Usefulness of echocardiographic tissue synchronization imaging to predict acute response to cardiac resynchronization therapy

Echocardiographic tissue synchronization imaging (TSI) consists of color-coding time-to-peak tissue Doppler velocities. This study of 29 patients who underwent cardiac resynchronization therapy (CRT) demonstrated that differences in baseline time-to-speak velocities of opposing ventricular walls by TSI were greater in 15 patients, with an acute hemodynamic improvement. A >/=65 ms delay from the anterior septum to the posterior wall using the apical long-axis view had 87% sensitivity and 100% specificity for predicting an acute response. Although a subgroup without acute improvement had later decreases in end-systolic volume, suggesting that acute response underestimates long-term effects, TSI has potential to assist in guiding CRT.     

Septal to posterior wall motion delay fails to predict reverse remodeling or clinical improvement in patients undergoing cardiac resynchronization therapy.

OBJECTIVES: The aim of this study was to test the hypothesis that a longer septal-to-posterior wall motion delay (SPWMD) would predict greater reverse remodeling and an improved clinical response in heart failure patients randomized to cardiac resynchronization therapy (CRT) in the CONTAK-CD trial. BACKGROUND: The SPWMD predicted clinical benefit with CRT in two previous studies from the same center. METHODS: In this retrospective analysis of the CONTAK-CD trial, SPWMD was measured from the baseline echocardiogram of 79 heart failure patients (ejection fraction 22 +/- 7%, QRS duration 159 +/- 27 ms, 72% ischemic, 84% male) randomized to CRT and compared with six-month changes in echocardiographic and clinical parameters. Patients with a left ventricular end-systolic volume index (LVESVI) reduction of at least 15% were considered responders. RESULTS: The feasibility and reproducibility of performing the SPWMD measurements were poor. Larger values for SPWMD did not correlate with six-month changes in left ventricular end-diastolic volume index (p = 0.26), LVESVI (p = 0.41), or left ventricular ejection fraction (p = 0.36). Responders did not have a significantly different SPWMD than non-responders (p = 0.26). The SPWMD did not correlate with measures of clinical improvement. At a threshold of SPWMD >130 ms, the test characteristics to predict reverse remodeling or a clinical response were inadequate. CONCLUSIONS: The previous findings that SPWMD predicts reverse remodeling or clinical improvement with CRT were not reproducible in patients randomized in the CONTAK-CD trial.     

Usefulness of triplane tissue Doppler imaging to predict acute response to cardiac resynchronization therapy

This study evaluated the value of triplane tissue Doppler imaging (TDI) to predict acute response after cardiac resynchronization therapy (CRT). Forty-nine patients scheduled for CRT underwent triplane echocardiography with simultaneous TDI acquisition before and 48 hours after implantation. A 3-dimensional left ventricular (LV) volume was generated and LV volumes and ejection fraction were calculated. A parametric imaging technique, tissue synchronization imaging, was applied to portray the area of latest mechanical activation. LV dyssynchrony was quantitatively analyzed by evaluating time from QRS onset to peak myocardial velocity in 12 LV segments from the triplane dataset. Acute response was defined as > or =15% decrease in LV end-systolic volume. Receiver-operating characteristic curves of dyssynchrony parameters were analyzed to identify predictors of response to CRT. Acute response was observed in 47% of patients. Responders had a significantly larger extent of LV dyssynchrony at baseline compared with nonresponders. Optimal prediction of acute response to CRT was obtained with the SD of time delays in all LV segments (sensitivity 91%, specificity 85%). In conclusion, 3-dimensional TDI echocardiography permits parametric and quantitative analyses of LV dyssynchrony and assessment of LV volumes and ejection fraction. LV dyssynchrony parameters, derived from the triplane TDI dataset, were highly predictive for acute volumetric response to CRT.     

Doppler echocardiographic methods for optimization of the atrioventricular delay during cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is beneficial for a majority of patients with medically refractory heart failure due to severe left ventricular (LV) systolic dysfunction and prolonged interventricular conduction to improve symptoms and LV performance. An optimally programmed atrioventricular delay (AVD) during CRT can be also important to maximize the response in left ventricular function. Several Doppler echocardiographic methods have been reported to be useful for determination of the optimal AVD. This review will discuss the various Doppler-based approaches to program the AVD in patients that receive CRT.     

