Prediction of response to cardiac resynchronization therapy using left ventricular pacing lead position and cardiovascular magnetic resonance derived wall motion patterns: a prospective cohort study

Background

Despite marked benefits in many heart failure patients, a considerable proportion of patients treated with cardiac resynchronization therapy (CRT) fail to respond appropriately. Recently, a “U-shaped” (type II) wall motion pattern identified by cardiovascular magnetic resonance (CMR) has been associated with improved CRT response compared to a homogenous (type I) wall motion pattern. There is also evidence that a left ventricular (LV) lead localized to the latest contracting LV site predicts superior response, compared to an LV lead localized remotely from the latest contracting LV site.

Methods

We prospectively evaluated patients undergoing CRT with pre-procedural CMR to determine the presence of type I and type II wall motion patterns and pre-procedural echocardiography to determine end systolic volume (ESV). We assessed the final LV lead position on post-procedural fluoroscopic images to determine whether the lead was positioned concordant to or remote from the latest contracting LV site. CRT response was defined as a ≥ 15 % reduction in ESV on a 6 month follow-up echocardiogram.

Results

The study included 33 patients meeting conventional indications for CRT with a mean New York Heart Association class of 2.8 ± 0.4 and mean LV ejection fraction of 28 ± 9 %. Overall, 55 % of patients were echocardiographic responders by ESV criteria. Patients with both a type II pattern and an LV lead concordant to the latest contracting site (T2CL) had a response rate of 92 %, compared to a response rate of 33 % for those without T2CL (p = 0.003). T2CL was the only independent predictor of response on multivariate analysis (odds ratio 18, 95 % confidence interval 1.6-206; p = 0.018). T2CL resulted in significant incremental improvement in prediction of echocardiographic response (increase in the area under the receiver operator curve from 0.69 to 0.84; p = 0.038).

Conclusions

The presence of a type II wall motion pattern on CMR and a concordant LV lead predicts superior CRT response. Improving patient selection by evaluating wall motion pattern and targeting LV lead placement may ultimately improve the response rate to CRT.     

Relationship between mechanical dyssynchrony and intra-operative electrical delay times in patients undergoing cardiac resynchronization therapy

Background

It is important to understand the relationship between electrical and mechanical ventricular activation in CRT patients. By measuring local electrical activation at multiple locations within the coronary veins and myocardial contraction at the same locations in the left ventricle, we determined the relationship between electrical and mechanical activation at potential left ventricular pacing locations.

Methods

In this study, mechanical contraction times were computed using high temporal resolution cine cardiovascular magnetic resonance (CMR) data, while electrical activation times were derived from intra-procedural local electrograms.

Results

In our cohort, there was a strong correlation between electrical and mechanical delay times within each patient (R² = 0.78 ± 0.23). Additionally, the latest electrically activated location corresponded with the latest mechanically contracting location in 91% of patients.

Conclusions

This study provides initial evidence that our method of obtaining non-invasive mechanical activation patterns accurately reflects the underlying electromechanical substrate of intraventricular dyssynchrony.     

Feature tracking measurement of dyssynchrony from cardiovascular magnetic resonance cine acquisitions: comparison with echocardiographic speckle tracking

Background

Analysis of left ventricular (LV) mechanical dyssynchrony may provide incremental prognostic information regarding cardiac resynchronization therapy (CRT) response in addition to QRS width alone. Our objective was to quantify LV dyssynchrony using feature tracking post processing of routine cardiovascular magnetic resonance (CMR) cine acquisitions (FT-CMR) in comparison to speckle tracking echocardiography.

Methods

We studied 72 consecutive patients who had both steady-state free precession CMR and echocardiography. Mid-LV short axis CMR cines were analyzed using FT-CMR software and compared with echocardiographic speckle tracking radial dyssynchrony (time difference between the anteroseptal and posterior wall peak strain).

