Changes of ventricular septal myocardial injury current in left bundle branch area pacing / 中国综合临床

Objective:Explore the characteristics of injury current changes in ventricular septal myocardium during left bundle branch area pacing (LBBAP) surgery.Methods:Retrospective analysis of clinical data of patients who underwent permanent pacemaker implantation at The Second People's Hospital of Wuxi in Jiangsu Province from January 2020 to November 2022. Among them, 42 patients were treated with LBBAP (LBBAP group) and 56 patients with Right ventricle septum pacing (RVSP group). Compare the conventional parameters such as threshold, perception, impedance during electrode implantation, damage current values at 0, 5, and 10 minutes before and after electrode rotation, and the correlation between damage current and conventional parameters. The measurement data is represented by xˉ± s, analysis of variance is used for comparison between multiple groups, t-test is used for comparison between two groups, and repeated measurement analysis of variance is used for comparison between two groups at multiple time points; Counting data is represented as an example (%), and inter group comparisons are made using χ 2 Inspection; Pearson correlation analysis was used to analyze the correlation between the two variables. Results:There was no statistically significant difference in pacing threshold, perception, and impedance between the two groups of electrode implantation surgery (all P>0.05). The damage current values at 0, 5, and 10 minutes before and after electrode rotation in the LBBAP group were higher than those in the RVSP group [(7.19±1.26) mV compared to (5.33±0.79) mV, (22.50±3.06) mV compared to (10.85±1.70) mV, (15.75±2.63) mV compared to (8.01±1.09) mV, (9.24±2.00) mV compared to (5.51±0.98) mV]. The damage current values at 0 minutes after electrode rotation in both groups were higher than before electrode rotation, and gradually decreased thereafter, After 10 minutes of electrode placement, the damage current value of the LBBAP group was still higher than the level before electrode rotation (all P<0.05), while there was no statistically significant difference between the RVSP group and the level before electrode rotation ( P>0.05). The damage current value at 0 minutes after the LBBAP group electrode was in place was positively correlated with ventricular septal thickness and left ventricular posterior wall thickness ( r values 0.45 and 0.46, P values 0.003 and 0.002, respectively), and negatively correlated with conventional pacing parameter impedance ( r=-0.32, P=0.037). There was no correlation with threshold and perception ( r values 0.08 and 0.01, P values 0.604 and 0.968, respectively). The damage current value at 0 minutes after the RVSP group electrode was in place was negatively correlated with the threshold ( r=-0.28, P=0.036). Conclusions:The COI value of LBBAP interventricular septum myocardium increased significantly after the electrode was rotated out. The COI value at 0 min after the electrode put in place was positively correlated with the interventricular septum thickness and left ventricular posterior wall thickness, and negatively correlated with the electrode impedance, but there was no correlation with threshold and perception.

Quantification of Acute Myocardial Damage Secondary to Implantation of Electrodes for the Left Bundle Branch Area Pacing

ABSTRACT Background: Different from the traditional right ventricular pacing, the left bundle branch area pacing (LBBAP) is accomplished with deeper lead implantation and more attempts. However, myocardial damage is unclear in LBBAP. Objective: The objective of the study was to observe the change of troponin T and explore possible factors associated with greater myocardial damage in LBBAP. Methods: Patients with an indication for pacemaker implantation underwent attempts for LBBAP by transventricular septal method. Levels of troponin T were determined before operation, 12 h and 1 week after the operation. Parameters of intraoperation and follow-up were recorded and analyzed. Results: In total, successful LBBAP was achieved in 126 patients. The levels of troponin T increased significantly at 12 h after the operation compared with those before operation (96.45 ± 11.07 [69.06] vs. 16.59 ± 1.84 [11.92] ng/L, p < 0.001), while there were no significant differences between pre- and post-operative levels at 1 week. Correlation and regression analysis showed that only the number of attempts was an independent factor related to the change of troponin T. During 1 year of follow-up, LBBAP was safe and feasible with few complications. Conclusions: Myocardial damage of LBBAP was clinically significant. The number of attempts was an independent factor related to the myocardial damage.

