双极食管导联记录右心房电位探讨

目的　探讨双极食管导联记录右心房电位的方法及其临床意义。　方法　心内电生理检查时同步记录高位右心房、希氏束、冠状静脉窦和双极食管导联心电图 ,分析食管导联中右心房电位和左心房电位的关系。　结果　双极食管导联记录到的窦性 P波由圆钝直立的右心房电位和尖锐高大的左心房电位组成。 2 8例右心房、左心房传导时间分别为 (4 2 .86± 8.81) ms和 (6 4.2 8± 6 .78) ms,右心房/左心房 =0 .10± 0 .0 3。在窦性心律 ,右心房、左心房和右心室起搏时 ,食管导联的右心房电位和心腔内高位右心房导联的 A波一致 ,左心房电位与冠状静脉窦导联的 A波基本一致。　结论　双极食管导联记录方法能够可靠记录到右心房电位 ,并且分别反映出右心房和左心房激动顺序 ,对了解心房间传导功能 ,分析房性心律失常 ,初步判断隐匿性房室旁路部位等方面 ,有一定的实用价值     

超声心动图评估高血压及慢性心力衰竭患者右心房结构和功能的变化

目的探讨超声心动图评估高血压及慢性心力衰竭(心衰)患者右心房结构和功能的改变。方法选取我院就诊的高血压患者127例为高血压组、慢性心衰患者130例为慢性心衰组,健康体检者125例为对照组。采用超声心电图检测常规超声参数,包括LVEF、右心室侧壁收缩期位移速度、三尖瓣环收缩期位移(TAPSE)、肺动脉收缩压(PASP),计算右心房总排空容积指数(RAVIt)、右心房被动排空容积指数(RAVIp)、右心房主动排空容积指数(RAVIa)及右心房总排空分数(RAVtEF)、右心房被动排空分数(RAVpEF)、右心房主动排空分数(RAVaEF)。结果慢性心衰组LVEF、右心室侧壁收缩期位移速度及TAPSE明显低于对照组和高血压组(P0.05)。与对照组比较,慢性心衰组PASP、RAVIt、RAVIp、RAVIa和高血压组PASP、RAVIa、RAVaEF明显升高,慢性心衰组RAVtEF、RAVpEF、RAVaEF明显降低(P0.05)。慢性心衰组PASP、RAVIt、RAVIa明显高于高血压组(P0.05),RAVpEF、RAVaEF明显低于高血压组[(29.2±5.5)%vs (38.4±3.4)%,(27.6±4.8)%vs (37.6±6.3)%,P0.05]。结论较低的右心房整体射血分数和较高的右心房容积指数作为高血压及慢性心衰患者右心房结构和功能受损的标志。     

探讨三维超声心动图评价房间隔缺损封堵术后右心房功能的价值

目的:探讨三维超声心动图(RT-3DE)在评价房间隔缺损(ASD)封堵术后右心房功能变化的价值。方法:纳入继发孔型ASD患者50例为ASD组,30例体检正常者为正常对照组。ASD组的所有患者均成功接受介入封堵术,并分别在术前、术后3天、1个月、3个月接受RT-3DE检查。测量右心房功能相关指标:右心房收缩前容积(Vpre)、右心房最小容积(Vmin)、右心房最大容积(Vmax)、右心房总排空容积(Vt)、右心房总排空容积分数(Ft)、主动排空容积分数(Fa)、被动排空容积分数(Fp)。结果:封堵术前,ASD组患者的Vmax、Vmin、Vpre、Vt、Fa均明显高于正常组(P0.05),而Ft、Fp均低于正常组(P0.05);ASD组患者术后第3天Vmax、Vmin、Vpre、Vt均高于正常组(P0.05),而Ft、Fp、Fa均低于正常组(P0.05);ASD组患者封堵术后第3天、1个月、3个月的Vmax、Vmin、Vpre、Vt、Fa均明显低于术前(P0.05),Ft、Fp均高于术前(P0.05);ASD组患者术后第3个月时的Vmax、Vmin、Vpre、Vt、Fa、Ft、Fp与正常组比较,差异均无统计学意义(P0.05)。结论:RT-3DE显示ASD患者右心房容积及功能存在异常,封堵术后,右心房容积及功能在短期内即得到改善,但与正常右心房尚有差异;3个月后,基本恢复至正常水平。RT-3DE对评价ASD封堵术后右房容积及功能的变化有重要价值。     

