Myocardial dysfunction and left ventricular (LV) geometry deformation may reduce the accuracy of tissue Doppler imaging (TDI) in assessing myocardial contractility.Methods
In 92 patients with heart failure who underwent cardiac resynchronization therapy (CRT), we assessed the impact of LV end-diastolic volume on the accuracy of peak longitudinal velocity (TDI) and strain (εL by speckle tracking) to assess regional wall motion and LV dyssynchrony.Results
Peak-ε correlated to normal (−13% ± 6%, n = 259), hypokinetic (−10% ± 5%, n = 347), and akinetic (−7% ± 5%, n = 498, P < .0001) wall motion independent of LV size. In contrast, velocity failed to distinguish normal from dysfunctional segments in patients with severe LV dilatation (end-diastolic volume > 250 mL). The 12 standard deviation of time to peak systolic velocity and the opposing septal-lateral wall delay by strain and TDI failed to predict response to CRT, whereas the 12 segment standard deviation of time to peak ε correlated to end-systolic volume reduction (r = −0.39, P < .001).Conclusion
Accuracy of TDI in assessing LV wall regional motion is limited in severely dilated ventricles and probably affects LV dyssynchrony measurement.