在世界范围内，充血性心力衰竭（congestive heartfailure，CHF）和心房纤颤（AV）已经成为影响人类健康的两种主要心血管疾病。据统计，目前全世界大约有1500—2000万CHF患者，美国约有500万CHF患者。AF与CHF一样，影响着成千上万的人，平均人群发病率是1．5％，并随着年龄增大发病率骤升。美国大约有230万房颤患者，欧洲房颤患病人数与美国接近。根据美国房颤抗凝和危险因素研究计划（anticoagulation and risk factors in atrial fibrillation，ATRIA）预测，在下一个50年中，房颤在美国的发病人数将增加1．5倍，估计到2050年达到约560万人。令人关注的是，AF与CHF常合并存在而且相互影响。许多引起CHF的疾病过程同样是AF发生的危险因素，如高血压、糖尿病、冠心病、心脏瓣膜病等。同样，在CHF患者中常见的超声表现如左房扩大、左室壁肥厚等也是AF发生的原因。本文主要探讨CHF在AF发生，维持机制中的作用以及CHF合并AF时的治疗进展。
Objective To study the effect of ivabradine on hyperpolarization activated cation current in canine pulmonary vein(PY) sleeve cardiomyocytes with atrial fibrillation.Methods Dissociation of PVs yielded single cardiomyocytes from a Landengorff column without or with pacemaker activity from long-term rapidly atrial pacing (RAP) canines.If current was measured with the whole-cell patch-clamp technique.Results Compared with the control group,the rapidly atrial pacing canine PV cardiomyocytes had spontaneous diastolic depolarization and had larger If densities.Ivabradine (Iva,1 μM),a selective inhibitor of the If current,markedly reduced If currents in the RAP from -2.66±0.4 pA/pF to -1.58±0.1 pA/pF at the test potential of-120 mV (P＜0.01,n=12).Inhibition effect of Iva of If current showed concentration-dependent range from 0.1 to 10.0μM,with IC50 of 2.2 μ M ( 1.8-2.9 μM,95% CL).Furthermore,V1/ of steady-state activated curve was shifted from -84.3±4.9 mV to -106.9±3.4 mV and k value of steady-state activated curve was changed from 12.1+2.6 mV to 9.9±3.4 mV by the application of.1.0 μM Iva ( P＜0.01,n=12).Conclusions Our study revealed that Ivarbadine may significantly decrease If of rapidly atrial pacing pulmonary vein sleeve ceUs with atrial fibdllation.(J Geriatr Cardiol 2008;5:39-42)
Yang Li Yan Huang Zongbin Li Hao Wang Jianguo Song Yuqi Liu Lei Gao Shiwen Wang
