Right-left ventricular balance in implanted electrically powered artificial hearts.
An electrohydraulic total artificial heart (EHTAH), using an interatrial shunt (IAS) for right-left heart balance, was evaluated in acute, in vivo, open-chested calves. The EHTAH system demonstrated physiologic autoregulation with Starling-like responsiveness to preload. Output varied from 4 to 9 L/min, as right atrial pressure increased from 3 to 15 mmHg. Device output was minimally influenced by afterload. The efficacy of an IAS to balance the EHTAH was demonstrated over a wide range of preload and afterload conditions. Interatrial shunt flow rates, reflective of the degree of right-left imbalance, varied from 2% to 14% (IAS flow from left to right) of cardiac output. Left atrial pressures typically did not exceed right atrial pressures by more than 6-8 mmHg using an instrumented vascular graft such as the IAS. The simplicity and distinct anatomic, surgical, and engineering advantages of the IAS approach to right-left balance of implanted electrically powered artificial hearts justify further development toward a reliable long-term design.
Long
J W
JW
Artificial Heart Research Laboratory, University of Utah, Salt Lake City 84103.
Khanwilkar
P
P
Crump
K R
KR
Pantalos
G M
GM
Kinoshita
M
M
Kim
H C
HC
Olsen
D B
DB
D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D002417:Cattle; D011211:Electric Power Supplies; D004867:Equipment Design; D006354:Heart, Artificial; D006439:Hemodynamics / Q000502:physiology*