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Background: This study adopted a new multi-layer approach of measuring myocardial deformation by two-dimensional (2D) speckle tracking imaging to examine whether a transmural gradient exists in normal subjects and cardiac diseases., Methods: Eighty patients were included with 20 in each group: (1) normal control; (2) acute coronary syndrome (ACS) with ejection fraction (EF) >45%; (3) right ventricular apical (RVA) pacing with EF>45%; (4) systolic heart failure (SHF) with EF<45%. Circumferential strain (ε-circum), torsion (Tor) and systolic dyssynchrony defined as the maximal difference in the time to peak circumferential strain were measured in the subendocardial and subepicardial myocardium layers (QLab 6.0, Philips)., Results: In all the 4 groups, a subendocardial to subepicardial gradient was present in both ε-circum (-20.7 ± 7.6 vs. -14.9 ± 5.6%, p<0.001) and Tor (12.0 ± 6.0 vs. 9.3 ± 4.7°, p<0.05), with higher values in the subendocardial layer. However, it was significantly narrowed for ε-circum (2.7 ± 1.2%) and Tor (0.8 ± 0.9°) in SHF patients (all p ≤ 0.001 vs. other groups). On the contrary, systolic dyssynchrony measured in the 2 layers showed no difference (264 ± 107 vs. 273 ± 110 ms, p = NS) and a homogenous distribution in ε-circum was observed from basal to apical planes (-17.0 ± 6.8 vs. -18.1 ± 7.4 vs. -18.1 ± 7.8%, all p = NS)., Conclusions: A transmural gradient exists in circumferential strain and torsion, with higher values in the subendocardial layer. It might be reduced when systolic function is impaired. Therefore, the multi-layer approach of 2D speckle tracking imaging provides further information on assessment of myocardial diseases., (Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.)

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]

Aims LV reverse remodelling has been shown to be a favourable response after cardiac resynchronization therapy (CRT) in many clinical trials. This study investigated whether left ventricular (LV) reverse remodelling after CRT has any structural benefit, which include the improvement of LV mass or regional wall thickness. [ABSTRACT FROM PUBLISHER]

Background: Right ventricular apical (RVA) pacing is associated with adverse left ventricular (LV) remodeling and biventricular (BiV) pacing may prevent it although the mechanisms remain unclear. The current study aimed to assess the role of early pacing-induced systolic dyssynchrony (DYS) to predict adverse LV remodeling. Methods: Patients with standard pacing indications and normal LV ejection fraction were randomized either to BiV (n=89) or RVA pacing (n=88). Pacing-induced DYS, defined as the standard deviation of the time to peak systolic velocity (Dyssynchrony Index) >33ms in a 12-segmental model of LV, was measured by tissue Doppler echocardiography at 1month. Results: At 1month, 59 patients (33%) had DYS which was more prevalent in RVA than BiV pacing group (52% vs. 15%, χ2 =28.3, p<0.001), though Dyssynchrony Index was similar at baseline (30±14 vs. 26±11ms, p=0.06). At 12months, those developing DYS had significantly lower LV ejection fraction (55.1±9.7 vs. 62.2±7.9%, p<0.001) and larger LV end-systolic volume (35.3±14.3 vs. 27.0±10.4ml, p<0.001) when compared to those without DYS. Reduction of ejection fraction ≥5% occurred in 67% (39 out of 58) of patients with DYS, but only in 18% (21 out of 115) in those without DYS (χ2 =40.8, p<0.001). Both DYS at 1month (odds ratio [OR]: 4.725, p=0.001) and RVA pacing (OR: 3.427, p=0.009) were independent predictors for reduction of ejection fraction at 12months. Conclusion: Early pacing-induced DYS is a significant predictor of LV adverse remodeling and the observed benefit of BiV pacing may be related to the prevention of DYS. Clinical trial registration: Centre for Clinical Trials number, CUHK_CCT00037 (URL: http://www.cct.cuhk.edu.hk/Registry/publictrialrecord.aspx?trialid=CUHK_CCT00037). [ABSTRACT FROM AUTHOR]

Abstract: Background: This prospective study was to examine the impact of right ventricular apical (RVA) pacing on atrial remodeling and function. Methods and results: 103 patients (age 70±11years; 53 men) with preserved left ventricular (LV) ejection fraction (LVEF>45%) who received RVA pacing had Doppler echocardiography performed at baseline and after one year follow up. At one year follow up, left atrial (LA) volumes (pre-atrial contraction volume and the minimal volume) and their indexes were significantly increased with reduction in passive emptying fraction and total emptying fraction (all p<0.05). LA segmental tissue velocities – mean peak systolic (Sm-la), peak early diastolic (Em-la) and late diastolic (Am-la) – were also significantly reduced (all p<0.001). A reduction of Am-la>30% occurred in 24% of patients, and was more prevalent in patients with an elevation of LV filling pressure (E/e''>15) at one year (44.1% vs. 11.7%, χ2 =12.75, p<0.001) as well as those with a reduction of LVEF≥5% (34.0% vs. 14.3%, χ2 =5.140, p=0.023). By multivariate regression analysis, E/e''>15 at one year (odds ratio [OR] 5.213; 95% confidence interval [CI] 1.778–15.281) and reduction of LVEF≥5% (OR 3.181; 95% CI 1.045–9.686) were independent predictors of reduction of Am-la>30%. Conclusions: Chronic RVA pacing results in LA remodeling and reduced atrial function. This is related to elevated filling pressures and impairment of LV systolic function. [Copyright &y& Elsevier]

Abstract: Objective: Angiotensin-converting enzyme inhibitor (ACEI) is beneficial in patients with congestive heart failure (CHF). Some, but not all, angiotensin receptor blocker (ARB) was demonstrated to be effective as “add-on” therapy. We investigated whether irbesartan is useful as an add-on therapy in CHF. Design: Randomized control trial. Setting: Single center. Patients: 50 CHF patients on stable doses of ACEI. Interventions: Add-on therapy with irbesartan (300 mg/day) or continuation of conventional therapy (control group) for 1 year. Main outcome measures: Serial clinical and echocardiographic assessment were performed as baseline, 3 months and 1 year after therapy. Results: There was no difference in clinical characteristics between 2 groups. Patients in the add-on therapy group had significant increase in 6-Minute Hall-Walk distance (351±89 to 392±84 m, P <0.01), achieved higher METs exercise time on treadmill test (3.9±1.1 to 4.6±1.3 METs, P =0.01), reduction of NYHA Class (2.4±0.5 to 2.0±0.8, P <0.005) and improvement of QOL score (28±19 to 17±18, P <0.05). These parameters were not improved in the control group and a worsening of exercise capacity was observed (P <0.05). A reduction of left ventricular end-systolic diameter (4.94±0.85 vs 4.30±1.17 cm, P <0.05) was observed in the add-on group. At the end of 1 year, more patients have normal or abnormal relaxation pattern in the add-on group than the control group (82% vs 53% χ 2 =7.1, P =0.02). Blood pressure and renal function were unchanged in both groups. Conclusion: The addition of irbesartan to conventional ACEI therapy in CHF further improves symptoms, exercise capacity and quality of life without adverse effects on hemodynamics and renal function. [Copyright &y& Elsevier]

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]

Currently, a clear definition of response to cardiac resynchronization therapy (CRT) is still lacking, and clinical and echocardiographic end points are used. It is also unclear whether patients with clinical responses also improve in echocardiographic end points (and vice versa). To better understand and define response to CRT, the relation between improvement in clinical and echocardiographic parameters was evaluated in 144 patients. [Copyright &y& Elsevier]