title: Dynamic ventricular dyssynchrony: an exercise-echocardiography study.
abstract: OBJECTIVE
  We sought to assess the effects of exercise on ventricular dyssynchrony in patients with normal and depressed left ventricular (LV) function.
  
  
  BACKGROUND
  Asynchronous myocardial contraction adversely influences ventricular function and is associated with a poor prognosis in heart failure. Exercise-induced changes in ventricular dyssynchrony may be an important determinant of dynamic changes in cardiac output and mitral regurgitation.
  
  
  METHODS
  A total of 65 consecutive heart failure patients and 50 matched healthy control patients underwent exercise echocardiography. Conventional and tissue Doppler parameters were measured before and during symptom-limited exercise. Left ventricular dyssynchrony was defined as the standard deviation of 12 LV segmental electromechanical delays. Analysis of the control group allowed delimitation of normal cutoff values.
  
  
  RESULTS
  In patients with normal left ventricular function, exercise did not modify the extent of LV asynchrony. In contrast, in heart failure patients, LV dyssynchrony increased by at least 20% in 34%, remained stable in 37%, and decreased by at least 20% in 29%. Moreover, 26% of heart failure patients had either exercise induction or normalization of ventricular dyssynchrony. A significant association was found between exercise-induced changes in dyssynchrony and the presence of ischemic cardiomyopathy (p < 0.05). Rest-exercise differences in ventricular dyssynchrony were correlated with changes in cardiac output and mitral regurgitation (r = -0.63 and 0.56, respectively).
  
  
  CONCLUSIONS
  In heart failure patients, exercise can alter the magnitude of ventricular dyssynchrony. Some patients have a response to exertion with induction of ventricular dyssynchrony, whereas others show normalization. Changes in ventricular dyssynchrony during exercise correlate with alterations in cardiac output and mitral regurgitation.
authors.affiliation: Cardiologic Hospital, Pessac and Bordeaux 2 University, Bordeaux, France.
authors.forename: Stephane
authors.initials: S
authors.lastname: Lafitte
authors.forename: Pierre
authors.initials: P
authors.lastname: Bordachar
authors.forename: Marianne
authors.initials: M
authors.lastname: Lafitte
authors.forename: Stephane
authors.initials: S
authors.lastname: Garrigue
authors.forename: Sylvain
authors.initials: S
authors.lastname: Reuter
authors.forename: Patricia
authors.initials: P
authors.lastname: Reant
authors.forename: Karim
authors.initials: K
authors.lastname: Serri
authors.forename: Valerie
authors.initials: V
authors.lastname: Lebouffos
authors.forename: Marianne
authors.initials: M
authors.lastname: Berrhouet
authors.forename: Pierre
authors.initials: P
authors.lastname: Jais
authors.forename: Michel
authors.initials: M
authors.lastname: Haissaguerre
authors.forename: Jacques
authors.initials: J
authors.lastname: Clementy
authors.forename: Raymond
authors.initials: R
authors.lastname: Roudaut
authors.forename: Anthony N
authors.initials: AN
authors.lastname: DeMaria
mesh_terms: D000368:Aged; D002303:Cardiac Output, Low / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D016022:Case-Control Studies; D004452:Echocardiography; D015444:Exercise; D005080:Exercise Test; D006801:Humans; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D011446:Prospective Studies; D015203:Reproducibility of Results; D012146:Rest; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*