右室流出道特发性室速的射频消融治疗体会

目的 总结不同起源部位特发性右室流出道室性心动过速（ＩＲＶＯＴ）经导管射频消融（ＲＦＣＡ）治疗的方法和结果。方法 对３５例ＩＲＶＯＴ进行ＲＦＣＡ治疗,男性１８例、女性１７例,平均年龄（３９．１±１８．３）岁（８～７２岁）。其中１５例用常规方法消融,２０例用非常规方法消融,非常规方法加用８Ｆ ＳＢ０ Ｓｗａｒｔｚ鞘并在右室流出道放置参考电极。两者均采用起搏与激动标测来确定消融靶点。结果ＲＦＣＡ治疗ＩＲＶＯＴ的总成功率为８８．６％（３３／３５）,常规方法组成功率为８６．７％,复发率为１５．３％,非常规方法组分别为９０．１％和５．６％;常规方法组的导管操作时间为（７１±１２）ｍｉｎ,Ｘ线曝光时间平均为（３２±８）ｍｉｎ,非常规组分别为（４０± ９）ｍｉｎ和（１６ ±５）ｍｉｎ。ＩＲＶＯＴ起自右室流出道近间隔部１３例、游离壁１０ 例及介于两者之间 １２例。成功消融部位激动标测 Ｖ波提前 ＱＲＳ波 １８～３８ｍｓ,起搏标测与心动过速时１２导联心电图（ＥＣＧ）之ＱＲＳ波形态完全相同。结论ＩＲＶＯＴ非常规方法消融可以明显缩短导管操作时间、减少Ｘ线曝光时间及降低复发率;ＩＲＶＯＴ采用ＲＦＣＡ治疗具有较高的成功率和较低的复发率及并发症。     

红花总黄素抑制血小板激活因子所致毛细血管通透性增加的研究

本文研究了红花总黄素（ＳＹ） 拮抗血小板激活因子（ＰＡＦ） 诱导的小鼠毛细血管通透性增加的作用。小鼠随机分为正常动物空白对照组（Ａ）,模型动物对照组（Ｂ） ,模型动物大剂量（Ｃ） ,中剂量（Ｄ） ,低剂量（Ｅ） 药物组共五组（ｎ ＝ １２） 。Ａ,Ｂ组腹注ＮＳ,Ｃ,Ｄ,Ｅ组腹腔注射ＳＹ;３０ｍｉｎ 后,各组尾静脉注射伊文斯蓝;尾注后３０ｍｉｎ,Ａ组腿部肌肉注射ＮＳ,Ｂ,Ｃ,Ｄ,Ｅ组肌注ＰＡＦ造模;肌注３０ｍｉｎ 后处死小鼠。提取腿部肌肉中的染料,测定提取液６２０ｎｍ 的吸收度反映毛细血管通透性。比色结果：Ａ 组０－０８０ ±０－０４５ ,Ｂ组０－４５６ ±０－１５６（ 与Ａ组比较,Ｐ＜ ０－０１） ,Ｃ 组（１００ｍｇ／ｋｇ ＳＹ）０－２２２ ±０－０７１ ,Ｄ 组（７０ｍｇ／ｋｇ ＳＹ）０－３２２ ±０－１３５ ,Ｅ 组（５０ｍｇ／ｋｇ ＳＹ）０－３４２ ±０－１２９ ,（Ｃ,Ｄ,Ｅ,组与Ｂ 组比较依次为,Ｐ＜ ０－０１ ,０－０５ ,０－０５） ,提示ＳＹ 具有明显抑制ＰＡＦ诱发的小鼠毛细血管通透性增加的作用,并且这种作用随着ＳＹ 剂量增加而加强     

