Abstract 15422: Synchronicity of Left Ventricular Contraction As a Determinant of Left Ventricular Twist Mechanics : Serial Speckle-tracking Analysis in Wolff-Parkinson-White Syndrome Pre- and Post-radiofrequency Catheter Ablation
Objectives: This study was set out to investigate the isolated impact of synchronous patterns of left ventricular(LV) contraction(i.e.LV synchronicity) on LV twist behavior.
Background: Although the relationships between LV loading status/LV contractility and twist are well established,no data is available regarding the relation between LV twist and LV synchronicity,without any interference by changes in LV preload, afterload, and contractility.Serial assessment of patients with Wolff-Parkinson-White syndrome(WPW) pre-and post-radiofrequency catheter ablation(RFCA) allows this to be explored.
Method: Of the 40 patients initially screened,34 WPW patients were enrolled.Two-dimensional and Doppler echocardiography along with speckle tracking-derived LV twist mechanics, apical-basal rotation delay and LV dyssynchrony index(LVdys) were obtained before and after RFCA.LVdys was defined as the maximal delay in time-to-peak radial strain of different LV segments at the papillary muscle level.
Results: Overall,no significant changes were demonstrated in LV volumes,systolic,diastolic function and end-systolic wall stress before versus after RFCA.After RFCA,median value of LVdys was attenuated from 33.5 to 14.0(P=0.002),which was accompanied by a reduction in apical-basal rotation delay from 9.7 to 3.3 (P=0.004).In contrast, LV twist increased from 14.2° before to 19.7° after RFCA (P=0.002).ΔLV twist pre-to post-RFCA displayed a significant inverse correlation with changes in apical-basal rotation dela (r=−0.42,P=0.01)and ΔLVdy (r=-0.39, P=0.02) When we divided patients into 2 subgroups according to the presence or absence of a significant LVdys increment,these changes were observed only in patients with a significant LVdys improvement.
Conclusions: LV synchronous contraction is an independent determinant of LV twist, regardless of LV preload, afterload or contractility.
- © 2010 by American Heart Association, Inc.