A clinical study on hemodynamic effects of external counterpulsation (ECP)
Nakamura, S.
Nihon Kyobu Geka Gakkai 30(12): 1970-1979
1982
ISSN/ISBN: 0369-4739 PMID: 7169561 Document Number: 182745
The limitation of conventional medical therapy in cardiogenic shock after myocardial infarction, low output syndrome (LOS) after open heart surgery and failure to wean from cardiopulmonary bypass have resulted in innovative therapeutic methods, among the most significant of which is mechanical circulatory assist device. One of the most popular mechanical circulatory assist devices of counterpulsation is intra-aortic balloon pumping (IABP). IABP has been now widely demonstrated in clinical use treating LOS and cardiogenic shock impending acute myocardial infarction. Because IABP is an invasive method, complications have been reported. External Counterpulsation (ECP) is a noninvasive, atraumatic and practical method of producing counterpulsation effect. ECP was performed in 30 clinical cases (14 cases of ischemic heart disease (IHD), 16 cases of valvular diseases) after open heart surgery. Cardiassist (Cardiassist Corp., Illinois USA) was used for ECP. The patient's legs are placed in the leg unit (Cardiassist consists of 2 units, leg unit and control console). A water bag, wrapped around the legs, completely fills the intervening space, exerting a uniform pressure over the legs and vessels within. The application of pressure during diastole is triggered by ECG. During ECP, arterial pressure, central venous pressure (CVP), pulmonary artery wedge pressure (PAWP), cardiac output (CO) were measured to evaluate hemodynamic effects. Systolic peak arterial pressure was unchanged, but diastolic arterial pressure was elevated significantly. CVP and PAWP were unchanged, but CVP in valvular disease was higher than that in IHD. Cardiac Index (CI) was increased an average of + 9.4 .+-. 7.4% at 120 min after ECP started. The diastolic augmentation effect was significant. Apparently, ECP is a safe and effective counterpulsation technique, but systolic unloading is less effective than IABP.