Feasibility of Left Bundle Branch Area Pacing Combined with Atrioventricular Node Ablation in Atrial Fibrillation Patients with Heart Failure.

BACKGROUND: Pacemaker implantation combined with atrioventricular node ablation (AVNA) could be a practical choice for atrial fibrillation (AF) patients with heart failure (HF). Left bundle branch area pacing (LBBaP) has been widely reported. OBJECTIVES: To explore the safety and efficacy of LBBaP combined with AVNA in AF patients with HF. METHODS AND RESULTS: Fifty-six AF patients with HF attempted LBBaP and AVNA from January 2019 to December 2020. Standard LBBaP was achieved in forty-six patients, and another ten received left ventricular septal pacing (LVSP). The cardiac function indexes and pacemaker parameters were evaluated at baseline, and we conducted a 1-month and 1-year follow-up. RESULT: At the time of implantation and 1-month and 1-year follow-up, QRS duration of LVSP group was longer than that of LBBaP group. The pacemaker parameters remained stable in both the LBBaP and LVSP groups. At 1-month and 1-year follow-up after LBBaP and AVNA, left ventricular ejection fraction, left ventricular end-diastolic diameter, and NYHA classification continued to improve. Baseline left ventricular ejection fraction and QRS duration change at implantation can predict the magnitude of improvement of left ventricular ejection fraction at 1-year after LBBaP. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP. CONCLUSION: LBBaP combined with AVNA is safe and effective for patients with AF and HF. Baseline right atrial left-right diameter, the degree of tricuspid regurgitation, and interventricular septum thickness may be the factors affecting the success of LBBaP.

Low bone mineral density is associated with global coronary atherosclerotic plaque burden in stable angina patients.

BACKGROUND: Accelerated atherosclerosis is considered to be the linking factor between low bone mineral density (BMD) and increased cardiovascular events and mortality, while some coronary angiographic studies do not support this point. In this study, we attempt to provide a distinct comprehensive view of the relationship between BMD and the angiographically determined coronary atherosclerotic burden. METHODS: A total of 459 consecutive patients with stable chest pain suspected of coronary artery disease (CAD) underwent both dual-energy X-ray absorptiometry scan and selective coronary angiography. The association between BMD and global coronary atherosclerotic plaque burden as represented by the multivessel involvement and the modified Gensini score was analyzed. RESULTS: Multivariable analysis revealed that the low BMD at femoral neck and total hip was an independent correlate of multivessel CAD. The T-scores measured at femoral neck and total hip were both negatively and independently associated to the modified Gensini score. These inversely correlated relationships between BMD and CAD were not observed at lumbar spine 1-4. CONCLUSION: This cross-sectional study elucidated an inverse relationship between hip BMD and the modified Gensini score, and low hip BMD values (T-scores) were significantly and independently associated with increased risk of multivessel coronary disease in patients hospitalized for stable chest pain.

Ivabradine inhibits the production of proinflammatory cytokines and inducible nitric oxide synthase in acute coxsackievirus B3-induced myocarditis.

The role of ß-adrenergic stimulation on viral myocarditis has been investigated in animal models. The beneficial action of the ß-blocker carvedilol in murine viral myocarditis can be explained partly by the resulting heart rate reduction and the inhibition of proinflammatory cytokine production. The modulation of myocardial necrosis and contractile dysfunction by proinflammatory cytokines may be partially mediated by the production of nitric oxide (NO). The selective I(f) current inhibitor ivabradine reduces the heart rate without affecting cardiac contractility and has been shown to be cardioprotective in failing hearts. However, little is known about the effects of ivabradine in viral myocarditis, and in particular, its effects on inducible NO synthase (iNOS) have not been investigated. This study was therefore designed to examine the effects of ivabradine in murine viral myocarditis. In a coxsackievirus B3 murine myocarditis model, the effects of ivabradine and carvedilol on the myocardial histopathological changes and fibrosis, NO production, iNOS protein and cytokine levels were studied. Both ivabradine and carvedilol similarlyattenuated myocardial lesions and fibrosis, inhibited NO synthesis by iNOS, and decreased the production of TNF-α and IL-6. These results show that ivabradine has a therapeutic benefit in murine CVB3-induced myocarditis. The beneficial effects of ivabradine in viral myocarditis are partially mediated by the inhibition of both the production of proinflammatory cytokines and the synthesis of NO by iNOS.

