assistance, has been shown not to lower myocardial oxygen eonsumption.7 The earliest method of synchronous assistance is counterpulsation.4 In this method, blood is aspirated from the arterial reservoir during cardiac systole, thereby lowering the pressure within the left ventricle. This blood is then returned during diastole. Although the theoretical benefits which may be accrued from synchronously assisted circulation appear to be self evident, it has been difficult to define these benefits experimentally. In this regard, we have chosen to examine the relationship between myocardial oxygen consumption and
منابع مشابه
Vital organ perfusion during assisted circulation by manipulation of intrathoracic pressure.
BACKGROUND We have previously shown, in dogs with severe cardiac depression, that modest cyclic increases in intrathoracic pressure, starting synchronously with left ventricular isovolumic contraction, significantly increase aortic flow and pressure. However, little is known of changes in vital organ perfusion during this technique of assisted circulation. METHODS AND RESULTS We studied regio...
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تاریخ انتشار 2005