Quantitative Evaluation Of Left Ventricular Myocardial Systolic Dyssynchrony In Patients With Heart Failure By Novel Technology

PrefaceRecently, cardiac resynchronization therapy(CRT) appears a good clinical application prospect in patients with heart failure (HF), who do not respond to drug treatment very well. At the same time, CRT developed therapeutic methods in patients with organic HF of terminal stage, which has been a hot topic in cardiac pacing and electrophysiology in recent years throughout the world. Novel echocardiography techniques, which have been used to supervise CRT, can evaluate myocardial motion dyssynchrony quickly, noninvasively, quantitatively and reproducibly. This study is to evaluate left ventricular myocardial systolic dyssynchrony in patients with HF by tissue velocity imaging(TVI), strain rate imaging(SRI), strain imaging(SI) and real-time three-dimensional echocardiography(RT-3DE) simultaneously.Objective1. To evaluate left ventricular myocardial systolic dyssynchrony in patients with HF by TVI, SRI, SI and RT-3DE.2. To assess relation of electrocardiographic QRS duration and systolic dyssynchrony index(SDI).3. To study correlation between SDI and left ventricular ejection fraction(LVEF).Materials and Methods57 subjects were divided into two groups. Group A consisted of 27 normal subjects, and group B included 30 patients with HF. Patients in group B were divided into three subgroups according to LVEF and two subgroups on the basis of QRS width. The former consisted of mild(6), moderate(18) and severe(6) HF patients, and the latter included narrow QRS subgroup(22) and wide one(8). Tissue Doppler imaging(TDI) and full volume were performed with Philips IE33. The times to the point of peak velocity(Tv), strain rate(Tsr), strain(Ts) during systolic phase, to the point of minimal volume(Tmv) and cardiac cycle were obtained by the on-line Qlab soft ware. The LVEF was derived from RT-3DE.Results1. There were no significant difference in age, heart rate between the two groups(P>0.05). LV end-diastolic internal diameter(LVIDd), LV end-diastolic volume (LVEDV) and LV end-systolic volume(LVESV) of group B were significantly larger than that of group A(P<0.05). LVEF of group B was much lower than that of group A(P<0.05).2. LV systolic dyssynchrony in patients with HF was evaluated by TVI, SRI, SI and RT-3DE. There were significant difference in normal subjects, mild, moderate and severe HF patients(P<0.05).3. Curves in group A arranged orderly by TVI, SRI, SI and RT-3DE, while that in group B ranked disorderly.4. There was no significant difference of SDI between wide QRS subgroup and narrow one.5. Significant negative correlation existed between LVEF and SDI, where RT-3DE and TVI appeared better than SRI and SLConclusions1. All the TVI, SRI, SI and RT-3DE can evaluate LV systolic dyssynchrony noninvasively and quantitatively, but RT-3DE can provide a novel, quick and convenient technique.2. SDI is a valuable index in quantitating LV systolic dyssynchrony. There is significant negative correlation between SDI and LVEF, which can better supervise CRT.3. There was no significant correlation between QRS width and SDI, so QRS during≥120ms can not be selected as CRT reliable evidence.