IMPROVEMENT OF HEART-PERFORMANCE, LUNG-PERFORMANCE, AND LIVER-PERFORMANCE DURING MECHANICAL CIRCULATORY SUPPORT BY THE NOVACOR-SYSTEM

Objective: Since its clinical introduction, the Novacor left ventricul ar assist system (LVAS) has proved to be a reliable and safe method fo r bridging to cardiac transplantation. To find out whether univentricu lar assistance is sufficient in patients with severe global heart fail ure, multi organ monitoring using the COLD system was performed. Metho ds: In seven patients (mean age 38.8 years), the wearable Novacor syst em N100 was implanted. Preoperatively, during the first 72 h thereafte r and before heart transplantation right and left ventricular cardiac output, right ventricular ejection fraction, pulmonary-, intrathoracic -and total blood volume, extravascular lung water and excretory liver function were monitored by means of double indicator dilution techniqu e with the COLD system. Conventional hemodynamic parameters have also been documented. Results: During left ventricular assistance, both pul monary and systemic arterial cardiac outputs increased significantly ( Student's t-test, P < 0.05). Right ventricular ejection fraction rose from 17 to 26%, preoperatively elevated pulmonary-and intrathoracic bl ood volumes and extravascular lung water fell significantly to normal ranges. Total blood volume remained constant, excretory liver function improved markedly. Conclusions: Pulmonary cardiac output improves due to the reduced right ventricular afterload by unloading the impaired left ventricle with the Novacor pump. The drop in pulmonary blood volu me, intrathoracic blood volume and extravascular lung water also indic ates a decrease of pulmonary congestion. Since total blood volume rema ins unchanged, a volume shift to the systemic circulation is suggested , resulting in an improved splanchnic perfusion as demonstrated by a b etter excretory liver function. In the absence of primary pulmonary hy pertension, treatment of global heart failure with a left ventricular assist device is possible. The COLD system is a useful tool for managi ng this patient group during the postoperative period. (C) 1997 Elsevi er Science B.V.