Two-dimensional speckle strain and dyssynchrony in single left ventricles vs. normal left ventricles

Patients with single left ventricle (LV) physiology maybe at increased risk for myocardial dysfunction and mechanical dyssynchrony. Newer echocardiographic modalities may be able to better quantitate LV function in this unique population. Our objective was to use 2D-speckle analysis of strain and strain rate to quantify systolic function and dyssynchrony in single LV post-Fontan patients and compare them to control LV patients.

Patients with single LV status post-Fontan procedure and patients with normal biventricular anatomy were studied. Two-dimensional speckle echocardiography was used to measure strain, strain rate, time to peak, and longitudinal displacement in a six-segment model of the LV. Independent t-tests were used to compare group means.

Twelve patients with single LV physiology and thirteen control patients were studied. There was no significant difference in ages for the single LV patients vs. control patients (7.1 + 2.8 years vs. 5.7 + 1.8 years). Single LV strain values were significantly lower in four of the six segments compared with control LV (mid interventricular septal [IVS]: -19.3 + 6.4% vs. -23.8 + 3.5%, apical IVS: -20.8 + 5.4% vs. -27.4 + 4.7%, basal LV: -20.6 + 6.6% vs. -25.8 + 3.4%, and apical LV: -21.0 + 6.2% vs. -26.1 + 4.3%). Longitudinal displacement was lower for all three segments of the IVS for the single LV vs. control LV. Modified Yu index for strain and strain rate time to peak was longer in the single LV patients vs. controls (51.2 + 18.2 ms vs. 27.9 + 8.0 ms and 90.2 + 24.2 ms vs. 52.5 + 23.7 ms, respectively).

Significant differences in strain analysis between single LV patients vs. control patients with normal biventricular physiology exist at a relatively young age. Future studies are needed to determine the significance of these differences.