Benefits of cardiac resynchronization therapy for heart failure patients with narrow QRS complexes and coexisting systolic asynchrony by echocardiography.

OBJECTIVES: This study was designed to evaluate the role of cardiac resynchronization therapy (CRT) in heart failure (HF) patients with narrow QRS complexes (<120 ms) and echocardiographic evidence of mechanical asynchrony. BACKGROUND: Cardiac resynchronization therapy is currently recommended to advanced HF patients with prolonged QRS duration. Echocardiographic assessment of systolic mechanical asynchrony has been proven useful to predict a favorable response after CRT. METHODS: A total of 102 HF patients with New York Heart Association (NYHA) functional class III or IV were enrolled. Among them, 51 had wide QRS (>120 ms) and 51 had narrow QRS (<120 ms). Tissue Doppler imaging (TDI) was employed to select patients with systolic asynchrony (increased asynchrony index) in the narrow-QRS group. Clinical and echocardiographic assessments were performed at baseline and 3 months after CRT. RESULTS: There was a significant reduction of left ventricular (LV) end-systolic volume in both narrow (122 +/- 42 cc vs. 103 +/- 47 cc, p < 0.001) and wide (148 +/- 74 cc vs. 112 +/- 64 cc, p < 0.001) QRS groups. Improvement of NYHA functional class (both p < 0.001), maximal exercise capacity (both p < 0.05), 6-min hall-walk distance (both p < 0.01), ejection fraction (both p < 0.001), and mitral regurgitation (both p < 0.005) was also observed. In both groups, the degree of baseline mechanical asynchrony determined LV reverse remodeling to a similar extent, as shown by the superimposed regression lines. Withholding CRT for 4 weeks resulted in loss of echocardiographic benefits. CONCLUSIONS: Cardiac resynchronization therapy for HF patients with narrow QRS complexes and coexisting mechanical asynchrony by TDI results in LV reverse remodeling and improvement of clinical status. The amplitude of benefit is similar to the wide-QRS group provided that similar extent of systolic asynchrony is selected.     

Analysis of inter- and intraventricular asynchrony by tissue Doppler echocardiography

BACKGROUND AND INTRODUCTION: Cardiac resynchronization therapy (CRT) is a promising non-pharmacological treatment option for patients (pts) with severe severe heart failure (CHF), systolic left ventricular (LV) dysfunction, and ventricular conduction abnormalities (VCA). Pt selection for CRT, however, is still controversial. Tissue Doppler echocardiography (TDE) can be used to analyze regional wall motion with high temporal resolution. PATIENTS AND METHODS: In 33 CHF pts with VCA (QRS width > or =140 ms) and 20 normal probands, left and right ventricular (RV) filling and emptying were analyzed by flow and tissue Doppler to assess regional (anterior, lateral, inferior, and septal) asynchrony within the LV as well as asynchrony between the RVand LV. All time measurements were corrected for a heart rate of 60 bpm. Results Maximum interventricular and segmental intraventricular delay was 30 ms in the normals. LV asynchrony, defined as a regional delay of > or =40 ms, was found in 29/33 (88%) of the CHF pts, in 4 cases there was synchronous LV contraction despite VCA. In the pts with LV asynchrony, 22 (67%) showed the maximum delay in the lateral wall, 7 (21%) in the septum. Inter- and intra-ventricular asynchrony correlated weakly. CONCLUSIONS: In many CHF pts with VCA, there is a delay both between the two ventricles, and among different LV regions. Predominantly but not exclusively, the LV lateral wall shows the maximum intra-LV delay. Some CHF pts, however, seem to have a synchronous LV contraction despite VCA. TDE thus adds important information for pt selection with respect to CRT.     

Are left ventricular diastolic function and diastolic asynchrony important determinants of response to cardiac resynchronization therapy?

