治疗心房颤动新药的研究进展与评价

目前应用的抗心律失常药物的安全性和有效性的问题较多，还远远不能满足临床的需要，因此人们一直在努力探索和研发新的抗房颤药物，包括改进现有药物（主要兴趣是新Ⅲ类药物）和针对新靶点的新药研发（主要研究集中在阻断钾通道）。同时人们也在对一些非抗心律失常药物对房颤的可能作用进行了研究，提出了一些新的思路。在此，笔者结合文献简要讨论相关研究的现状。     

阵发性心房颤动后心跳长间歇与窦房结恢复时间的关系及肺静脉隔离对其影响

目的 检测由于阵发性心房颤动反复发作导致心跳长间歇患者的窦房结恢复时间(SNRT),并分析肺静脉隔离对其影响. 方法 11例接受导管射频消融治疗的阵发性心房颤动患者,在4支肺静脉口外进行节段性肺静脉隔离,分析心跳长间歇与160次/min心房刺激测得的SNRT(SNRT160)及模拟心房颤动600次/min测得的SNRT(SNRT600)的关系及肺静脉隔离前后SNRT160及SNRT600的差异. 结果 11例患者均成功隔离所有肺静脉.12导联心电图或动态心电图提示与症状相关的心跳长间歇为(3464±918)ms.肺静脉隔离前测定的SNRT160为(1655±378)ms,SNRT600为(1682±419)ms;肺静脉隔离后测定的SNRT160为(1491±284)ms,SNRT600为(1518±218)ms.SNRT160及SNRT600肺静脉隔离前后比较差异无统计学意义.心跳长间歇与肺静脉隔离前后SNRT无相关性. 结论 阵发性心房颤动终止后发生的心跳长间歇与病态窦房结综合征所致的心跳长间歇的发生机制可能不尽相同.肺静脉隔离是治疗阵发性心房颤动诱发心跳长间歇安全有效的方法.     

室性早搏后心率漂移对室性早搏危险性预测的临床分析

目的　对冠心病室性早搏患者及无器质性心脏病室性早搏患者心率漂移进行分析以揭示心率漂移的临床应用价值。方法　分析对 5 0例冠心病及 5 0例无器质性心脏病室性早搏患者的心率漂移进行分析 ,测定室性早搏后心率加速 ,RR加速 =(R1R2 +R2 R3+R3R4 ) / 3 ;室性早搏后心率减慢 ,RR减缓 =(R7R8+R8R9+R9R10 ) / 3;室性早搏前心率 ,RR =(R-1R-2 +R-2 R-3 +R-3R-4 ) / 3 ;心率漂移指标 :RR加速 -RR ,RR加速 -RR减缓 ,RR减缓 -RR。R1R2 、R2 R3、R3R4 为室性早搏后第 1至第 4次窦性心律 ,R7R8、R8R9、R9R10 为室性早搏后第 7至第 10个窦性心律 ,R-1R-2 、R-2 R-3 、R-3R-4 为室性早搏前第 1至第 4个窦性心律。结果　无器质性心脏病组RR、RR加速 、RR减缓 分别为 842± 6 7ms、72 3± 96ms、919± 89ms,冠心病组RR、RR加速 、RR减速 分别为 879± 83ms、80 7± 10 3ms、912± 12 1ms。非器质性心脏病组RR加速 与RR减速 及RR加速 与RR之间有显著性差异 (P <0 0 1) ,RR减速 与RR有显著差异 (P <0 0 5 )。冠心病组RR加速 与RR减速 之间有显著差异 (P <0 0 1) ,RR加速 与RR有显著性差异 (P <0 0 5 ) ,RR减速 与RR无显著性 (P >0 0 5 )。二组间RR加速 -RR减缓 分别为 183± 12ms及 10 2± 9ms(P <0 0 5 ) ,RR     

心脏记忆的研究现状

心脏记忆是指T波的持续可逆的变化,本文对心脏记忆的研究现状进行论述.     

阵发性室上性心动过速合并胸痛者冠状动脉情况研究

随着冠心病发病率的升高，人们对它的重视程度也越来越高。胸痛是冠心病的主要临床症状，当患者出现室上性心动过速发作时合并胸痛且心电图有缺血性改变(ST段压低≥0．1mV)，其冠状动脉情况如何?为此，我们在行心内电生理检查和射频消融治疗的同时行冠状动脉造影术，观察冠状动脉的改变。     

先天性QT延长综合征合并阵发性三度房室传导阻滞一例

先天性QT延长综合征（LQTS）患者是心原性猝死的高危人群。LQTS合并房室传导阻滞（AVB）非常少见，而且死亡率高，半年死亡率在50％以上。本文报道1例LQTS合并阵发性三度AVB，在置入起搏器前后反复出现心原性晕厥。     

