title: Effects of Thoratec pulsatile ventricular assist device timing on the abdominal aortic wave intensity pattern.
abstract: Arterial waves are seen as possible independent mediators of cardiovascular risks, and the wave intensity analysis (WIA) has therefore been proposed as a method for patient selection for ventricular assist device (VAD) implantation. Interpreting measured wave intensity (WI) is challenging, and complexity is increased by the implantation of a VAD. The waves generated by the VAD interact with the waves generated by the native heart, and this interaction varies with changing VAD settings. Eight sheep were implanted with a pulsatile VAD (PVAD) through ventriculoaortic cannulation. The start of PVAD ejection was synchronized to the native R wave and delayed between 0 and 90% of the cardiac cycle in 10% steps or phase shifts (PS). Pressure and velocity signals were registered, with the use of a combined Doppler and pressure wire positioned in the abdominal aorta, and used to calculate the WI. Depending on the PS, different wave interference phenomena occurred. Maximum unloading of the left ventricle (LV) coincided with constructive interference and maximum blood flow pulsatility, and maximum loading of the LV coincided with destructive interference and minimum blood flow pulsatility. We believe that noninvasive WIA could potentially be used clinically to assess the mechanical load of the LV and to monitor the peripheral hemodynamics such as blood flow pulsatility and risk of intestinal bleeding.
authors.affiliation: Institute for Dynamic Systems and Control, ETH Zurich, Zurich, Switzerland; esilje@gmail.com.
authors.forename: Silje Ekroll
authors.initials: SE
authors.lastname: Jahren
authors.affiliation: Institute for Dynamic Systems and Control, ETH Zurich, Zurich, Switzerland;
authors.forename: Raffael
authors.initials: R
authors.lastname: Amacher
authors.affiliation: Department of Cardiology, University Hospital Bern, Bern, Switzerland;
authors.forename: Alberto
authors.initials: A
authors.lastname: Weber
authors.affiliation: Department of Cardiology, University Hospital Bern, Bern, Switzerland;
authors.forename: Henriette
authors.initials: H
authors.lastname: Most
authors.affiliation: Department of Clinical Veterinary Medicine, University of Bern, Bern, Switzerland; and.
authors.forename: Shannon Axiak
authors.initials: SA
authors.lastname: Flammer
authors.affiliation: Department of Cardiology, University Hospital Bern, Bern, Switzerland;
authors.forename: Tobias
authors.initials: T
authors.lastname: Traupe
authors.affiliation: Department of Cardiology, University Hospital Bern, Bern, Switzerland;
authors.forename: Michael
authors.initials: M
authors.lastname: Stoller
authors.affiliation: Department of Cardiology, University Hospital Bern, Bern, Switzerland;
authors.forename: Stefano
authors.initials: S
authors.lastname: de Marchi
authors.affiliation: Institute for Dynamic Systems and Control, ETH Zurich, Zurich, Switzerland; ARTORG Center for Biomedical Research, University of Bern, Bern, Switzerland.
authors.forename: Stijn
authors.initials: S
authors.lastname: Vandenberghe
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000502:physiology*; D006348:Cardiac Surgical Procedures / Q000295:instrumentation / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000601:surgery*; D006353:Heart-Assist Devices; D006439:Hemodynamics; D012756:Sheep; D025321:Surgery, Computer-Assisted / Q000379:methods; D014463:Ultrasonography; D016276:Ventricular Function
keywords: arterial wave interference; heart-ventricular assist device interaction; pulsatility; ventricular assist device; wave intensity analysis