Evaluation of left ventricular twist in rabbit model with heart failure by speckle tracking imaging

Abstract

Objective To assess left ventricular twist and untwist in rabbit models with diastolic heart failure(DHF) and systolic heart failure(SHF) by speckle tracking imaging(STI).Methods Thirtythree male New Zealand rabbits were divided into three groups:one group was used to establish DHF model by suprarenal abdominal aortic constriction(n = 12) and the other was used to establish SHF model by abdominal aortic constriction subdiaphragmly above celiac artery origin(n = 11),another was control group established by sham operation(n = 10).After two weeks,left ventricular twist-related parameters were measured.by STE.Finallly,left ventricular catheterization and myocardial pathological examination were performed.Results Compared with control group,peak twist angle (Ptw) and peak twisting velocity(PTV)remained unchanged in DHF group (P ＞ 0.05) and decreased in SHF group (P ＜ 0.05).Isovolumic untwisting rate (IUR) decreased,untwisting half-time(UHT) was prolonged,time to peak twist (tPtw) and peak untwisting velocity (tPUTV) were delayed in SHF and DHF groups.In additon,Peak untwisting velocity(PUTV) decreased in SHF group,but increased in DHF group (P ＜0.05).Ptw correlated correlated positively with LVEF,+ dp/dtmax significantly in both groups (DHF group:r = 0.897,P =0.002; r = 0.719,P = 0.044;SHF group:r = 0.727,P = 0.041; r = 0.780,P = 0.022).A significantly positive correlation was observed between PUTV and - dp/dtmax Tau,LVEDP(r = 0.801,P = 0.017; r =0.814,P = 0.014; r = 0.875,P = 0.004) in SHF group.Conclusions STI is useful in evaluating left ventricular twist and untwist in rabbit model of DHF and SHF. Key words: Echocardiography; Heart failure,congestive; Torsion; Speckle tracking imaging