His bundle pacing versus left bundle branch pacing on ventricular function in atrial fibrillation patients referred for pacing: a prospective crossover comparison.

BACKGROUND: His bundle pacing (HBP) and left bundle branch pacing (LBBP) both provide physiologic pacing which maintain left ventricular synchrony. They both improve heart failure (HF) symptoms in atrial fibrillation (AF) patients. We aimed to assess the intra-patient comparison of ventricular function and remodeling as well as leads parameters corresponding to two pacing modalities in AF patients referred for pacing in intermediate term. METHODS: Uncontrolled tachycardia AF patients with both leads implantation successfully were randomized to either modality. Echocardiographic measurements, New York Heart Association (NYHA) classification, quality-of-life assessments and leads parameters were obtained at baseline and at each 6-month follow up. Left ventricular function including the left ventricular endo-systolic volume (LVESV), left ventricular ejection fraction (LVEF) and right ventricular (RV) function quantified by tricuspid annular plane systolic excursion (TAPSE) were all assessed. RESULTS: Consecutively twenty-eight patients implanted with both HBP and LBBP leads successfully were enrolled (69.1 ± 8.1 years, 53.6% male, LVEF 59.2% ± 13.7%). The LVESV was improved by both pacing modalities in all patients (n = 23) and the LVEF was improved in patients with baseline LVEF at less than 50% (n = 6). The TAPSE was improved by HBP but not LBBP (n = 23). CONCLUSION: In this crossover comparison between HBP and LBBP, LBBP was found to have an equivalent effect on LV function and remodeling but better and more stable parameters in AF patients with uncontrolled ventricular rates referred for atrioventricular node (AVN) ablation. HBP could be preferred in patients with reduced TAPSE at baseline rather than LBBP.

Comparison of synchronization between left bundle branch and his bundle pacing in atrial fibrillation patients: An intra-patient-controlled study.

BACKGROUND: His bundle pacing (HBP) is a physiological pacing strategy to preserve the electrical synchrony of ventricular conduction and left ventricular (LV) function. Left bundle branch pacing (LBBP) has emerged as an alternative physiological pacing technique. OBJECTIVE: To evaluate cardiac electrical and mechanical synchrony comparing LBBP and HBP in patients with permanent atrial fibrillation (AF). METHODS: Consecutive patients with symptomatic bradycardia and AF were enrolled from January to June of 2019. The cardiac electrical and mechanical synchrony in different pacing mode were evaluated at baseline and after implantation. RESULTS: Both HBP and LBBP were performed in 20 patients. LBBP significantly widened the QRS duration compared with the intrinsic conduction (113.2 ± 14.5  vs. 96.5 ± 16.2 ms; p = .01), while HBP did not (104.5 ± 22.3  vs. 96.5 ± 16.2 ms; p = .12). Both LBBP and HBP patients had similar LV myocardial strain measurements for the mechanical synchrony evaluation without significant change compared with baseline. There was no significant difference in right ventricular synchrony measurement between LBBP and HBP. Compared to HBP, LBBP had less interventricular synchrony (IMVD, 14.7 ± 9.2  vs. 3.1 ± 12.7 ms, p < .01; Ts-LV-RV, 37.9 ± 10.7  vs. 18.5 ± 10.8 ms, p < .001). CONCLUSIONS: Although LBBP's a physiological pacing mode can achieve a similar cardiac electrical and mechanical synchronization when compared to HBP, LBBP results in modest delay in RV activation, and the clinical implication remains to be studied.

Hyperbaric oxygen may improve vascular endothelial function in patients undergoing coronary stent implantation.