Cardiac resynchronization therapy (CRT) has been shown to reduce symptoms and reverse left ventricular (LV) remodeling. It is not known, however, whether diastolic function will improve after CRT and diastolic asynchrony will predict LV reverse remodeling. Seventy-six patients (mean age 65 +/- 12 years, 74% men) who received CRT were studied at baseline and after 3 months. Diastolic function was assessed by transmitral Doppler and tissue Doppler imaging. LV systolic and diastolic asynchrony were assessed by the time to peak myocardial contraction (Ts) and early diastolic relaxation (Te) using the 6 basal, 6 mid-segmental model. There were 42 responders (55%) with LV reverse remodeling (defined as a reduction of LV end-systolic volume >or=15%). Parameters of systolic function were significantly improved only in the responders. For diastolic function, there were reductions of transmitral E velocity in the 2 groups, without any change in atrial velocity or the E/A ratio. Tissue Doppler imaging revealed that myocardial early diastolic velocity was unchanged in responders but was significantly worsened in nonresponders. The systolic asynchrony index (the SD of Ts of 12 LV segments) correlated significantly with LV reverse remodeling (r = -0.64, p <0.001) but not the diastolic asynchrony index (the SD of Te of 12 LV segments) (r = -0.10, p = NS). The systolic asynchrony index was the only independent predictor of reverse remodeling (beta = -0.99, 95% confidence interval -1.41 to -0.58, p <0.001). In conclusion, CRT improves systolic function and systolic asynchrony but has a neutral effect on diastolic function and diastolic asynchrony. LV reverse remodeling response is determined by the severity of prepacing systolic asynchrony but not diastolic asynchrony or the diastolic filling pattern.     

Cardiac resynchronization therapy tailored by echocardiographic evaluation of ventricular asynchrony

OBJECTIVES: The value of interventricular and intraventricular echocardiographic asynchrony parameters in predicting reverse remodeling after cardiac resynchronization therapy (CRT) was investigated. BACKGROUND: Cardiac resynchronization therapy has been suggested as a promising strategy in patients with severe heart failure and left bundle branch block (LBBB), but the entity of benefit is variable and no criteria are yet available to predict which patients will gain. METHODS: Interventricular and intraventricular mechanical asynchrony was evaluated in 20 patients (8 men and 12 women, 63 +/- 10 years) with advanced heart failure caused by ischemic (n = 4) or nonischemic dilated cardiomyopathy (n = 16) and LBBB (QRS duration of at least 140 ms) using echocardiographic Doppler measurements. Left ventricular end-diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were calculated before and one month after CRT. Patients with a LVESVI reduction of at least 15% were considered as responders. RESULTS: Cardiac resynchronization therapy significantly improved ventricular volumes (LVEDVI from 150 +/- 53 ml/m(2) to 119 +/- 37 ml/m(2), p < 0.001; LVESVI from 116 +/- 43 ml/m(2) to 85 +/- 29 ml/m(2), p < 0.0001). At baseline, the responders had a significantly longer septal-to-posterior wall motion delay (SPWMD), a left intraventricular asynchrony parameter; only QRS duration and SPWMD significantly correlated with a reduction in LVESVI (r = -0.54, p < 0.05 and r = -0.70, p < 0.001, respectively), but the accuracy of SPWMD in predicting reverse remodeling was greater than that of the QRS duration (85% vs. 65%). CONCLUSIONS: In patients with advanced heart failure and LBBB, baseline SPWMD is a strong predictor of the occurrence of reverse remodeling after CRT, thus suggesting its usefulness in identifying patients likely to benefit from biventricular pacing.     

Diastolic and systolic asynchrony in patients with diastolic heart failure: a common but ignored condition.

OBJECTIVES: The present study aimed to examine whether diastolic and systolic asynchrony exist in diastolic heart failure (DHF) and their prevalence and relationship to systolic heart failure (SHF) patients. BACKGROUND: Few data exist on mechanical asynchrony in DHF. METHODS: Tissue Doppler echocardiography was performed in 373 heart failure patients (281 with SHF and 92 with DHF) and 100 normal subjects. Diastolic and systolic asynchrony was determined by measuring the standard deviation of time to peak myocardial systolic (Ts-SD) and peak early diastolic (Te-SD) velocity using a 6-basal, 6-mid-segmental model, respectively. RESULTS: Both heart failure groups had prolonged Te-SD (DHF vs. SHF vs. controls subjects: 32.2 +/- 18.0 ms vs. 38.0 +/- 25.2 ms vs. 19.5 +/- 7.1 ms) and Ts-SD (31.8 +/- 17.0 ms vs. 36.7 +/- 15.2 ms vs. 17.6 +/- 7.9 ms) compared with the control group (all p < 0.001 vs. control subjects). Based on normal values, the DHF group had comparable diastolic (35.9% vs. 43.1%; chi-square = 1.48, p = NS), but less systolic asynchrony than the SHF group (39.1% vs. 56.9%; chi-square = 8.82, p = 0.003). Normal synchrony, isolated systolic, isolated diastolic, and combined asynchrony were observed in 39.1%, 25.0%, 21.7%, and 14.1% of DHF patients, respectively, and these were 25.6%, 31.3%, 17.4%, and 25.6%, correspondingly, in SHF (chi-square = 10.01, p = 0.019). The correlation between systolic and diastolic asynchrony, and between the myocardial velocities and corresponding mechanical asynchrony appeared weak. A wide QRS duration (>120 ms) was rare in DHF (10.9% vs. 37.7% in SHF) (chi-square = 16.69, p < 0.001). CONCLUSIONS: Diastolic and/or systolic asynchrony was common in 61% of DHF patients despite narrow QRS complex. The presence of asynchrony was not related to myocardial systolic or diastolic function. Systolic and diastolic asynchrony were not tightly coupled, implying distinct mechanisms.     

