Artikel
The Contribution Of Myocardial Layers To Propagation Of Ecxitation In Renovascular Hypertensive Rats
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Veröffentlicht: | 8. Februar 2007 |
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Gliederung
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The present study investigates the relationship between the chronotopography of the excitation wave propagation and architecture of the working myocardium in renovascular hypertensive rats. The renovascular hypertension was produced by placing a clip around the left renal artery of Wistar rats (n=10). After a 4-wk follow-up, the ventricular activation process was carried out using a 128-channal computer system for simultaneous registration. After registration the architecture of the working myocardium was studied by making serial cross-histological sections. Nonuniform thickening of left ventricle (LV) walls in renovascular hypertensive rats in comparison with controls was shown. The maximal thickening was observed on the posterior side in the area of the transition of free wall of the LV to the interventricular septum (the posterior wall). It was shown that different myocardial layers make heterogeneous contribution to the evolution of the LV hypertrophy. The thickness of the subepicardial layer and the orientation of its fibers don’t change. The thickness of the middle layer and the orientation of its fibers in various regions of the LV and the interventricular septum change nonuniformly. The orientation of the subendocardial fibers doesn’t change but the thickness of this layer increases. When comparing the architecture of the working myocardium and chronotopography of the excitation wave propagation in renovascular hypertensive rats it was revealed, that the conduction velocity significantly decreases in the LV posterior wall. Apparently, it was caused by the maximal increasing of the middle layer thickness in this area. The work is supported by the grant of the academician M.P.Roshchevsky SS-5118.2006.4, Russian Science Support Foundation.