Left ventricular three-dimensional quadripolar lead acute clinical study: the LILAC study.

Aims: This multicenter acute clinical study was designed to verify novel three-dimensional (3D) quadripolar lead designs that can achieve ≤2.5 V average pacing capture threshold (PCT) not only at the apex, but also at the base of the left ventricle with phrenic nerve stimulation (PNS) avoidance for cardiac resynchronization.

Methods: During the implant procedure, up to two different left ventricular investigational leads were introduced and tested in the same target coronary vein based on the coronary sinus venogram in a wedged and unwedged position.

Biventricular pacing is superior to right ventricular pacing in bradycardia patients with preserved systolic function: 2-year results of the PACE trial.

Aims: The Pacing to Avoid Cardiac Enlargement (PACE) trial is a prospective, double-blinded, randomized, multicentre study that reported the superiority of biventricular (BiV) pacing to right ventricular apical (RVA) pacing in the prevention of left ventricular (LV) adverse remodelling and deterioration of systolic function at 1 year. In the current analysis, we report the results at extended 2-year follow-up for changes in LV function and remodelling.

Methods And Results: Patients (n = 177) with bradycardia and preserved LV ejection fraction (EF ≥45%) were randomized to receive RVA or BiV pacing.

Different determinants of improvement of early and late systolic mitral regurgitation contributed after cardiac resynchronization therapy.

Background: Functional mitral regurgitation (MR) at different phases of the regurgitant period may respond differently to cardiac resynchronization therapy (CRT). The aims of this study were to examine the impact of CRT on the phasic changes of MR (early vs late systole) and to explore the mechanisms of such changes.

Methods: Instantaneous MR flow rate and total MR volume were evaluated in 60 patients who had more than mild functional MR before and 3 months after CRT.

Impact of reduction in early- and late-systolic functional mitral regurgitation on reverse remodelling after cardiac resynchronization therapy.

Aims: To examine whether the presence of pre-pacing functional mitral regurgitation (MR) and its improvement would affect the extent of left ventricular (LV) reverse remodelling after cardiac resynchronization therapy (CRT).

Methods And Results: Echocardiographic assessment was performed in 83 patients before and 3 months after CRT. Total MR volume and the early- and late-systolic MR flow rate were assessed.

Impact of cardiac contractility modulation on left ventricular global and regional function and remodeling.

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.

Prevalence and determinants of left ventricular systolic dyssynchrony in patients with normal ejection fraction received right ventricular apical pacing: a real-time three-dimensional echocardiographic study.

Aims: Right ventricular apical (RVA) pacing may induce mechanical dyssynchrony. However, its impact on patients with normal ejection fraction (EF) is not fully understood. This study examined the prevalence and predictors of RVA pacing-induced systolic dyssynchrony by real-time three-dimensional echocardiography (RT3DE), and evaluated its impact on left ventricular (LV) function.

Biventricular pacing in patients with bradycardia and normal ejection fraction.

Background: Observational studies suggest that conventional right ventricular apical pacing may have a deleterious effect on left ventricular function. In this study, we examined whether biventricular pacing is superior to right ventricular apical pacing in preventing deterioration of left ventricular systolic function and cardiac remodeling in patients with bradycardia and a normal ejection fraction.

Methods: In this prospective, double-blind, multicenter study, we randomly assigned 177 patients in whom a biventricular pacemaker had been successfully implanted to receive biventricular pacing (89 patients) or right ventricular apical pacing (88 patients).

A novel multi-layer approach of measuring myocardial strain and torsion by 2D speckle tracking imaging in normal subjects and patients with heart diseases.

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.

Changes in global left ventricular function by multidirectional strain assessment in heart failure patients undergoing cardiac resynchronization therapy.

Background: The aim of this study was to evaluate the acute and late effects of cardiac resynchronization therapy (CRT) on multidirectional left ventricular (LV) strain assessed by two-dimensional speckle-tracking imaging and automated function imaging (AFI).

Methods: Multidirectional LV strain (global radial strain [GRS Avg], global circumferential strain [GCS Avg], and global longitudinal peak systolic strain [GLPSS Avg]) were measured in 141 patients with heart failure before CRT implantation, immediately afterward, and after 3 to 6 months of follow-up. Moreover, the acute effects on multidirectional LV strain were evaluated after interrupting CRT at follow-up.