Results

Radial dyssynchrony analysis was possible by FT-CMR in all patients, and in 67 (93%) by echocardiography. Dyssynchrony by FT-CMR and speckle tracking showed limits of agreement of strain delays of ± 84 ms. These were large (up to 100% or more) relative to the small mean delays measured in more synchronous patients, but acceptable (mainly <25%) in those with mean delays of >200 ms. Radial dyssynchrony was significantly greater in wide QRS patients than narrow QRS patients by both FT-CMR (radial strain delay 230 ± 94 vs. 77 ± 92* ms) and speckle tracking (radial strain delay 242 ± 101 vs. 75 ± 88* ms, all *p < 0.001).

Conclusions

FT-CMR delivered measurements of radial dyssynchrony from CMR cine acquisitions which, at least for the patients with more marked dyssynchrony, showed reasonable agreement with those from speckle tracking echocardiography. The clinical usefulness of the method, for example in predicting prognosis in CRT patients, remains to be investigated.     

Longitudinal two-dimensional strain rate imaging: a potential approach to predict the response to cardiac resynchronization therapy

The purpose of our study was to test the usefulness of speckle-tracking two-dimensional echocardiography (in particular longitudinal strain and strain rate) in predicting the response to cardiac resynchronization therapy. The standard approach has been tissue Doppler-based echocardiographic imaging (TDI) has initially showed promising results in small clinical trials. However, recent larger, prospective randomized clinical trials (PROSPECT, ReTHINK) showed that TDI is inadequate to predict response from CRT in patients with heart failure. Altogether, these data suggest the need to identify alternative echocardiographic parameters to predict the response to CRT. We included 53 patients suffering from heart failure, who received CRT. TDI and two-dimensional speckle tracking imaging in addition to standard echocardiography were performed prior to CRT. The standard deviation of time to peak longitudinal strain in 12 LV segments (Tstrain-SD) and the standard deviation of time to the end of longitudinal systolic strain rate in six basal LV segments (Tsr-SD) were calculated. Standard echocardiography was performed 6 months after CRT. Patients were classified as echocardiographic responders if the LV end-systolic volume was reduced >15% compared with baseline volumes. No significant difference was seen in baseline Ts-SD, and Tstrain-SD between non-responders and responders. However, the Tsr-SD was much higher in responders than non-responders (95.9 ± 33.0% vs. 64.8 ± 39.6%, P < 0.05), and it showed a sensitivity of 73% and specificity of 65% for the defined echocardiographic response using a cutoff value of 70.7 ms. Our study demonstrates that longitudinal two-dimensional strain rate imaging is a promising potential echocardiographic parameter to predict benefit from CRT in patients with heart failure. This hypothesis needs to be further tested in prospective randomized clinical trials.     

二维超声斑点追踪预测充血性心力衰竭患者心脏再同步化治疗的急性期反应

目的 观察二维超声斑点追踪(2D-STE)是否可预测充血性心力衰竭患者心脏再同步化治疗(CRT)的急性期反应.方法 24例充血性心力衰竭患者接受CRT治疗,术后7天分别在CRT关闭(OFF)和开启(ON)状态接受超声检查.将2D-STE测量的左心室短轴前间壁和后壁达峰值径向应变的时间差(T_(AS-POST))≥130 ms定义为左心室收缩不同步.将CRT-ON时左心室压力最大上升速率(LVdp/dt)的增长率Δdp/dt%>25%定义为急性反应有效.结果 15例患者(62.50%) CRT有反应,CRT-ON时左心室射血分数和LVdp/dt增大,T_(AS-POST) 缩短.T_(AS-POST) 是预测Δdp/dt%>25%的独立因素,T_(AS-POST)≥130 ms预测CRT急性反应的敏感度和特异度分别为86.24%和70.38%.结论 2D-STE技术能够有助于选择CRT最适病例,并预测其急性期反应.     

A CMR study of the effects of tissue edema and necrosis on left ventricular dyssynchrony in acute myocardial infarction: implications for cardiac resynchronization therapy

Background

In acute myocardial infarction (AMI), both tissue necrosis and edema are present and both might be implicated in the development of intraventricular dyssynchrony. However, their relative contribution to transient dyssynchrony is not known. Cardiovascular magnetic resonance (CMR) can detect necrosis and edema with high spatial resolution and it can quantify dyssynchrony by tagging techniques.

