Aim To evaluate ventricular synchronization and function in patients
with right bundle-branch block after left bundle-branch-area pacing
(LBBAP) by echocardiography. Methods Forty patients who successfully
received LBBAP were selected and divided into the right bundle-branch
block group (RBBB group) and the non-RBBB group by pre-operation ECG.
Echocardiography and follow-up were performed 1 month after operation.
Interventricular synchronization was evaluated by tissue Doppler (TDI),
tissue mitral annular displacement (TMAD), and interventricular
mechanical delay (IVMD). The ventricular longitudinal strain and the
standard deviation of peak time of longitudinal strain were analyzed by
two-dimensional speckle tracking imaging (2D-STI) to evaluate
intraventricular synchronization and ventricular function. Results (1)
The deviation of systolic time to the peak of the tricuspid and mitral
valves, namely ΔPTTV-MV measured by TMAD and ΔTsTV-MV measured by TDI,
were statistically different between the two groups (P <
0.05). (2) Compared with the non-RBBB group, there were no statistically
significant differences in longitudinal strain (LS), peak strain time,
standard deviation of peak strain time (SDt), and global longitudinal
strain (GLS) in the right and left ventricle in the RBBB group (P
> 0.05). Conclusion Echocardiography technology including
2D-STI, TDI, and TMAD can effectively analyze interventricular
synchronization, intraventricular synchronization, and ventricular
function. Although the movement of the right ventricular myocardium in
the RBBB group treatment was slightly later than that of the left
ventricular myocardium after LBBAP, LBBAP is still an effective pacing
therapy for RBBB patients with pacing indication.
Further Observations on the Etiology of the Right Bundle Branch Block Pattern Following Right Ventriculotomy
