Prognostic value of tissue Doppler-derived ventricular asynchrony in patients with left bundle branch block but not advanced heart failure

Evaluation of Right and Left Ventricular Deformation Analysis in İdiopathic Right Bundle Branch Block by Speckle Tracking Echocardiography

BACKGROUND

Idiopathic right bundle branch block (RBBB) is often seen as harmless and common. However, many studies show it might be linked to negative health outcomes. So, it is crucial to fully understand how RBBB affects the heart's ventricles.

OBJECTIVES

This study aims to examine the right and left ventricular systolic functions in patients with idiopathic RBBB and compare them to those in a healthy control group.

MATERIAL AND METHODS

Echocardiographic images were obtained from patients with idiopathic RBBB and healthy control participants. Conventional echocardiographic parameters were measured. Two-dimensional (2D) speckle tracking strain analysis was used to assess deformation indices.

RESULTS

Thirty-nine patients with idiopathic RBBB and 35 healthy participants were included in the study. There were no significant differences in the chamber dimensions of the left ventricle (LV) and right ventricle (RV) between the groups. LV ejection fraction (EF), RV fractional area change (FAC), and tricuspid annular plane systolic excursion (TAPSE) measurements were similar between the groups. LV global longitudinal strain (GLS) (-25.5 ± 5.7% vs. -22.1 ± 4.2%, p < 0.05), RV GLS (-26.9 ± 4.6% vs. -24.0 ± 4.4%, p < 0.05), and interventricular septum longitudinal strain (IVS LS) (-24.3 ± 4.9% vs. -19.1 ± 4.2%, p < 0.05) were significantly reduced in patients with idiopathic RBBB compared to controls, indicating impaired myocardial shortening. Significant differences were also observed in LV (15 [5-30] vs. 30 [20-60], p < 0.05) and RV (18 [7-35] vs. 36 [24-80], p < 0.05) mechanical dispersion, with the differences being more pronounced for the RV between the groups. LV torsion (2.1 ± 0.6 vs. 1.6 ± 0.5, p < 0.05) was also worse in patients with idiopathic RBBB.

CONCLUSION

Our findings show that idiopathic RBBB significantly affects the longitudinal strain and synchronization of both the LV and RV.

Phase analysis of gated myocardial perfusion single-photon emission computed tomography after coronary artery bypass graft surgery: reflection of late reverse remodeling in patients with patent grafts after coronary artery bypass graft surgery

OBJECTIVE

Phase analysis using gated myocardial perfusion single-photon emission computed tomography (GMPS) is a tool used to assess left ventricular (LV) dyssynchrony. We attempted to investigate the role of LV dyssynchrony assessed by GMPS using phase analysis for the late LV function after coronary artery bypass graft surgery (CABG) in patients with patent grafts.

METHODS

A total of 45 patients who received off-pump CABG with patent graft 1 year after CABG and preserved perfusion reserve were enrolled retrospectively. All patients underwent GMPS before and 3 months and 1 year after CABG. Using the Emory Cardiac Toolbox, both phase histogram bandwidth (PBW) and phase SD derived by phase analysis were used for the analysis, in addition to the conventional perfusion parameters. For the evaluation of LV function, transthoracic echocardiography was also performed.

RESULTS

All of the patients showed perfusion improvement (paired t-test, P<0.05) after CABG. Nonetheless, 30 of 45 patients showed LV dyssynchrony 3 months after CABG. One year after CABG, however, 25 out of 45 patients showed reverse remodeling. Among those patients with reverse remodeling, 19 patients had shown LV 3 months after CABG. Using stepwise logistic regression with forward selection, PBW 3 months after CABG could predict reverse remodeling 1 year after CABG (odds ratio 1.03, P<0.05). Using receiver operating characteristic analysis, PBW 3 months after CABG had the largest area under the curve to detect reverse remodeling 1 year after CABG with a cut-off value of 82 (sensitivity 0.95, specificity 0.56, P<0.001).

CONCLUSION

Postoperative LV dyssynchrony assessed by GMPS using phase analysis may reflect late reverse remodeling and potential of further functional improvement in patients with patent grafts and preserved perfusion reserve after CABG.