Left Ventricular Global Longitudinal Strain Is Associated With Cardiovascular Outcomes in Patients Who Underwent Permanent Pacemaker Implantation

Background: Patients who underwent permanent pacemaker (PM) implantation have a potential risk of left ventricular (LV) systolic dysfunction. However, assessment of LV ejection fraction (LVEF) shows a limited role in identifying subclinical LV systolic dysfunction and predicting cardiovascular (CV) outcomes.

Methods: We reviewed 1,103 patients who underwent permanent PM implantation between January 2007 and December 2017. After excluding patients who did not undergo echocardiograms before or after PM implantation and those with LV ejection fraction (LVEF) <50%, significant valve dysfunction, and history of cardiac surgery before PM implantation, 300 (67 ± 13 years, 119 men) were finally analyzed. LV mechanical function was assessed with LV global longitudinal strain (LV-GLS) using 2-dimensional speckle-tracking echocardiography. CV outcomes were defined as a composite of CV death and hospitalization for heart failure.

Results: At 44 ± 28 months after post-PM echocardiogram, 23 patients (7.7%) had experienced CV outcomes. Patients with CV outcomes were older and had more comorbidities and a lower baseline |LV-GLS| than those without CV outcomes. LV mechanical function worsened after PM implantation in patients with CV outcomes. The cut-off value of 11.2% in |LV-GLS| on post-PM echocardiogram had a better predictive value for CV outcomes (AUC; 0.784 vs. 0.647, p = 0.012). CV outcome in patients with |LV-GLS| <11.2% was worse than that in those with |LV-GLS| ≥ 11.2% (log-rank p < 0.001). Multivariate Cox model revealed that reduced |LV-GLS| was independently associated with CV outcomes.

Conclusions: Pacing deteriorates LV mechanical function. Impaired LV-GLS is associated with poor CV outcomes in patients who underwent PM implantation.

Quantitative assessment of left ventricular function by 3-dimensional speckle-tracking echocardiography in patients with chronic heart failure: a meta-analysis

OBJECTIVES

To provide a comprehensive analysis of the clinical utility of 3-dimensional (3D) speckle-tracking echocardiography for left ventricular (LV) function in patients with chronic heart failure (CHF).

METHODS

Literature searches were conducted in the PubMed, Embase, Web of Science, and China BioMedicine databases on relevant articles published before October 1, 2012. Crude standardized mean differences with 95% confidence intervals (CIs) were calculated.

RESULTS

Seven case-control studies were included with a total of 375 patients with CHF and 181 healthy control participants. Meta-analysis results showed that the LV ejection fraction in the patients was significantly lower than in the controls (standardized mean difference, -4.62; 95% CI, -6.19 to -3.04), whereas the LV end-diastolic volume (LVEDV) and LV end-systolic volume (LVESV) in the patients were higher than in the controls (LVEDV: standardized mean difference, 1.76; 95% CI, 1.09 to 2.44; LVESV: standardized mean difference, 2.04, 95% CI, 1.30 to 2.78). The results also indicated that the patients had a greater delay in the standard deviation of the time to peak area tracking and the maximum difference in the time to peak area tracking in the 16 LV segments than the controls (standard deviation of the time to peak area tracking: standardized mean difference, 3.01; 95% CI, 1.73 to 4.29; maximum difference in the time to peak area tracking: standardized mean difference, 3.26; 95% CI, 1.58 to 4.93). Furthermore, global longitudinal, circumferential, and radial strain were also significantly impaired in the patients compared to the controls (longitudinal strain: standardized mean difference, 2.75; 95% CI, 1.11 to 4.39; circumferential strain: standardized mean difference, 2.71; 95% CI, 1.15 to 4.27; radial strain: standardized mean difference, 1.80; 95% CI, 0.45 to 3.14).

CONCLUSIONS

This meta-analysis suggests that LV function in patients with CHF can be noninvasively and objectively measured by 3D speckle-tracking echocardiography.

Left ventricular endocardial dysfunction in patients with preserved ejection fraction after receiving anthracycline

BACKGROUND

Anthracycline chemotherapy generates progressive dose-dependent left ventricular (LV) dysfunction associated with a poor prognosis. Early detection of minor LV myocardial dysfunction caused by the cardiotoxicity of anthracycline is thus important for predicting global LV dysfunction.

METHODS

Fifty patients with preserved ejection fraction (all ≥55%) after receiving anthracycline chemotherapy were recruited for this study. Two-dimensional speckle tracking was used to assess global radial and circumferential strains from mid-LV short-axis views and global longitudinal strain from the apical four- and two-chamber view as peak global strain curves. Three-dimensional (3D) radial, circumferential, and longitudinal myocardial function was quantified as a peak global strain curve using 3D speckle tracking from all 16 LV segments. 3D speckle tracking imaging was used to evaluate LV endocardial area change ratio (area strain) quantified as peak global area strain curve (3D-GAS) to determine LV endocardial function. Twenty age-, gender-, and EF-matched normal volunteers were studied for comparisons.

RESULTS

Only 3D-GAS and peak 3D global circumferential strains of the anthracycline group were significantly worse than those of the control group (-43.3 ± 3.1 vs. -45.8 ± 4.3% and -31.6 ± 3.5% vs. -34.4 ± 4.2%, respectively; P = 0.008, P = 0.004) even though global LV systolic and diastolic functions were similar. 3D-GAS correlated significantly with the cumulative doxorubicin dose (r = 0.316, P = 0.026). It was noteworthy that multivariate analysis showed only 3D-GAS (β = 0.323, P = 0.025) was independently associated with cumulative doxorubicin dose.

CONCLUSIONS

Three-dimensional speckle tracking area strain was found useful for early detection of minor LV endocardial dysfunction associated with the use of anthracycline, and may thus prove to be clinically useful for predicting global LV dysfunction.

The year 2012 in the European Heart Journal-Cardiovascular Imaging: Part I

The new multi-modality cardiovascular imaging journal, European Heart Journal - Cardiovascular Imaging, was started in 2012. During its first year, the new Journal has published an impressive collection of cardiovascular studies utilizing all cardiovascular imaging modalities. We will summarize the most important studies from its first year in two articles. The present 'Part I' of the review will focus on studies in myocardial function, myocardial ischaemia, and emerging techniques in cardiovascular imaging.

The role of 3D wall motion tracking in heart failure

Heart failure is a major health problem in developed countries and a growing one in developing countries. Cardiac remodeling in heart failure affects myocardial mechanics, which requires comprehensive evaluation in three dimensions. The novel technique of 3D wall motion tracking applies speckle tracking technology to full volume, 3D echocardiographic datasets. Quantification of conventional and novel left ventricular (LV) parameters including volumes, ejection fraction, global and regional 3D strain, endocardial area strain, twist, and dyssynchrony, and identification of the site of latest mechanical activation are feasible on the basis of a single acquisition of a full-volume dataset. Clinical applications of 3D wall motion tracking include the assessment of global and regional LV performance in ischemic and nonischemic heart diseases, evaluation of mechanics in cardiomyopathies and congenital heart disease, potential selection of patients for cardiac resynchronization therapy and prediction of their response, and detection of subclinical cardiac dysfunction in diseases with likelihood of progression to heart failure. Technological advances with improvement in spatial and temporal resolution of this novel imaging modality are expected. Although 3D wall motion tracking is still in its infancy, this method has begun to provide new insights into LV mechanics and has already found clinical applications. Future developments in 3D assessment of right ventricular and myocardial layer-specific mechanics are awaited.