title: A novel pediatric biventricular assist device: in vitro test results.
abstract: Most ventricular assist devices (VADs) currently used in infants are extracorporeal. These VADs require long-term anticoagulation therapy and extensive surgery, and two devices are needed for biventricular support. We designed a biventricular assist device based on shape memory alloy that reproduces the hemodynamic effects of cardiomyoplasty, supporting the heart with a compressing movement, and evaluated its performance in a dedicated mockup system. Nitinol fibers are the device's key component. Ejection fraction (EF), cardiac output (CO), and generated systolic pressure were measured on a test bench. Our test bench settings were a preload range of 0-15 mm Hg, an afterload range of 0-160 mm Hg, and a heart rate (HR) of 20, 30, 40, and 60 beats/min. A power supply of 15 volts and 3.5 amperes was necessary. The EF range went from 34.4% to 1.2% as the afterload and HR increased, along with a CO from 180 to 6 ml/min. The device generated a maximal systolic pressure of 25 mm Hg. Cardiac compression for biventricular assistance in child-sized heart using shape memory alloy is technically feasible. Further testing remains necessary to assess this VAD's in vivo performance range and its reliability.
authors.affiliation: From the Department of Cardiovascular Surgery, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland.
authors.forename: Stéphanie F
authors.initials: SF
authors.lastname: Perrodin
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Tozzi
mesh_terms: D000497:Alloys; D000925:Anticoagulants / Q000737:chemistry; D001794:Blood Pressure; D002302:Cardiac Output; D006321:Heart / Q000502:physiology; D006339:Heart Rate; D006353:Heart-Assist Devices; D006439:Hemodynamics; D006801:Humans; D007223:Infant; D011474:Prosthesis Design; D015203:Reproducibility of Results; D013599:Systole; D013997:Time Factors
chemical_list: D000497:Alloys; D000925:Anticoagulants