Comparison of efficacy of reverse remodeling and clinical improvement for relatively narrow and wide QRS complexes after cardiac resynchronization therapy for heart failure

INTRODUCTION: Cardiac resynchronization therapy (CRT) has been shown to reverse left ventricular (LV) remodeling and improve symptoms in heart failure patients with wide QRS complexes; however, its role in patients with mildly prolonged QRS complexes is unclear. This study investigated if CRT benefited patients with mildly prolonged QRS complexes >120 to 150 ms and explored if the severity of systolic asynchrony determined such a response. METHODS AND RESULTS: Fifty-eight patients (age 66 +/- 11 years, 66% male) who had undergone CRT were studied prospectively. Of these patients, 27 had QRS duration between 120 and 150 ms (group A), and 31 had QRS duration >150 ms (group B). Tissue Doppler echocardiography and clinical assessment were performed at baseline and 3 months after CRT. Both groups had significant reduction of LV volume and increased ejection fraction, +dP/dt, and sphericity index (all P < 0.05). These improvements were greater in group B and were explained by the higher prevalence of systolic intraventricular asynchrony. Significant reverse remodeling (reduction of LV end-systolic volume >15%) was evident in 46% of group A patients and 68% of group B patients. Improvement in clinical endpoints was observed in both groups (all P < 0.01), although the changes in metabolic equivalent and New York Heart Association functional class were greater in group B. In both groups, systolic asynchrony index (TS-SD) was the most important predictor of reverse remodeling (r =-0.78, P < 0.001) and was the only independent predictor in the multivariate model (beta=-1.80, confidence interval =-2.18 to -1.42, P < 0.001); QRS duration was not. A predefined TS-SD value >32.6 ms had a sensitivity of 94% and specificity of 83% to predict reverse remodeling. Improvement of intraventricular asynchrony after CRT was evident only in responders (P = 0.01). CONCLUSION: Improvement of LV remodeling and clinical status is evident after CRT in heart failure patients with QRS duration >120 to 150 ms. These responders are closely predicted by the severity of prepacing intraventricular asynchrony but not QRS duration.     

Systolic and diastolic regional myocardial motion of pacing-induced versus idiopathic left bundle branch block with and without left ventricular dysfunction

To demonstrate systolic and diastolic asynchrony in patients with left bundle branch block (LBBB), tissue Doppler imaging (TDI) of 4 different walls was performed in 27 normal controls, 29 patients with right ventricular pacing and normal left ventricular (LV) ejection fraction (EF; pacing LBBB), and 35 patients with idiopathic LBBB. Patients with idiopathic LBBB were further classified into those with LVEF >50% and those with LVEF <35%. Asynchrony was calculated as the coefficient of variation of the time intervals from the QRS complex to the peak systolic velocity and to the peak of early diastolic relaxation. Patients with pacing and idiopathic LBBB had significantly longer QRS durations (162 +/- 20 vs 92 +/- 7 ms, p <0.001) and larger systolic (15.9 +/- 5.0% vs 4.1 +/- 2.1%, p <0.001) and diastolic (3.7 +/- 2.0% vs 1.4 +/- 0.6%, p <0.001) asynchrony than controls. Those with idiopathic LBBB and low EF had significantly larger diastolic asynchrony (5.7 +/- 2.1%) than those with pacing LBBB (2.9 +/- 1.1%) and those with idiopathic LBBB and normal EF (2.0 +/- 0.6%). Diastolic asynchrony was the only independent factor that correlated with LVEF (r = -0.64, p <0.001). Thus, idiopathic LBBB with LV dysfunction is characterized not only by systolic but also by diastolic asynchrony.     

