ABSTRACT
Traditional right ventricular pacing is non-physiological pacing, can lead to ventricular electrical and mechanical dyssynchmnization, which increases the risk of heart failure and atrial fibrillation. His-Purkinje system pacing is the hot research of physiological pacing method. The high thresholds and difficult implantation of his bundle pacing limits its application and popularization. In recent years, domestic scholars have proposed left bundle branch area pacing. Many studies have confirmed the safety and feasibility of left bundle branch area pacing. Left bundle branch pacing transmit down the conduction system, which can effectively achieve ventricular electrical and mechanical synchrony, At the same time, it also has many others advantages, such as good and stable electrical parameters, significantly improved cardiac function, and pacing across blocked parts. It will become the main development direction of physiological pacing in the future. This article aims to review the origin, standard and classification, advantages and limitations of left bundle branch area pacing.
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Objective To observe the impact of lysophosphatidyl choline(LPC) on the expression of scavenger receptor class B type Ⅰ(SRBI) in L-20 cells and the impact of simvastatin.Methods Cultured hepatocytes were randomly assigned to normal group,LPC-damaged group and simvastatin group.The changes of mRNA and protein expression of SRBI in hepatic tissue were assayed by RT-PCR,immunocytochemistry and Western blot,respectively.Results The expression of SRBI was higher in LPC-damaged hepatocytes than that in normal cells at both mRNA and protein level(P
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Objective To observe the protective effect of levo-anlodipine on the calcium overload in the anoxic myocardial cells. Methods Myocardial cells were cultured, and in vitro model of anoxic myocardial cells was established. Fura2/am fluorescent probe was used to measure the free calcium concentration of the myocardial cells by spectrofluorometer. The expression of Ca~2+ ATPase of cellular membrane was detected by RT-PCR, and the content of calcium pump in sarcoplasmic reticulum was measured by western blot. Results The levo-anlodipine could decrease the free calcium concentration of the anoxic myocardial cells markedly(359.06?75.00nM), and increase the expression of Ca~2+ ATPase of cellular membrane and the content of calcium pump of sarcoplasmic reticulum in the anoxic myocardial cells. Conclusion Levo-anlodipine could enhance the resistance to calcium overload in anoxic myocardial cells through increasing the expression of Ca~2+ ATPase.
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AIM: To observe the influence of serum contained Tongmai herbal medicine on calcium overload of the anoxic myocardial cells. METHODS: Serum contained Tongmai herbal medicine was prepared with the serum pharmacological method and the model of anoxic myocardial cells was established. The intracellular free calcium concentration and the expression of the L-type calcium channel were determined with Fura-2/AM and RT-PCR, respectively. RESULTS: The serum contained Tongmai herbal medicine and levo-anlodipine decreased the intracellular free calcium concentration in the anoxic myocardial cells. The serum contained Tongmai herbal medicine also suppressed the expression of L-type calcium channel in the anoxic myocardial cells, but levo-anlodipine had no effect on the expression of L-type calcium channel. CONCLUSION: Tongmai herbal medicine can attenuate calcium overload in anoxic myocardial cells.