NITRIC OXIDE INHALATION FACILITATES RECOVERING FROM THE RIGHT VENTRICULAR FAILURE; EVALUATION UNDER BIVENTRICULAR ASSISTANCE:

The necessity of the right ventricular assist device (RVAD) support is temporary in most of the cases who need biventricular assist device (BVAD) support because of severe and uncontrollable heart failure. In the other hand, nitric oxygen (NO) has attracted as the right ventricular recovery effect with the pulmonary artery dilatation. The objective of this study is to investigate the effect of NO for right heart function recovery with continuous flow BVAD by in-vivo studies. Ten male piglets (31–46kg) were randomly divided to two acute experimental groups: global ischemia with BVAD support as control group (group-C) and NO inhalation- added group (group-N). Two continuous flow pumps (mixed-flow pumps) as a left ventricular assist device (LVAD) and a RVAD were set via left thoracotomy, and global ischemia was induced by clamping the base of the ascending aorta for 30 minutes, followed by 6-hour reperfusion. The LVAD was driven at the flow rate of over 75ml/min/kg, and the RVAD was weaned according to the right ventricular recovering as far as the LVAD flow was maintained. Mean pulmonary artery pressure increased in C-group from 19.9 mmHg to 39.3 mmHg, while that was kept significantly lower in N-group (mean 23 mmHg). SvO2 could be maintained more than 60% in all cases in both groups. Although any piglets of group-C could not alive without BVAD support, all cases of group-N could reduce the RVAD flow ratio (RVAD flow / total systemic flow) and 4 cases could wean from the RVAD support. In conclusion, NO inhalation facilitates recovering from the right ventricular failure and prompt weaning from the RVAD support.