IIZUKA Kei
   Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine
   Position   Assistant Professor
Language English
Title Electrocardiogram-Synchronized Rotational Speed Modulation System Can Reduce The Recirculation Due To Aortic Insufficiency In LVAD Support
Conference ASAIO 64th Annual Conference
Promoters ASAIO (The American Society for Artificial Internal Organs)
Conference Type International society and overseas society
Presentation Type Poster notice
Lecture Type General
Publisher and common publisher◎IIZUKA Kei, AKIYAMA Daichi, TAKEWA Yoshiaki, TSUKIYA Tomonori, MIZUNO Toshihide, NISHIMURA Takashi, TATSUMI Eisuke
Date 2018/06/15
Venue
(city and name of the country)
Washington, USA
Summary Study: Aortic Insufficiency (AI) is one of the worrisome complications in LVAD support. Progressive AI can cause to increase recirculation from LVAD to LV. Our previous study suggested that high rotational speed of LVAD can lead to increasing LVAD-LV recirculation. We have previously developed Electrocardiogram-Synchronized Rotational Speed Modulation System (ESRSM), which can change the rotational speed synchronously to ECG cycle. The aim of this study was to reduce the LVAD-LV recirculation by controlling the rotational speed with ESRSM.

Methods: Eight goats (45 ± 2 kg) underwent LVAD (EVAHEART) implantation. Cardiac dysfunction was induced by continuous infusion of beta-blockade (esmolol). The AI model was established by placing a temporary inferior vena cava filter in the aortic valve. The degree of AI was controlled to three levels (none, mild, severe). Hemodynamics was evaluated in three levels of AI with the three modes of the ESRSM. The Co-pulse mode raises rotational speed in systolic phase, the Counterpulse mode does in diastolic phase, and the Continuous mode does not change rotational speed (normal control). The rotational speed of each modes was set to maintain the same systemic flow. Recirculation rate which indicates the percentage of LVAD-LV recirculation to LVAD output was calculated as the index of AI.

Results: Continuous mode was driven with 1825 rpm (mean), and mean systemic flow was 2.1 L/min. The rotational speed needed to maintain the same flow was 2113 and 1563 rpm (systolic and diastolic phase) in Copulse mode, and 1488 and 1813 rpm in Counter-pulse mode. The mean rotational speed of each modes was 1746 and 1704 rpm (Co-pulse and Counter-pulse mode). The recirculation rate in Counter-pulse mode was significantly lower than Continuous mode in mild and severe AI. It was indicated that the recirculation was reduced by lower mean rotational speed. ESRSM has the potential to reduce the recirculation due to the AI