Effect of counter-pulsation control of a pulsatile left ventricular assist device on working load variations of the native heart.
BACKGROUND
When using a pulsatile left ventricular assist device (LVAD), it is important to reduce the cardiac load variations of the native heart because severe cardiac load variations can induce ventricular arrhythmia. In this study, we investigated the effect of counter-pulsation control of the LVAD on the reduction of cardiac load variation.


METHODS
A ventricular electrocardiogram-based counter-pulsation control algorithm for a LVAD was implemented, and the effects of counter-pulsation control of the LVAD on the reduction of the working load variations of the left ventricle were determined in three animal experiments.


RESULTS
Deviations of the working load of the left ventricle were reduced by 51.3%, 67.9%, and 71.5% in each case, and the beat-to-beat variation rates in the working load were reduced by 84.8%, 82.7%, and 88.2% in each ease after counter-pulsation control. There were 3 to 12 premature ventricle contractions (PVCs) before counter-pulsation control, but no PVCs were observed during counter-pulsation control.


CONCLUSIONS
Counter-pulsation control of the pulsatile LVAD can reduce severe cardiac load variations, but the average working load is not markedly affected by application of counter-pulsation control because it is also influenced by temporary cardiac outflow variations. We believe that counter-pulsation control of the LVAD can improve the long-term safety of heart failure patients equipped with LVADs.
Seong Wook
SW
Choi
Department of Biomedical Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 133-791, Korea. kwnam@bme.hanyang.ac.kr.
Kyoung Won
KW
Nam
Ki Moo
KM
Lim
Eun Bo
EB
Shim
Yong Soon
YS
Won
Heung Myong
HM
Woo
Ho Hyun
HH
Kwak
Mi Ryoung
MR
Noh
In Young
IY
Kim
Sung Min
SM
Park
D000465:Algorithms; D000818:Animals; D001698:Biomedical Engineering / Q000379:methods*; D004562:Electrocardiography / Q000379:methods; D004867:Equipment Design; D006333:Heart Failure / Q000503:physiopathology*; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology*; D006353:Heart-Assist Devices; D006801:Humans; D008955:Models, Cardiovascular; D012815:Signal Processing, Computer-Assisted; D013552:Swine