心脏再同步治疗对慢性心力衰竭的临床疗效观察

目的观察心脏再同步治疗（CRT）对慢性心力衰竭的长期临床疗效。方法24例接受CRT的慢性心力衰竭患者,心功能Ⅲ～Ⅳ级（NYHA分级）,左心室射血分数（LVEF）≤0．35,左心室舒张末内径（LVEDD）／〉55mm,QRS时限≥120／TIS。植入前超声心动图及组织多普勒检查以评价心功能及心脏收缩不同步指标,并指导左心室电极导线的植入。植入后3、6个月及随后的每6个月进行随访,随访内容包括临床症状、心电图、LVEDD、LVEF及多普勒超声评价心脏收缩同步性指标。结果随访时间（12．0±4．6）个月,结果显示患者临床症状明显改善,QRS时限植入后较植入前缩短[（137．50±38．96）ms对（144．60±45．78）ms,P=0．67],但差异无统计学意义。植人后LVEDD较植入前明显缩小[（6．24±0．89）cm对（6．78±0．42）cm,P=0．03];LVEF则明显提高（0．36±0．09对0．31±0．03,P〈0．01）,左心房内径（LAD）也较术前明显缩小[（4．22±8．43）cm对（5．32±7．63）cm,P=0．01]。心脏收缩不同步指标与植入前相比也明显改善。结论对慢性心力衰竭的患者,CRT治疗可改善左心室功能,逆转左心室重构。     

Assessment of left ventricular dyssynchrony in patients with conduction delay and idiopathic dilated cardiomyopathy: head-to-head comparison between tissue doppler imaging and velocity-encoded magnetic resonance imaging.

OBJECTIVES: This study sought to compare tissue Doppler imaging (TDI) with velocity-encoded (VE) magnetic resonance imaging (MRI) for left ventricular (LV) dyssynchrony assessment. BACKGROUND: Cardiac resynchronization therapy (CRT) is proposed for patients with heart failure, depressed LV function, and a wide QRS complex. Selection is based mainly on electrocardiogram criteria, but recent data suggest that intraventricular dyssynchrony may be preferred for selection. An LV dyssynchrony can adequately be assessed with TDI, but this has not been compared directly with other imaging modalities. A VE MRI potentially allows direct myocardial wall motion measurements similar to TDI. METHODS: Twenty patients with heart failure, systolic LV dysfunction, and a wide QRS complex were included, as well as 10 normal individuals with normal QRS duration and LV function. The TDI and VE MRI data were acquired to study intraventricular dyssynchrony. RESULTS: Left ventricular dyssynchrony was not observed in normal individuals (mean dyssynchrony -2 +/- 15 ms on TDI; mean -5 +/- 17 ms on MRI, p = NS). In patients, mean LV dyssynchrony was 55 +/- 37 ms on TDI; 49 +/- 38 ms on MRI (p = NS). Good correlation between both modalities was observed (linear regression TDI = 0.99 x MRI - 5, n = 30, r = 0.98, p < 0.01). The MRI showed a small, nonsignificant underestimation of 5 +/- 8 ms compared with TDI. Agreement between MRI and TDI for classification according to severity of LV dyssynchrony (minimal, intermediate, and extensive) was excellent (kappa +/- SE = 0.96 +/- 0.07, p < 0.01) with 95% of patients classified identical. CONCLUSIONS: Both MRI and TDI yield comparable information on LV dyssynchrony; MRI is useful in the selection of patients for CRT.     

Tissue Doppler imaging predicts improved systolic performance and reversed left ventricular remodeling during long-term cardiac resynchronization therapy

OBJECTIVES: We sought to evaluate the long-term impact of cardiac resynchronization therapy (CRT) on left ventricular (LV) performance and remodeling using three-dimensional echocardiography and tissue Doppler imaging (TDI). BACKGROUND: Three-dimensional echocardiography and TDI allow rapid and accurate evaluation of LV volumes and performance. METHODS: Twenty-five consecutive patients with severe heart failure and bundle branch block who underwent biventricular pacemaker implantation were included. Before and after implantation of the pacemaker, three-dimensional echocardiography and TDI were performed. These examinations were repeated at outpatient visits every six months. RESULTS: Five patients (20%) died during one-year follow-up. In the remaining 20 patients, significant reductions in LV end-diastolic volume and LV end-systolic volume of 9.6 +/- 14% and 16.5 +/- 15%, respectively (p < 0.01), could be demonstrated during long-term follow-up. Accordingly, LV ejection fraction increased by 21.7 +/- 18% (p < 0.01). According to a newly developed TDI technique-tissue tracking-all regional myocardial segments improved their longitudinal systolic shortening (p < 0.01). The extent of the LV base displaying delayed longitudinal contraction, as detected by TDI before pacemaker implantation, predicted long-term efficacy of CRT. The QRS duration failed to predict resynchronization efficacy. CONCLUSIONS: Cardiac resynchronization significantly improved LV function and reversed LV remodeling during long-term follow-up. Patients likely to benefit from CRT can be identified by TDI before implantation of a biventricular pacemaker.     