Feasibility and safety of new simplified left bundle branch area pacing via nine-partition method / 中华心血管病杂志

Objective: To investigate the efficacy and safety of left bundle branch area pacing (LBBaP) with the new simplified approach (nine-partition method). Methods: A total of 118 patients with clinical indications and received pacemaker implantation from December 1, 2018 to December 31, 2019 in Beijing Anzhen Hospital were enrolled. LBBaP was performed with the nine-partition method (in the right anterior oblique 30° position, the ventriculogram was divided into nine partitions and the initial implant sites were located in the lower base 1/3 partitions). In X-ray image, the 3830 lead is located in the left bundle branch area, the unipolar pacing QRS wave is in the form of right bundle branch block, and the peak time from stimulation to left ventricular activation<90 ms is defined as successful operation. The clinical characters, such as the methods of venipuncture, electrode parameters, operation duration, fluoroscopy duration, the peak time from stimulation to left ventricular, pacemaker types, surgical success rate, complications, and immediate postoperative ECG parameters were collected. The patients were followed up after the operation, and the electrode parameters and postoperative complications were recorded. Results: This study is a retrospective study. There were 62 (52.5%) male patients in this cohort, the average age was (65.9±13.4) years old,and there were 49(41.5%) sick sinus syndrome, 6(5.1%) abnormal sinus node and atrioventricular node simultaneously, 63(53.4%) atrioventricular block, 26(22.0%) atrial fibrillation, 20(16.9%) cardiomyopathy; the baseline duration of QRS was (109.21±39.03) ms. Successful LBBaP was achieved in 109 patients with"nine-partition method"and the success rate was 92.4%; 104 patients (95.5%) were axillary vein puncture, 5 (4.6%) were subclavian vein puncture; the operation duration was (80.3±23.0) min, the fluoroscopy duration was (12.29±5.13) min; the QRS duration after LBBaP was (116.36±18.11) ms. The threshold of the left bundle branch (LBB) lead was (0.92±0.63) V, the R wave amplitude was (10.60±5.04) mV and the impedance was (798.71±194.90) Ω. In 1 V pacing, the peak time from stimulation to left ventricular activation was (67.91±12.15) ms, and in 5 V pacing was (67.52±12.45) ms; 1 case (0.9%) with a single-chamber pacemaker implanted, 106 cases (97.3%) with dual-chamber pacemaker and 2 cases (1.8%) with three-chamber pacemakers. There were no hematomas, pneumothorax, hemothorax, electrode dislocation, infection, and capsular hemorrhage and other serious surgery-related complications during the operation. A total of 97 patients (89.0%) were followed up for (6.21±2.90) months. The electrode parameters of all patients were stable and no complications observed. Conclusions: The LBBaP with nine-partition method is a simple, safe and effective physiological pacing approach. However, its long-term effect still needs to be further verified.

Evaluation of cardiac synchrony in patients with permanent left bundle branch area pacing by tissue Doppler imaging / 中华超声影像学杂志

Objective To compare and analyze the synchrony of cardiac contraction when left bundle branch area pacing ( LBBP ) using tissue Doppler imaging ( TDI ) . Methods T wenty‐four patients with LBBP and 20 patients with right ventricular pacing ( RVP ) were enrolled in the study . Among them , 35 cases were diagnosed as sick sinus syndrome ( SSS ) and 9 cases were diagnosed as Ⅱ or Ⅲ degree atrioventricular block ( AVB) before operation . Echocardiographic images were collected with ventricular pacemaker‐on ,and patients with SSS in LBBP group under the condition of pacemaker program control also collected the image of self‐conduction . TDI was used to measure time of the peak velocity ( T s ) of myocardial contraction in the left ventricular 12 segments ,right ventricle 2 segments ,and atrial 3 walls .The difference between the basal segment of left ventricular lateral wall and right ventricular free wall ( T s‐LV‐RV ) ,the mean value of the right ventricular 2 segments ( T s‐2‐RV ) ,the average( T s‐12‐LV ) and standard deviation ( T sd‐12‐LV ) of the left ventricular 12 segments ,and the difference in peak systolic time among 3 walls T AL‐R ,T AI‐R ,T AL‐I were calculated . Results Compared with the RVP pacing state ,the parameters of left ventricular systolic synchrony in LBBP pacing were shortened ,and the difference was statistically significant ( P ＜ 0 .05 ) . T here was no significant difference in parameters of left ventricular/right ventricular systolic synchrony and cardiac function between the LBBP group and the self‐conduction status ( P＞0 .05) . Conclusions Left ventricular systolic synchrony is superior to RVP in LBBP pacing ,and left/right ventricular systolic synchrony and cardiac function are not different from self‐conduction . LBBP is a new physiological pacing . TDI is able to quantitatively assess cardiac systolic synchrony .