title: Long-term response of the left ventricle to cardiac resynchronization therapy: insights from standard and strain echocardiography.
abstract: Left ventricular (LV) response to cardiac resynchronization therapy (CRT) has typically been studied over 3- to 12-month periods. Longer-term data are unclear and response of strain parameters has not been reported. The authors evaluated long-term response with standard and strain echocardiography in 57 patients (52±15 years; 40 male; 30 white; 15 with ischemic etiology) who received a CRT-defibrillator between January 2004 and December 2005. Median ejection fraction (EF) at baseline was 22% (17%-25%). Global longitudinal, radial, and circumferential strain were -6.5% (-5.0% to -8.4%), 10.4% (6.9%-15.1%), and -7.6% (-5.5% to -10.8%), respectively. After a median of 42 months, EF increased by 5% (-1% to 15%; P<.001), with improvements in circumferential (-3.2% [-5.2% to 1.5%]; P=.001), longitudinal (-0.5% [-3.4% to 1.2%]; P=.035), and radial (1.4% [-1.1% to 9.2%]; P=.035) strain. Changes in volumes were nonsignificant. EF improvement ≥5% was observed in 29 patients (50.9%). Relative improvement ≥15% in longitudinal, radial, and circumferential strain was observed in 26 (45.6%), 29 (50.9%), and 37 (64.9%) patients, respectively. Improvement in longitudinal strain and EF was strongly associated with lower rates of heart failure-related and all-cause readmissions. A wide range of long-term LV responses to CRT was observed, with approximately 50% of patients showing favorable responses.
authors: Emory Clinical Cardiovascular Research Institute, 1462 Clifton Road NE, Atlanta, GA 30322, USA. akaloge@emory.edu
authors: Andreas
authors: A
authors: Kalogeropoulos
authors: Louise P
authors: LP
authors: Savoye
authors: Vasiliki
authors: V
authors: Georgiopoulou
authors: Leah
authors: L
authors: Raj
authors: Michael S
authors: MS
authors: Lloyd
authors: John
authors: J
authors: Chiladakis
authors: Stamatios
authors: S
authors: Lerakis
authors: Dimitrios
authors: D
authors: Alexopoulos
authors: Javed
authors: J
authors: Butler
mesh_terms: D058406:Cardiac Resynchronization Therapy / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016896:Treatment Outcome