title: Sympathetic ganglion transcutaneous electrical nerve stimulation after coronary artery bypass graft surgery improves femoral blood flow and exercise tolerance.
abstract: We tested the hypothesis that transcutaneous electrical nerve stimulation (TENS) over the stellate ganglion region would reduce sympathetic overstimulation and improve femoral blood flow (FBF) after coronary artery bypass graft surgery. Thirty-eight patients (20 men, 24 New York Heart Association class III-IV) were randomized to 5-day postoperative TENS (n = 20; 4 times/day; 30 min/session) or sham TENS (n = 18) applied to the posterior cervical region (C7-T4). Sympathetic nervous system was stimulated by the cold pressor test, with FBF being measured by ultrasound Doppler. Femoral vascular conductance (FVC) was calculated as FBF/mean arterial pressure (MAP). Six-min walking distance established patients' functional capacity. Before and after the intervention periods, pain scores, opiate requirements, and circulating β-endorphin levels were determined. As expected, preoperative MAP increased and FBF and FVC decreased during the cold pressor test. Sham TENS had no significant effect on these variables (P > 0.05). In contrast, MAP decreased in the TENS group (125 ± 12 vs. 112 ± 10 mmHg). This finding, in association with a consistent increase in FBF (95 ± 5 vs. 145 ± 14 ml/min), led to significant improvements in FVC (P < 0.01). Moreover, 6-min walking distance improved only with TENS (postsurgery-presurgery = 35 ± 12 vs. 6 ± 10 m; P < 0.01). TENS was associated with lesser postoperative pain and opiate requirements but greater circulating β-endorphin levels (P < 0.05). In conclusion, stellate ganglion TENS after coronary artery bypass graft surgery positively impacted on limb blood flow during a sympathetic stimulation maneuver, a beneficial effect associated with improved clinical and functional outcomes.
authors.affiliation: Physical Therapy Department, University of Brasilia, Brasilia, Brazil;
authors.forename: Gerson
authors.initials: G
authors.lastname: Cipriano
authors.affiliation: Laboratory of Clinical Exercise Physiology, Division of Respiratory and Critical Care Medicine, Kingston General Hospital, Queen's University, Kingston, Ontario, Canada;
authors.forename: J Alberto
authors.initials: JA
authors.lastname: Neder
authors.affiliation: Exercise Pathophysiology Research Laboratory and Cardiology Division, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil;
authors.forename: Daniel
authors.initials: D
authors.lastname: Umpierre
authors.affiliation: Department of Physical Therapy, College of Applied Health Sciences, University of Illinois Chicago, Chicago, Illinois;
authors.forename: Ross
authors.initials: R
authors.lastname: Arena
authors.affiliation: Exercise Pathophysiology Research Laboratory and Cardiology Division, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil;
authors.forename: Paulo J C
authors.initials: PJ
authors.lastname: Vieira
authors.affiliation: Intensive Care Unit, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil; and.
authors.forename: Adriana M Güntzel
authors.initials: AM
authors.lastname: Chiappa
authors.affiliation: Exercise Pathophysiology Research Laboratory and Cardiology Division, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil;
authors.forename: Jorge P
authors.initials: JP
authors.lastname: Ribeiro
authors.affiliation: Exercise Pathophysiology Research Laboratory and Cardiology Division, Hospital de Clinicas de Porto Alegre, Porto Alegre, Brazil; Public Health Research Group, Division of Physical Therapy, Serra Gaucha College, Caxias do Sul, Brazil gaspar.chiappa@gmail.com.
authors.forename: Gaspar R
authors.initials: GR
authors.lastname: Chiappa
mesh_terms: D000368:Aged; D003080:Cold Temperature; D001026:Coronary Artery Bypass; D003324:Coronary Artery Disease / Q000503:physiopathology / Q000601:surgery; D017079:Exercise Tolerance; D005260:Female; D005263:Femoral Artery; D005728:Ganglia, Sympathetic; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D004561:Transcutaneous Electric Nerve Stimulation; D016896:Treatment Outcome; D014661:Vasoconstriction; D016138:Walking / Q000502:physiology
keywords: TENS; blood flow; exercise; exercise capacity; sympathetic nervous system