Relation of left ventricular lead placement in cardiac resynchronization therapy to left ventricular reverse remodeling and to diastolic dyssynchrony

The effects of left ventricular (LV) lead placement for cardiac resynchronization therapy (CRT) on LV remodeling and dyssynchrony are not well defined. Sixty-one patients (age 60 +/- 11 years, 76% men) were evaluated by echocardiography before and 4 +/- 2 months after CRT and grouped by the LV lead placement (lateral, posterolateral, or anterolateral). Echocardiographic measurements included LV volumes and LV ejection fraction. Tissue Doppler imaging was used to assess for inter- and intraventricular systolic and diastolic dyssynchrony. Analysis of variance was used to determine the effect of the LV lead placement on echocardiographic variables after CRT. The LV lead was placed in a lateral cardiac vein in 33 patients (54%), posterolateral in 15 (25%), and anterior in 13 (21%). Lateral LV lead placement was associated with significantly smaller LV volumes compared with the posterolateral lead placement (p <0.01). Diastolic dyssynchrony improved significantly with lateral lead placement compared with the anterior lead location (p <0.05). Improvement in LV ejection fraction and inter- and intraventricular systolic dyssynchrony was similar among the 3 groups. In conclusion, in patients undergoing CRT, a lateral lead location resulted in greater reverse LV remodeling and improved diastolic dyssynchrony compared with other lead placement locations.     

组织多普勒超声评价窄QRS间期患者心脏再同步治疗效果

目的组织多普勒超声（TDI）指导下评价窄QRS间期合并心室不同步患者行心脏再同步治疗（CRT）对临床预后的影响。方法91例经超声心动图和TD[确诊为心脏收缩不同步的慢件心力衰竭患者,按是否接受CRT分为CRT组（窄QRS间期21例,宽QRS间期22例）和对照组（宽QRS间期25例,窄QRS间期23例）。对所有患者进行1年的随访,评价心功能及生存率。结果CRT组6min步行试验、生活质量积分、心功能（NYHA分级）明显改善。超声心动图及TDI结果显示,CRT组左心室收缩未容积、左心室舒张末容积明显减少,射血分数明显增加。与各对照组亚组相比,CRT组中窄QRS亚组心功能改善,6min步行试验距离、左心室射血分数、生活质量积分明垃增加,左心室收缩末容积和左心窀舒张末容积明显减少。结论在TDI指导下,窄QRS间期慢性心力衰竭可以从CRT中获益。     

6 VENTRICULAR INTER‐ AND LEFT VENTRICULAR INTRA VENTRICULAR SYSTOLIC ASYNCHRONY IN PATIENTS WITH DILATED CARDIOMYOPATHY AND THE EFFECT OF CARDIAC RESYNCHRONIZATION THERAPY

Aim: Data dealing with the effect of cardiac resynchronization therapy (CRT) on myocardial or interventricular systolic asynchrony derived by pulsed Doppler tissue imaging (PDTI) and pulsed flow Doppler imaging are scare. The purpose of this study was to evaluate ventricular inter‐ and left ventricular intraventricular systolic asynchrony and to describe the effects of CRT on Doppler imaging in patients with dilated cardiomyopathy (DCM) and reduced left ventricular ejection fraction (LVEF). Methods: 217 consecutive patients (96 patients with left bundle branch bloc[LBBB]) with DCM underwent a standard and PDTI echocardiography examination. We measured the interval between Q wave in the electrocardiogram and the beginning of the systolic velocity profile (Q ‐ Sb) recorded from the right and left ventricular outflow tract by pulsed Doppler imaging (PWD) and from 5 basal segments (right ventricle, septal‐, lateral‐, anterior‐, inferior left ventricle) by PDTI from an apical approach. In 18 patients a biventricular pacing system was implanted and the effect of the cardiac resynchronization therapy was evaluated 1 month after implantation by echo examination. Results: A high‐grade interventricular systolic asynchrony (> 60 ms) was measured in 3 patients (2.5%) without LBBB versus 33 patients (16%) with LBBB. A severe left ventricular intraventricular systolic asynchrony (> 60 ms) was documented in 33 patients (27%) without LBBB versus 27 patients (28%) with LBBB. CRT in 18 patients reduced the interventricular systolic asynchrony from 52 ± 29 (20–116) ms to 14 ± 10 (0–32) ms (p < 0.01). Left ventricular intraventricular systolic asynchrony was reduced from 87 ± 35 (42–168) ms to 29 ± 14 (4–52) ms (p < 0.001). All patients with CRT showed an improvement in NYHA functional status. Conclusions: Patients with LBBB and DCM showed a significant intense degree of interventricular systolic asynchrony compared with patients without LBBB. The incidence of high‐grade left ventricular intraventricular systolic asynchrony was not influenced by LBBB. CRT is able to reduce inter‐ and left ventricular intraventricular systolic asynchrony. We recommend the use of PWD and PDTI in all patients with DCM as an additional important selection criteria for CRT.     

