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Objectives: This study aimed to evaluate the impact of cardiac contractility modulation (CCM) on left ventricular (LV) size and myocardial function. Background: CCM is a device-based therapy for patients with advanced heart failure. Previous studies showed that CCM improved symptoms and exercise capacity; however, comprehensive assessment of LV structure, function, and reverse remodeling is not available. Methods: Thirty patients (60 ± 11 years, 80% male) with New York Heart Association (NYHA) functional class III heart failure, ejection fraction <35%, and QRS <120 ms were assessed at baseline and 3 months. LV reverse remodeling was measured by real-time 3-dimensional echocardiography. Using tissue Doppler imaging, the peak systolic velocity (Sm) and peak early diastolic velocity (Em) were calculated for LV function, while the standard deviation of the time to peak systolic velocity (Ts-SD) and the time to peak early diastolic velocity (Te-SD) were calculated for mechanical dyssynchrony. Results: LV reverse remodeling was evident, with a reduction in LV end-systolic volume by −11.5 ± 10.5% and a gain in ejection fraction by 4.8 ± 3.6% (both p < 0.001). Myocardial contraction was improved in all LV walls, including sites remote from CCM delivery (all p < 0.05); hence, the mean Sm of 12 (2.2 ± 0.6 cm/s vs. 2.5 ± 0.7 cm/s) or 6 basal LV segments (2.5 ± 0.6 cm/s vs. 3.0 ± 0.7 cm/s) were increased significantly (both p < 0.001). In contrast, CCM had no impact on regional or global Em (2.9 ± 1.3 cm/s vs. 2.9 ± 1.1 cm/s), whereas Ts-SD (28.2 ± 11.2 ms vs. 27.9 ± 12.7 ms) and Te-SD (30.0 ± 18.3 ms vs. 30.1 ± 20.7 ms) remained unchanged (all p = NS). Mitral regurgitation was reduced (22 ± 14% vs. 17 ± 15%, p = 0.02). Clinically, there was improvement of NYHA functional class (p < 0.001) and 6-min hall walk distance (p = 0.015). A 24-h Holter monitor showed that premature ventricular contractions were not increased during CCM. Conclusions: CCM improves both global and regional LV contractility, including regions remote from the impulse delivery, and may contribute to LV reverse remodeling and gain in systolic function. Such improvement is unrelated to diastolic function or mechanical dyssynchrony. [Copyright &y& Elsevier]

Introduction: The optimal left ventricular (LV) pacing site for cardiac resynchronization therapy (CRT) is unclear. The current study aims to explore the clinical significance of LV lead concordance to delayed contraction segment in CRT. Methods and Results: Concordant LV lead position was defined as the lead tip located by fluoroscopy at or immediately adjacent to the LV segment with latest contraction determined by tissue Doppler imaging. Echocardiographic and clinical outcomes among 101 consecutive patients with or without concordant LV lead positions were compared. There was no significant difference in changes in LV volumes and clinical parameters between patients with concordant (n = 46) or nonconcordant (n = 55) LV lead positions at 3 and 6 months. In multivariate analysis, the baseline asynchrony index (β= 1.092, 95% CI: 1.050–1.114; P < 0.001), but not LV lead concordance, was the only independent predictor of LV reverse remodeling. By Cox regression analysis, ischemic etiology, and LV reverse remodeling, but not LV lead concordance, were independent predictors of mortality (β= 2.475, 95% CI: 1.183–5.178; P = 0.016, and β= 0.272, 95% CI: 0.130–0.567; P < 0.001, respectively), cardiovascular hospitalization (β= 1.551, 95% CI: 1.032–2.333; P = 0.035, and β= 0.460, 95% CI: 0.298–0.708; P < 0.001, respectively), and heart failure hospitalization (β= 0.486, 95% CI: 0.320–0.738; P = 0.001 for LV reverse remodeling). Conclusion: LV lead concordance to the delayed contraction segment may not be a major determining factor for favorable echocardiographic and clinical outcomes after CRT. [ABSTRACT FROM AUTHOR]

