Document Detail


Parasympathetic effects on cardiac electrophysiology during exercise and recovery in patients with left ventricular dysfunction.
MedLine Citation:
PMID:  19525382     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Depressed parasympathetic activity has been proposed to be associated with an increased risk of sudden death. Parasympathetic effects (PE) on cardiac electrophysiology during exercise and recovery have not been studied in patients with left ventricular dysfunction. We performed noninvasive electrophysiological studies (NI-EPS) and characterized the electrophysiological properties of the sinus node, atrioventricular (AV) node, and ventricle in subjects with depressed left ventricular ejection fraction and dual-chamber defibrillators. NI-EPS were performed during rest, exercise, and recovery at baseline and after parasympathetic blockade with atropine to assess PE (the difference between parameter values in the 2 conditions). Ten subjects (9 men: age, 60 +/- 9 yr; and left ventricular ejection fraction, 29 +/- 8%) completed the study. All NI-EPS parameters decreased during exercise and trended toward rest values during recovery. PE at rest, during exercise, and during recovery, respectively, were on sinus cycle length, 320 +/- 71 (P = 0.0001), 105 +/- 60 (P = 0.0003), and 155 +/- 82 ms (P = 0.0002); on AV block cycle length, 137 +/- 136 (P = 0.09), 37 +/- 19 (P = 0.002), and 61 +/- 39 ms (P = 0.006); on AV interval, 58 +/- 32 (P = 0.035), 22 +/- 13 (P = 0.002), and 36 +/- 20 ms (P = 0.001); on ventricular effective refractory period, 15.8 +/- 11.3 (P = 0.02), 4.7 +/- 15.2 (P = 0.38), and 6.8 +/- 15.5 ms (P = 0.20); and on QT interval, 13 +/- 12 (P = 0.13), 3 +/- 17 (P = 0.6), and 20 +/- 23 (P = 0.04). In conclusion, we describe for the first time the changes in cardiac electrophysiology and PE during rest, exercise, and recovery in subjects with left ventricular dysfunction. PEs are preserved in these patients. Thus the role of autonomic changes in the pathophysiology of sudden death requires further exploration.
Authors:
Alexandru B Chicos; Prince J Kannankeril; Alan H Kadish; Jeffrey J Goldberger
Publication Detail:
Type:  Clinical Trial; Journal Article; Research Support, N.I.H., Extramural     Date:  2009-06-12
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  297     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2009 Aug 
Date Detail:
Created Date:  2009-07-28     Completed Date:  2009-09-01     Revised Date:  2010-09-27    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H743-9     Citation Subset:  IM    
Affiliation:
Division of Cardiology, Bluhm Cardiovascular Center, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
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MeSH Terms
Descriptor/Qualifier:
Aged
Atrioventricular Block / diagnosis,  drug therapy,  physiopathology
Atrioventricular Node / drug effects,  innervation,  physiology
Atropine / administration & dosage*
Blood Pressure / physiology
Defibrillators, Implantable
Electrocardiography
Exercise / physiology*
Female
Heart Failure / physiopathology
Heart Rate / physiology
Heart Ventricles / innervation
Humans
Male
Middle Aged
Parasympathetic Nervous System / drug effects*,  physiology*
Parasympatholytics / administration & dosage*
Rest / physiology
Sinoatrial Node / drug effects,  innervation,  physiology
Stroke Volume / physiology
Ventricular Dysfunction, Left / physiopathology*
Grant Support
ID/Acronym/Agency:
1-RO1-HL-70179-01A2/HL/NHLBI NIH HHS; M01-RR-00048/RR/NCRR NIH HHS
Chemical
Reg. No./Substance:
0/Parasympatholytics; 51-55-8/Atropine
Comments/Corrections

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