title: Effects of physical training on cardiovascular control after heart transplantation.
abstract: BACKGROUND
  Exercise performance in heart-transplanted patients increases with respect to pre-transplantation but remains subnormal, and it does not improve with time after surgery. Possible causes include persisting denervation, and sympathetic vasoconstriction inducing functional vascular abnormalities that prevent adequate increase in blood flow to the exercising limbs. We tested the effects of physical training on baroreceptors-mediated control of heart rate and blood pressure in recently heart-transplanted subjects.
  
  
  METHODS
  Patients were randomly allocated to physical training (n=13, 30 min cycling at 60-70% of peak oxygen consumption for 5 days/week for 6 months) or to control (n=11). Upright exercise test to exhaustion was performed at the beginning of the study after 3 and 6 months. Reflex changes in RR interval and blood pressure in response to sinusoidal neck suction (6 and 12 cycles/min 0 to -30 mm Hg swing) were considered as evidence of reinnervation and baroreflex control of blood pressure, respectively.
  
  
  RESULTS
  After 6 months peak oxygen consumption (p<0.001), exercise time (p<0.01) and workload (p<0.01) increased in trained patients. Before training RR interval and blood pressure were not modified by neck suction. After physical training systolic (p<0.01) and diastolic blood pressure decreased, RR interval and blood pressure could be modulated (p<0.05) by slow (6 cycles/min) neck suction, indicating initial cardiac sympathetic reinnervation and restored sensitivity to autonomic modulation on the arteries. No changes were observed in controls.
  
  
  CONCLUSIONS
  Physical training improved exercise performance and the control exerted by the autonomic nervous system through the sympathetic nerves at both cardiac and vascular level.
authors.affiliation: Department of Internal Medicine, IRCCS Policlinico S Matteo, University of Pavia, Italy. lbern1ps@unipv.it <lbern1ps@unipv.it>
authors.forename: Luciano
authors.initials: L
authors.lastname: Bernardi
authors.forename: Alberto
authors.initials: A
authors.lastname: Radaelli
authors.forename: Claudio
authors.initials: C
authors.lastname: Passino
authors.forename: Colomba
authors.initials: C
authors.lastname: Falcone
authors.forename: Carla
authors.initials: C
authors.lastname: Auguadro
authors.forename: Luigi
authors.initials: L
authors.lastname: Martinelli
authors.forename: Mauro
authors.initials: M
authors.lastname: Rinaldi
authors.forename: Mario
authors.initials: M
authors.lastname: Viganò
authors.forename: Giorgio
authors.initials: G
authors.lastname: Finardi
mesh_terms: D000328:Adult; D001795:Blood Pressure Determination; D015444:Exercise / Q000502:physiology*; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000502:physiology; D016027:Heart Transplantation / Q000379:methods* / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D010807:Physical Endurance / Q000502:physiology*; D011182:Postoperative Care; D011311:Pressoreceptors / Q000502:physiology; D011659:Pulmonary Gas Exchange; D012016:Reference Values; D012307:Risk Factors; D016896:Treatment Outcome