经它种导管径路射频消融治疗阵发性室上性心动过速的意义

本文报告５例阵发性室上性心动过速（ＰＳＶＴ）射频消融术（ＲＦＣＡ）采用的它种导管径路与消融结果：１例因双髂动脉迂曲改由右腋动脉穿刺送入大头导管至左室消融左侧壁旁道（ＡＰ）成功；１例为伴永存左上腔静脉的房室结双径路（ＤＡＶＮＰ），导管由左锁骨下静脉送入不成，改由右颈内静脉送入冠状窦（ＣＳ）标测电极消融成功；１例为中间隔主ＡＰ和右游离壁次ＡＰ，两种房室折返性心动过速（ＡＶＲＴ），分别经右股静脉和右颈内静脉径路消融无复发；ＣＳ内消融２例，１例为ＣＳ近端消融左后间隔隐匿性ＡＰ（ＣＡＰ），即刻成功，术后复发，再于左室侧消融阻断ＡＰ；１例于左室侧行ＲＦＣＡ二次未成，第三次先后于左室侧，导管逆行推进入左房和经房间隔穿刺于左房侧消融亦未成，最后将大头导管送入ＣＳ内一次成功阻断左侧壁ＡＰ。提示：对于特殊患者采用它种导管径路可提高ＲＦＣＡ成功率。     

经食管电生理检查中的交替文氏现象

在５６１例经食管电生理检查中，检出各类交替文氏现象（ＡＷ）８１例，共１３７例次，占１４．４％，其中Ａ型、Ｂ型、ＡＢ混合型、三层房室ＡＷ分别为４４，６０，１８，６例次，分别占３２．１％、４３．８％、１３．１％、４．４％；房室结双径路间、束支、房室旁束的ＡＷ分别为５，２，２例次，分别占３．６％、１．５％、１．５％。将７９例ＡＷ者（Ａ组）与８０例无ＡＷ者（Ｂ组）的电生理资料进行比较，显示：①窦性心率（ＳＲ），Ａ组较Ｂ组慢（７２±１４．２ｂｐｍｖｓ７８±１２．６ｂｐｍ，Ｐ＜０．００１）。②房室相对不应期（ＡＶＲＲＰ）、房室功能不应期（ＡＶＦＲＰ）、房室有效不应期（ＡＶＥＲＰ），Ａ组分别为６０９．０±１１９．４，４９６．６±９６．０，３６０．０±８８．０ｍｓ，与Ｂ组（５４６．０±６８．９，４２９．３±６１．５，３０７．０±５１．３ｍｓ）比较差异有高度显著性，Ｐ均＜０．００１。③心房有效不应期（ＡＥＲＰ），Ａ组与Ｂ组比较无显著差异（２６５．０±４２．３ｍｓｖｓ２６５．０±３７．３ｍｓ，Ｐ＞０．０５）。④随Ｓ１Ｓ１刺激间距缩短，Ａ组的房室传导顺序为：１１→文氏型→２１→交替文氏型→３１或心房Ｐ波脱漏；Ｂ组的房室传导顺序则?     

心率变异时域分析对糖尿病患者自主神经功能的评价

采用２４小时动态心电图对８２例糖尿病患者进行心率变异（ＨＲＶ）和心率（ＨＲ）检测。８２例分为五组：Ａ组（无血管合并症）３０例、Ｂ组（合并大血管病变）１１例、Ｃ组（合并小血管病变）１２例、Ｄ组（同时合并大、小血管病变）１９例和Ｅ组（心肾功能不全）１０例，并设正常对照组。结果：糖尿病各组ＨＲＶ显著降低，Ａ组仅２４ｈ内全部正常ＲＲ间期标准差（ＳＤＮＮ，１０４．２０±２９．１９ｍｓ）和２４ｈ内５ｍｉｎ节段平均正常ＲＲ间期的标准差（ＳＤＡＮＮｉｎｄｅｘ，９３．７３±２７．５８ｍｓ）降低（对照组分别为１２７．５２±３８．５７ｍｓ和１１６．１９±３５．７０ｍｓ），Ｐ均＜０．０１；ＨＲ异常主要表现为夜间平均ＨＲ增快，白昼平均ＨＲ仅Ｅ组（８６．７６±１１．３６ｂｐｍ）高于对照组（７６．３８±９．４０ｂｐｍ），Ｐ＜０．０１。表明糖尿病患者存在自主神经受累，白昼心率增快可能是病情严重的征兆。     

