An intriguing case of regular RR and QRS alternans during idiopathic left posterior fascicle ventricular tachycardia.

This study represents a case of idiopathic left posterior fascicle ventricular tachycardia (LPF-VT), which is intriguing due to regular alternation of short-long RR intervals and QRS morphology. Transthoracic echocardiogram analysis did not detect any structural heart disease. A baseline electrophysiological study was performed. Intracardiac recording during tachycardia showed V-A dissociation, confirming the final diagnosis of idiopathic LPF-VT. No regularity in the monomorphic VT was recorded. Previous relevant studies suggested that a single focus with two exits in distal branches of the left posterior fascicle or two different foci localized in the Purkinje-myocardial network of the left posterior fascicle can clarify the mechanisms. Our team proposed an additional explanation that combines the physiological refractory period with the Ashman phenomenon in individual reentrant LPF-VT circuit.

Exploring the mediating role of calcium homeostasis in the association between diabetes mellitus, glycemic traits, and vascular and valvular calcifications: a comprehensive Mendelian randomization analysis.

BACKGROUND: The interplay between diabetes mellitus (DM), glycemic traits, and vascular and valvular calcifications is intricate and multifactorial. Exploring potential mediators may illuminate underlying pathways and identify novel therapeutic targets. METHODS: We utilized univariable and multivariable Mendelian randomization (MR) analyses to investigate associations and mediation effects. Additionally, the multivariable MR analyses incorporated cardiometabolic risk factors, allowing us to account for potential confounders. RESULTS: Type 2 diabetes mellitus (T2DM) and glycated hemoglobin (HbA1c) were positively associated with both coronary artery calcification (CAC) and calcific aortic valvular stenosis (CAVS). However, fasting glucose (FG) was only linked to CAVS and showed no association with CAC. Additionally, CAVS demonstrated a causal effect on FG. Calcium levels partially mediated the impact of T2DM on both types of calcifications. Specifically, serum calcium was positively associated with both CAC and CAVS. The mediation effects of calcium levels on the impact of T2DM on CAC and CAVS were 6.063% and 3.939%, respectively. The associations between T2DM and HbA1c with calcifications were influenced by body mass index (BMI) and smoking status. However, these associations were generally reduced after adjusting for hypertension. CONCLUSION: Our findings suggest a genetically supported causal relationship between DM, glycemic traits, and vascular and valvular calcifications, with serum calcium playing a critical mediating role.

[An overview of phylogenetic relationship between Mus and Microtus].

Muriod is the most successful one among rodents struggling for existence, and biologists have been paying much attention to it, especially Mus musculus. Because of the thorough study on Mus musculus, it has been widely applied in lab, and becomes a good material for studying other animals. Phylogenetic relationship between different species and populations of Mus and Microtus are more clearly revealed with some genetic markers of modern genetics, such as protein, mtDNA, and rDNA. Taxonomy and evolution of species of both genus have also been revealed. Whereas the taxonomy and genetic relationships of some species and populations between both genus need to be further studied.