永久性心脏起搏器植入术中发生心房纤颤时心房电极导线定位经验

目的:研究永久性心脏起搏器植入术中心房纤颤(房颤)发作时以右心房波振幅最大处为右心房电极导线固定位置的可行性。方法:22例房颤发作时植入右心房电极导线的患者术中,测试右心房波振幅,术后随访恢复窦性心律(窦律)时测试右心房波振幅、起搏阈值,2者进行对比分析。结果:房颤心律时,所测得的右心房振幅与转为窦律后所测得的右心房波振幅有较好相关性,2者差异无统计学意义[(2.4±1.0)mv比(2.7±1.2)mv,P>0.05]。房颤时术中右心房波振幅平均(2.4±1.0)mv(1.6～3.7mv)者,在房颤转为窦律后所测定的心房感知和起搏功能良好。结论:在房颤发作时,右心房波振幅作为永久心脏起搏器合适的感知及起搏参数,有一定的临床实用价值。     

心房内、外调搏术对病窦综合征的诊断价值

病窦综合征(简称SSS)是由多种原因所致窦房结功能低下引起的常见病症。为探讨窦房结功能测定法的临床意义,我们对经静脉右心房内调搏术、经食管心房外调搏术、阿托品试验、登楼运动试验四种方法进行了研究,并对经食管心房外调搏术能否取代经静脉右心房内调搏术、调搏电极的合适位置     

心房追踪技术对心房颤动患者右心房功能的评价

目的 应用心房追踪技术（AVT）评价高血压心房颤动（HAF）和孤立性心房颤动（LAF）患者右心房整体结构及功能的变化.方法 实验组为60例心房颤动患者,包含LAF组36例,HAF组24例（左心室结构正常）,对照组为30名健康成人,分别应用M型超声测量：舒张末期室间隔厚度（IVSTd）、舒张末期左心室后壁厚度（LVPWTd）,左心室舒张末期内径（LVEDD）、左心室收缩末期内径（LVESD）,右心室舒张末期内径（RVEDD）,以校正立方体积法（Teich）计算左心室射血分数（LVEF）;应用二维超声测量患者收缩末期右心房上下径（RAD1）、横径（RAD2）,收缩末期左心房前后径（LAD1）、上下径（LAD2）、横径（LAD3）;应用AVT测量右心房最大面积（RAAmax）、右心房最大容积（RAVmax）、右心房最小容积（RAVmin）,计算右心房排空分数（RAEF）,收缩期右心房充盈速率峰值（dv/dtS）、舒张早期右心房排空速率峰值（dv/dtE）.结果 与健康对照组相比,心房颤动组的RAD1、RAD2、RAAmax、RAVmax、RAVmin、dv/dtE、LAD1、LAD2、LAD3明显升高,RAEF、dv/dtS明显减低（均为P＜0.05）,LVEDD、LVESD、RVEDD、IVSTd、LVPWTd、LVEF各组间差异无统计学意义（均为P＞0.05）.与HAF组相比,LAF组RAD1、RAD2、RAAmax、RAVmax、RAVmin、dv/dtE明显升高,LAD1、LAD2、LAD3、RAEF、dv/dtS明显减低（均为P＜0.05）.结论 LAF患者右心房结构和功能损害程度较HAF患者更为明显.而AVT是一种简捷、准确评价右心房功能的方法.     

心脏再同步化治疗的自动阈值管理功能

起搏器的自动阈值管理功能因其安全性、节能性被越来越多地用于临床.心脏再同步化治疗的原理为分别起搏右心房、左右心室,并实现双心室同步起搏.与右心房、右心室起搏阈值相比,左心室起搏电极较普通心外膜电极阈值高,且变化大,因此其自动阈值管理相对困难.对于心脏再同步化治疗的自动阈值管理功能的研究及临床使用仍然在探索中.     

心房快速激动对兔心房P选择素及血管性血友病因子表达的影响

目的利用兔心房快速起搏模型,探讨心房颤动与心房内血栓前状态形成的关系。方法将14只新西兰白兔随机分为起搏组和对照组,每组7只,麻醉后自上腔静脉置入电极于右心房,起搏组给予心房快速起搏,对照组不给予刺激,3h后开胸取左、右心房血,分离左、右心耳,分别测定心房血浆中及内皮组织中P选择素和血管性血友病因子(vWF)的表达水平。结果起搏组左、右心房内血浆中和内皮组织中P选择素及vWF水平明显高于对照组(P<0.01);起搏组左心房P选择素及vWF水平明显高于右心房(P<0.05,P<0.01)。对照组左、右心房P选择素及vWF水平比较,差异无统计学意义(P>0.05)。结论心房颤动本身会导致心房特别是左心房内血小板活化、内皮功能损伤等血栓前状态形成。     

