Additive Prognostic Value of Echocardiographic Global Longitudinal and Global Circumferential Strain to Electrocardiographic Criteria in Patients With Heart Failure Undergoing Cardiac Resynchronization Therapy.

Background: Response to cardiac resynchronization therapy is most favorable in patients with heart failure with QRS duration ≥150 ms and left bundle branch block and less predictable in those with QRS width 120 to 149 ms or non-left bundle branch block.

Methods And Results: We studied 205 patients with heart failure referred for cardiac resynchronization therapy with QRS ≥120 ms and ejection fraction ≤35%. We tested the hypothesis that contractile function using speckle-tracking echocardiographic global circumferential strain (GCS) from 2 short-axis views and global longitudinal strain (GLS) from 3 apical views add prognostic value to electrocardiographic criteria.

Right Ventricular Function in Peripartum Cardiomyopathy at Presentation Is Associated With Subsequent Left Ventricular Recovery and Clinical Outcomes.

Background: Peripartum cardiomyopathy has variable disease progression and left ventricular (LV) recovery. We hypothesized that baseline right ventricular (RV) size and function are associated with LV recovery and outcome.

Methods And Results: Investigations of Pregnancy-Associated Cardiomyopathy was a prospective 30-center study of 100 peripartum cardiomyopathy women with LV ejection fraction (LVEF) <45% within 13 weeks after delivery.

Mechanical Dyssynchrony by Tissue Doppler Cross-Correlation is Associated with Risk for Complex Ventricular Arrhythmias after Cardiac Resynchronization Therapy.

Background: Tissue Doppler cross-correlation analysis has been shown to be associated with long-term survival after cardiac resynchronization defibrillator therapy (CRT-D). Its association with ventricular arrhythmia (VA) is unknown.

Methods: From two centers 151 CRT-D patients (New York Heart Association functional classes II-IV, ejection fraction ≤ 35%, and QRS duration ≥ 120 msec) were prospectively included.

Mechanical dyssynchrony is additive to ECG criteria and independently associated with reverse remodelling and clinical response to cardiac resynchronisation therapy in patients with advanced heart failure.

Background: QRS duration and morphology are known established predictors of cardiac resynchronisation therapy (CRT) response, whereas mechanical dyssynchrony is not. Our aim was to determine if mechanical dyssynchrony provides independent prognostic information on CRT response.

Methods: We studied 369 consecutive patients with heart failure (HF) with low ejection fraction (EF) and widened QRS receiving CRT.

Mechanical dyssynchrony after cardiac resynchronization therapy for severely symptomatic heart failure is associated with risk for ventricular arrhythmias.

Background: Risk factors for ventricular arrhythmias after cardiac resynchronization defibrillator therapy (CRT-D) for severely symptomatic heart failure are of clinical importance but are not clearly defined. The objective of this study was to test the hypothesis that mechanical dyssynchrony after CRT-D is a risk factor for ventricular arrhythmias.

Methods: A total of 266 consecutive CRT-D patients with class III or IV heart failure, QRS duration ≥120 msec, and ejection fractions ≤ 35% were prospectively studied.

The association of left ventricular lead position related to regional scar by speckle-tracking echocardiography with clinical outcomes in patients receiving cardiac resynchronization therapy.

Background: Response to cardiac resynchronization therapy is variable. The aim of this study was to test the hypothesis that left ventricular (LV) lead position in proximity to myocardial scar is associated with less favorable outcomes.

Methods: A total of 149 patients were included in this substudy of the Speckle Tracking Assisted Resynchronization Therapy for Electrode Region trial using echocardiographic radial strain for basal and middle LV segments and transverse strain for apical segments to estimate scar.

Usefulness of echocardiographically guided left ventricular lead placement for cardiac resynchronization therapy in patients with intermediate QRS width and non-left bundle branch block morphology.

The current guidelines most strongly support cardiac resynchronization therapy (CRT) for patients with heart failure with a QRS width of ≥150 ms and left bundle branch block (LBBB). Our objective was to assess the potential benefit of echocardiographically guided left ventricular (LV) lead positioning for patients with a QRS width <150 ms or non-LBBB as a substudy of the Speckle Tracking Assisted Resynchronization Therapy for Electrode Region (STARTER) prospective, randomized controlled trial. The STARTER trial randomized 187 patients with heart failure, a QRS of ≥120 ms, and ejection fraction of ≤35% to LV lead guided to the site of latest mechanical activation by speckle tracking radial strain versus routine implantation.

Feature tracking measurement of dyssynchrony from cardiovascular magnetic resonance cine acquisitions: comparison with echocardiographic speckle tracking.

Background: Analysis of left ventricular (LV) mechanical dyssynchrony may provide incremental prognostic information regarding cardiac resynchronization therapy (CRT) response in addition to QRS width alone. Our objective was to quantify LV dyssynchrony using feature tracking post processing of routine cardiovascular magnetic resonance (CMR) cine acquisitions (FT-CMR) in comparison to speckle tracking echocardiography.

Methods: We studied 72 consecutive patients who had both steady-state free precession CMR and echocardiography.

Mechanistic features associated with improvement in mitral regurgitation after cardiac resynchronization therapy and their relation to long-term patient outcome.

Background: Mechanisms of mitral regurgitation (MR) reduction with cardiac resynchronization therapy (CRT) are complex, and their association with long-term outcome is unclear. We sought to elucidate mechanistic features of reduction in MR with CRT, which impact long-term patient survival.

Methods And Results: A prospective longitudinal study of 277 patients with heart failure with QRS width ≥ 120 ms and ejection fraction ≤ 35% for CRT was performed.

The Contemporary Role of Echocardiography in Improving Patient Response to Cardiac Resynchronization Therapy.

Cardiac resynchronization therapy (CRT) is an important therapy for heart failure patients with widened electrocardiographic QRS complexes and depressed ejection fractions, however, approximately one-third do not respond. This article presents a practical contemporary approach to the utility of echocardiography to improve CRT patient response by assessing mechanical dyssynchrony, optimizing left ventricular lead positioning, and performing appropriate echo-Doppler optimization, along with future potential roles. Specifically, recent long-term outcome data are presented that demonstrates that baseline dyssynchrony is a powerful marker associated with CRT response, in particular for patients with narrower QRS duration or non left bundle branch block morphology.