Left ventricular mechanical dispersion in flow-gradient patterns of severe aortic stenosis with narrow QRS complex

AbstractPatients with severe aortic stenosis are classified according to flow-gradient patterns. We investigated whether left ventricular (LV) mechanical dispersion, a marker of dyssynchrony and predictor of mortality, is associated with low-flow status in aortic stenosis. 316 consecutive patients with aortic stenosis and QRS duration  <  120 ms were included in the retrospective analysis. Patients with severe aortic stenosis (aortic valve area ≤ 1.0 cm2) were classified as normal-flow (NF; stroke volume index  >  35 ml/m2) high-gradient (HG; mean transvalvular gradient  ≥ 40 mmHg) (n = 79), NF low-gradient (LG) (n = 62), low-flow (LF) LG ejection fraction (EF) ≥ 50% (n = 57), and LF LG EF <  50% (n = 23). Patients with moderate aortic stenosis (aortic valve area 1.5–1.0 cm2; n  = 95) served as comparison group. Mechanical dispersion (calculated as standard deviation of time from Q/S onset on electrocardiogram to peak longitudinal strain in 17 left ventricular segments) was similar in patients with NF HG (49.4 ± 14.7 ms), NF LG (43.5 ± 12.9 ms), LF LG EF  ≥ 50% (47.2 ± 16.3 ms) and moderate aortic stenosis (44.2 ± 15.7 ms). In patients with LF LG EF <  50%, mechanical dispersion was increased (60.8 ± 20.7 ms, p <  0.05 vs. NF HG, NF LG, LF LG EF ≥ 50% and moderate AS). Mechanical dispersion correlated with global longitudinal strain (r = 0.1354, p =â...
Source: The International Journal of Cardiovascular Imaging - Category: Radiology Source Type: research