动脉搏动指导和解剖标志指导穿刺颈内静脉方法的比较

为对动脉搏动和解剖标志指导穿刺颈内静脉的两种方法进行比较，对５９８例患者颈内静脉穿刺的结果及并发症进行分析。前２１３例采用动脉搏动指导穿刺法，后３８５例采用解剖标志指导穿刺法。结果表明：解剖标志指导穿刺法的总穿刺和一次穿刺成功率均显著高于动脉搏动指导穿刺法（９９．２％ｖｓ９５．７％、８３．８％ｖｓ７３．７％，Ｐ＜０．０５和＜０．０１），而平均穿刺次数和时间前者明显少于后者（１．２±０．５次ｖｓ２．７±２．９次、１．９±５．３ｍｉｎｖｓ３．１±４．７ｍｉｎ，Ｐ均＜０．０５）；两种穿刺方法的并发症发生率分别为３．４％和１１．７％（Ｐ＜０．０１），主要并发症为误穿颈总动脉（８．０％ｖｓ２．１％，Ｐ＜０．０１），２例血胸均发生于动脉搏动指导穿刺法。提示解剖标志指导穿刺法可提高穿刺成功率和减少并发症的发生。     

对六轴系统法诊断左前分支阻滞的评价

为了对新的六轴系统法（ＨＳＡ）诊断左前分支阻滞（ＡＤＢ）进行评价,１２０例电轴在－９０°～＋３０°之间的住院病人按电轴水平－９０°≤Ａ＜－３０°、－３０°≤Ｂ≤０°、０°＜Ｃ≤＋３０°标准划分为Ａ、Ｂ、Ｃ三组,各组均４０例。应用ＨＳＡ和１９８５年世界卫生组织和国际心脏病学会与联合会（ＷＨＯ／ＩＳＦＣ）诊断ＡＤＢ的标准分别对三组病例进行诊断。应用ＨＳＡ诊断Ａ、Ｂ、Ｃ三组ＡＤＢ的阳性率分别为７５．０％、３０．０％和１５．０％,Ａ组阳性率明显高于Ｂ、Ｃ两组,Ｐ均＜０．００１;而应用ＷＨＯ／ＩＳＦＣ标准三组阳性率分别为７０．０％、０、０。两种方法诊断Ａ组中ＡＤＢ的阳性率比较,差异无显著性（７５．０％ｖｓ７０．０％）。Ａ、Ｂ、Ｃ三组中合并右束支阻滞（ＲＢＢＢ）分别为３０％、７．５％和２．５％,Ａ组明显高于Ｂ、Ｃ两组（Ｐ＜０．０１和０．００１）,依据ＨＳＡ诊断的ＡＤＢ中,三组合并ＲＢＢＢ分别占４０．０％、８．３％和０;Ａ组高于Ｂ组,Ｐ＜０．０５。Ａ、Ｂ、Ｃ三组及依据ＨＳＡ方法诊断ＡＤＢ阳性的三组间合并器质性心脏病,左、右室肥大均无差异（Ｐ均＜０．０５）。结果表明：采用ＨＳＡ诊断ＡＤＢ具有简单易行,可能不受电轴及左、右室?     

心肌缺血大鼠的心率功率谱变化及其与心脏性猝死关系的研究

采用心率变异（ＨＲＶ）频域指标定量评价心肌缺血大鼠的心脏自主神经功能变化及其与心脏性猝死（ＳＣＤ）的关系。Ｈｏｌｔｅｒ监测仪记录假手术组（２０只）及心肌缺血后存活组（５４只）与ＳＣＤ组（３６只）大鼠的心电信号。结果显示存活组或ＳＣＤ组大鼠于心肌缺血初始１５ｍｉｎ内的低频（ＬＦ）及低频／高频比值（ＬＦ／ＨＦ）较假手术组明显升高〔ＬＦ（ｍｓ２／Ｈｚ）：１９８．８±４１．３或２２６．７±５６．４ｖｓ６５．４±１９．６，Ｐ均＜０．０１；ＬＦ／ＨＦ：４．０８±１．１或５．１２±１．４ｖｓ１．８７±０．７，Ｐ均＜０．０１〕，而且ＳＣＤ组大鼠的ＬＦ与ＬＦ／ＨＦ较存活组增高〔ＬＦ（ｍｓ２／Ｈｚ）：２２６．７±５６．４ｖｓ１９８．８±４１．３，Ｐ均＜０．０５；ＬＦ／ＨＦ：５．１２±１．４ｖｓ４．０８±１．１，Ｐ＜０．０５〕，各组间ＨＦ无明显变化；ＳＣＤ组大鼠于ＳＣＤ发生前１５ｍｉｎ内，心率功率谱动态变化表现为ＬＦ及ＬＦ／ＨＦ随死亡时间的濒临而呈进行性升高（Ｐ＜０．０１及０．０５）。表明大鼠心肌缺血后其交感神经活性明显亢进，ＨＲＶ降低与ＳＣＤ的发生密切相关。     