心房肌的复极与阵发性心房颤动发生机制的实验研究

目的　对在体犬左、右心房肌的复极时间进行研究 ,探讨阵发性心房颤动 (房颤 )发生与维持的潜在机制。方法　记录基础心律、非程序刺激及早搏刺激 (SR、S1 、S2 )时 1 4只犬左、右心房的单相动作电位 (MAP)和有效不应期 (ERP) ,测量每个动作电位的幅度和动作电位时程 [复极达90 %、80 %、5 0 %时的动作电位时程 (ms,APD90 、APD80 、APD50 ) ]。并在记录过程中同时观察房颤的诱发情况。结果　记录满意MAP信号 1 2例 ,共标测 2 6点 (右房 1 7点 ,左房 9点 ) ,MAP振幅平均(6 98± 1 76 )mV ,左心房APD90 和APD50 小于右心房 [(1 5 7 4± 4 3 5 0 )ms比 (1 70 9± 37 9)ms ,P <0 0 5 ;(88 4± 1 9 1 )ms比 (1 0 0 1± 2 1 2 )ms,P <0 0 5 )。其中左房刺激发作 38阵 ,明显多于右房 2 3阵 (P <0 0 5 )。由左房诱发房颤的早搏的偶联间期明显比在右房诱发的短 (P <0 0 5 )。起源于左房的房颤的早搏参数小于起源于右房的 (P <0 0 5 )。结论　左、右心房间具有MAP的异质性的复极特性 ,是诱发折返、发生和维持房颤的基质。     

房室结慢径消融对心房电生理性质的影响

Objective The ablation of the atrioventricular node slow pathway may reduce the inducibility of atrial fibrillation (AF) ,but the mechanisms remain unknown. We tried to investigate the impact of ablation on atria refractory period, and to elucidate the underlying mechanism. Methods Thirty-two patients with atrioventricular node reentrant tachycardia (AVNRT) were enrolled in the study. Atria effective refractory period (ERP) and vulnerable window (VW) at high right atrium (HRA),inferior right atrium (IRA),distal (CSd) and proximal CS (CSp) ,as well as sinus rate (SR) and effective refractory period of fast pathway (FERP) were measured before and after ablation. Results ( 1 ) After ablation, the ERP at HRA did not change:(214. 4 ± 35. 1 ) ms, (213.4 ± 37. 3) ms, P = 0. 6, on the other hand, the ERPs at following sites were significantly prolonged:CSp(218. 1 ±21.8)ms, (235.3 ± 23.6) ms,P ＜0. 0001 ;CSd(230. 9 ±21.0) ms, (244. 7 ±25. 1)ms,P＜0. 01;IRA(198.8 ±26.7)ms,(219.7 ±28. 7) ms,P ＜ 0.005,respectively. (2) The VW of HRA remained unchanged after ablation, while the VWs of CSp, CSd and IRA trended to decline despite no statistic significant. (3)SR showed a little increasing but without statistic significant after ablation (P = 0. 17 ).(4) ERP of fast pathway was significantly decreased after ablation: ( 391 ± 55 ) ms, ( 369 ± 78 ) ms, P ＜ 0. 01.Conclusions The decrease of ERPs at CS and IRA, as well as F-ERP after ablation may decline the inducibility of atrial fibrillation and indicates regional vagal denervation to the atrium.     

肺静脉电隔离对阵发性心房颤动患者P向量环的影响

目的探讨成功的肺静脉电隔离对心房除极的影响。方法记录接受环肺静脉电隔离术的18例阵发性心房颤动(PAF)患者术前及术后第1天窦性心律时的心向量图。测量P环的运行时间、P向量环在正交导联额面(F)、水平面(H)、左侧面(LS)的最大振幅及方向。同时记录P环从运行开始后每10ms的除极振幅。结果肺静脉隔离术后P环F最大振幅较术前降低(0.109±0.038mVvs0.128±0.040mV,P0.05)。P环运行时间,H及LS的最大振幅,F、H、LS的最大振幅方向,术前术后无差异(P0.05)。消融成功组(n=12)术后P环H最大振幅较术前降低(0.092±0.019mVvs0.122±0.030mV,P0.05),而术后复发组(n=6)则无明显变化。肺静脉隔离术后P环振幅降低发生在P环运行至40～80ms的部分,即P向量环的中部。结论PAF病人在肺静脉电隔离成功后P环最大振幅发生改变。     

心房肌复极的电整复性与阵发性心房颤动发生机制的实验研究

Objective Electrical restitution was believed to be a determinant responsible for the stability of heart rhythm. Although numerous studies focused on the role of action potential duration restitution (APDR) in the initiation and maintenance of ventricular fibrillation (VF), the relationship between atrial APDR and atrial fibrillation (AF) has not been fully understood. This study aims to investigate the characteristics of APDR of left atrium (LA) and right atrium (RA) in canines and the relevance to induction of AF. Methods Monophasic action potential (MAP) was recorded from LA and RA in 14 canines using the MAP recording-pacing combination catheter. APDR, plotted as action potential duration (APD) on the preceding diastolic interval (DI), was assessed by use of programmed stimulation with a single extrastimulus (S_1S_2) at LA and RA. Episodes of AF were recorded and analyzed. Results APD_(90) was significantly shorter in the LA than that in the RA [( 157.4 ± 43.5 ) ms vs. ( 170. 9 ± 37. 9)ms, P < 0. 05]. The mean slope of the APDR curve by S_1S_2 in the LA was significantly greater than that in the RA ( 1.3 ±0. 4 vs. 0. 9 ± 0. 3, P < 0. 05 ). The incidence of induced AF was significantly higher in the LA than in the RA (11/18 vs. 7/18, P < 0. 05). Conclusions The APDR and MAP characteristics are not uniform between atriums, which may be one of the important mechanisms responsible for the initiation of AF. Heterogeneity of APDR between LA and RA might create critical gradients or a dispersion of repolarization and subatrate for re-entrant arrhythmias and vulnerability to AF.