Catheter ablation of atrial fibrillation in patients with left bundle branch block.

BACKGROUND: Left bundle branch block (LBBB) and atrial fibrillation (AF) are commonly coexisting conditions. The impact of LBBB on catheter ablation of AF has not been well determined. This study aims to explore the long-term outcomes of patients with AF and LBBB after catheter ablation. METHODS: Forty-two patients with LBBB of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as LBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without LBBB were enrolled as non-LBBB group. Late recurrence and a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization were compared between the two groups. RESULTS: Late recurrence rate was significantly higher in the LBBB group than that in the non-LBBB group (54.8% vs. 31.5%, p = .034). Multivariate analysis showed that LBBB was an independent risk factor for late recurrence after catheter ablation of AF (hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.09-4.40, p = .031). LBBB group was also associated with a significantly higher incidence of the composite endpoint (21.4% vs. 6.5%, HR 3.98, 95% CI 1.64-9.64, p = .002). CONCLUSIONS: LBBB was associated with a higher risk for late recurrence and a higher incidence of composite endpoint in the patients underwent catheter ablation.

Modifications of the Langendorff Method for Simultaneous Isolation of Atrial and Ventricular Myocytes from Adult Mice.

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction and electrical activity. Hence, isolating viable, high-quality cardiomyocytes from the heart is the initial and most crucial experimental step. Comparing the various protocols for isolating the cardiomyocytes of adult mice, the Langendorff retrograde perfusion is the most successful and reproducible method reported in the literature, especially for isolating ventricular myocytes. However, isolating quality atrial myocytes from the perfused heart remains challenging, and few successful isolation reports are available. Solving this complicated problem is extremely important because apart from ventricular disease, atrial disease accounts for a large part of heart diseases. Therefore, further investigations on the cellular level to reveal the mechanisms are warranted. In this paper, a protocol based on the Langendorff retrograde perfusion method is introduced and some modifications in the depth of aorta cannulation and the steps that may affect the digestion process to isolate atrial and ventricular myocytes were simultaneously made. Moreover, the isolated cardiomyocytes are confirmed to be amenable to patch clamp investigation.

Elevated CCL2/MCP-1 Levels are Related to Disease Severity in Postmenopausal Osteoporotic Patients.

BACKGROUND: Chemokine (C-C) ligand-2 (CCL2), also named monocyte chemoattractant protein 1 (MCP-1), is an important chemotactic factor involved in a wide range of diseases. Recent studies have shown that CCL2/MCP-1 plays crucial roles in the osteoclastogenic process. The current study was performed to measure serum CCL2 levels in postmenopausal osteoporotic patients and investigate the relationship between CCL2 concentrations in serum and disease severity in postmenopausal osteoporotic patients. METHODS: A total of 62 postmenopausal osteoporotic female patients (PMOP group), 68 postmenopausal non-osteoporotic female patients (PMNOP group), and 65 healthy women of childbearing age (Control group) were enrolled in the study. The calcaneal quantitative ultrasound was utilized to conduct bone mineral density (BMD) measurements, confirmed at the left femoral neck, greater trochanter, total hip, and L1 - L4 lumbar spine by dual energy X-ray absorptiometry (DXA). Serum CCL2, TNF-α as well as IL-6 levels were measured with enzyme-linked immunosorbent assay. Estrogen-2 (E2) was measured with radioimmunoassay. The Visual Analogue Scores (VAS) was utilized to assess the extent of pain in PMOP. RESULTS: We demonstrated for the first time that CCL2 levels were increased in postmenopausal women compared with controls. We also found that elevated CCL2 levels were linked with decreased BMD and attenuated E2 concentrations. In addition, CCL2 levels were positively correlated with inflammation markers TNF-α, IL-6, and VAS scores. CONCLUSIONS: CCL2 in serum serves as a potential biomarker for reflecting disease severity in postmenopausal osteoporotic patients. Therapeutic interventions that target CCL2 and its related signaling pathways in order to delay osteoporosis development deserve further study.