Recent studies have demonstrated that the septal-to-posterior motion delay (SPWMD) assessed by M-mode echo and the longitudinal intra-LV dyssynchrony assessed by tissue Doppler imaging (TDI) can predict chronic effects of cardiac resynchronization therapy (CRT). A newly developed 2D speckle tracking imaging (STI) has enabled assessment of not only longitudinal but circumferential regional strain of LV. We investigated the usefulness of STI in selecting patients for CRT.
Methods:
Fifty-one patients with heart failure symptoms and QRS duration>120 ms underwent standard echocardiography, TDI and STI before CRT. Time to peak systolic velocity was measured in 12 basal and mid LV segments in apical views by TDI. The time difference between the basal septal and the basal lateral segments was calculated (TDI-SLPVD).The standard deviation of those among 12 segments was calculated (TDI-SD). Time to peak circumferential strain, radial strain and longitudinal strain were measured in basal segments in parasternal short axis and apical views by STI. The time difference between the septal and the lateral segments was calculated (CS-SL, RS-SL and LS-SL). A responder to CRT was defined as a patient whose NYHA class improved by >1 class and whose LVESV reduced by >10% at 6 months after CRT.
Results:
Thirty-six patients (71%) responded to CRT. CS-SL showed high sensitivity and specificity for predicting the responders at a cut-off point of 124 ms (Table
). The area under the ROC curve (AUC) of CS-SL was larger than that of QRS duration, SPWMD, TDI-SLPVD, TDI-SD, RS-SL and LS-SL.
Conclusion:
Assessment of circumferential dyssynchrony using STI seems useful in selecting patients for CRT.
Improvement of Left Ventricular Function After Cardiac Resynchronization Therapy Is Predicted by Tissue Doppler Imaging Echocardiography