Cardiac resynchronization therapy in patients with a narrow QRS complex.

OBJECTIVES: The purpose of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) in heart failure patients with narrow QRS complex (<120 ms) and evidence of left ventricular (LV) dyssynchrony on tissue Doppler imaging (TDI). BACKGROUND: Cardiac resynchronization therapy is beneficial in selected heart failure patients with wide QRS complex (> or =120 ms). Patients with narrow QRS complex are currently not eligible for CRT, and the potential effects of CRT are not well studied. METHODS: Thirty-three consecutive patients with narrow QRS complex and 33 consecutive patients with wide QRS complex (control group) were prospectively included. All patients needed to have LV dyssynchrony > or =65 ms on TDI, New York Heart Association (NYHA) functional class III/IV heart failure, and LV ejection fraction < or =35%. RESULTS: Baseline characteristics, particularly LV dyssynchrony, were comparable between patients with narrow and wide QRS complex (110 +/- 8 ms vs. 175 +/- 22 ms; p = NS). No significant relationship was observed between baseline QRS duration and LV dyssynchrony (r = 0.21; p = NS). The improvement in clinical symptoms and LV reverse remodeling was comparable between patients with narrow and wide QRS complex (mean NYHA functional class reduction 0.9 +/- 0.6 vs. 1.1 +/- 0.6 [p = NS] and mean LV end-systolic volume reduction 39 +/- 34 ml vs. 44 +/- 46 ml [p = NS]). CONCLUSIONS: Cardiac resynchronization therapy appears to be beneficial in patients with narrow QRS complex and severe LV dyssynchrony on TDI, with similar improvement in symptoms and comparable LV reverse remodeling to patients with wide QRS complex. The current results need confirmation in larger patient cohorts.     

Left ventricular systolic dyssynchrony index by three-dimensional echocardiography in patients with decreased left ventricular function: comparison with tissue Doppler echocardiography

Background: Three‐dimensional echocardiography (3DE) can simultaneously assess left ventricular (LV) regional systolic motion and global LV mechanical dyssynchrony. Methods: We used 3DE to measure systolic dyssynchrony index (SDI) (standard deviation of the time from cardiac cycle onset to minimum systolic volume in 17 LV segments) in 100 patients and analyzed the association of SDI with other parameters for LV systolic function or dyssynchrony. Eighteen patients who underwent cardiac resynchronization therapy (CRT) were also evaluated at 6 months after CRT, and the association of baseline SDI and tissue Doppler imaging (TDI) dyssynchrony index (Ts‐SD) with the change of LV end‐systolic volume (ESV) analyzed. Ts‐SD was calculated using the standard deviation of the time from the QRS complex to peak systolic velocity. Results: There was a significant inverse correlation between LVEF and SDI (r =?0.686, P < 0.0001). QRS duration was also significantly correlated to SDI (r = 0.407, P < 0.0001). There was a significant positive correlation between baseline SDI and the decrease in LVESV after CRT (r = 0.42). Baseline SDI was significantly greater in responders (10 patients) than in nonresponders (16.4 ± 5.1 vs. 7.9 ± 2.4%, P < 0.01), but there was no significant difference in Ts‐SD. SDI > 11.9% predicted CRT response with a sensitivity of 90% and a specificity of 75%. Conclusions: SDI derived from 3DE is a useful parameter to assess global LV systolic dyssynchrony and predict responses to CRT. (Echocardiography 2012;29:346‐352)     

Correlation between Doppler derived dP/dt and left ventricular asynchrony in patients with dilated cardiomyopathy: A combined study using strain rate imaging and conventional Doppler echocardiography