室房逆传对窦房结功能及心房肌电活动影响及其意义的实验研究

目的:探讨室房逆传(VAC)对兔窦房结功能低下动物模型窦房结功能及心房肌电活动的影响.方法:选用40只健康新西兰大耳白家兔,其中32只成功制作窦房结功能低下动物模型,以200次/分的起搏频率起搏右心室,将家兔分为1:1VAC组(22只)、非1:1VAC组(10只).观察心室起搏1 h,2 h,4 h,7 d后窦房结功能低下家兔模型右心房压、心房有效不应期、心房激动时间、心肌波长指数、校正窦房结恢复时间的变化,并比较两组上述指标的差别.结果:①1:1VAC组心室起搏1 h后右心房压明显升高(P＜0.01),心房有效不应期、心房激动时间、心肌波长指数、校正窦房结恢复时间无明显变化(P＞0.05);2 h后右心房压继续升高(P＜0.01),校正窦房结恢复时间、心房激动时间延长(P＜0.01),心房有效不应期缩短(P＜0.01),心肌波长指数减小(P＜0.01);4 h后上述指标变化更明显(P＜0.01);7 d后右心房压恢复至原来水平(P＞0.05),心房有效不应期、心房激动时间、心肌波长指数、校正窦房结恢复时间变化更明显(P＜0.01).②非1:1VAC组心室起搏1 h后右心房压明显升高(P＜0.01),校正窦房结恢复时间、心房有效不应期、心房激动时间、心肌波长指数无明显变化(P＞0.05);2 h、4 h后右心房压进一步升高(P＜0.01),校正窦房结恢复时间、心房有效不应期、心房激动时间、心肌波长指数无明显变化(P＞0.05);7 d后右心房压恢复至原来水平(P＞0.05),心房有效不应期、心房激动时间缩小(P＜0.05),校正窦房结恢复时间、心肌波长指数无明显变化(P＞0.05).③1:1VAC组与非1:1VAC组比较:1 h时两组间右心房压、校正窦房结恢复时间、心房有效不应期无明显变化(P＞0.05),但1:1VAC组心房激动时间延长(P＜0.05)、心肌波长指数减小(P＜0.05);2 h时右心房压、心房有效不应期无明显变化(P＞0.05),1:1VAC组校正窦房结恢复时间、心房激动时间明显延长(P＜0.01),心肌波长指数明显减少(P＜0.01);心室起搏4 h,7 d后右心房压无明显变化(P＞0.05),但1:1VAC组心房有效不应期、校正窦房结恢复时间、心房激动时间、心肌波长指数变化更明显(P＜0.01).结论:VAC对窦房结功能及心房肌电活动能产生不良影响.病态窦房结综合征患者应尽量避免使用VVI起搏器,最好安装生理性起搏器.     

C-型钠尿肽对兔离体右心房功能的影响

目的:探讨C-型钠尿肽(CNP)对兔离体右心房动力和内分泌功能的影响.方法:选用雄性新西兰兔47只.随机分七组:为观察CNP的浓度依赖性效应,兔右心房分别用CNP 10-8mol/L(10-8mol/L组,n=6)、10-7 mol/L(10-7mol/L组,n=6)、10-6mol/L(10-6mol/L组,n=6)处理30min;心房灌流对照组(n=6),心房灌流实验组(n=8);自律心房对照组(n=6),自律心房实验组(n=9).采用兔离体搏动右心房灌流模型和放射免疫分析方法,观察CNP对右心房每搏输出量、每搏压和心房钠尿肽(ANP)分泌的效应;采用兔离体自律心房模型,观察CNP对窦性心律的影响.结果:CNP(10-8mol/L,10-7mol/L,10-6mol/L)三种浓度对右心房的每搏输出量和ANP分泌均有抑制作用,并且抑制效应呈浓度依赖性地增强(P<0.05或<0.01).心房灌流对照组和自律心房对照组后期与前期比较,右心房每搏输出量、每搏压、ANP分泌和心率均处于稳定状态,差异无统计学意义(P>0.05).心房灌流实验组和自律心房实验组CNP处理后与CNP处理前比较,右心房每搏输出量、每搏压和ANP分泌明显降低(P<0.01),但心率增加明显(P<0.01),差异有统计学意义.结论:CNP可抑制右心房的收缩和ANP分泌功能,增加窦性心律.     

Effects of atrial pacing site on atrial and atrioventricular nodal function.