Infusa Sleeve导管血管内局部给药的实验研究

目的：评价ＩｎｆｕｓａＳｌｅｅｖｅ（ＩＳ）导管局部给药的可行性。方法：１３只家兔随机分成Ａ组（ｎ＝８）和Ｂ组（ｎ＝５），给药压力分别为６０７．９ｋＰａ（６个标准大气压）（Ａ组）和２０２．６ｋＰａ（２个标准大气压）（Ｂ组），用标准血管成形导管损伤腹主动脉下端后，经ＩＳ导管向腹主动脉下端球囊损伤处局部注入１ｍｌ放射性同位素锝标记的甲氧基异丁基异腈（９９ｍＴｃ－ＭＩＢＩ）注射液。术后３０分钟、６小时、２４小时分别处死动物后，取两组动物靶点血管（腹主动脉下端）、心、肝、骨骼肌、小肠、血液、非靶点血管（肺动脉）组织，用γ计数仪计数后称组织重量。结果：Ａ组和Ｂ组给药后３０分钟靶点血管局部的放射强度分别占给药总量的４９．２５０％和２２．０００％、分别是血液的４５倍和８倍、是非靶点血管的７０倍和１２倍。靶点血管局部放射强度Ａ组大于Ｂ组（Ｐ＜０．０５）。６小时和２４小时后靶点血管局部放射强度占给药总量的０．３４３％（Ａ组）和０．２５５％（Ａ组）。结论：ＩＳ导管可经血管局部靶向给药。ＩＳ导管局部导入的药物浓度呈压力依赖性。     

不同起搏方式对病窦综合征患者远期效果的影响

为了解不同起搏方式对病窦综合征特别是慢－快综合征患者心功能及房性心律失常的影响，利用超声心动图、体表心电图及Ｈｏｌｔｅｒ检查，对２１１例病窦综合征患者采用自身对照方法进行回顾性分析。结果发现：生理性起搏（ＡＡＩ／ＤＤＤ）组术后左室射血分数（ＬＶＥＦ）、心输出量（ＣＯ）明显增加（ＡＡＩ：５３．５±６．１％ｖｓ４７．２±７．８％，４．９５±０．５７Ｌ／ｍｉｎｖｓ４．２０±０．６２Ｌ／ｍｉｎ；ＤＤＤ：５２．５±６．８％ｖｓ４４．３±０．１％，５．１２±０．７１Ｌ／ｍｉｎｖｓ４．４１±０．３８Ｌ／ｍｉｎ；Ｐ均＜０．０１），左房内径（ＬＡＤ）无明显变化；ＤＤＤ组Ｅ／Ａ比值明显增加（０．９８±０．０９ｖｓ０．８７±０．１５，Ｐ＜０．０１），ＡＡＩ组Ｅ／Ａ比值呈增加趋势（Ｐ＝０．０５７）。房性心律失常发生率明显减少（１５．９％ｖｓ５０％，Ｐ＜０．０１）。非生理性起搏（ＶＶＩ）组术后ＬＶＥＦ、ＣＯ明显下降（４４．１±４．７％ｖｓ４８．３±４．３％，３．７７±０．４２Ｌ／ｍｉｎｖｓ４．１７±０．８５Ｌ／ｍｉｎ，Ｐ均＜０．０１），ＬＡＤ明显增大（３９．２６±２．３７ｍｍｖｓ３６．８１±２．３５ｍｍ，Ｐ＜０．０１），Ｅ／Ａ比值呈?     

