title: Effect of continuous and pulsatile flow left ventricular assist on pulsatility in a pediatric animal model of left ventricular dysfunction: pilot observations.
abstract: Pediatric ventricular assist devices are being developed that can produce pulsatile flow (PF) or continuous flow (CF). An important aspect of choosing between these two modes is understanding the consequences of each mode on pediatric vascular pulsatility. Differences in vascular pulsatility generated by PF and CF operation of the 3-inch pediatric cardiopulmonary assist system (pCAS, Ension, Inc., Pittsburgh, PA) were investigated while providing left atrium-to-aorta left ventricular assist (LVA), using an infant animal model of left ventricular dysfunction. Hemodynamic data were digitally recorded with the pCAS providing LVA at incremental flow rates while operating in continuous mode, pulsatile mode at 100 bpm, and pulsatile mode at 140 bpm. These data were used to calculate vascular input impedance (Zart), energy equivalent pressure, and surplus hemodynamic energy as indices of pulsatility for partial (50% of maximum) and maximum LVA flow. Both CF and PF LVA by the pCAS resulted in favorable hemodynamic rectification of left ventricular dysfunction while generating equivalent flows. PF LVA maintained a greater degree of pulsatility compared with CF, as evidenced by increasing energy equivalent pressure and a lesser drop in surplus hemodynamic energy with increasing pCAS flow. Differences in Zart modulus and phase were indiscernible. The selection of flow mode may have long-term consequences on Zart and end-organ perfusion affecting clinical outcomes in pediatric patients.
authors.affiliation: Division of Cardiothoracic Surgery, Department of Bioengineering, Cardiovascular Innovation Institute, University of Louisville, Louisville, Kentucky 40202, USA.
authors.forename: George M
authors.initials: GM
authors.lastname: Pantalos
authors.forename: Guruprasad
authors.initials: G
authors.lastname: Giridharan
authors.forename: Jeff
authors.initials: J
authors.lastname: Colyer
authors.forename: Michael
authors.initials: M
authors.lastname: Mitchell
authors.forename: Jeff
authors.initials: J
authors.lastname: Speakman
authors.forename: Chris
authors.initials: C
authors.lastname: Lucci
authors.forename: Greg
authors.initials: G
authors.lastname: Johnson
authors.forename: Mark
authors.initials: M
authors.lastname: Gartner
authors.forename: Steven C
authors.initials: SC
authors.lastname: Koenig
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic; D015924:Blood Pressure Monitors; D004195:Disease Models, Animal; D006325:Heart Atria; D006353:Heart-Assist Devices; D006801:Humans; D007223:Infant; D008955:Models, Cardiovascular; D010865:Pilot Projects; D011673:Pulsatile Flow; D013552:Swine; D014159:Transducers; D014655:Vascular Resistance; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology* / Q000601:surgery*