持续性心房颤动患者心房肌内向整流钾电流的研究

目的研究不同病程持续性心房颤动(房颤)患者心房肌内向整流钾电流(IK1)的变化,探讨其与房颤自我发展的可能关系。方法采用急性酶消化法分离单个心房肌细胞。以窦性心律(窦律)的风湿性心脏病患者为对照,应用膜片钳全细胞技术记录房颤≤6个月和>6个月的风湿性心脏病患者心房肌IK1。结果与窦律组相比,在-50~-100mV之间,房颤≤6个月组心房肌IK1密度无明显改变,房颤>6个月组心房肌IK1密度绝对值明显增大(P<0.05)。与房颤≤6个月组相比,房颤>6个月组心房肌IK1密度绝对值也明显增大(P<0.05)。在-100mV,IK1密度绝对值在窦律组为(4.05±0.96)pA/pF(n=18),房颤≤6个月组为(4.35±0.49)pA/pF(n=18),房颤>6个月组为(8.94±0.15)pA/pF(n=18)。结论心房肌IK1在持续性房颤自我发展过程的表现不同,IK1的这种表现可能有利于房颤的自我发展。

Human inward rectifying potassium current in myocytes isolated from patients with rheumatic atrial fibrillation

OBJECTIVE: To compare the changes of inward rectifying K(+) (Kir) current (I(K1)) density in atrial myocytes of patients with rheumatic atrial fibrillation (RAF) less or longer than 6 months. METHOD: I(K1) density was measured with whole-cell patch clamp technique in single myocyte isolated by an enzymatic dissociation method from right atrial appendages in patients with RAF less than 6 months (n = 18) and longer than 6 months (n = 18), RAF patients with normal sinus rhythm (NSR, n = 18) served as control. RESULTS: The average resting membrane potentials were similar between various groups. I(K1) density in single myocyte at -50 to -100 mV of patients with RAF longer than 6 months was significantly increased compared to that in patients with RAF less than 6 months and NSR patients. I(K1) density in single myocyte at hyperpolarized potential level (-100 mV) was also significantly increased in patients with RAF longer than 6 months (8.94 +/- 0.15) than that in patients with RAF less than 6 months (4.35 +/- 0.49) and NSR patients compared to that in NSR (4.05 +/- 0.96, P < 0.05 vs RAF longer than 6 months). CONCLUSION: The data suggest I(K1) current increase might contribute to the electrical remodeling in RAF patients.