An artificial myocardium assist system: electrohydraulic ventricular actuation improves myocardial tissue perfusion in goats.
Artificial hearts and ventricular assist devices have been widely used clinically to assist patients with severe heart failure. Unfortunately, direct contact between the device and the patient's blood leads to thromboembolic events, and then the need for anticoagulation and infections contribute significantly to complication and mortality. Compressing the dysfunctional heart from its epicardial surface, a nonblood-contacting method of direct mechanical ventricular actuation could provide ventricular support, pulsatile blood flow, and avoid interactions between blood and the surface of the artificial assistance system. An ElectroHydraulic Artificial Myocardial (EHAM) assist system that might assist heart muscle contraction has been developed. The purpose of this study is to determine the efficiency of the EHAM system in perfusing myocardial tissue in an acute animal experiment.


METHODS
Healthy adult goats (n = 8) were used in acute animal experiments. A left lateral thoracotomy was done and the chest was opened through the 4th and 5th rib resection. Hemodynamic parameters were continuously monitored including ECG, aortic blood pressure, left ventricular pressure, and pulmonary artery pressure. Myocardial tissue perfusion was measured by using an Omega flow laser fiber attached on the surface of the heart.


RESULTS
All the animals achieved significantly increased blood pressure, pulmonary artery flow, and myocardial tissue perfusion during the EHAM compression compared with the nondriving (pre-assisted) mode.


CONCLUSIONS
The EHAM system can effectively improve myocardial tissue perfusion and increase blood pressure thus demonstrating a potential for treating failing cardiac performance.
Department of Medical Engineering and Cardiology, Institute of Development, Aging and Cancer, Tohoku University, Aoba-ku, Sendai-shi, Japan. qingtian@idac.tohoku.ac.jp
Qingtian
Q
Wang
Tomoyuki
T
Yambe
Yasuyuki
Y
Shiraishi
Xudong
X
Duan
Shinichi
S
Nitta
Kouichi
K
Tabayashi
Mitsuo
M
Umezu
D000818:Animals; D004867:Equipment Design; D006041:Goats; D006353:Heart-Assist Devices; D009200:Myocardial Contraction; D015425:Myocardial Reperfusion / Q000295:instrumentation*; D016276:Ventricular Function / Q000502:physiology