Butova X A, Khokhlova A D, Kopylova G V, Shchepkin D V, Protsenko Yu L
Institute of Immunology and Physiology, Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russia.
Bull Exp Biol Med. 2025 May;179(1):24-28. doi: 10.1007/s10517-025-06426-7. Epub 2025 Jul 18.
Myocardial stretch is a factor that forms an arrhythmogenic substrate for the progression of atrial fibrillation (AF). The features of force generation remodeling during stretching in the atrial myocardium in AF remain poorly understood. In this study, we analyzed changes in active and passive tension of left and right rat atrial myocardial strips at their diastolic stretching and the slopes of the "length-tension" relationship in acetylcholine-CaCl-induced paroxysmal AF. In AF, neither magnitudes of the active and passive tension, nor the slope coefficients of the "length-tension" relationship changed significantly relative to the intact control values. However, the differences between the left and right atria in the parameters of length-dependent regulation of passive tension typical of normal atrial myocardium disappeared in paroxysmal AF.
心肌牵张是心房颤动（AF）进展过程中形成致心律失常基质的一个因素。AF时心房肌拉伸过程中力产生重塑的特征仍知之甚少。在本研究中，我们分析了乙酰胆碱 - 氯化钙诱导的阵发性AF中大鼠左右心房肌条舒张期拉伸时主动和被动张力的变化以及“长度 - 张力”关系的斜率。在AF中，相对于完整对照值，主动和被动张力的大小以及“长度 - 张力”关系的斜率系数均无显著变化。然而，阵发性AF中正常心房肌典型的被动张力长度依赖性调节参数在左右心房之间的差异消失了。