Echocardiographic measures of acute haemodynamic response after cardiac resynchronization therapy predict long-term clinical outcome.

AIMS: Although acute haemodynamic improvement in response to cardiac resynchronization therapy (CRT) is reflective of a favourable cardiac contractile response, there is limited information regarding not only its ability to predict long-term clinical outcome but also cardiac-substrate-specific differences in the prognostic value of this measure. METHODS AND RESULTS: Fifty-three heart failure patients (69 +/- 11 years) with low left ventricle ejection fraction (LVEF) (22 +/- 6%), wide QRS (169 +/- 31 ms), and indications for CRT were included. There were no significant differences in age, New York Heart Association (NYHA) class, medications, QRS width, or LVEF between ischaemic (n = 37) and non-ischaemic (n = 16) groups. Echocardiograms were performed within 24 h of implantation with device OFF and ON. Acute haemodynamic response was measured as LV dP/dt derived from the CW Doppler of mitral regurgitation. Percentage change in dP/dt was used to classify patients: high- (HR: DeltadP/dt > 25%) or poor-responders (PR: DeltadP/dt 相似文献   

二维斑点追踪显像技术预测心脏再同步治疗的疗效

目的旨在比较二维斑点追踪显像技术与现有的超声心动图技术对心脏再同步治疗（CRT）疗效的预测价值。方法施行CRT的患者50例,每个患者植入术前均采用血流多普勒、组织多普勒和二维斑点追踪显像的方法进行收缩不同步的评价,有效者定义为术后6个月左心室收缩末容积缩小〉15％或左心室射血分数（LVEF）绝对值增加〉5％的患者。结果CRT有效组起搏前左心室射血前时间显著长于无效组[（146．0±34．5）ms对（123．5±32．0）ms,P〈0．05],其余常规超声心动图参数和组织多普勒参数在两组间差异无统计学意义。二维斑点追踪显像技术示CRT有效组和无效组的左心室应变达峰时间标准差（Tstrain—SD）的差异无统计学意义（P〉0．05）,而CRT有效组的应变率结束时间标准差（Tsr—SD）显著高于无效组（P〈0．05）。两组间左心室应变均值（Strain-12）的差异亦无统计学意义（P〉0．05）,而CRT有效组的左心室12节段纵轴反向应变总和（Pstrain-12）显著高于无效组[（12．5±7．9）％对（7．1±8．4）％,P〈0．05]。将140．5ms作为截点值,左心室射血前时间预测超声心动图有效的敏感性和特异性分别为63％和79％,将70．7ms作为截点值,Tsr—SD预测CRT有效的敏感性和特异性分别为73％和65％。结论常规超声心动图参数中仅左心室射血前时间能预测CRT疗效,二维斑点追踪显像技术的部分参数预测CRT疗效优于组织多普勒。     

Tailored echocardiographic interventricular delay programming further optimizes left ventricular performance after cardiac resynchronization therapy.

BACKGROUND: The aim of cardiac resynchronization therapy is correction of left ventricular (LV) dyssynchrony. However, little is known about the optimal timing of LV and right ventricular (RV) stimulation. OBJECTIVES: The purpose of this study was to evaluate the acute hemodynamic effects of biventricular pacing, using a range of interventricular delays in patients with advanced heart failure. METHODS: Twenty patients with dilated ischemic (n = 12) and idiopathic (n = 8) cardiomyopathy (age 66 +/- 6 years, New York Heart Association class III-IV, LV end-diastolic diameter >55 mm, ejection fraction 22% +/- 18%, and QRS 200 +/- 32 ms) were implanted with a biventricular resynchronization device with sequential RV and LV timing (VV) capabilities. Tissue Doppler echocardiographic parameters were measured during sinus rhythm before implantation and following an optimal AV interval with both simultaneous and sequential biventricular pacing. The interventricular interval was modified by advancing the LV stimulus (LV first) or RV stimulus (RV first) up to 60 ms. For each stimulation protocol, standard echocardiographic Doppler and tissue Doppler imaging (TDI) echo were used to measure the LV outflow tract velocity-time integral, LV filling time, intraventricular delay, and interventricular delay. RESULTS: The highest velocity-time integral was found in 12 patients with LV first stimulation, 5 patients with RV first stimulation, and 3 patients with simultaneous biventricular activation. Compared with simultaneous biventricular pacing, the optimized sequential biventricular pacing significantly increased the velocity-time integral (P <.001) and LV filling time (P = .001) and decreased interventricular delay (P = .013) and intraventricular delay (P = .010). The optimal VV interval could not be predicted by any clinical nor echocardiographic parameter. At 6-month follow-up, the incidence of nonresponders was 10%. CONCLUSION: Optimal timing of the interventricular interval results in prolongation of the LV filling time, reduction of interventricular asynchrony, and an increase in stroke volume. In patients with advanced heart failure undergoing cardiac resynchronization therapy, LV hemodynamics may be further improved by optimizing LV-RV delay.     

