Embi Abraham A, Scherlag Benjamin J, Ritchey Jerry W
Independent, Miami, Florida, USA.
Heart Rhythm Institute, University of Oklahoma Health Science Center, Professor of Medicine, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma, USA.
N Am J Med Sci. 2014 Oct;6(10):510-5. doi: 10.4103/1947-2714.143282.
Previous experimental studies have demonstrated electrophysiological and structural remodeling in pacing induced atrial fibrillation. The latter has been characterized by glycogen accumulation but no connection to atrial fibrillation induction and maintenance has as yet been proposed.
We determined the presence of glycogen in the right and left atrial appendages in the goat heart, in order to find any intrinsic disparity in distribution and concentration between these sites.
Atrial appendages from 5 goats were stained by the Periodic acid Schiffmethod to determine the presence of glycogen and the concentration of glycogen by morphometric analysis.
We are reporting for the first time that the right atrial appendage showed scattered glycogen granules throughout the atrial myocytes which delineated the intercalated discs; whereas glycogen in the left atrial appendage was more dense within cells and coalesced against the intercalated discs and side to side junctions between myocytes. Also, morphometric analysis determined that the stained regions of the right atrial appendages averaged, 0.8 ± 1.3 μm(2) compared to the left atrial appendage sections, 2.6 ± 3 μm(2), P = 0.02. We show that glycogen is heterogeneously distributed in both atria in the normal goat heart; however, the density of glycogen deposits concentrating against the intercalated discs and side to side connections in the left atrial appendage is a critically distinct difference. Impediment of cell to cell conduction could result in a non-uniform wavefront of activation, with areas of slowed conduction, predisposing the left atrium to reentrant based atrial fibrillation.
These findings provide a basis for the well-known greater propensity for atrial fibrillation in the left versus the right atrium.
先前的实验研究已证实在起搏诱导的心房颤动中存在电生理和结构重塑。后者的特征是糖原积累，但尚未提出与心房颤动诱导和维持的关联。
我们确定山羊心脏左右心耳中糖原的存在情况，以找出这些部位在分布和浓度上的任何内在差异。
对5只山羊的心耳进行过碘酸希夫染色，以确定糖原的存在，并通过形态计量分析确定糖原浓度。
我们首次报告，右心耳在整个心房肌细胞中显示出散在的糖原颗粒，勾勒出闰盘；而左心耳中的糖原在细胞内更密集，聚集在闰盘以及心肌细胞之间的侧向连接处。此外，形态计量分析确定，右心耳的染色区域平均为0.8±1.3μm²，而左心耳切片为2.6±3μm²，P = 0.02。我们表明，在正常山羊心脏中，糖原在两个心房中分布不均；然而，左心耳中糖原沉积物聚集在闰盘和侧向连接部位的密度存在显著差异。细胞间传导的阻碍可能导致激活波前不均匀，出现传导减慢区域，使左心房易发生基于折返的心房颤动。
这些发现为左心房比右心房更易发生心房颤动这一众所周知的现象提供了依据。