AIM: To evaluate the relationship between Doppler-derived left ventricular (LV) dP/dt and the degree of LV mechanical asynchrony measured by strain rate imaging. METHODS AND RESULTS: The study group consisted of 69 patients with variable degree of LV dysfunction and mitral regurgitation (MR). Conventional echo variables and LV dP/dt were calculated from the MR Doppler spectrum by rate-pressure-rise method. Strain rate traces were obtained by 12-segment model and LV long axis images were analyzed off-line. The longest time intervals between the peak negative strain rate waves at isovolumic contraction period and peak systole from reciprocal segments were defined as asynchrony index AIc or AIs, respectively. The maximum differences in time-to-peak systolic velocities between opposing walls were also measured as asynchrony index by tissue Doppler (AItd). The dP/dt, mean QRS duration, AIc, AIs, and AItd were 836 +/- 266 mmHg/sec, 125 +/- 31, 38 +/- 28, 64 +/- 44, and 52 +/- 32 m, respectively. No significant correlation between the dP/dt and the LV dimension, ejection fraction or QRS duration was observed. However, dP/dt correlated negatively with AIc, or AIs (r:-0.78, -0.72, P < or = 0.0001) and AItd (r:-0.65, P < or = 0.001). A cutoff dP/dt value of under 700 mmHg/sec can discriminate patients over median AIs (55 ms) or patients with AIc over 30 ms with high sensitivity and specificity. CONCLUSIONS: Doppler-derived LV dP/dt is related to the degree of LV dyssynchrony rather than the conventional systolic function indices such as EF% in patients with severe heart failure. Noninvasive dP/dt assessment in addition to advanced imaging techniques can be used to define patients for cardiac resynchronization therapy (CRT).     

Has Mechanical Dyssynchrony Still a Role in Predicting Cardiac Resynchronization Therapy Response?

Current guidelines for cardiac resynchronization therapy (CRT) include electrical but not mechanical dyssynchrony assessment. Our study aims to investigate the effects of isolated or combined mechanical and electrical dyssynchrony, according, respectively, to a standard deviation of tissue Doppler imaging (TDI) derived time to systolic peak ≥32.6 ms and to a QRS duration ≥120 ms, in predicting CRT reverse remodeling. Method: One hundred ninety‐two CRT patients were studied. All patients underwent a complete standard and TDI echocardiography examination before and 6 months after CRT. According to baseline evaluation patients were divided into Group 1, patients with isolated electrical dyssynchrony (QRS ≥ 120 ms, TS‐SD < 32.6), Group 2, patients with isolated mechanical dyssynchrony (QRS < 120 ms, TS‐SD ≥ 32.6) and Group 3, patients with combined electrical and mechanical dyssynchrony (QRS ≥ 120 ms, TS‐SD ≥ 32.6). Patients were considered CRT responders according to ≥15 left ventricular end‐systolic volume (LVESV) reduction at follow‐up (FU). Result: At FU, 86 (45%) patients were responders. The highest CRT response rate was observed in Group 3 (62/119, 52%, P < 0.001 vs. Group 1). No significant differences in response rate were observed between Group 1 (13/47, 27%) and Group 2 (11/26, 42%). In Group1, CRT did not induce any significant change in LV end‐diastolic volume (LVEDV), LVESV, LV ejection fraction (LVEF), myocardial performance index (MPI), while in Group 2, LVEF (P < 0.001) and MPI (P < 0.05) were improved. In Group 3, LVEDV, LVESV, LVEF, MPI were significantly improved (P < 0.0001 for all). Conclusion: Our data demonstrate that the highest CRT response rate can be achieved by combining traditional QRS criterion and a currently used echocardiographic dyssynchrony parameter. (Echocardiography, 2010;27:831‐838)     

Quantification of Left Ventricular Asynchrony Throughout the Whole Cardiac Cycle with a Computed Algorithm: Application for Optimizing Resynchronization Therapy