Carvedilol treatment ameliorates acute coxsackievirus B3-induced myocarditis associated with oxidative stress reduction.

Oxidative stress has been implicated in the pathogenesis of acute myocarditis. The imbalance between the occurrence of reactive oxygen species and the cellular antioxidant defense mechanism plays a key role in myocardial injury of viral myocarditis. Carvedilol, a nonselective beta-adrenoceptor antagonist with additional alpha1-adrenergic blocking and antioxidant properties, has been shown to be cardioprotective in experimental myocarditis. However, the expression of 4-hydroxy-2-nonenal (4-HNE), the most reliable marker of lipid peroxidation, has not been studied, and the antioxidative effects of carvedilol have not been investigated in the setting of acute viral myocarditis. This study was therefore designed to determine whether levels of lipid peroxides are elevated in the myocardium and whether carvedilol reduces the lipid peroxidation level and increases antioxidant enzyme activities. In a coxsackievirus B3 murine myocarditis model (Balb/c), effects of carvedilol and metoprolol on 14-day survival rate, myocardial histopathological changes, cardiac function, the expression of 4-HNE, virus titers, malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidases (GSH-Px) activities were studied. Lipid peroxidations including 4-HNE and MDA, were elevated in murine coxsackievirus-induced acute viral myocarditis. Carvedilol, but not metoprolol, improved survival, reduced lipid peroxidations including 4-HNE and MDA, and increased antioxidant enzyme activities including SOD and GSH-Px with amelioration of acute viral myocarditis. These results show that carvedilol but not metoprolol exerts some of its beneficial effects by inhibiting peroxidants.

[Inhibition of puerarin on pulmonary hypertension in rats with hypoxia and hypercapnia].

OBJECTIVE: To study the effects of puerarin on pulmonary Vascular remodeling in rats with pulmonary hypertension induced by chronic hypoxia and hypercapnia. METHOD: Forty male rats (180-220) g of grade two were randomly divided into five groups: normal control group (NC), hypoxia-hypercapnia 1, 2, 3 week groups (LH1, LH2, LH3) and hypoxia-hypercapnia 3-week + puerarin group (LHP3 group, puerarin intraperitoneal injection, 20 mg x kg(-1) x d(-1)). Collagen I, III and their mRNA were observed in pulmonary arterioles by the technique of immunohistochemistry and in situ hybridization. RESULT: Light microscopy showed media thickness of pulmonary arterioles was much higher in LH3 group than that of NC group, and, vessel cavity turned more straiter in LH3 group than that of NC group. Howerer, the damage of pulmonary arterioles in LHP3 group was much slighter than that of LH3 group. The levels of plasma ET-1 and lung homogenates Hyr and MDA were much higher in rats of LH3 group than those of NC group (P < 0.01), and lower in LHP3 group than LH3 groups (P < 0.01). The activities of SOD in lung homogenates were significantly lowered in hypoxic and hypercapnic groups compared with control group (P < 0.01), but higher in LHP3 group than that of LH3 group. Plasma NO content of group LH was lower than that of group NC (P < 0.01), it was highter in group LHP3 than that of group LH3 (P < 0.01). Expression of collagen I and collagen I mRNA in pulmonary arterioles were significantly higher in rats of LH groups than those of NC group (P < 0.01), and they were lower in rats of LHP3 group than those of LH3 group (P < 0. 01). Expression of collagen III and collagen III mRNA were not significant difference among three groups. CONCLUSION: Puerarin could improve pulmonary vascular remodeling in rats with pulmonary hypertension by inhibiting the deposition of collagen.