Baseline scintigraphic abnormalities by myocardial perfusion imaging predict echocardiographic response to cardiac resynchronization therapy in nonischemic cardiomyopathy

BACKGROUND: Significant myocardial scar in the posterolateral left ventricle (LV) has been associated with a diminished response to cardiac resynchronization therapy (CRT) in patients with coronary artery disease, but the effects of resting perfusion abnormalities in nonischemic cardiomyopathy (NICM) are yet to be described. HYPOTHESIS: We sought to characterize the effect of myocardial perfusion abnormalities upon echocardiographic outcomes of CRT in patients with NICM. METHODS: Twenty-one patients (mean age 64.4 +/- 13.3; 71.4% male; mean left ventricular ejection fraction [LVEF] 20.2 +/- 6.9%) with NICM who underwent CRT implantation and Thallium-201 single positron emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included. MPI studies were read quantitatively, assigning each of 17 myocardial segments a perfusion score (0-4) and cumulatively generating a summed perfusion score (SPS). The LV lead position was determined by chest radiography. Echocardiograms were performed both before and after (median 12 mo) CRT in 15 patients. RESULTS: Echocardiographic response, defined as > or = 15% relative increase in LVEF, was documented in 8 (53.3%) of 15 patients. All patients (5/5) with an SP < or =6 responded to CRT, whereas only 30.0% (3/10) with an SPS > or = 6 responded (odds ratio 3.33 [95% confidence interval {CI} 1.29-8.59]; p = 0.01). All nonresponders had inferior perfusion defects. Defect density adjacent to the LV lead tip had little demonstrable effect upon CRT efficacy. CONCLUSIONS: The presence of significant myocardial perfusion defects negatively influences echocardiographic response to CRT in NICM. These findings warrant prospective confirmation and histopathological correlation with explanted hearts.     

Myocardial tissue Doppler echocardiography and cardiac resynchronization therapy

Cardiac resynchronization therapy (CRT) is a promising technique for patients with end-stage, drug-refractory heart failure. Still 20-30% of the patients treated with CRT do not respond. Accordingly, the current selection criteria need to be refined, and it appears that demonstration of left ventricular dyssynchrony may be mandatory for response to CRT. Novel echocardiographic methods are currently investigated to detect left ventricular dyssynchrony and thereby improve the selection of candidates for CRT. In this brief review, these techniques will be discussed.     

Reverse electric remodeling after cardiac resynchronization therapy and relation to clinical and echocardiographic outcomes