Abstract: Background: The clinical significance of atrial fibrillation (AF) in heart failure with normal ejection fraction (HFNEF) remains undetermined. Methods and Results: We compared the clinical and echocardiographic characteristics among 238 patients hospitalized for HF. Using the cutoff of left ventricular EF of 50%, there were 146 patients with HFNEF (AF = 42) and 92 with systolic HF (AF = 30). When compared among HFNEF, the New York Heart Association (NYHA) class (2.61 ± 0.51 versus 2.21 ± 0.46; P < .05), 6-minute walk distance (279.7 ± 66.0 versus 338.0 ± 86.1 m; P < .01), quality of life score (26.1 ± 14.3 versus 19.5 ± 10.3; P < .05), and previous HF hospitalization were significantly worse in the AF group. These variables were significantly better in HFNEF than systolic HF with sinus rhythm, but the differences were not detected among those with AF. Patients with HFNEF and AF were associated with more severe diastolic dysfunction when compared to sinus rhythm. With a median follow-up of 10.5 months, the proportion of HFNEF patients in AF with recurrent HF hospitalization or death was significantly higher than those in sinus rhythm (28.6% versus 10.6%; P < .01). Both AF and restrictive diastolic dysfunction were independent predictors of HF hospitalization or death in HFNEF. Conclusion: Patients with HFNEF and AF were associated with more severe diastolic dysfunction and worse clinical outcomes than those in sinus rhythm. [Copyright &y& Elsevier]

Background: We sought to investigate the effect of cardiac resynchronization therapy (CRT) on disease progression in patients with moderate left ventricular (LV) systolic dysfunction. Methods and Results: This is a prospective study to explore the effect of CRT in 15 optimally treated patients (age: 66.1 ± 12.8 years; male = 13) with New York Heart Association (NYHA) class III, LV ejection fraction >35% and <45% and QRS duration >120 msec. Echocardiographic examination and standard heart failure assessment was performed before and 3 months after CRT implantation. The magnitude of echocardiographic remodeling measurements was compared with 30 age, sex, NYHA class, and heart failure etiology matched patients with conventional CRT indication. There were significant reductions in LV end-systolic (86.2 ± 24.1 to 69.7 ± 22.2 mL, P < 0.01)/end-diastolic (135.5 ± 36.8 to 120.5 ± 34.6 mL, P < 0.01) volumes, improvement in LV ejection fraction (39.1 ± 2.2 to 44.2 ± 5.5%, P = 0.01), and NYHA class (3.0 ± 0.0 to 2.07 ± 0.46, P < 0.001). There was no difference in changes in LV volumes, ejection fraction, NYHA class, and exercise capacity before and after CRT between the study and conventional groups except for greater improvement in the quality of life score in the conventional group. Conclusion: In this prospective study, significant LV reverse remodeling by CRT in those with a wide QRS complex and moderate LV systolic dysfunction was observed. Further studies to explore the benefit of CRT in patients with less severe heart failure are recommended. [ABSTRACT FROM AUTHOR]

Efficacy of CRT for Mildly Prolonged QRS.. 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 (β=−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.(J Cardiovasc Electrophysiol, Vol. 15, pp. 1-8, September 2004) [ABSTRACT FROM AUTHOR]

Objectives: We sought to examine whether cardiac resynchronization therapy (CRT) improves atrial function and induces atrial reverse remodeling. Background: Cardiac resynchronization therapy is an established therapy for advanced heart failure with prolonged QRS duration, which improves left ventricle (LV) function and is associated with LV reverse remodeling. Methods: A total of 107 heart failure patients (66 ± 11 years) who received CRT and were followed up for 3 months were studied. Atrial function was assessed by M-mode, 2-dimensional echocardiography, transmitral Doppler, tissue Doppler velocity, and strain (ε) imaging. Left atrial (LA) emptying fraction based on the change in areas (LAA-EF) and volumes (LAV-EF) were calculated. The LV reverse remodeling was defined by a reduction of LV end-systolic volume >10%. Results: In the responders of LV reverse remodeling (n = 62), LAA-EF and LAV-EF were significantly increased (p < 0.001). Responders also had significant decrease in LA size area and volumetric measurements, both before (p < 0.05) and after atrial systole (p < 0.001). However, these parameters were unchanged in the nonresponders (n = 45, p = NS). In the responders, tissue Doppler velocity analysis showed improvement of contraction velocity in both left (p = 0.005) and right atria (p = 0.018), whereas ε in both atria were increased in all the phases of cardiac cycle, namely ventricular end-systole (p < 0.001), early diastole (p < 0.001), and late diastole (p = 0.007). Conclusions: Cardiac resynchronization therapy improves both left and right atrial pump function. The increase in atrial ε throughout the cardiac cycle is likely reflecting the improvement of atrial compliance. These changes lead to LA reverse remodeling with reduction of LA size before and after atrial systole. [Copyright &y& Elsevier]

A new echocardiographic technology, the timing of regional volumetric changes by 3-dimensional echocardiography, was applied to assess intraventricular mechanical synchronicity in 13 patients who had received cardiac resynchronization therapy (CRT). When biventricular pacing was withheld, left ventricular (LV) asynchrony occurred as reflected by these echocardiographic parameters, whereas LV volume increased and the ejection fraction decreased. Further studies are needed to explore whether this novel method can be used to select suitable candidates for CRT and to predict a favorable response. [Copyright &y& Elsevier]