PMID- 25059240
OWN - NLM
STAT- MEDLINE
DCOM- 20150526
LR  - 20211021
IS  - 1522-1601 (Electronic)
IS  - 8750-7587 (Print)
IS  - 0161-7567 (Linking)
VI  - 117
IP  - 6
DP  - 2014 Sep 15
TI  - Acute volume loading and exercise capacity in postural tachycardia syndrome.
PG  - 663-8
LID - 10.1152/japplphysiol.00367.2014 [doi]
AB  - Postural tachycardia syndrome (POTS) is associated with exercise intolerance, 
      hypovolemia, and cardiac atrophy, which may contribute to reduced stroke volume 
      and compensatory exaggerated heart rate (HR) increases. Acute volume loading with 
      intravenous (iv) saline reduces HR and improves orthostatic tolerance and 
      symptoms in POTS, but its effect on exercise capacity is unknown. In this study, 
      we determined the effect of iv saline infusion on peak exercise capacity 
      (VO2peak) in POTS. Nineteen patients with POTS participated in a sequential 
      study. VO2peak was measured on two separate study days, following administration 
      of placebo or 1 liter of i.v. saline (NaCl 0.9%). Patients exercised on a 
      semirecumbent bicycle with resistance increased by 25 W every 2 min until maximal 
      effort was achieved. Patients exhibited blood volume deficits (-13.4 +/- 1.4% ideal 
      volume), consistent with mild to moderate hypovolemia. At baseline, saline 
      significantly increased stroke volume (saline 80 +/- 8 ml vs. placebo 64 +/- 4 ml; P 
      = 0.010), increased cardiac output (saline 6.9 +/- 0.5 liter/min vs. placebo 5.7 +/- 
      0.2 liter/min; P = 0.021), and reduced systemic vascular resistance (saline 992.6 
      +/- 70.0 dyn-s/cm(5) vs. placebo 1,184.0 +/- 50.8 dyn-s/cm(5); P = 0.011), with no 
      effect on HR or blood pressure. During exercise, saline did not produce 
      differences in VO2peak (saline 26.3 +/- 1.2 mg.kg(-1).min(-1) vs. placebo 27.7 +/- 
      1.8 mg.kg(-1).min(-1); P = 0.615), peak HR [saline 174 +/- 4 beats per minute (bpm) 
      vs. placebo 175 +/- 3 bpm; P = 0.672] or other cardiovascular parameters. These 
      findings suggest that acute volume loading with saline does not improve VO2peak 
      or cardiovascular responses to exercise in POTS, despite improvements in resting 
      hemodynamic function.
CI  - Copyright (c) 2014 the American Physiological Society.
FAU - Figueroa, Rocio A
AU  - Figueroa RA
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Arnold, Amy C
AU  - Arnold AC
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Nwazue, Victor C
AU  - Nwazue VC
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Okamoto, Luis E
AU  - Okamoto LE
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Paranjape, Sachin Y
AU  - Paranjape SY
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Black, Bonnie K
AU  - Black BK
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Diedrich, Andre
AU  - Diedrich A
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and.
FAU - Robertson, David
AU  - Robertson D
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and Autonomic Dysfunction 
      Center, Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt 
      University, Nashville, Tennessee.
FAU - Biaggioni, Italo
AU  - Biaggioni I
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and Autonomic Dysfunction 
      Center, Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt 
      University, Nashville, Tennessee.
FAU - Raj, Satish R
AU  - Raj SR
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and Autonomic Dysfunction 
      Center, Division of Clinical Pharmacology, Department of Pharmacology, Vanderbilt 
      University, Nashville, Tennessee.
FAU - Gamboa, Alfredo
AU  - Gamboa A
AD  - Autonomic Dysfunction Center, Division of Clinical Pharmacology, Department of 
      Medicine, Vanderbilt University, Nashville, Tennessee; and 
      alfredo.gamboa@Vanderbilt.edu.
LA  - eng
GR  - K23 HL095905/HL/NHLBI NIH HHS/United States
GR  - U54 RR-032646/RR/NCRR NIH HHS/United States
GR  - K23 HL-95905/HL/NHLBI NIH HHS/United States
GR  - T32 GM007569/GM/NIGMS NIH HHS/United States
GR  - P01 HL-056693/HL/NHLBI NIH HHS/United States
GR  - 5U54 NS-065736/NS/NINDS NIH HHS/United States
GR  - P01 HL056693/HL/NHLBI NIH HHS/United States
GR  - UL1 TR-000445/TR/NCATS NIH HHS/United States
GR  - R01 HL-102387/HL/NHLBI NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
DEP - 20140724
PL  - United States
TA  - J Appl Physiol (1985)
JT  - Journal of applied physiology (Bethesda, Md. : 1985)
JID - 8502536
RN  - 0 (Isotonic Solutions)
SB  - IM
MH  - Adolescent
MH  - Adult
MH  - Aged
MH  - Anaerobic Threshold/drug effects
MH  - Blood Pressure
MH  - Blood Volume/*drug effects
MH  - *Exercise
MH  - Exercise Test
MH  - *Exercise Tolerance
MH  - Female
MH  - Humans
MH  - Infusions, Intravenous
MH  - Isotonic Solutions
MH  - Male
MH  - Middle Aged
MH  - Oxygen Consumption
MH  - Postural Orthostatic Tachycardia Syndrome/*physiopathology
MH  - Young Adult
PMC - PMC4157162
OTO - NOTNLM
OT  - POTS
OT  - autonomic diseases
OT  - deconditioning
EDAT- 2014/07/26 06:00
MHDA- 2015/05/27 06:00
PMCR- 2015/09/15
CRDT- 2014/07/26 06:00
PHST- 2014/07/26 06:00 [entrez]
PHST- 2014/07/26 06:00 [pubmed]
PHST- 2015/05/27 06:00 [medline]
PHST- 2015/09/15 00:00 [pmc-release]
AID - japplphysiol.00367.2014 [pii]
AID - JAPPL-00367-2014 [pii]
AID - 10.1152/japplphysiol.00367.2014 [doi]
PST - ppublish
SO  - J Appl Physiol (1985). 2014 Sep 15;117(6):663-8. doi: 
      10.1152/japplphysiol.00367.2014. Epub 2014 Jul 24.