Related Experiment Video
Updated: Mar 31, 2026
Increasing Pulmonary Artery Pulsatile Flow Improves Hypoxic Pulmonary Hypertension in Piglets
Published on: May 11, 2015
Restoration of Pulsatile Flow Reduces Sympathetic Nerve Activity Among Individuals With Continuous-Flow Left
William K Cornwell1, Takashi Tarumi1, Abigail Stickford1
1From Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas (W.K.C., T.T., A.S., J.L., M.R., R.P., Q.F., B.D.L.); Division of Cardiology, Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas (W.K.C., C.F., J.K., C.A., M.H.D., B.D.L.); and Division of Cardiology, Department of Medicine, Emory University, Atlanta, GA (D.M.).
Background:
Current-generation left ventricular assist devices provide circulatory support that is minimally or entirely nonpulsatile and are associated with marked increases in muscle sympathetic nerve activity (MSNA), likely through a baroreceptor-mediated pathway. We sought to determine whether the restoration of pulsatile flow through modulations in pump speed would reduce MSNA through the arterial baroreceptor reflex.
Methods And Results:
Ten men and 3 women (54 ± 14 years) with Heartmate II continuous-flow left ventricular assist devices underwent hemodynamic and sympathetic neural assessment. Beat-to-beat blood pressure, carotid ultrasonography at the level of the arterial baroreceptors, and MSNA via microneurography were continuously recorded to determine steady-state responses to step changes (200-400 revolutions per minute) in continuous-flow left ventricular assist device pump speed from a maximum of 10,480 ± 315 revolutions per minute to a minimum of 8500 ± 380 revolutions per minute. Reductions in pump speed led to increases in pulse pressure (high versus low speed: 17 ± 7 versus 26 ± 12 mm Hg; P<0.01), distension of the carotid artery, and carotid arterial wall tension (P<0.05 for all measures). In addition, MSNA was reduced (high versus low speed: 41 ± 15 versus 33 ± 16 bursts per minute; P<0.01) despite a reduction in mean arterial pressure and was inversely related to pulse pressure (P=0.037).
Conclusions:
Among subjects with continuous-flow left ventricular assist devices, the restoration of pulsatile flow through modulations in pump speed leads to increased distortion of the arterial baroreceptors with a subsequent decline in MSNA. Additional study is needed to determine whether reduction of MSNA in this setting leads to improved outcomes.