The effects of the site used for atrial pacing on atrial and atrioventricular nodal conduction were assesed in 16 patients. In 13 patients, three atrial pacing sites were used: high right atrium, low lateral right atrium, and midcoronary sinus. Two recording sites were used: low septal right atrium, including His electrogram, and high right atrium. Stimulus (S) to high right atrium interval was longest with coronary sinus pacing (76 plus or minus 7 ms) (P less than 0.001), and shortes with high right atrial pacing (41 plus or minus 3 ms) (P less than 0.05). There was no significant difference in stimulus to low septal right atrium from all three pacing sites. Atrial functional and effective refractory periods were not significantly different. Mean low septal right atrium to His was significantly shorter from the coronary sinus (93 plus or minus 8 ms) (P less than 0.001), as compared to high right atrium (139 plus or minus 16 ms), and low lateral right atrium (129 plus or minus 13 ms) pacing. AV nodal functional and effective refractory periods, and the paced rate producing AV nodal Wenckebach were not significantly different when comparing the three sites. Left atrial appendage and high right atrium were similarly compared in three additional patients, and no significant differences were found in conduction times and refractory periods.     

Effects of atrial pacing site on atrial and atrioventricular nodal function.

The effects of the site used for atrial pacing on atrial and atrioventricular nodal conduction were assesed in 16 patients. In 13 patients, three atrial pacing sites were used: high right atrium, low lateral right atrium, and midcoronary sinus. Two recording sites were used: low septal right atrium, including His electrogram, and high right atrium. Stimulus (S) to high right atrium interval was longest with coronary sinus pacing (76 plus or minus 7 ms) (P less than 0.001), and shortes with high right atrial pacing (41 plus or minus 3 ms) (P less than 0.05). There was no significant difference in stimulus to low septal right atrium from all three pacing sites. Atrial functional and effective refractory periods were not significantly different. Mean low septal right atrium to His was significantly shorter from the coronary sinus (93 plus or minus 8 ms) (P less than 0.001), as compared to high right atrium (139 plus or minus 16 ms), and low lateral right atrium (129 plus or minus 13 ms) pacing. AV nodal functional and effective refractory periods, and the paced rate producing AV nodal Wenckebach were not significantly different when comparing the three sites. Left atrial appendage and high right atrium were similarly compared in three additional patients, and no significant differences were found in conduction times and refractory periods.     

不同部位及不同方式心房起搏对心房激动的影响

目的 了解不同部位、不同方式心房起搏时P波、P－R间期以及心房激动顺序的特点，从而寻找最佳的心房单部位起搏方式。方法 对20例射频消融成功后的患者，分别放置高位右房、右心耳、Koch三角、希氏束以及冠状窦电极，若为左侧旁路则加置左心房电极，行不同部位、不同方式心房起搏。结果 Koch三角、Koch三角＋高位右房、左房、双房起膊时P波宽度、P－R间期无差异，但右心耳起搏时各导联P波增宽，P－R间期延长。从心房激动顺序分析，右心耳起搏时，激动传至希氏束区及冠状窦区的时间最长，而Koch三角、Koch三角＋高位右房及双房起搏时则较短，尤其是Koch三角、Koch三角＋高位右房起搏缩短更明显。另外，不同部位、不同方式起搏时右心房压力无差异。结论 Koch三角起搏在某种程度上可替代高位右房＋冠状窦起搏及双房起搏。     

A Case of Widely Split Double P Waves with Marked Intra-Atrial Conduction Delay

Widely Split Double P Wave. We report a 78-year-old man as the first documented case of double P waves separated by 400 msec on 12-lead ECG. These P waves had different polarities on lead V₁. The first P wave represented activation of the lateral wall of the right atrium, and the latter P wave represented activation of the nudial right atrium and the left atrium. Widely spaced double potentials were recorded craniocaudally along the line, presumably corresponding to the crista terminalis during sinus rhythm. For this to occur, conduction disturbance has to be present both in the upper and lower right atrium. Conduction disturbance in the upper right atrium would interrupt excitation from the sinus node to the medial wall, and conduction disturbance in the lower right atrium would interrupt excitation spreading from the lower lateral right atrium to the isthmus area where fragmented potentials were recorded. These multiple discrete lesions appear to constitute a unique electrical atriopathy in this patient.     

The left hand as a model for the right atrium: a simple teaching tool.