Methods

Patients with a first AMI underwent percutaneous coronary interventions (PCI) of the infarct-related artery within 24 h of onset of chest pain. Within 5–7 days after the event and at 4 months, CMR was performed. The CMR protocol included the evaluation of intraventricular dyssynchrony by applying a novel 3D-tagging sequence to the left ventricle (LV) yielding the CURE index (circumferential uniformity ratio estimate; 1 = complete synchrony). On T₂-weighted images, edema was measured as high-signal (>2 SD above remote tissue) along the LV mid-myocardial circumference on 3 short-axis images (% of circumference corresponding to the area-at-risk). In analogy, on late-gadolinium enhancement (LGE) images, necrosis was quantified manually as percentage of LV mid-myocardial circumference on 3 short-axis images. Necrosis was also quantified on LGE images covering the entire LV (expressed as %LV mass). Finally, salvaged myocardium was calculated as the area-at-risk minus necrosis (expressed as % of LV circumference).

Results

After successful PCI (n = 22, 2 female, mean age: 57 ± 12y), peak troponin T was 20 ± 36ug/l and the LV ejection fraction on CMR was 41 ± 8%. Necrosis mass was 30 ± 10% and CURE was 0.91 ± 0.05. Edema was measured as 58 ± 14% of the LV circumference. In the acute phase, the extent of edema correlated with dyssynchrony (r² = −0.63, p < 0.01), while extent of necrosis showed borderline correlation (r² = −0.19, p = 0.05). PCI resulted in salvaged myocardium of 27 ± 14%. LV dyssynchrony (=CURE) decreased at 4 months from 0.91 ± 0.05 to 0.94 ± 0.03 (p < 0.004, paired t-test). At 4 months, edema was absent and scar %LV slightly shrunk to 23.7 ± 10.0% (p < 0.002 vs baseline). Regression of LV dyssynchrony during the 4 months follow-up period was predicted by both, the extent of edema and its necrosis component in the acute phase.

Conclusions

In the acute phase of infarction, LV dyssynchrony is closely related to the extent of edema, while necrosis is a poor predictor of acute LV dyssynchrony. Conversely, regression of intraventricular LV dyssynchrony during infarct healing is predicted by the extent of necrosis in the acute phase.     

超声指导下参数优化提高心脏再同步化治疗疗效的应用价值

目的 探讨超声引导下参数优化提高心脏再同步化治疗(CRT)疗效的价值.方法 对17例慢性心力衰竭的患者,CRT术后在超声心动图指导下优化AV间期、VV间期.结果 17例患者CRT优化后心功能均得到不同程度改善,心功能NYHA分级从Ⅲ～Ⅳ级改善为Ⅱ～Ⅲ级,心房起搏AV间期/心房自身感知AV间期优化至130～180 ms/100～150 ms,使得左室充盈时间从(354±147)ms升至(420±112)ms,二尖瓣反流由(9.33±4.69)cm2减少至(5.44±4.62)cm2;VV间期优化至4～40 ms,使得左室内各室壁收缩期达峰时间标准差从(48.4±17.9)ms减少至(30.2±18.6)ms,左室流出道速度时间积分由(21.6±9.3) cm/s上升至(26.3±3.4)cm/s.3个月后左室收缩末容积减少(15±6)%.结论 CRT术后行超声指导下个体化参数优化可以提高CRT疗效.

Abstract：

Objective To investigate the effects of echocardiography-guided pacemaker parameters optimization in order to enhance the efficacy of cardiac resynchronization therapy(CRT).Methods Seventeen patients with chronic heart failure received biventricular resynchronous pacing therapy.A-V delay and V-V delay was optimized under the guiding of spectral Doppler echocardiography and tissue Doppler imaging.Results The indices of heart function in all patients were significantly improved after the treatment.The NYHA class of the patients was improved from class Ⅲ～Ⅳ to class Ⅱ～Ⅲ.Since PAV/SAV was optimized to 130-180/100-150 ms,left ventricular filling time(LVFT) was increased from (354±147)ms to (420±112)ms,mitral reflux (MR) was decreased from (8.41±4.55)cm2 to (5.36±4.71)cm2.After VV delay was optimized to 4-40ms,standard deviation of time to regional peak systolic velocity (Ts-SD-12) was decreased from (48.4±17.9)ms to (30.2±18.6)ms,left ventricular outflow tract velocity time integral(VTI LVOT) was increased from (20.6±9.0)cm/s to (26.1±3.1)cm/s.Conclusions Echocardiography-guided optimization of the pacemaker parameters is necessary in order to enhance the efficacy of CRT.     

