title: Acute left ventricular dyssynchrony improvement predicts long-term benefit from cardiac resynchronization therapy.
abstract: OBJECTIVE
  To evaluate the relationship between acute response to cardiac resynchronization therapy (CRT) and long-term clinical outcome in patients with drug refractory heart failure.
  
  
  RESULTS
  In 28 patients undergoing CRT implant, left ventricular (LV) dyssynchrony was evaluated by tissue Doppler imaging (TDI)-derived longitudinal strain by mean of septum-lateral basal asynchrony index (S-Li) and basal delayed longitudinal contraction (DLC). TDI measurements were made before, and 30 minutes and 1 year after implant. Baseline and 1-year follow-up New York Heart Association (NYHA) functional class, 6-minute walking test (6-MWT) distance, and quality of life (QoL) score were measured. Responders (n = 22) were defined by a >/= 1 decrease in NYHA functional class and 6-MWT >/= 25% at 1 year. At baseline, no differences were observed between responders and nonresponders in clinical and echocardiographic measurements. LV dyssynchrony acutely recovered only in responders 30 minutes after implantation, with a significant reduction in S-Li and DLC. Moreover, the percent decreases in S-Li and DLC were highly correlated with those observed in NYHA class (r = 0.70, and r = 0.81, respectively, P < 0.001), 6-MWT (r = 0.59, and r = 0.57, respectively, P < 0.001 and P < 0.01), and QoL score (r = 0.71, and r = 0.83, respectively, p < 0.001) at 1-year follow-up.
  
  
  CONCLUSIONS
  Acute recovery of LV intraventricular dyssynchrony is a major discriminator between responders and nonresponders to CRT, which strongly correlates with a favorable long-term clinical outcome.
authors.affiliation: Laboratorio di Elettrofisiologia, Casa di Cura San Michele Maddaloni (CE), Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Capasso
authors.forename: Anna
authors.initials: A
authors.lastname: Giunta
authors.forename: Antonio
authors.initials: A
authors.lastname: De Simone
authors.forename: Pietro
authors.initials: P
authors.lastname: Turco
authors.forename: Vincenzo
authors.initials: V
authors.lastname: La Rocca
authors.forename: M Gabriella
authors.initials: MG
authors.lastname: Grimaldi
authors.forename: Assunta
authors.initials: A
authors.lastname: Iuliano
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Stabile
mesh_terms: D000208:Acute Disease; D000368:Aged; D002304:Cardiac Pacing, Artificial; D015150:Echocardiography, Doppler; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*