Document Detail

Echocardiographic study of the optimal atrioventricular delay at rest and during exercise in recipients of cardiac resynchronization therapy systems.
MedLine Citation:
PMID:  19560086     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: It is unclear whether, in recipients of cardiac resynchronization therapy (CRT) systems, the optimal AV delay should be the same, shorter, or longer during exercise than at rest. OBJECTIVE: This study sought to examine the effects of atrioventricular (AV) delay optimization at rest and during exercise in 50 recipients of CRT systems. METHODS: We measured left ventricular (LV) outflow tract velocity time integral (OT-VTI) and LV filling time (FT) echocardiographically, at rest and during exercise to 60% of the maximal predicted heart rate, with the sensed AV delay set at 40, 70, 100, 120, 150, and 200 ms. The measurements made at rest versus those made during exercise, and among the several programmed AV delays, were compared. RESULTS: The optimal AV delay based on LVOT-VTI was shorter during exercise than at rest in 37%, unchanged in 37%, and longer in 26% of patients. The optimal AV delay based on LVFT was shorter during exercise than at rest in 27%, unchanged in 23%, and longer in 50% of patients. Optimization of the AV delay during exercise increased LVFT and LVOT-VTI significantly (P < .05) compared with (1) any other arbitrarily chosen AV delay, (2) the optimal AV delay at rest, (3) an AV delay systematically shortened from rest to exercise. CONCLUSION: Optimization of the AV delay had a positive effect on echocardiographic indices of LV function. The systematic shortening of the AV delay during exercise is not recommended because, in a high proportion of patients, the optimal AV delay was longer during exercise than at rest.
Bilel Mokrani; Stephane Lafitte; Antoine Deplagne; Sylvain Ploux; Julien Laborderie; Patricia Reant; Pierre Dos Santos; Raymond Roudaut; Pierre Jais; Michel Haissaguerre; Jacques Clementy; Pierre Bordachar
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article     Date:  2009-03-19
Journal Detail:
Title:  Heart rhythm : the official journal of the Heart Rhythm Society     Volume:  6     ISSN:  1556-3871     ISO Abbreviation:  Heart Rhythm     Publication Date:  2009 Jul 
Date Detail:
Created Date:  2009-06-29     Completed Date:  2009-09-30     Revised Date:  2009-10-27    
Medline Journal Info:
Nlm Unique ID:  101200317     Medline TA:  Heart Rhythm     Country:  United States    
Other Details:
Languages:  eng     Pagination:  972-7     Citation Subset:  IM    
University Victor Segalen, 33000 Bordeaux, France.
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MeSH Terms
Atrioventricular Node / physiopathology*,  ultrasonography*
Electrodes, Implanted
Exercise / physiology*
Middle Aged
Pacemaker, Artificial*
Prospective Studies
Rest / physiology*

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