Cardiac output and cardiac index measured with cardiovascular magnetic resonance in healthy subjects,elite athletes and patients with congestive heart failure

Background

Cardiovascular Magnetic Resonance (CMR) enables non-invasive quantification of cardiac output (CO) and thereby cardiac index (CI, CO indexed to body surface area). The aim of this study was to establish if CI decreases with age and compare the values to CI for athletes and for patients with congestive heart failure (CHF).

Methods

CI was measured in 144 healthy volunteers (39 ± 16 years, range 21–81 years, 68 females), in 60 athletes (29 ± 6 years, 30 females) and in 157 CHF patients with ejection fraction (EF) below 40% (60 ± 13 years, 33 females). CI was calculated using aortic flow by velocity-encoded CMR and is presented as mean ± SD. Flow was validated in vitro using a flow phantom and in 25 subjects with aorta and pulmonary flow measurements.

Results

There was a slight decrease of CI with age in healthy subjects (8 ml/min/m² per year, r² = 0.07, p = 0.001). CI in males (3.2 ± 0.5 l/min/m²) and females (3.1 ± 0.4 l/min/m²) did not differ (p = 0.64). The mean ± SD of CI in healthy subjects in the age range of 20–29 was 3.3 ± 0.4 l/min/m², in 30–39 years 3.3 ± 0.5 l/min/m², in 40–49 years 3.1 ± 0.5 l/min/m², 50–59 years 3.0 ± 0.4 l/min/m² and >60 years 3.0 ± 0.4 l/min/m². There was no difference in CI between athletes and age-controlled healthy subjects but HR was lower and indexed SV higher in athletes. CI in CHF patients (2.3 ± 0.6 l/min/m²) was lower compared to the healthy population (p < 0.001). There was a weak correlation between CI and EF in CHF patients (r² = 0.07, p < 0.001) but CI did not differ between patients with NYHA-classes I-II compared to III-IV (n = 97, p = 0.16) or patients with or without hospitalization in the previous year (n = 100, p = 0.72). In vitro phantom validation showed low bias (−0.8 ± 19.8 ml/s) and in vivo validation in 25 subjects also showed low bias (0.26 ± 0.61 l/min, QP/QS 1.04 ± 0.09) between pulmonary and aortic flow.

Conclusions

CI decreases in healthy subjects with age but does not differ between males and females. We found no difference in CI between athletes and healthy subjects at rest but CI was lower in patients with congestive heart failure. The presented values can be used as reference values for flow velocity mapping CMR.     

组织多普勒成像技术对心脏再同步化治疗的评价

目的探讨应用组织多普勒成像(TDI)技术评价心脏再同步化治疗(CRT)慢性心力衰竭患者的临床应用价值。方法选择拟行CRT的慢性心力衰竭患者31例,应用TDI测量收缩速度达峰时间判断左室收缩延迟部位,根据左室电极的位置是否与收缩延迟部位相符,将患者分为电极位置和收缩延迟部位符合者20例(A组)和不符合者11例(B组)。应用常规超声心动图及TDI技术观察两组术前及术后1,3,6个月左室收缩功能指标和心脏同步性参数的变化,评价CRT治疗效果。结果所有患者术前TDI技术评估均提示存在左室内收缩不同步,TDI技术能够指导左室电极植入理想靶静脉。术后1,3,6个月,患者的纽约心脏病协会心功能(NYHA)分级、6min步行距离、左室射血分数(LVEF)、左室舒张末期内径(LVEDd)、二尖瓣反流(MR)程度及室间机械延迟(IVMD)、左室12节段达峰时间标准差(Ts-SD)、左室内最晚收缩-最早收缩(Ts max-min)均较术前明显改善,术后6个月各参数改变最明显(P<0.05)。术后6个月,A,B组间NYHA分级、6min步行距离、LVEF、MR程度、IVMD、Tsmax-min及Ts-SD比较,差异均有统计学意义(均P<0.05)。结论 TDI技术可以用于慢性心力衰竭患者接受CRT的筛选,并能指导左室电极植入位置和评价疗效。     

