Abstract 10438: Echocardiographic Mechanical Dispersion is a Marker for Ventricular Arrhythmia in Patients With Cardiac Resynchronization Therapy
Background: Mechanisms and predictors of ventricular arrhythmia (VA) in heart failure patients eligible for cardiac resynchronization therapy (CRT) are not fully clarified. Mechanical dispersion reflects left ventricular (LV) dyssynchrony of myocardial contraction and has been shown to predict VA in different cardiomyopathies. We assessed left ventricular (LV) function and mechanical dispersion to explore mechanisms of VA in heart failure patients treated with CRT. We hypothesized that improvement of mechanical dispersion by CRT, would be associated with less VA.
Methods: We investigated candidates for CRT treatment with LV ejection fraction (EF) < 35%, QRS > 120 ms, NYHA functional class 2-4 and no VA prior to CRT implantation. Speckle tracking strain analyses from 2D echocardiographic examination were performed before and 6 months after CRT-implantation. Mechanical dispersion was calculated as standard deviation of time to peak negative longitudinal strain from 16 LV segments. VA was defined as non-sustained or sustained ventricular tachycardia/fibrillation during 2 years following CRT implantation.
Results: We included 56 patients (age 64±9 years, EF 29±10%, NYHA class 2.8±0.4,), 41% with ischemic and 59% with non-ischemic cardiomyopathy. In all patients, mechanical dispersion decreased from baseline to 6 months after CRT (122±54ms vs. 79±33ms, p<0.001). VA was documented in 11 patients (20%). Mechanical dispersion at 6 months was higher in those patients with documented VA during 2 years follow up compared to those without VA (104±47 vs. 75±28ms, p=0.02) (Figure).
Conclusions: Mechanical dispersion at 6 months after CRT implantation was higher in patients who experienced VA during 2 years follow up than those without VA. Mechanical dispersion may reflect the mechanisms for VA in CRT patients and be important in the evaluation of CRT patients.
- © 2013 by American Heart Association, Inc.