Impact of Left Ventricular Afterload on Longitudinal Dyssynchrony in Patients With Severe Aortic Stenosis and Preserved Ejection Fraction

Background: The purpose of this study was to investigate whether patients with severe aortic stenosis (AS) and preserved ejection fraction (EF) have dyssynchrony and whether it improves after aortic valve replacement (AVR). Methods and Results: We studied 30 consecutive patients with severe AS and preserved EF undergoing AVR. For baseline comparison, we studied 17 EF-matched patients with mild-to-moderate AS, and 18 EF-matched normal volunteers. Longitudinal dyssynchrony was determined as the standard deviation for time-to-peak speckle-tracking strain in apical 4- and 2-chamber views at the basal- and mid-levels. Radial and circumferential dyssynchrony was determined as the difference for time-to-peak strain between the anteroseptum and posterior wall from the mid-left ventricular (LV) short-axis view. Each of the myocardial functions was also evaluated by averaging each peak systolic strain. Longitudinal dyssynchrony and function in patients with severe AS was significantly worse than in the patients with mild-to-moderate AS and the controls (94 +/- 46 vs. 66 +/- 18ms* and 52 +/- 17ms*, and 12.5 +/- 3.7% vs. 16 +/- 3.5%* and 18.7 +/- 3.7%*, respectively, *P<0.05, vs. severe AS). In contrast, radial and circumferential dyssynchrony were similar for the 3 groups. Importantly, the dyssynchrony of patients with severe AS significantly improved after AVR from 94 +/- 46ms to 68 +/- 22ms (P<0.005). Conclusions: Significant longitudinal dyssynchrony was present in patients with severe AS and preserved EF, and it improved after AVR. (Circ J 2012; 76: 744-751)