Mapping of the Coronary Sinus and Great Cardiac Vein Using a 2-French Electrode Catheter and a Right Femoral Approach

Coronary Sinus Mapping. Introduction: Local electrogranis recorded from the coronary sinus and great cardiac vein provide important information for the diagnosis of various arrhythmias and identification of target sites for ablation of left-sided accessory pathways. One limitation of present techniques is the inability, in many cases, to probe the great cardiac vein at the anterior mitral annulus. We tested the feasibility of a new technique for catheterization of the coronary sinus and great cardiac vein by means of a small-diameter electrode catheter advanced via a right femoral approach through an angiography catheter. Methods and Results: Of 22 patients (12 men and 10 women; ages 44.5 ± 13.4 years) undergoing radiofrequency ablation of a supraventricular tachycardia, cannulation of the coronary sinus orifice using a 6-French 1L or 2L Amplatz catheter was achieved in 20 patients (91%) within 0.9 ± 0.6 minutes; after cannulation, a 2-French octapolar electrode catheter with a soft radiopaque tip and a 3-mm interelectrode distance could he advanced in all 20 patients through the guiding catheter to the great cardiac vein in the anterior region of the AV sulcus within 0.8 ± 0.7 minutes. Atrial and ventricular local potentials were recorded all along the mitral annulus during sinus rhythm, atrial and ventricular pacing, or supraventricular tachycardia. Variation of local potential amplitude never exceeded 20% of the mean and presented similar stability at all annular regions. The arrhythmogenic substrate was identified in all patients. Of 18 patients with 21 left-sided accessory pathways, an accessory pathway potential could he recorded at the ablation site by one or more adjacent epicardial electrode pairs in 10 pathways. No procedure-related complications were observed. Conclusions: The technique introduced in this study proved feasible in 91% of patients. Its main advantages are the simplicity and rapidity of coronary sinus cannulation and the ability to advance the electrode catheter to the anterior cardiac vein. In addition, closely spaced bipolar electrograms resulted in enhanced atrial, ventricular, and accessory pathway potential resolution.     

心房颤动时显性房室旁道的射频消融治疗

对 2 6例预激综合征患者于心房颤动 (简称房颤 )时射频消融显性房室旁道。其中左侧旁道 9例、右侧旁道17例 ,2 2例有阵发性房颤史。房颤发作伴旁道前传时的心室率为 171± 32 ( 132～ 2 37)bpm。采用经主动脉逆行法或穿间隔法消融左侧旁道、经股静脉途径消融右侧旁道 ,以最早心室前向激动点且有小A波处为消融靶点。房颤时成功消融靶点的V波较体表心电图预激波的起点提前 37.2± 8.1( 2 6～ 5 3)ms。放电 6± 3( 1～ 16 )次后 ,2 6例中有2 5例 ( 96 % )旁道前传被阻断 ,1例失败。阻断旁道前传后 30min ,3例自行恢复窦性心律 ,2 2例经直流电复律后恢复窦性心律 ,心室起搏示 2 5例中有 2 3例旁道逆传已被阻断 ,2例仍存在 ,经继续消融获得成功。随访 19.2± 11.7( 1～ 38)个月 ,除 1例复发正向前传型房室折返性心动过速 (O AVRT) ,经再次消融旁道逆传成功外 ,其他患者无O AVRT发作及旁道前传恢复的证据。结论 :心房颤动时射频消融显性房室旁道方法可行、成功率高     

心房颤动导管消融术中迷走反射时肺静脉和心房电位周长的变化

目的评价心房颤动(简称房颤)导管消融过程中迷走反射对肺静脉和心房电位周长的影响。方法分析行环肺静脉消融且术中发生迷走反射的12例房颤患者(阵发性房颤10例,持续性房颤2例)心内电生理记录资料。分别测定迷走反射前10s、迷走反射过程中以及迷走反射后60s时的靶肺静脉电位和冠状静脉窦心房电位平均周长(PVCL及CSCL)。结果12例中5例消融时为房颤心律,迷走反射时平均最长RR间期为4025.42±1774.35ms。这5例中,迷走反射时PVCL及CSCL较迷走反射前明显缩短(分别为168.80±47.00msvs174.80±46.41ms;176.80±43.03msvs181.80±40.90ms,P均<0.05)。消融时为窦性心律者中,迷走反射后PVCL及CSCL较迷走反射前明显缩短(分别为882.86±86.74msvs1267.14±214.53ms,880.00±92.92msvs1261.43±209.95ms,P均<0.05)。结论房颤导管消融过程中迷走神经兴奋时,肺静脉和冠状静脉窦心房颤动波周长明显缩短,提示迷走神经兴奋可能在驱动或者加速肺静脉电位传导中起一定作用。     

