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.
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.
Authors: Cullen Buchanan; Manreet Kanwar; John R Cockcroft; Barry McDonnell; Eric J Stöhr; William K Cornwell Journal: Exp Physiol Date: 2020-03-18 Impact factor: 2.969
Authors: Matthieu Gautier; Lois Mahe; Jan Elaine Soriano; Andreas Rowald; Jordan W Squair; Arnaud Bichat; Newton Cho; Mark A Anderson; Nicholas D James; Jerome Gandar; Anthony V Incognito; Giuseppe Schiavone; Zoe K Sarafis; Achilleas Laskaratos; Kay Bartholdi; Robin Demesmaeker; Salif Komi; Charlotte Moerman; Bita Vaseghi; Berkeley Scott; Ryan Rosentreter; Claudia Kathe; Jimmy Ravier; Laura McCracken; Xiaoyang Kang; Nicolas Vachicouras; Florian Fallegger; Ileana Jelescu; YunLong Cheng; Qin Li; Rik Buschman; Nicolas Buse; Tim Denison; Sean Dukelow; Rebecca Charbonneau; Ian Rigby; Steven K Boyd; Philip J Millar; Eduardo Martin Moraud; Marco Capogrosso; Fabien B Wagner; Quentin Barraud; Erwan Bezard; Stéphanie P Lacour; Jocelyne Bloch; Grégoire Courtine; Aaron A Phillips Journal: Nature Date: 2021-01-27 Impact factor: 49.962
Authors: Suneet N Purohit; William K Cornwell; Jay D Pal; JoAnn Lindenfeld; Amrut V Ambardekar Journal: Circ Heart Fail Date: 2018-06 Impact factor: 8.790