Background: Hyperbaric oxygen (HBO2) therapy improves myocardial function and reduces clinical restenosis in coronary arteries. This study aims to evaluate whether the HBO2 therapy can improve vascular endothelial dysfunction in patients undergoing coronary stent implantation. Methods: The retrospective study included 115 patients undergoing coronary stent implantation. Patients receiving HBO2 therapy were included in the HBO2 group (n=55) and those without HBO2 therapy were included as controls (n=60). The levels of brachial artery endothelial-dependent flow-mediated dilation (FMD), endothelial-independent nitrate-mediated dilatation (NMD), nitric oxide (NO), endothelin-1(ET-1), calcitonin gene-related peptide (CGRP) and high-sensitivity C-reactive protein (hs-CRP) were used to evaluate vascular endothelial function. Results: There were no significant differences with regard to the above parameters at baseline in either group (p⟩0.05). In both the HBO2 and control groups the levels of FMD, NO and CGRP after treatment were significantly higher than those before treatment (p⟨0.05). The levels of hs-CRP and ET-1 after treatment were significantly lower than those before treatment (p⟨0.05). After treatment, the levels of FMD, NO and CGRP in the HBO2 group were significantly higher than those of the control group (p⟨0.05), whereas the hs-CRP and ET-1 levels were significantly lower than those of the control group (p⟨0.05). Conclusion: Using HBO2 therapy as an adjunct treatment in patients undergoing coronary stent implantation may significantly improve vascular endothelial function. HBO2 therapy may have the potential to alter the course of coronary artery disease in the future. Further randomized, multicenter, prospective studies are needed.

Vortex solitons in defocusing media with spatially inhomogeneous nonlinearity.

The analytical two- and three-dimensional vortex solitons with arbitrary values of vorticity are constructed in the cubic defocusing media with spatially inhomogeneous nonlinearity. The values of the nonlinearity coefficients are zero near the center and increase rapidly toward the periphery. In addition to the analytical ones, a number of vortex solitons are found numerically. It is shown that analytical vortex solitons are stable. Also, the stability region of the numerically constructed vortex solitons are given.

Controllable optical rogue waves in the femtosecond regime.

We derive analytical rogue wave solutions of variable-coefficient higher-order nonlinear Schrödinger equations describing the femtosecond pulse propagation via a transformation connected with the constant-coefficient Hirota equation. Then we discuss the propagation behaviors of controllable rogue waves, including recurrence, annihilation, and sustainment in a periodic distributed fiber system and an exponential dispersion decreasing fiber. Finally, we investigate nonlinear tunneling effects for rogue waves.

Exact soliton solutions and their stability control in the nonlinear Schrödinger equation with spatiotemporally modulated nonlinearity.

We put forward a generic transformation which helps to find exact soliton solutions of the nonlinear Schrödinger equation with a spatiotemporal modulation of the nonlinearity and external potentials. As an example, we construct exact solitons for the defocusing nonlinearity and harmonic potential. When the soliton's eigenvalue is fixed, the number of exact solutions is determined by energy levels of the linear harmonic oscillator. In addition to the stable fundamental solitons, stable higher-order modes, describing array of dark solitons nested in a finite-width background, are constructed too. We also show how to control the instability domain of the nonstationary solitons.

Propagation of dark similaritons on the compact parabolic background in dispersion-managed optical fibers.

The propagation of optical pulses inside dispersion-managed fibers is considered. It is found that the chirped compact parabolic pulse can propagate inside the dispersion-managed fibers self-similarly. Such a finite-width pulse can be served as the background for the propagation and interaction of dark similaritons. Approximate but highly accurate analytical methods are proposed to describe the interaction dynamics of multiple dark similaritons on the self-similar compact parabolic background.

Similaritons in nonlinear optical systems.

By using the lens-type transformation, exact soliton and quasi-soliton similaritons are found in (1+1), (2+1) and (3+1)-dimensional nonlinear Schrödinger equations in the context of nonlinear optical fiber amplifiers and graded-index waveguide amplifiers. The novel analytical and numerical results show that, in addition to the exact solitonic optical waves, quasi-solitonic optical waves with Gaussian, parabolic, vortex and ring soliton profiles can evolve exact self-similarly without any radiation.