Difference in prevalence and pattern of mechanical dyssynchrony in left bundle branch block occurring in right ventricular apical pacing versus systolic heart failure.

Background: This study compared the prevalence and pattern of mechanical dyssynchrony in patients with normal heart and right ventricular apical (RVA) pacing versus patients with systolic heart failure (SHF) and spontaneous left bundle branch block (LBBB).

Methods: A total of 112 patients having LBBB pattern on surface electrocardiogram were included (57 with ejection fraction>50% received RVA pacing; 55 had SHF with ejection fraction<35%). Using tissue Doppler imaging, systolic and diastolic dyssynchrony was defined by the standard deviation of the time to peak systolic and peak early diastolic velocity, respectively.

Leveraging cardiac resynchronization therapy devices to monitor patients with heart failure.

Cardiac resynchronization therapy is a standard therapy for heart failure patients with cardiac dyssynchrony. The implantable device provides a convenient and continuous platform for heart failure monitoring. Information such as heart rate variability and activity status retrieved from the device allows physicians to more comprehensively evaluate these high-risk patients.

Usefulness of tissue Doppler velocity and strain dyssynchrony for predicting left ventricular reverse remodeling response after cardiac resynchronization therapy.

The assessment of systolic dyssynchrony by echocardiography is useful in predicting a favorable response to cardiac resynchronization therapy (CRT). Tissue Doppler velocity and tissue Doppler longitudinal strain have been suggested for this purpose. This study compared parameters of systolic dyssynchrony derived from these 2 imaging modalities for their predictive values of CRT response.

Improvement of atrial function and atrial reverse remodeling after cardiac resynchronization therapy for heart failure.

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.

The Pacing to Avoid Cardiac Enlargement (PACE) trial: clinical background, rationale, design, and implementation.

Background: Deleterious effect on left ventricular (LV) function was observed with conventional right ventricular apical (RVA) pacing. Preliminary data suggested that biventricular pacing (BiV) may be superior to RVA pacing in patients with LV systolic dysfunction. However, the optimal pacing mode and site(s) for patients with normal LV systolic function remain controversial.

The role of repeating optimization of atrioventricular interval during interim and long-term follow-up after cardiac resynchronization therapy.

Background: Cardiac resynchronization therapy (CRT) is an effective therapy for heart failure patients with electromechanical delay. Optimization of atrioventricular interval (AVI) is a cardinal component for the benefits. However, it is unknown if the AVI needs to be re-optimized during long-term follow-up.

Comparison of angiotensin-converting enzyme inhibitor alone and in combination with irbesartan for the treatment of heart failure.

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.

Implantable cardiac resynchronization therapy devices to monitor heart failure clinical status.

Cardiac resynchronization therapy is a standard therapy for selected patients with heart failure. With advances in technology and storage capacity, the device acts as a convenient platform to provide valuable information about heart failure status in these high-risk patients. Unlike other modalities of investigation which may only allow one-off evaluation, heart failure status can be monitored by device diagnostics including heart rate variability, activity status, and intrathoracic impedance in a continuous basis.

Comparison of intensive and low-dose atorvastatin therapy in the reduction of carotid intimal-medial thickness in patients with coronary heart disease.

Background: Intensive statin therapy has been shown to improve prognosis in patients with coronary heart disease (CHD). It is unknown whether such benefit is mediated through the reduction of atherosclerotic plaque burden.

Aim: To examine the efficacy of high-dose atorvastatin in the reduction of carotid intimal-medial thickness (IMT) and inflammatory markers in patients with CHD.

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.

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.

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.

Differential change in left ventricular mass and regional wall thickness after cardiac resynchronization therapy for heart failure.

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.

Methods And Results: Fifty patients (66 +/- 11 years) receiving CRT were followed up for at least 3 months.

Clinical versus echocardiographic parameters to assess response to cardiac resynchronization therapy.

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.

Understanding nonresponders of cardiac resynchronization therapy--current and future perspectives.

Introduction: Cardiac resynchronization therapy (CRT) is now an established nonpharmacologic therapy for advanced heart failure with electromechanical delay. Despite compelling evidence of the benefits of CRT, one troubling issue is the lack of a favorable response in about one-third of patients.

Methods And Results: Currently, there is no unifying definition of responders, and published data were based on acute hemodynamic changes, chronic left ventricular reverse remodeling, as well as the intermediate or long-term clinical response.