title: In vitro and in vivo evaluation of a left-right balancing capacity of an interatrial shunt in an electrohydraulic total artificial heart system.
abstract: The authors evaluated the basic performance of an interatrial shunt (IAS) made by punching a hole in the atrial septum, in accommodating the left-right imbalance in our electrohydraulic total artificial heart (EHTAH) system. In an in vitro study conducted in a closed mock circuit connected with the EHTAH, the interatrial pressure gradient changed in compliance with the amount of bronchial flow and the size of the IAS. The IAS of 4.4 mm diameter or larger maintained the interatrial pressure gradient within physiologically permissible limits when the amount of bronchial flow was 5% of cardiac output or less. A left-to-right one-way valve made of a piece of pericardium, a possible option in this IAS method, successfully prevented right-to-left reverse shunt flow through the IAS. In a chronic in vivo study using a calf implanted with the EHTAH for 10 days, a 4.5 mm IAS without the one-way valve demonstrated satisfactory dynamic left-right balancing capacity with a stable interatrial pressure gradient of 4 +/- 1 mmHg over a wide range of atrial pressures. No thrombus was found in or around the IAS at autopsy. The authors conclude that the IAS is a simple and promising means of left-right balancing in the EHTAH system.
authors.affiliation: Department of Artificial Organs, National Cardiovascular Center Research Institute, Osaka, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Tatsumi
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: T
authors.initials: T
authors.lastname: Masuzawa
authors.forename: Y
authors.initials: Y
authors.lastname: Taenaka
authors.forename: Y S
authors.initials: YS
authors.lastname: Sohn
authors.forename: T
authors.initials: T
authors.lastname: Nishimura
authors.forename: M
authors.initials: M
authors.lastname: Nakata
authors.forename: T
authors.initials: T
authors.lastname: Nakatani
authors.forename: T
authors.initials: T
authors.lastname: Ohno
authors.forename: S
authors.initials: S
authors.lastname: Endo
authors.forename: K
authors.initials: K
authors.lastname: Takiura
authors.forename: Y
authors.initials: Y
authors.lastname: Takewa
authors.forename: Y
authors.initials: Y
authors.lastname: Kakuta
authors.forename: H
authors.initials: H
authors.lastname: Takano
mesh_terms: D000818:Animals; D016275:Atrial Function; D001698:Biomedical Engineering; D001783:Blood Flow Velocity; D001794:Blood Pressure; D002417:Cattle; D005069:Evaluation Studies as Topic; D005260:Female; D006354:Heart, Artificial; D006439:Hemodynamics; D006801:Humans; D066298:In Vitro Techniques; D011474:Prosthesis Design