房颤患者心房肌I_f电流mRNA表达的变化

Alterations of I_f mRNA expression in atria of patients with persistent atrial fibrillation

目的 观察了房颤患者If电流mRNA表达的变化 ,从分子水平探讨房颤发生的机制。方法 2 6例因冠状动脉粥样硬化性心脏病、风湿性心脏瓣膜病或先天性心脏病行开胸心脏手术的患者 ,术中取右心耳 5 0mg。分为两组 :窦性心律组 15例 ;持续房颤组 11例。采用逆转录聚合酶链反应的方法测定两组患者起搏电流离子通道mRNA表达的变化。结果 持续房颤患者左心房内径明显较窦性心律患者大 (5 1.18± 9.12mm∶3 4.2 7± 4.0 6mm ,P <0 .0 1)。其他临床特征匹配。房颤患者If 基因表达明显增加 (0 .3 0± 0 .0 3∶0 .3 4± 0 .0 5P <0 .0 5 )。结论 无论窦性心律患者还是持续房颤患者 ,其心房中都有If 的表达 ,证明If 不仅存在于起搏细胞 ,也在非起搏细胞心房肌组织中有表达。持续房颤患者IfmRNA表达明显高于窦性心律患者 ,提示此电流可能参与房颤发生的某种机制。

Objectives To measure I f channel mRNA expression in atrial tissue of patients with AF and without AF in order to study on the mechanism of AF. Method Right atrial appendages were obtained from 26 patients undergoing open heart surgery including patients with coronary heart disease, rheumatic heart disease and congenital heart disease. Among them 11 had persistent AF and 15 were matched controls in sinus rhythm. Funny channel mRNA were measured by semiquantitative polymerase chain reaction.Results Clinical parameters were matched between 2 groups except that left atrial diameter were larger in patients with AF than in patients with sinus rhythm (51.18±9.12mm vs 34.27±4.06mm, P <0.01). mRNA levels of I f were increased from 0.30±0.03 in patients with AF to 0.34±0.05 in patients with sinus rhythm ( P <0.05).Conclusions I f exists in atria regardless of patient with sinus rhythm or AF, which shows that I f exists both in pacing cells and in nonpacing tissue-atria. Moreover, mRNA of I f is increased among AF patients compared with patients with sinus rhythm, which suggests that this channel may be involved in some mechanism of AF onset.