普伐他汀对快速起搏心房肌结构重构的影响

Effects of pravastatin on rapid pacing-induced structural remodeling in canine atrium

目的 通过普伐他汀干预快速起搏的心房肌 ,观察普伐他汀对快速起搏心房肌结构重构的作用 ,从而探讨他汀药治疗心房颤动 (房颤 )的机制及可行性。方法 将 17条犬分为对照组、起搏组及干预组。对照组不给任何处理及干预 ;起搏组采用快速起搏心房的方法建立房颤模型 ,分别给犬植入 4 2 0～ 5 0 0次 /min的固定频率起搏器 ,起搏时间为 4周。干预组以同样的方法植入起搏器并同时服用普伐他汀 4周。采用超声心动图检查起搏组及干预组起搏前及起搏、干预 4周后左心房前后径及各项容量指标。分别取 3组犬左心耳心房肌进行苏木精 伊红及Masson染色 ,观察细胞形态 ,有无炎细胞浸润及纤维化情况。结果 (1)心脏超声部分 :起搏组术后 4周与术前比左心房前后径及各项容量指标均有显著增加 ,干预组术后 4周与术前比差异无显著性 ;(2 )组织细胞学检查部分 :对照组 ,肌纤维排列整齐 ,胞浆染色均匀 ,间质无炎细胞浸润。起搏组胞膜不清 ,胞浆淡染 ,部分细胞可见空泡变性及片状粘液变性。间质可见炎细胞浸润 ,可见间质及心肌细胞纤维化。干预组 ,部分细胞胞膜不清 ,胞浆淡染 ,无炎细胞浸润 ,无间质及心肌细胞纤维化。结论 普伐他汀可显著抑制快速起搏引起的心房结构重构。

Objectives This study aims to observe the effects of provastatin on structural remodeling of atrial fibrillation in canine atria by pravastatin therapy for the canine which subjected to atrial rapid pacing.The mechanism and feasibility of statins treatment for atrial fibrillation were evaluated. Methods Seventeen dogs were divided into three groups—control,pacing and intervention group.Pacing group subjected to rapid atrial pacing (fix rate of 420 or 500 bpm) for 4 weeks.Intervention group received pravastatin therapy while under rapid atrial pacing .Comparison with the difference of LA diameter,Vmin,Vp,Vmax,Vmax-Vmin before and after pacemaker implantation through echocardiography.Histological studies were performed to identify the potential pathological substrate by stained with HE and Masson's trichroma for pieces of left atrial appendages of all three groups.Results 1.Echocardiography showed LA,Vmin,Vp,Vmax and Vmax-Vmin had significantly increased after procedure than before in pacing group.Whereas,all these parameters from intervention group had nearly no changes.2. Histological and ultrastructural findings was normal in specimens from control group.Abnormality was found from pacing group such as myofibrillar disorder,degeneration,lymphomononuclear infiltrates,interstitial fibrosis with focal replacment.Slight changes from intervention group.Conclusion Pravastatin could significantly suppress the structural remodeling induced by rapid atrial pacing.