BackgroundIn heart failure, there are structural and electric changes that affect the long term prognosis. While structural remodeling could be reversed by cardiac resynchronization therapy (CRT), little is known regarding reverse electric remodeling and its relation to the response to CRT.ObjectivesTo study the electric changes following CRT and their relation to patients’ response.MethodsThirty patients with implanted CRT device were included. Echocardiograms and surface electrocardiograms (ECGs) done before CRT were retrospectively analyzed. At the time of enrollment, echocardiography and ECG (during setting the CRT to off mode) were done. QRS duration (QRSD), QT interval, QTc interval, QT dispersion (QTd), and T wave peak to end (TPE) interval were measured.ResultsMean time since implantation was 15.26 ± 6 months. QRSD decreased from 146.33 ± 16.29 to 134.33 ± 17.15 ms (p < 0.001). QT interval decreased from 420.33 ± 28.46 to 398.66 ± 21.29 ms (p < 0.001). QTc interval decreased from 505.66 ± 45.53 to 475.23 ± 31.08 ms (p < 0.001). QTd decreased from 58 ± 13.23 to 34.66 ± 13.82 ms (p < 0.001). TPE interval decreased from 124 ± 24.3 to 102 ± 22.5 ms (p < 0.001). Responders to CRT (19 patients, 63.3%) had larger ΔQRSD, ΔQTd, and ΔTPE than non responders (p = 0.002, 0.002, and 0.004, respectively). Cutoff values of −20 ms for each of ΔQRSD, ΔQTd, and ΔTPE could predict response to CRT with odds ratio (95% CI) of 4.05 (1.12–14.6), 2.75 (1.25–6), and 4.43 (1.21–15.5), respectively.ConclusionsCRT induced reverse electric remodeling affecting both depolarization and repolarization parameters on surface ECG. Reverse electric remodeling was associated with favorable clinical and echocardiographic outcomes.     

Utility of echocardiographic radial strain imaging to quantify left ventricular dyssynchrony and predict acute response to cardiac resynchronization therapy

Echocardiographic strain imaging was used to quantify radial mechanical dyssynchrony in 38 patients who underwent cardiac resynchronization therapy. Dyssynchrony, defined as the time difference of peak radial strain in the septum versus the posterior wall, was significantly greater in patients with acute hemodynamic responses, and changes in radial dyssynchrony correlated with changes in stroke volume. A > or =130-ms difference in septal versus posterior wall peak strain when combined with a favorable left ventricular lead position was strongly predictive of immediate improvement in stroke volume with resynchronization therapy (95% sensitivity, 88% specificity), regardless of electrocardiographic QRS duration.     

Prospective comparison of echocardiographic atrioventricular delay optimization methods for cardiac resynchronization therapy

BACKGROUND: Atrioventricular (AV) delay optimization can be an important determinant of the response to cardiac resynchronization therapy (CRT) in patients with medically refractory heart failure and a ventricular conduction delay. OBJECTIVES: The purpose of this study was to compare two Doppler echocardiographic methods of AV delay optimization after CRT. METHODS: Forty consecutive patients (age 59 +/- 12 years) with severe heart failure, New York Heart Association class 3.1 +/- 0.4, QRS duration 177 +/- 23 ms, and left ventricular ejection fraction 26% +/- 6% referred for CRT were studied using two-dimensional Doppler echocardiography. In each patient, the acute improvement in stroke volume with CRT in response to two methods of AV delay optimization was compared. In the first method, the AV delay that produced the largest increase in the aortic velocity time integral (VTI) derived from continuous-wave Doppler (aortic VTI method) was measured. In the second method, the AV delay that optimized the timing of mitral valve closure to occur simultaneously with the onset of left ventricular systole was calculated from pulsed Doppler mitral waveforms at a short and long AV delay interval (mitral inflow method). RESULTS: The optimized AV delay determined by the aortic VTI method resulted in an increase in aortic VTI of 19% +/- 13% compared with an increase of 12% +/- 12% by the mitral inflow method (P <.001). The optimized AV delay by the aortic VTI method was significantly longer than the optimized AV delay calculated from the mitral inflow method (119 +/- 34 ms vs 95 +/- 24 ms, P <.001). There was no correlation in the AV delay determined by the two methods (r = 0.03). CONCLUSION: AV delay optimization by Doppler echocardiography for patients with severe heart failure treated with a CRT device yields a greater systolic improvement when guided by the aortic VTI method compared with the mitral inflow method.     

组织多普勒指导心脏再同步治疗中左心室电极导线的植入

心脏再同步化治疗（CRT）作为慢性充血性心力衰竭治疗的有效方法之一，已逐渐被人们接受，在多数病人中，它能改善临床症状，逆转或终止慢性心脏重构。然而，仍有约20％～30％的患者起搏后症状未改善甚至恶化。究其原因可能与患者入选不合适以及左心室电极导线位置不恰当有关，但目前国内外对于如何指导左心室电极导线的放置还没有理想的方法。我们运用组织多普勒技术，在术前直接测量心室机械不同步性，识别室壁运动最延迟的部位及其程度，指导术中左心室起搏电极导线的放置，取得了较好的临床效果。