Comparison of single and double vein approaches for His bundle ablation and pacemaker placement for symptomatic rapid atrial fibrillation

Background  His Bundle ablation (HBA) with permanent pacemaker (PPM) implantation is an effective strategy for controlling heart rate in symptomatic patients with rapid atrial fibrillation (AF), resistant to pharmacologic therapy. The standard double vein (DV) approach involves mapping and HBA from a femoral approach to achieve complete heart block (CHB), while single chamber (SC), dual chamber (DC), or biventricular (BiV) PPM is then placed via a subclavian approach. Methods  We compared 7 patients with drug-resistant rapid AF who underwent the standard DV approach to 8 patients who underwent a single vein (SV) approach, in which HBA and PPM implantation were performed through the subclavian vein. The two groups were compared for acute success in creating CHB, total procedure and fluoroscopy times and patient discomfort. Results are expressed as mean ± standard error (SEM). Results  The procedure times for the SV versus DV were 70.4 ± 11.4 v 100.0 ± 19.2 min, and the fluoroscopy times, 13.9 ± 3.1 (SV) v 13.0 ± 2.9 (DV). All patients were discharged in stable condition with CHB and SC, DC pacemaker or BiV/Implantable Cardioverter Defibrillator (ICD). CHB with symptomatic improvement was maintained in all patients over a mean follow-up period of 22.6 months (SV), and 9.6 months (DV). Conclusion  The SV approach for HBA combined with PPM implantation was at least as effective and may be more efficient than the classic DV approach, and should be considered as an alternative to DV technique to reduce procedural time and patient discomfort.     

Endomyocardial biopsy in heterotopic heart transplant recipients via the femoral vein

The results of endomyocardial biopsy (EMB) via the femoral vein in heterotopic heart transplant recipients were retrospectively analyzed and compared with those obtained using the right internal jugular vein approach. A total of 139 EMB were performed in 8 patients using the femoral (35) or the jugular (104) approach. Twenty three (64.7%) of the procedures performed via the femoral vein were part of the yearly hemodynamic and coronary artery study, and 12 (35.3%) constituted a routine postoperative evaluation of the myocardium rejection state in patients with imperviousness of the right internal jugular vein. Comparing the results obtained with the femoral approach, we observed a higher overall success rate (94.3 vs 88.5%, NS) and obtained more samples that were useful for histologic evaluation (95.5 vs 85.9%, NS); with the jugular procedure, the fragments were significatively larger in diameter (1.28 ± 0.55 vs 1.61 ± 0.85 mm, mean ± SD) and in area (1.49 ± 1.16 vs 2.28 ± 2.24 mm², mean ± SD). No cardiac or local complications were noted when the femoral approach was used, while two attempts to perform biopsy via the jugular vein resulted in obstruction of this vessel. Our data suggest that the femoral venous approach for endomyocardial biopsy in heterotopic heart transplant recipients is a valid alternative to the more commonly used routes.     

Use of a Long Preshaped Sheath to Facilitate Cannulation of the Coronary Sinus at Electrophysiologic Study

INTRODUCTION: Catheterization of the coronary sinus (CS) from the femoral vein can be challenging. We tested whether use of a long preshaped sheath facilitates CS cannulation. METHODS AND RESULTS: One hundred four patients were randomized into two phases. In phase 1, consecutive patients were allocated to CS catheterization using the long sheath (n = 26) or standard 7-French 15-cm sheath (n = 25). If unsuccessful within 10 minutes, the alternative technique was used. Phase 2 assessed the utility of the long sheath in difficult cases. All patients initially were approached using the standard sheath. If cannulation failed after 10 minutes, patients were randomly allocated to the standard or long sheath approach. In phase 1, the standard approach failed in 4 (16%) of 25 cases. In each case, a long sheath proved successful (mean 3.2 min). The long sheath approach was successful within 10 minutes in all 26 cases. Catheter deployment was significantly quicker with the long sheath, but this was offset by the time required for sheath insertion. In phase 2, the standard approach was successful in 46 (87%) of 53 cases. Of 7 "failures," 3 were randomized to continue the standard approach, which was successful in 1; 4 were randomized to the long sheath approach, and success was achieved in all (mean 4.4+/-1.5 min). Overall, the CS could not be promptly catheterized in 15% of cases within 10 minutes using the standard sheath, and no failures were seen using the long sheath. No complications arose from the use of either technique. CONCLUSION: The long sheath was uniformly successful in permitting catheterization of the CS from the femoral approach in both unselected and difficult cases.     

