Changes of repolarization parameters after left bundle branch area pacing and the association with echocardiographic response in heart failure patients

Abstract

Background: Left bundle branch area pacing (LBBAP) has become a safe and effective option for heart failure (HF) patients indicated for cardiac resynchronization therapy (CRT) and/or ventricular pacing, yet the response rate was only 70%. Repolarization parameters were demonstrated to be associated with cardiac mechanics and systolic function. This study aimed to investigate the effects of LBBAP on repolarization parameters and the potential association between those parameters and echocardiographic response.Methods and results: A total of 59 HF patients undergoing successful LBBAP were consecutively included. QTc, Tpeak-Tend (TpTe), and TpTe/QTc were measured before and after the implantation. The results turned out that the dispersion of ventricular repolarization (DVR) improved after LBBAP among the total population. Although trends of repolarization parameters varied according to different QRS configurations at baseline, the post-implant parameters showed no significant difference between groups. The association between repolarization parameters and LBBAP response was then evaluated among patients with wide QRS. Multivariate analysis demonstrated that post-implant TpTe was the independent predictor of LBBAP response (p < 0.05). Receiver operating characteristic analysis indicated an area under the curve of 0.77 (95% CI, 0.60–0.93) with a cutoff value of 81.2 ms (p < 0.01). Patients with post-implant TpTe<81.2 ms had a significantly higher rate of echocardiographic response (93.3 vs. 44.4%, p < 0.01). Further subgroup analysis indicated that the predictive value of post-implant TpTe for LBBAP response was more significant in non-left bundle branch block (LBBB) patients than in LBBB patients.Conclusion: LBBAP improved DVR significantly in HF patients. Post-implant TpTe was associated with the echocardiographic response after LBBAP among patients with wide QRS, especially for non-LBBB patients.

Comparison of electrocardiographic parameters between left bundle optimized cardiac resynchronization therapy (LOT‐CRT) and left bundle branch pacing—cardiac resynchronization therapy (LBBP‐CRT)

“…A prolonged TpTe interval and TpTe/QT ratio have been shown to be associated with arrhythmogenesis and sudden cardiac death 30 . LBBP‐CRT has been shown to reduce the TpTe interval in two recent studies 28,29 . Our study also found a significant reduction in the TpTe interval with LBBP‐CRT.…”

“…30 LBBP-CRT has been shown to reduce the TpTe interval in two recent studies. 28,29 Our study also found a significant reduction in the TpTe interval with LBBP-CRT.…”

“…Conventional CRT can have a proarrhythmic effect in some patients, and this has been attributed to a reversal in the sequence of ventricular depolarization and an increase in QT interval with LV epicardial pacing 27 . On the other hand, LBBP‐CRT has been shown in two recent studies to reduce the QT interval significantly 28,29 . We also found that LBBP‐CRT significantly reduced the QT interval when compared to the baseline.…”

“…27 On the other hand, LBBP-CRT has been shown in two recent studies to reduce the QT interval significantly. 28,29 We also found that LBBP-CRT significantly reduced the QT interval when compared to the baseline. LOT-CRT also achieved a reduction in the QT interval compared to the baseline.…”

Comparison of Depolarization and Repolarization Parameters in Left vs. Right Ventricular Septal Pacing—An Intraprocedural Electrocardiographic Study

“…These studies have shown that increased values of these postprocedural parameters are associated with a higher risk of malignant ventricular arrhythmia occurrence due to the inhomogeneity of myocardial repolarization between different parts or layers of the myocardium creating the basis for arrhythmogenesis. Recent data have shown that LBBAP improved the dispersion of repolarization in heart failure patients, and this improvement was associated with positive echocardiographic response [ 11 ].…”