Determination of atrial shunt size needed to balance an electrohydraulic total artificial heart.
An interatrial shunt (IAS) was developed and tested to balance a volumetrically coupled electrohydraulic total artificial heart (EHTAH). The IAS diameter was determined theoretically with the equation: [formula: see text] where D = orifice diameter, delta P = pressure drop across the orifice, rho = fluid density, Q = volume flow through the orifice, and C = empiric constant. The calculated orifice diameter was 2.9-5.3 mm to keep a 3-5 mmHg pressure difference between left and right atria, with 0.42-1.05 L/min of expected flow through the IAS. Three different sizes (3.4, 5.4, and 5.5 mm) of IAS were implanted and tested in four calves. The in vivo left-right pressure difference ranged from 3 to 8 mmHg, with 0.57-1.38 L/min of theoretically calculated flow through the IAS. At autopsy, none of the IAS showed macroscopic thrombus formation.
Kinoshita
M
M
Artificial Heart Research Laboratory, University of Utah, Salt Lake City 84103-1414.
Hansen
C A
CA
Khanwilkar
P S
PS
White
K R
KR
Olsen
D B
DB
D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D002417:Cattle; D006325:Heart Atria / Q000503:physiopathology*; D006344:Heart Septal Defects, Atrial / Q000503:physiopathology*; D006354:Heart, Artificial; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008955:Models, Cardiovascular