心脏再同步化治疗慢性充血性心力衰竭患者舒张功能的评价

目的 应用超声心动图评价心脏同步化治疗对重度心衰患者左室舒张功能的长期影响.方法 18例左室非同步的慢性充血性心衰患者行心脏同步化治疗.并于治疗前,治疗后1周、6个月、12个月行超声心动图检查,测量左室射血分数(LVEF),二尖瓣血流E、A峰值,应用组织多普勒技术测量二尖瓣瓣环收缩期峰值速度(Sm),舒张早期峰值速度(Em),舒张晚期峰值速度(Am).结果 起搏后第1周LVEF明显高于起搏前(P<0.001).二尖瓣环间隔部Am术后6个月[(11.3±2.9)cm/s]、1年[(12.5±3.6)cm/s]明显高于起搏前[(9.2±1.7) cm/s](P<0.05).二尖瓣环侧壁Am术后6个月[(12.1±3.2)cm/s]和术后1年[(13.5±3.2)cm/s]高于起搏前[(11.8±2.9)cm/s](P<0.05).二尖瓣环间隔部Em起搏前后未见显著性变化.结论 超声心动图是评价心脏同步化治疗左室运动不同步的心衰患者舒张功能明显改善的一种可靠方法.     

超声心动图评价心脏再同步化治疗疗效

目的探讨超声心动图在慢性充血性心力衰竭患者心脏再同步化治疗疗效评价中的应用价值。方法 27例接受心脏再同步化治疗的慢性充血性心力衰竭患者,分别于术前及术后6个月应用超声心动图测量左心室大小、左心室容积、左心室射血分数、二尖瓣反流面积、房室间、心室间及左心室内同步性。结果术后6个月患者左心室收缩末内径、左心室舒张末内径、左心室收缩末容积、左心室舒张末容积小于术前（P〈0.05或P〈0.01）,房室间、心室间、左心室内收缩同步性改善（P〈0.05或P〈0.01）。结论超声心动图可通过多项参数综合评价心脏再同步化治疗的效果。     

超声评价心脏再同步治疗的临床应用进展

心脏再同步治疗对顽固性心力衰竭的疗效可使患者的心室和/或室间达到最大的同步化,从而改善心衰患者的血流动力学和心功能,提高患者的生活质量.超声在心脏再同步治疗患者的入选,疗效的预测,指导起搏器电极位置的放置及术后随访过程中起搏参数的调控等方面有重要作用.本文就超声在心脏再同步治疗中的临床应用价值做一综述.     

瞬时波强技术评价心脏再同步化治疗术后短期疗效的临床研究

目的 探讨瞬时波强(WI)技术评价心脏再同步化治疗(CRT)术后短期疗效的临床应用价值.方法 对16例充血性心力衰竭患者于CRT术前、术后1周、术后1月和术后3月,应用Aloka α10分别测量左室内径及容积,计算左室收缩末容积变化率(△ESV)及左室射血分数(LVEF),应用WI技术测量W1及R-W1间期、W1-W2间期等指标.结果 慢性心力衰竭患者CRT治疗后左室发生逆重构,其中术后1月及术后3月左室收缩末期及舒张末期内径、左室收缩末期及舒张末期容积明显小于术前(P＜0.01,P＜0.05);左室收缩力增加,LVEF明显提高(P＜0.01).W1显著增加,W1-W2间期延长(P＜0.01).结论 WI为评价慢性充血性心力衰竭患者心脏再同步化治疗术后短期疗效提供了一种新的方法.     

Simplified post processing of cine DENSE cardiovascular magnetic resonance for quantification of cardiac mechanics

Background

Cardiovascular magnetic resonance using displacement encoding with stimulated echoes (DENSE) is capable of assessing advanced measures of cardiac mechanics such as strain and torsion. A potential hurdle to widespread clinical adoption of DENSE is the time required to manually segment the myocardium during post-processing of the images. To overcome this hurdle, we proposed a radical approach in which only three contours per image slice are required for post-processing (instead of the typical 30–40 contours per image slice). We hypothesized that peak left ventricular circumferential, longitudinal and radial strains and torsion could be accurately quantified using this simplified analysis.

