Abstract 2138: Improvement in Speckle Tracking Radial Strain Dyssynchrony After Cardiac Resynchronization Therapy
Background: Speckle tracking radial strain from routine 2D images has utility to assess cardiac dyssynchrony in left bundle block heart failure (LBBB HF) patients. Our objective was to test the hypothesis that changes in activation pattern are detectable after cardiac resynchronization therapy (CRT) using speckle tracking radial strain.
Methods: 27 patients (68±10 yrs, EF 24±8%, QRS duration 161±31 ms) were studied before and the day after CRT. Computer software (GE Corp) utilizing an application to track acoustic “speckle” patterns within the myocardial wall from routine 2D images was used to calculate segmental radial strain over the cardiac cycle. Time from onset of QRS to peak strain measurements were taken over six radial segments at the mid ventricular level. 10 patients were also re-evaluated by speckle tracking radial strain at 5 ± 1 months after CRT.
Results: LBBB HF patients had significant baseline septal to posterior wall dyssynchrony by speckle tracking: 229 ± 146 ms. Dyssynchrony was characterized by early peak strain at the anterior septum (time to peak strain 260 ± 125 ms), that normalized significantly post CRT. Septal to posterior wall delay by was significantly improved 24 hours post CRT (144 ± 86 ms, p< 0.001). This trend persisted 5 ± 1 months after CRT (time to peak anterioseptal strain 472 ± 89 ms, p<0.01 vs. Pre CRT; septal to posterior wall dyssynchrony 33 ± 106 ms, p<0.01). QRS duration was not improved post CRT.
Conclusion: Speckle tracking radial dyssynchrony is able to characterize septal to posterior wall dyssynchrony in LBBB HF patient, which is acutely improved post CRT. These improvements in radial dyssynchrony by speckle tracking persist at later follow up.