Left ventricular activation imaging by 3-dimensional speckle-tracking echocardiography. Comparison with electrical...

Area of Science:

• Cardiovascular Imaging
• Biomedical Engineering
• Electrophysiology

Background:

• 3D speckle-tracking echocardiography (3D-STE) activation imaging aims to map regional contraction onset relative to electrical activation.
• The study hypothesized that optimal activation imaging settings correlate with electrical activation patterns.
• Assessing the feasibility of 3D-STE for activation imaging compared to voltage mapping was the primary goal.

Purpose of the Study:

• To determine the optimal setting for 3D-STE activation imaging by comparing it with a gold-standard voltage mapping system.
• To evaluate the feasibility of using 3D-STE for noninvasive assessment of electromechanical dyssynchrony.
• To establish the correlation between electrical and mechanical intraventricular activation times.

Main Methods:

• Seven patients undergoing electrical voltage mapping were included.
• Regional deformation was quantified using 3D-STE area change ratio (ACR).
• Activation imaging thresholds were tested at 10%, 25%, 50%, and 100% of maximal ACR.

Main Results:

• A strong correlation (R=0.80, P<0.001) between electrical and mechanical intraventricular activation times (IVAT) was found at the 25% maximal ACR setting.
• The optimal setting demonstrated 90.5% concordance in identifying the first and latest activated segments compared to voltage mapping.
• Data from 21 sets under varied conduction and pacing configurations were analyzed.

Conclusions:

• Activation imaging with 3D-STE is a feasible noninvasive method for assessing cardiac dyssynchrony.
• The study identified an optimal setting (25% maximal ACR) for 3D-STE activation imaging that correlates well with electrical activation.
• This technique holds promise for evaluating electromechanical coupling in clinical settings.