Document Detail

Relation of systemic venous return, pulmonary vascular resistance, and diastolic dysfunction to exercise capacity in patients with single ventricle receiving fontan palliation.
MedLine Citation:
PMID:  20381672     Owner:  NLM     Status:  MEDLINE    
Fontan patients have a reduced exercise capacity, primarily owing to limitations in the ability to augment pulmonary blood flow and stroke volume. To date, the mechanism of peak exercise pulmonary blood flow restriction has not been elucidated. We performed a single-center, prospective, crossover trial of supine and upright exercise in Fontan patients and healthy controls to determine the mechanisms of exercise limitation in the Fontan-palliated patient. A total of 29 Fontan patients and 16 control subjects completed the protocol. The duration of exercise, percentage of predicted peak oxygen consumption (VO(2)) and peak work were reduced in the Fontan group, regardless of posture (p < or = 0.03). The percentage of predicted oxygen pulse, a surrogate for pulmonary stroke volume, was not increased with supine posture in the Fontan cohort (upright, 82.3 + or - 18.8% vs supine, 82.4 + or - 19.7%; p = 0.6). In both groups, the percentage of predicted peak VO(2) was lower with supine exercise than with upright exercise (p < or =0.002). Diastolic dysfunction was present in 57% of the Fontan patients and was associated with a reduced percentage of predicted peak VO(2) (p = 0.04) and supine peak work (p = 0.008). Six Fontan patients who underwent supine exercise with indwelling catheters failed to demonstrate the expected decrease in pulmonary vascular resistance characteristically seen with peak exercise (at rest, 2.8 + or - 0.7 mm Hg/L/min/m(2) vs at peak, 2.8 + or - 0.9 mm Hg/L/min/m(2); p = 0.9). In conclusion, supine exercise in Fontan patients does not result in an increased VO(2) or oxygen pulse, suggesting that inadequate venous return might not be the primary limitation of exercise capacity in this population. Diastolic dysfunction and relatively excessive peak exercise pulmonary vascular resistance might be more important factors in Fontan exercise limitation.
Bryan H Goldstein; Chad E Connor; Lindsay Gooding; Albert P Rocchini
Publication Detail:
Type:  Comparative Study; Journal Article; Randomized Controlled Trial     Date:  2010-02-20
Journal Detail:
Title:  The American journal of cardiology     Volume:  105     ISSN:  1879-1913     ISO Abbreviation:  Am. J. Cardiol.     Publication Date:  2010 Apr 
Date Detail:
Created Date:  2010-04-12     Completed Date:  2010-06-15     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0207277     Medline TA:  Am J Cardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1169-75     Citation Subset:  AIM; IM    
Copyright Information:
Copyright 2010 Elsevier Inc. All rights reserved.
Division of Cardiology, C. S. Mott Children's Hospital, University of Michigan Health System, Ann Arbor, Michigan, USA.
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MeSH Terms
Cross-Over Studies
Echocardiography, Doppler
Exercise Test
Exercise Tolerance / physiology*
Follow-Up Studies
Fontan Procedure*
Heart Defects, Congenital / complications,  physiopathology*,  surgery
Heart Ventricles / abnormalities*
Myocardial Contraction / physiology
Oxygen Consumption
Preoperative Period
Prospective Studies
Risk Factors
Stroke Volume / physiology
Time Factors
Vascular Resistance / physiology*
Venous Pressure / physiology*
Ventricular Dysfunction, Left / etiology,  physiopathology*
Young Adult

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