Introduction: Measurement of left ventricular (LV) asynchrony is usually determined on single time points from spectral tissue Doppler imaging (TDI) scans that are frequently difficult to identify or not representative of the whole cardiac cycle. Our aim was to validate a new asynchrony index that evaluates the motion of the LV walls throughout the whole cardiac cycle.
Methods and Results: Ten healthy volunteers and 50 patients undergoing cardiac resynchronization therapy (CRT) were studied with TDI. Wall displacement tracings from the septal and lateral LV walls were analyzed. Cross-correlation was calculated and 2 indices were obtained to assess LV asynchrony: the time delay and the superposition index (SI) between wall displacements. These results were compared between healthy volunteers and CRT patients, and between responders and nonresponders to CRT. Also, the optimal interventricular (VV) interval was based upon the best matching level. Volunteers showed lower asynchrony indices (83 ± 2% SI, 17 ± 8 ms time delay) as compared with CRT patients (63 ± 15% SI, 73 ± 60 ms time delay, P < 0.05). Responders also had more LV dyssynchrony than nonresponders (58 ± 15% SI and 92 ± 66 ms vs 68 ± 12% and 48 ± 34 ms, P < 0.05). The optimum VV interval selected by the computed algorithm showed an excellent concordance (Kappa = 0.90, P < 0.05) with that determined by other validated methods for optimizing the programming of CRT devices.
Conclusions: This approach allows measurement of LV intraventricular asynchrony throughout the cardiac cycle, being useful to determine the optimum VV interval and to select candidates for CRT.     

Phase analysis of gated myocardial perfusion single-photon emission computed tomography compared with tissue Doppler imaging for the assessment of left ventricular dyssynchrony.

OBJECTIVES: The purpose of this study was to compare left ventricular (LV) dyssynchrony assessment by gated myocardial perfusion single-photon emission computed tomography (SPECT) (GMPS) and tissue Doppler imaging (TDI). BACKGROUND: Recently, it has been suggested that LV dyssynchrony is an important predictor of response to cardiac resynchronization therapy (CRT); dyssynchrony is predominantly assessed by TDI with echocardiography. Information on LV dyssynchrony can also be provided by GMPS with phase analysis of regional LV maximal count changes throughout the cardiac cycle, which tracks the onset of LV thickening. METHODS: In 75 patients with heart failure, depressed LV function, and wide QRS complex, GMPS and 2-dimensional echocardiography, including TDI, were performed as part of clinical screening for eligibility for CRT. Clinical status was evaluated with New York Heart Association functional classification, 6-min walk distance, and quality-of-life score. Different parameters (histogram bandwidth, phase SD, histogram skewness, and histogram kurtosis) of LV dyssynchrony were assessed from GMPS and compared with LV dyssynchrony on TDI with Pearson's correlation analyses. RESULTS: Histogram bandwidth and phase SD correlated well with LV dyssynchrony assessed with TDI (r = 0.89, p < 0.0001 and r = 0.80, p < 0.0001, respectively). Histogram skewness and kurtosis correlated less well with LV dyssynchrony on TDI (r = -0.52, p < 0.0001 and r = -0.45, p < 0.0001, respectively). CONCLUSIONS: The LV dyssynchrony assessed from GMPS correlated well with dyssynchrony assessed by TDI; histogram bandwidth and phase SD showed the best correlation with LV dyssynchrony on TDI. These parameters seem most optimal for assessment of LV dyssynchrony with gated SPECT. Outcome studies after CRT are needed to further validate the use of GMPS for assessment of LV dyssynchrony.     

Improvements in left ventricular diastolic function after cardiac resynchronization therapy are coupled to response in systolic performance.

OBJECTIVES: To determine the short-term effects of cardiac resynchronization therapy (CRT) on measurements of left ventricular (LV) diastolic function in patients with severe heart failure. BACKGROUND: Cardiac resynchronization therapy improves systolic performance; however, the effects on diastolic function by load-dependent pulsed-wave Doppler transmitral indices has been variable. METHODS: Fifty patients with severe heart failure were evaluated by two-dimensional Doppler echocardiography immediately prior to and 4 +/- 1 month after CRT. Measurements included LV volumes and ejection fraction (EF), pulsed-wave Doppler (PWD)-derived transmitral filling indices (E- and A-wave velocities, E/A ratio, deceleration time [DT], diastolic filling time [DFT], and isovolumic relaxation time). Tissue Doppler imaging was used for measurements of systolic and diastolic (Em) velocities at four mitral annular sites; mitral E-wave/Em ratio was calculated to estimate LV filling pressure. Color M-mode flow propagation velocities were also obtained. RESULTS: After CRT, LV volumes decreased significantly (p < 0.001) and LVEF increased >5% in 28 of 50 patients (56%) and were accompanied by reduction in PWD mitral E-wave velocity and E/A ratio (both p < 0.01), increased DT and DFT (both p < 0.01), and lower filling pressures (i.e., E-wave/Em septal; p < 0.01). Patients with LVEF response < or =5% after CRT had no significant changes in measurements of diastolic function; LV relaxation (i.e., Em velocities) worsened in this group. CONCLUSIONS: In heart failure patients receiving CRT, improvement in LV diastolic function is coupled to the improvement in LV systolic function.