床旁经左锁骨下静脉临时心脏起搏治疗急性心肌梗死心律失常

目的：探讨床旁经左锁骨下静脉临时心脏起搏治疗急性心肌梗死合并缓慢性心律失常患者的疗效与安全性。方法：在无X线透视下，为38例急性心肌梗死患者经左锁骨下静脉路径床旁安置临时心脏起搏器。结果：37例穿刺左锁骨下静脉送入临时电极成功，即刻起搏成功率97．3％，手术开始至起搏成功时间8．0±2．2min，电极导管留置时间1～21d，其中2例电极导管脱位。31例急性心肌梗死经临时起搏后，心肌供血得到改善，恢复自主心律，顺利渡过超急期，1例过渡到安置埋藏式心脏起搏器。结论：床旁经左锁骨下静脉安置临时心脏起搏器成功率高，快速，能改善急性心肌梗死并发严重缓慢心律引起的血流动力学变化，适合于临床推广应用。     

Mitral isthmus ablation with and without temporary spot occlusion of the coronary sinus: a randomized clinical comparison of acute outcomes

Role of CS Occlusion for Mitral Isthmus Ablation . Objective: To evaluate the safety and outcomes of mitral isthmus (MI) linear ablation with temporary spot occlusion of the coronary sinus (CS). Background: CS blood flow cools local tissue precluding transmurality and bidirectional block across MI lesion. Methods: In a randomized, controlled trial (CS‐occlusion = 20, Control = 22), MI ablation was performed during continuous CS pacing to monitor the moment of block. CS was occluded at the ablation site using 1 cm spherical balloon, Swan–Ganz catheter with angiographic confirmation. Ablation was started at posterior mitral annulus and continued up to left inferior pulmonary vein (LIPV) ostium using an irrigated‐tip catheter. If block was achieved, balloon was deflated and linear block confirmed. If not, additional ablation was performed epicardially (power ≤25 W). Ablation was abandoned after ～30 minutes, if block was not achieved. Results: CS occlusion (mean duration ?27 ± 9 minutes) was achieved in all cases. Complete MI block was achieved in 13/20 (65%) and 15/22 (68%) patients in the CS‐occlusion and control arms, respectively, P = 0.76. Block was achieved with significantly small number (0.5 ± 0.8 vs 1.9 ± 1.1, P = 0.0008) and duration (1.2 ± 1.7 vs 4.2 ± 3.5 minutes, P = 0.009) of epicardial radiofrequency (RF) applications and significantly lower amount of epicardial energy (1.3 ± 2.4 vs 6.3 ± 5.7 kJ, P = 0.006) in the CS‐occlusion versus control arm, respectively. There was no difference in total RF (22 ± 9 vs 23 ± 11 minutes, P = 0.76), procedural (36 ± 16 vs 39 ± 20 minutes, P = 0.57), and fluoroscopic (13 ± 7 vs 15 ± 10 minutes, P = 0.46) durations for MI ablation between the 2 arms. Clinically uneventful CS dissection occurred in 1 patient Conclusions: Temporary spot occlusion of CS is safe and significantly reduces the requirement of epicardial ablation to achieve MI block. It does not improve overall procedural success rate and procedural duration. Tissue cooling by CS blood flow is just one of the several challenges in MI ablation. (J Cardiovasc Electrophysiol, Vol. 23, pp. 489‐496, May 2012)     

Treatment of thrombotic saphenous vein bypass grafts using local urokinase infusion therapy with the Dispatch catheter

