Tomohiro Nishinaka    Department   School of Medicine(Tokyo Women's Medical University Hospital), School of Medicine    Position   Visiting Professor
Language	English
Title	Evaluation of Hemodynamics of Aortic Insufficiency under LVAD Support
Conference	26th Annual Meeting of the International Society for Mechanical Circulatory Support (ISMCS2018)
Promoters	ISMCS2018
Conference Type	International society and overseas society
Presentation Type	Speech
Lecture Type	General
Publisher and common publisher	◎IIZUKA Kei, NISHINAKA Tomohiro, NIINAMI Hiroshi, AKIYAMA Daichi, NAITO Noritsugu, MIZUNO Toshihide, TSUKIYA Tomonori, TAKEWA Yoshiaki, TATSUMI Eisuke
Date	2018/11/02
Venue (city and name of the country)	Tokyo, JAPAN
Society abstract	Abstract Book 146
Summary	Aortic insufficiency (AI) is a worrisome problem under left ventricular assist device (LVAD) support. The factors causing AI were still controversial. We evaluated some clinical questions from basic side. Progressive AI can lead to LVAD-LV recirculation, resulting low-output syndrome. Increasing of rotational speed to solve the low-output was controversial because it could also increase the LVADLV recirculation. We established an animal model of AI with LVAD, and evaluated the hemodynamics with changing rotational speed. It was suggested from experiments with five goats that the increasing of rotational speed did not contribute to improve the output in AI with Sellers classification 3 or more. Progressive AI can need surgical intervention, but the influence of AI progression on hemodynamics was not clarified enough. We evaluated the hemodynamics of AI progression with cardiac dysfunction model of five LVAD-AI goats. Left atrial and ventricular pressures showed marked increase when the recirculation rate surpassed 40%. It was demonstrated that the changes of left heart pressures can be the key sign to know the limitation of LVAD support against AI progression, and to consider the surgical intervention. Anatomical factors could be also one of factors causing AI. It was reported that the group of patients who have obtuse angle between outflow graft and the aorta (O-A angle) can progress AI earlier. We established LVAD-AI model with seven calves, and evaluated the influence of the O-A angle. It was suggested that the obtuse O-A angle could cause increase of recirculation without pressure changes. We performed those animal experiments to give some feedback for some clinical problems. The bidirectional approach from clinical and basic research is important.