Abstract 10921: Utility of Segmental Circumferential Strain Analysis as a Parameter of Intrinsic Left Ventricular Myocardial Function for Cardiac Resynchronization Therapy
Background: Left ventricular (LV) dyssynchrony appears to play a major pathophysiologic role in response to cardiac resynchronization therapy (CRT), and intrinsic LV myocardial function is also associated with response. However, the presence of significant LV dyssynchrony can underestimate the assessment of echocardiographic intrinsic LV myocardial function owing to time-phase mismatch contraction.
Methods: We studied consecutive132 patients undergoing CRT. LV dyssynchrony was determined by the anterior-septum and posterior wall delay from mid-LV short-axis view using two-dimensional speckle-tracking radial strain (≥130ms as significant). Global circumferential strain (GCS), considered as a parameter of intrinsic LV myocardial function, was determined as the peak global circumferential strain from the same view. Furthermore, sum of the peak circumferential strain from anterior-septum and posterior wall (AS-P-CS) was also determined. Long-term follow-up was tracked over 3.0 years.
Results: In total, 99 patients (75%) were characterized as exhibiting significant LV dyssynchrony. AS-P-CS in patients without cardiovascular events were significantly lower than that in patients with cardiovascular events (-16.6±6.4% vs. -11.3±4.8%, p=0.004), but GCS in patients with and without cardiovascular events were similar. Importantly, multivariate Cox proportional-hazards analysis showed that LV dyssynchrony and AS-P-CS (not GCS) were the independent predictor of cardiovascular events in patients with LV dyssynchrony. Furthermore, Kaplan-Meier curve indicated that patients with AS-P-CS ≤-13.16% experienced fewer cardiovascular events than patients with AS-P-CS >-13.16% (log-rank p=0.001).
Conclusions: LV dyssynchrony can cause the underestimation of the echocardiographic intrinsic LV myocardial function, and anterior-septum and posterior wall might be the key segments for the assessment of LV myocardial function in CRT patients.
- © 2013 by American Heart Association, Inc.