Analysis of baroreflex sensitivity during undulation pump ventricular assist device support.
The aim of this study was to examine the baroreflex sensitivity (BRS), which involves the autonomic nervous system, in a goat with a chronically implanted undulation pump ventricular assist device (UPVAD). The UPVAD involved transforming the rotation of a brushless DC motor into an undulating motion by a disc attached via a special linking mechanism, and a jellyfish valve in the outflow cannula to prevent diastolic backflow. The pump was implanted into the thoracic cavity of a goat by a left thoracotomy, and the inflow and outflow cannulae were sutured to the apex of the left ventricle and to the descending aorta, respectively. The driving cable was wired percutaneously to an external controller. Electrocardiogram and hemodynamic waveforms were recorded at a sampling frequency of 1 kHz. BRS was determined when awake by the slope of the linear regression of R-R interval against mean arterial pressure changes, which were induced by the administration of methoxamine hydrochloride, both with continuous driving of the UPVAD as well as without assistance. BRS values during the UPVAD support and without assistance were 1.60 +/- 0.30 msec/mm Hg and 0.98 +/- 0.22 msec/mm Hg (n = 5, P < 0.05), respectively. BRS was significantly improved during left ventricular assistance. Therefore, UPVAD support might decrease sympathetic nerve activity and increase parasympathetic nerve activity to improve both microcirculation and organ function.
Liu
Hongjian
H
Department of Medical Engineering and Cardiology, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai, Japan. hongjianliu63@yahoo.co.jp
Shiraishi
Yasuyuki
Y
Zhang
Xiumin
X
Song
Hojin
H
Saijo
Yoshifumi
Y
Baba
Atsushi
A
Yambe
Tomoyuki
T
Abe
Yusuke
Y
Imachi
Kou
K
D000818:Animals; D017704:Baroreflex / Q000187:drug effects; D004562:Electrocardiography; D004867:Equipment Design; D006041:Goats; D006352:Heart Ventricles / Q000187:drug effects; D006353:Heart-Assist Devices; D018056:Hemorheology / Q000187:drug effects; D008297:Male; D008729:Methoxamine / Q000494:pharmacology / Q000627:therapeutic use; D019919:Prosthesis Implantation; D014662:Vasoconstrictor Agents / Q000494:pharmacology / Q000627:therapeutic use
D014662:Vasoconstrictor Agents; D008729:Methoxamine