Methods and Results

We tested our hypothesis on a large multi-institutional dataset consisting of 541 DENSE image slices from 135 mice and 234 DENSE image slices from 62 humans. We compared measures of cardiac mechanics derived from the simplified post-processing to those derived from original post-processing utilizing the full set of 30–40 manually-defined contours per image slice. Accuracy was assessed with Bland-Altman limits of agreement and summarized with a modified coefficient of variation. The simplified technique showed high accuracy with all coefficients of variation less than 10% in humans and 6% in mice. The accuracy of the simplified technique was also superior to two previously published semi-automated analysis techniques for DENSE post-processing.

Conclusions

Accurate measures of cardiac mechanics can be derived from DENSE cardiac magnetic resonance in both humans and mice using a simplified technique to reduce post-processing time by approximately 94%. These findings demonstrate that quantifying cardiac mechanics from DENSE data is simple enough to be integrated into the clinical workflow.     

组织运动二尖瓣环位移自动追踪技术对心脏再同步化治疗短期疗效的评价

目的 探讨定量组织运动二尖瓣环位移技术(TMAD)对心脏再同步化治疗(CRT)患者短期疗效的评价作用.方法 使用TMAD技术测量26例慢性充血性心力衰竭(CHF)患者CRT前和CRT 1个月后左室壁二尖瓣环6个位点的收缩期最大位移(Ds)、二尖瓣环6个位点达峰时间的标准差(Td-sd)以及任意两位点收缩期最大位移达峰时间的最大差值(Tds-diff),并将平均Ds与简化双平面Simpson法计算的左室射血分数(LVEF)、左室收缩末容积(LVESV)及左室面积变化分数(FAC)进行相关分析.结果 CRT 1个月后二尖瓣环6个位点Ds及平均Ds比CRT前显著增高,差异有统汁学意义(P<0.01);Tds-diff较CRT前减少,差异有统汁学意义(P<0.05);二尖瓣环6个位点Td-sd较CRT、前减少,差异有统计学意义(P<0.05);二尖瓣环6个位点平均Ds与LVEF、LVESV、FAC呈正相关(r分别为0.419,0.529,0.567,P<0.05).结论 TMAD可以用来评价CRT患者的短期疗效.     

双心室再同步化起搏治疗充血性心力衰竭患者的效果与护理

目的探讨双心室再同步化起搏治疗充血性心力衰竭患者的疗效及护理。方法比较63例充血性心力衰竭患者术前及行双心室再同步化起搏治疗术后的心功能NYHA分级、心电图QRs时限、左心室射血分数LVEF以及运动耐量6min步行距离,并对患者的护理措施进行总结。结果患者治疗后6个月NYHA从术前（3．40±0．50）级改善为术后（2．30±0．60）级,QRS时限从（144．68±16．40）1]ms降至（100．02±14．76）ms,LVEF（％）从（33．18±5．60）提高至（41．8±7．45）,6min步行距离从（305．40±30．30）m提高至（406．20±70．50）m,差异均有统计学意义（t=11．18,4．562,6．728,10．426;P〈0．01）;术后跟踪随访3—24个月,无一例死亡。结论双心室再同步化起搏是治疗充血性心力衰竭患者的一种有效治疗方法,能明显改善患者心脏功能及生活质量。做好术前心理护理、术中心电监测、术后观察和预防并发症的发生以及重视出院后跟踪随访等都是取得较佳疗效的重要保证。     

