Abstract 3562: Usefulness of Longitudinal Strain by 2D-Speckle Tracking in Assessment of Myocardial Contractile Reserve During Exercise in Patients with Non-Ischemic Cardiomyopathy
Background; We previously proposed that the analysis of tissue velocity with negative strain data was useful for the quantification of longitudinal contractility in patients with heart failure. This study aimed to evaluate whether the baseline longitudinal strain (2DSL) by 2 dimensional- speckle tracking can predict myocaridal contractile reserve during exercise and overcome the technical limitation of tissue Doppler strain (SL) method.
Methods: Supine bicycle exercise was performed in 31 patients with non-ischemic cardiomyopathy (51 ± 12 years, EF <40%). In 6 LV segments on apical 4 chamber view, the peak systolic velocities were measured at baseline and peak exercise (Vb, Vp) by tissue Doppler imaging. ΔV was calculated as Vp - Vb, representing the contractile reserve. At baseline, SL and 2DSL of 6 LV segments were respectively obtained.
Results: With exercise (9.7 ± 2.4 min.), myocardial velocities of 186 segments increased from 3.1 ± 1.3 cm/s (Vb) to 4.4 ± 1.6 cm/s (Vp). The segments with Vb≥ 3 cm/s and 2DSL > −10 % (group C, 41 segments) showed much lower ΔV compared with the segments with Vb ≥ 3 cm/s and 2DSL < −10 % (group D, 51 segments) (ΔV; 0.8 ± 0.9 vs 1.7 ± 1.0 cm/s, p<0.001, fig 2⇓). In 186 segments, the baseline 2DSL showed significant correlation with ΔV (r= -0.326, p<0.001, fig 1⇓) and also with Vp (r=-0.188, p=0.010). Although SL correlated with 2DSL (r=0.305, p<0.001), there was no relation between SL and ΔV (p=0.090) or Vb and ΔV (p=0.358).
Conclusion: The 2DSL measured at baseline was a powerful index reflecting the contractile reserve (ΔV) during exercise in patients with non-ischemic cardiomyopathy.