Prediction of treatment response for cardiac resynchronization therapy by left ventricular twist using three-dimensional speckle tracking imaging in a heart failure canine model / 中华超声影像学杂志

ABSTRACT

Objective To assess left ventricular (LV) twist in a rapid pacing induced heart failure canine model undergoing cardiac resynchronization therapy (CRT) by three-dimensional speckle tracking imaging (3D-STI).Methods Rapid right ventricular pacing (RVP) was utilized in 22 adult beagle dogs for 3 weeks to induce heart failure.Then 15 dogs received CRT for 2 weeks and others were treated as control.Apical full-volume acquisition of the LV was obtained in conscious animals at baseline,the end of 3-week RVP and the end of 2-week CRT.Peak LV apical (AP-Prot) and basal rotation (MV-Prot) along with peak twist (Ptw) and torsion (Ptor) were automatically calculated by TomTec 4D LV Analysis 3.0 software to identify the ideal parameter in predicting treatment response of CRT.Results After 2 weeks of CRT,LV ejection fraction(LVEF) increased and LV end-systolic volume(LVESV) decreased significantly in dogs with heart failure.CRT treatment response,defined as improvement of LVESV≥15％,was observed in 9 dogs.Significant difference was found in Ptw [(7.43 ± 0.61) vs (6.06 ± 0.89)°,P ＜0.05] and Ptor [(1.43 ± 0.45) vs (0.67 ± 0.36)°/cm,P ＜0.05] between responders and nonresponders.Ptw and Ptor predicted CRT response with satisfying sensitivity as 89％ and 85％,specificity as 83％ and 84％,respectively.Conclusions Peak twist and torsion evaluated by 3D-STI represented overall LV twist and demonstrated potential prediction value for treatment response of CRT.