Abstract #3601

Marcus J, Zwanenburg J, de Cock C, Kuijer J, Kamp O, van Dijk J, Gotte M, Hofman M, van Rossum A

Background: To select responders to cardiac resynchronization therapy (CRT). Purpose: To investigate whether regional myocardial function should be characterized by mechanical asynchrony, or by instantaneous measures (differences in strain at one time). Methods: Using MRI myocardial tagging, asynchrony of circumferential shortening was measured in 12 heart failure patients. Further, instantaneous measures were: the coefficient of variation in end-systolic strain, the peak shortening reserve, and the septal strain at end systole. CRT was applied, and increase in dP/dtmax defined the response. Results: Only the instantaneous measures (but not asynchrony) predicted the response to CRT (P < 0.01).