Percutaneous treatment of thrombotic stenoses or total occlusions in aged saphenous vein bypass grafts is associated with a significant incidence of complications primarily related to distal embolization. The purpose of this study was to assess the efficacy of local urokinase delivery with the Dispatch catheter prior to balloon angioplasty and/or intragraft stent placement as a new technique of vein graft revascularization. Local urokinase delivery with the Dispatch catheter was performed in 15 saphenous vein grafts (mean age = 11.7 ± 2.5 yr) in 13 patients with unstable or postinfarction angina. The target lesion was a total occlusion in 5 of the procedures and a severe vein graft stenosis in the remaining 10. In all cases, urokinase was administered directly to the site of the stenosis/occlusion via the Dispatch catheter at 0.5 cc/min and at a concentration of 30,000 units/cc. The mean urokinase infusion time for the 15 procedures was 33 ± 10 min (range = 10–60 min) and the mean urokinase dose was 495,000 ± 158,000 units (range = 150,000–900,000 units). Following Dispatch therapy, mean minimal lumen diameter increased from 0.34 ± 0.32 to 1.81 ± 0.78 mm (P < 0.01), mean TIMI flow increased from 1.9 ± 1.4 to 2.8 ± 0.8 (P < 0.06), and mean thrombus score was reduced from 2.3 ± 0.6 to 0.3 ± 0.8 (P < 0.01). Mild no reflow was noted in two cases, although no patient demonstrated angiographic evidence of gross distal embolization. One of the patients with no reflow also demonstrated a small increase in cardiac enzymes. Subsequent balloon angioplasty/stent placement was successful in 14 of the 15 procedures (93% success rate). This preliminary report suggests that pretreatment of thrombotic saphenous vein graft stenoses with local urokinase delivery via the Dispatch catheter may decrease intragraft thrombus and possibly decrease the incidence of vascular complications associated with percutaneous intervention. This technique may allow for recanalization of totally occluded vein grafts with large clot burdens by using significantly less urokinase and shorter drug administration times than conventional infusion protocols. Cathet. Cardiovasc. Diagn. 41:261–267, 1997. © 1997 Wiley-Liss, Inc.     

Initial clinical experience with cardiac resynchronization therapy utilizing a magnetic navigation system

Introduction: The placement of left ventricular (LV) leads during cardiac resynchronization therapy (CRT) involves many technical difficulties. These difficulties increase procedural times and decrease procedural success rates. Methods and Results: A total of 50 patients with severe cardiomyopathy (mean LV ejection fraction was 21 ± 6%) and a wide QRS underwent CRT implantation. Magnetic navigation (Stereotaxis, Inc.) was used to position a magnet‐tipped 0.014″ guidewire (Cronus? guidewire) within the coronary sinus (CS) vasculature. LV leads were placed in a lateral CS branch, either using a standard CS delivery sheath or using a “bare‐wire” approach without a CS delivery sheath. The mean total procedure time was 98.1 ± 29.1 minutes with a mean fluoroscopy time of 22.7 ± 15.1 minutes. The mean LV lead positioning time was 10.4 ± 7.6 minutes. The use of a delivery sheath was associated with longer procedure times 98 ± 32 minutes vs 80 ± 18 minutes (P = 0.029), fluoroscopy times 23 ± 15 minutes vs 13 ± 4 minutes (P = 0.0007) and LV lead positioning times 10 ± 6 minutes vs 4 ± 2 minutes (P = 0.015) when compared to a “bare‐wire” approach. When compared with 52 nonmagnetic‐assisted control CRT cases, magnetic navigation reduced total LV lead positioning times (10.4 ± 7.6 minutes vs 18.6 ± 18.9 minutes; P = 0.005). If more than one CS branch vessel was tested, magnetic navigation was associated with significantly shorter times for LV lead placement (16.2 ± 7.7 minutes vs 36.4 ± 23.4 minutes; P = 0.004). Conclusions: Magnetic navigation is a safe, feasible, and efficient tool for lateral LV lead placement during CRT. Magnetic navigation during CRT allows for control of the tip direction of the Cronus? 0.014″ guidewire using either a standard CS delivery sheath or “bare‐wire” approach. Although there are some important limitations to the 0.014″ Cronus? magnetic navigation can decrease LV lead placement times compared with nonmagnetic‐assisted control CRT cases, particularly if multiple CS branches are to be tested.