No abstract

Objectives to Background To compare electromechanical ventricular synchrony when pacing from different sites, including right ventricular apex pacing (RVAP), right ventricular septum pacing (RVSP), His bundle pacing (HBP), left bundle branch pacing (LBBP), and RVSP during unipolar pacing from the ring electrode of LBBP lead (RVSP ring ) in each patient and evaluate the correlations between electrophysiological characteristics and ventricular synchrony. Methods Twenty patients with complete atrioventricular block indicated for dual‐chamber pacemaker implantation were included in the study. Unipolar pacing at different sites, including RVAP, RVSP, HBP, LBBP, and RVSP ring , was successively performed in each patient. The pacing characteristics and echocardiogram parameters were collected and compared among intrinsic rhythm and pacing at different sites. Results Similar to HBP (114.84 ± 18.67 ms), narrower paced QRSd was found in LBBP (116.15 ± 11.60 ms) as compared to RVSP ring (135.11 ± 13.68 ms), RVSP (141.65 ± 14.26 ms), and RVAP (160.15 ± 19.35 ms) ( p < .001). LBBP showed comparable pacing parameters to RVAP or RVSP and was significantly better than HBP, with maintained cardiac function. TS‐12‐SD was significantly improved in LBBP (41.80 ± 20.97 ms) than RVAP (69.70 ± 32.42 ms, p = .003) and RVSP (63.30.56 ± 32.53 ms, p = .018) but similar to HBP (51.50 ± 25.67 ms, p = .283) or RVSP ring (57.80 ± 25.65 ms, p = .198). Among these pacing strategies, negative values of interventricular mechanical delay (IVMD) were only identified in LBBP (−19.25 ± 18.43 ms), significantly different from RVAP (35.00 ± 30.72 ms), RVSP (22.85 ± 22.05 ms), HBP (5.20 ± 18.64 ms), and RVSP ring (16.00 ± 26.76 ms (all p < .05). Using Pearson's analysis, Sti‐LVAT was positively correlated with QRS duration, IVMD, TS‐12‐SD, LVEDV, and LVESV, while a negative relationship could be observed for left ventricular ejection fraction. Conclusions His‐Purkinje conduction system pacing (HPCSP) achieved better electrical and mechanical synchrony than conventional RV pacing. For interventricular synchrony, only LBBP initiated earlier LV activation than RV, in accordance with the right bundle branch block (RBBB) pattern of paced QRS during LBBP. Sti‐LVAT might be a good parameter correlating with LV systolic function and mechanical synchrony.

Cryptic transcription initiation has been previously linked to activation of oncogenic transcripts. However, the prevalence and impact of cryptic antisense transcription from the opposite strand of protein-coding genes were mostly unknown in cancer. Applying a robust computational pipeline to publicly available transcriptome and epigenome datasets, we identified hundreds of previously unannotated cryptic antisense polyadenylated transcripts (CAPTs) that were enriched in tumor samples. We showed that the activation of cryptic antisense transcription was associated with increased chromatin accessibility and active histone marks. Accordingly, we found that many of the antisense transcripts were inducible by treatment of epigenetic drugs. Moreover, CRISPR-mediated epigenetic editing assays revealed that transcription of a noncoding RNA LRRK1 -CAPT promoted LUSC cell proliferation, suggesting its oncogenic role. Our findings largely expand our understanding of cancer-associated transcription events, which may facilitate the development of novel strategies for cancer diagnosis and treatment.