Echo Doppler parameters predict response to cardiac resynchronization therapy

Background  Cardiac resynchronization therapy (CRT) has been shown to reduce heart failure related morbidity and mortality. However, approximately 30% of patients do not respond to CRT. We investigated the usefulness of Echo Doppler parameters to predict reverse remodelling, functional improvement and mortality following CRT.
Materials and methods  Our population consists of 200 consecutive heart failure patients evaluated for ventricular dyssynchrony by echocardiography between February 1999 and May 2007 who subsequently received CRT. Patients were reassessed for signs of reverse remodelling after a mean follow-up of 10 months. Information on vital status was obtained from local registration authorities.
Results  Three parameters significantly predicted reverse remodelling in the logistic regression analysis: the Q-to-E-wave-delay (QED) at a cutoff of 550 ms (odds ratio 4·5, P -value 0·001), the interventricular mechanical delay (IVMD) at a cutoff of 60 ms (odds ratio 2·4, P -value 0·02), and the aortic electromechanical delay (A-EMD) at a cutoff of 140 ms (odds ratio 2·9, P -value 0·004). Furthermore, the QED and the IVMD also predicted all-cause mortality (hazard ratio 0·36, P -value 0·02 and 0·21, P -value 0·004, respectively). Adjustment for confounders did not alter the results.
Conclusions  The QED and IVMD predict reverse remodelling and survival following CRT. These parameters are easy to obtain, provide valuable prognostic information, and should thus be measured in CRT candidates evaluated by echocardiography.     

斑点追踪显像对慢性心力衰竭患者心脏再同步化治疗短期疗效的评价

目的 探讨超声斑点追踪显像(STI)技术对慢性心力衰竭患者心脏再同步化治疗(CRT)短期疗效的评价价值.方法 16例慢性心力衰竭患者,获取心尖长轴观测量各节段收缩期纵向应变达峰时间、径向应变达峰时间,胸骨旁短轴观测环向应变达峰时间,计算CRT术后1个月、术后3个月18节段纵向、径向、环向应变达峰时间标准差(LS-SD18、RS-SD18、CS-SD18),左室各节段收缩期纵向、径向、环向应变达峰时间最大差值(LS-dif、RS-dif、CS-dif)作为应变非同步指标.将术后3个月、1个月18节段纵向、径向、环向应变达峰时间标准差与术前的差值(△LS-SD18、△RS-SD18、ACS-SD18)与术后3个月、1个月左室收缩末容积减少百分比(△ESV%)进行相关性分析.结果 CRT后1个月、术后3个月LS-SD18、RS-SD18、CS-SD18及RS-dif较术前显著减少,差异有统计学意义(P<0.05);术后3个月△RS-SD18与术后3个月△ESV%具有明显的相关性(r=0.694).结论 应变非同步指标对评价短期CRT后机械非同步性具有重要意义.     

心脏再同步化治疗对心力衰竭犬心脏功能及相关炎性因子的影响

目的 探讨心脏再同步化治疗(CRT)对心力衰竭(HF)犬心脏功能及相关炎性因子的影响.方法 10条雌性健康清洁比格犬采用随机数字表法分为2组,实验组与对照组各5只.2组均给予开胸结扎冠脉制作HF动物模型,成模后仅实验组实施为期4周的CRT,对照组不给予CRT.记录与观察所有大鼠在实验期间的活动与进食情况;分别于实验前、...     

组织同步显像技术在扩张型心肌病心脏同步化治疗的临床应用

目的 探讨常规超声心动图及组织同步显像（TSI）技术在扩张型心肌病心脏同步化治疗（CRT）前、后的临床应用价值.方法 53例CRT治疗的扩张型心肌病患者,于CRT术前3d、术后1周、3个月和6个月在超声心动图指导下进行个体化参数程控,观察CRT前后不同起搏参数时各指标变化.结果 CRT治疗后左心室发生逆重构,其中术后3个月及6个月左心室舒张末期内径、左心室舒张末期容积明显小于术前（P＜0.01,P＜0.05）,左心室舒张充盈时间增加,二尖瓣反流量减少,LVEF明显提高（P＜0.01）,重度延迟节段数减少,节段数量由术前的3.1±1.3减少至6个月的1.5±1.4（P ＜0.01）,左心室起搏电极所在节段的达峰时间有的回复到正常范围,收缩峰值速度亦有改善,但仍没有到正常水平,12节段达峰时间标准差（Ts-SD）由术前的（139±33）ms缩短至（110±40）ms,差异有统计学意义（P＜o.01）.结论 常规超声心动图和TSI技术是预测评价CRT疗效的临床应用最简便有效的方法,是参与CRT全程的一种无创、准确的检查手段.