Effect of left bundle branch pacing on left ventricular systolic function and synchronization in patients with third-degree atrioventricular block, assessment by 3- dimensional speckle tracking echocardiography.

OBJECTIVE: To explore the effect of left bundle branch pacing (LBBP) on left ventricular systolic function and synchronization in patients with third-degree atrioventricular block. METHODS: Fifty patients with third-degree atrioventricular block from 2019- to 01-01 to 2019-6-31 in The Affiliated Hospital of Qingdao University who were eligible for pacing indications were selected. According to different pacing locations, they were randomly divided into LBBP group and right ventricular septal pacing (RVSP) group. Three-dimensional speckle tracking technology was used to collect left ventricular global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) before surgery, 6 months after surgery, 12 months after surgery, and 18 months after surgery. At the same time, the percentage of the standard deviation of the time when the left ventricular 16 segments reach the minimum systolic volume in the cardiac cycle (Tmsv16-SD/R-R) was calculated. And the QRS duration of the two groups was followed up. RESULTS: 1. GLS in LBBP group and RVSP group after surgery was significantly higher than that before surgery. And GLS in LBBP group and RVSP group showed an upward trend after surgery. However, the increase rate in LBBP group was higher than that in RVSP group. At 18 months after surgery, LBBP group was significantly higher than that in RVSP [(29.92±4.73) vs (26.48±3.80), p<0.05]. GCS in LBBP group increased gradually after surgery. GCS in RVSP group was no significant change after surgery. At 18 months after surgery, GCS in RVSP group was significantly lower than that in LBBP group [(27.92±3.37) vs (29.48±4.40), p<0.05]. There was no significant change in GRS between the two groups(p＞0.05). 2. Tmsv16-SD/R-R in LBBP group and RVSP group after surgery were lower than that before surgery (p<0.05). Tmsv16-SD/R-R in the LBBP group after surgery remained stable (P>0.05). At 18 months after surgery, Tmsv16-SD/R-R was significantly lower than that in the RVSP group [(4.27±0.67) vs (6.34±1.70), P<0.05]. 3. The QRS duration in LBBP group after surgery was significantly lower than that before surgery. And the QRS duration of the patients in the LBBP group remained stable during the 18-month follow-up (P>0.05). The QRS duration in the RVSP group after surgery had no significant change compared with that before surgery.The QRS duration in the LBBP group was significantly lower than that in the RVSP group after surgery (P＜0.05). 4. The LVEF of the LBBP group and the RVSP group remained stable after surgery, and there was no statistical difference between the two groups. CONCLUSIONS: As an emerging pacing method, LBBP has good postoperative contractility and can maintain good electromechanical synchronization.

Prognostic value of circulating tumor DNA in lymphoma: a meta-analysis.

Circulating tumor DNA (ctDNA) can be used to evaluate the prognosis of lymphoma. However, there is no uniform consensus about the mechanistic role that ctDNA plays in the prognosis of lymphoma. This meta-analysis explores the prognostic value of ctDNA in lymphoma, especially in diffuse large B cell lymphoma (DLBCL). All relevant reports published as of May 14, 2020, were retrieved by searching electronic databases in Pubmed, Embase and Cochrane Library. The prognostic value of ctDNA was evaluated using meta-analysis. Revman 5.3 software was used for prognostic data extraction and analysis. Eight studies, including a total of 767 lymphoma patients, were enrolled in this meta-analysis. Five out of eight studies investigated the association between ctDNA levels and progression-free survival (PFS) in 501 lymphoma patients, indicating that high levels of ctDNA were significantly associated with poor PFS (HR 2.24, 95%CI: 1.63-3.08, P < 0.00001). We conducted a subgroup analysis of 379 patients with DLBCL across three of the studies and came to the same conclusion (HR 2.01, 95%CI: 1.42-2.85, P < 0.0001). Two studies with a total of 192 lymphoma patients described the association between ctDNA levels and event-free survival (EFS), showing that high levels of ctDNA were also associated with adverse EFS (HR 4.53, 95%CI: 1.79-11.47, P = 0.001). The remaining two studies analyzed the potential clinical value of ctDNA for predicting the overall survival time (OS) of DLBCL patients, demonstrating that high levels of ctDNA correlated with inferior OS (HR 3.09, 95%CI: 1.50-6.35, P = 0.002). Our meta-analysis showed that high levels of ctDNA were associated with poor prognosis in patients with lymphoma, especially DLBCL.