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Objective: To investigate atrial fibrillation (AF) last 48h on canine atrial neural remodeling and structural remodeling, electrical remodeling and cardiac function. Methods: Under general anesthesia, rapid pacing (600 beats / min) to establish the right atrium fibrillation canine model was the following results: 1. Dogs pacing 0,6,12,18,24,30,36,42, 48h left atrial diameter, AERP, ventricular ejection fraction (EF) changes; 2. contrast 48h atrial pacing and pacing changes in organizational structure; 3 by immunohistochemistry to observe the three nerve growth factor (GAP-43 , TH, CHAT) changes; 4. thoracotomy heart Langendorff perfusion system with isolated single enzymatic acute atrial myocytes, the application of technology in the whole-cell patch-clamp recording mode membrane L-type calcium current changes. Results: 1. As time continued pacing, left atrial diameter gradually increased, but not statistically significant increased significantly (P lt; 0.05); AERP gradually shortened, and the difference was statistically significant 0h (p lt ; 0.05); atrial ventricular ejection fraction decreased 12h 21.4%, 24h decreased 22.8%, 36h, 48h, respectively, decreased by 25.5% and 31.4%, compared with 0h difference was statistically significant (p lt; 0.05). 2 electron microscope AF48h Myocardial endoplasmic reticulum, mitochondria swelling and glycogen deposition; right atrial tissue HE staining 48hAF myocytes increased disorder, the gap widened between cells. Structural integrity of the control group myocardial cells, arranged in neat rows; Masson staining compared with the control group 48hAF visible collagen deposition, PAS staining 48hAF group showed glycogen deposition. 3 In 48h AF dogs left and right atrium and the left and right atrial appendage, GAP-43, CHAT, TH nerve density compared with the control group was significantly higher nerve density, was statistically significant (P lt; 0.05); addition, AF dogs, right atrial GAP-43 and CHAT nerve density and left atrium were significantly different (P lt; 0.05), endoscopic displayed in each sample uneven distribution of cardiac nerves; TH-positive nerve density left and right atrial and Left and right atrial appendage distribution was not statistically significant (P gt; 0.05). 4.48h AF group of L-type calcium current clamp voltage at different current values ??were lower, peak current density of -3.7 ± 0.50 PA / PF (n = 15), compared with the control group, -5.74 ± 0.20PA/PF (n = 13 ) compared to, L-type calcium current density is reduced by 35.5%, the difference was statistically significant (P lt; 0.05). Conclusions: 1. Induced right atrial pacing 48h atrial fibrillation, can cause atrial electrical remodeling and cardiac function was reduced; 2.48h AF group atrial ultrastructure, organizational structure changes; 3.48 hours continuous visible right atrial pacing dog significant neurological germination and neural remodeling; 4.48h AF group L-type calcium current was significantly reduced.
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