title: Effect of alteration in pump speed on pump output and left ventricular filling with continuous-flow left ventricular assist device.
abstract: Third-generation continuous-flow left ventricular assist devices (LVAD) provide reduced pulsatility flow. We examined the safe working range for LVAD pump speed and the effect on pump output and cardiac function in 13 stable outpatients with VentrAssist-LVAD (Ventracor Ltd, Australia). Pump speed was decreased from a baseline mean of 2,073 ± 86 revolutions per minute (RPM, with corresponding mean flow of 5.59 ± 1.18 L/min, mean ± standard deviation) to an average low-speed of 1,835 ± 55 RPM (corresponding flow 4.68 ± 0.99 L/min) and up to high-speed of 2,315 ± 66 RPM (corresponding flow 6.30 ± 1.29 L/min). There was a strong linear relationship between alteration in speed and flow rates (r(2) = 0.89, p < 0.00001) but marked interpatient variation. Downward titration to preset minimum 1,800 RPM was achieved in 9/13 (69%) and upward titration to the preset maximum 2,400 RPM was achieved in 4/13 (31%). Upward titration was stopped due to ventricular suction or nonsustained ventricular tachycardia (VT) in 4/13 (31%). Ventricular suction or VT (in 4/13) tended to be more common in patients with poor right ventricular (RV) function (p = 0.07). In summary, pump flow is stable within a relatively small speed range and should not be altered without close monitoring due to variation in response between patients, particularly with concomitant RV impairment.
authors: Heart Failure and Transplant Unit, St. Vincent's Hospital, Sydney, New South Wales, Australia. cshayward@stvincents.com.au
authors: Christopher S
authors: CS
authors: Hayward
authors: Robert
authors: R
authors: Salamonsen
authors: Anne M
authors: AM
authors: Keogh
authors: John
authors: J
authors: Woodard
authors: Peter
authors: P
authors: Ayre
authors: Roslyn
authors: R
authors: Prichard
authors: Robyn
authors: R
authors: Walker
authors: Eugene
authors: E
authors: Kotlyar
authors: Peter S
authors: PS
authors: Macdonald
authors: Paul
authors: P
authors: Jansz
authors: Phillip
authors: P
authors: Spratt
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003326:Coronary Circulation / Q000502:physiology*; D005260:Female; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011673:Pulsatile Flow; D016277:Ventricular Function, Left / Q000502:physiology*; D055815:Young Adult