AIMS: Knowledge of the complex three-dimensional anatomy of the right atrium is mandatory for the electrophysiologist and interventional cardiologist, but its understanding remains difficult. We hypothesized that the left hand, loosely clenched, is a good three-dimensional model to understand the position of the different anatomical and electrical regions in the right atrium. For validation, we compared the hand with an endocast that had been prepared from an adult human right atrium and with a three-dimensional electro-anatomical CT image of the right atrium. METHODS AND RESULTS: Views of the left hand were photographed from various angles to replicate as closely as possible the standard fluoroscopic views. Using the nomenclature of the bones of the hand, we assigned the different regions of the hand to represent regions and structures of the right atrium. An endocast was prepared from an adult human right atrium. A three-dimensional electro-anatomical right atrial map with CT integration (CartoMerge) was used as the gold standard for the exact localization of electrical regions such as the sinus node (SN), bundle of His, and slow pathway region. Using the left hand, it is possible to mark the free wall, terminal crest, appendage, septal surface, oval fossa and orifices of the caval veins, tricuspid valve, and coronary sinus. We also marked the anticipated locations of the SN, His bundle, triangle of Koch, slow pathway region, inferior isthmus, and right atrial insertion of Bachmann's bundle. When compared with an endocast and a three-dimensional electro-anatomical CT image, the position and orientation of the marked regions were deemed to be anatomically correct. CONCLUSION: Compared with an endocast and a CT-guided electro-anatomical reconstruction of the right atrium, the left hand is a reliable model to understand the position and orientation of the different anatomical and electrical regions in the right atrium. Although an oversimplification of the complex right atrial anatomy, this model is 'handy' to understand, guide, and teach electrophysiological and interventional procedures.     

Further observations on entrainment of atrial flutter in the dog

To determine whether the first postpacing interval after entrainment was affected by recording and pacing sites, overdrive atrial pacing was undertaken in 13 episodes of atrial flutter with a mean flutter cycle length (FCL) of 140 +/- 8 msec induced in seven dogs. Atrial flutter was induced by means of an anatomic obstacle. Seven recording sites, four in the right atrium and three in the left atrium, and three pacing sites, two in the right atrium and one in the left atrium, were selected. After entrainment from the right atrium at pacing cycle lengths that were 94% of the FCL, the first postpacing interval was not significantly different from the intrinsic FCL at each recording site, but it tended to be shorter than the FCL at the recording sites near pacing sites. For entrainment from the left atrium, the first postpacing interval was longer than the FCL at recording sites in the left atrium (p less than 0.001), but it was not different from the FCL at recording sites in the right atrium. These results are due to differences in placement of recording and pacing electrodes relative to the reentrant circuit. Also we observed that activation sequences involving three appropriately selected recording sites were always identical when paced from two different pacing sites at a single constant pacing cycle length. This new phenomenon may best be explained by postulating reentry as the mechanism for atrial flutter.     

Radiofrequency Catheter Ablation of Atrial Flutter After Orthotopic Heart Transplantation

Ablation of Atrial Flutter After Heart Transplantation. Introduction : Antiarrhythmic drug refractory recurrent atrial flutter occurred in a 39-year-old man who had undergone successful orthotopic heart transplantation 3 months ago.
Methods and Results : At electrophysiologic study, the transplanted right atrium showed type I atrial flutter. The recipient right atrium was in sinus rhythm with complete atrioatrial dissociation of electrical activity. Mapping demonstrated double-spike electrograms in the low posterior region of the donor right atrium. During radiofrequency current application near this site, the double potentials were dissociated progressively and atrial flutter was terminated immediately. Thereafter, both the recipient and the transplanted atria were in sinus rhythm of different cycle lengths with continued electrical dissociation.
Conclusion : This is the first report of successful radiofrequency catheter ablation of atrial flutter in a transplanted heart. Although mapping of the arrhythmia is more difficult due to the large circumference of the right atrium, which consists of parts of the recipient right atrium and the transplanted atrium, ablation should be considered in those patients with drug refractory supraventricular tachyarrhythmias.     

The pathological remnants of the right sinus venosus valve. A presentation of 6 hearts of the cor tritriatum dexter type

Six hearts specimens of cor triatriatum dextrum, eight with the Chiari's network, and 3 with a membranous remnant of the crista terminalis are studied. These anomalies are interpreted as varying degrees of persistence of the right valve of the sinus venous which reflect different stages of their morphogenesis. The most frequent congenital heart defects associated with these sinus remnants are the absence of a right atrioventricular connexion and pulmonary atresia with intact ventricular septum. There may be some haemodynamic factors in the right atrium such as partial of complete obstruction between the atrium and the right ventricle which explain the fact that the valve is not reabsorbed. In our specimens the persistent right valve divided the right atrium into two compartments; one is located in the medial sinusal portion where both cavae veins and coronary sinus are connected; the other is lateral compartment which represents the primitive right atrium. It must be noted that the persistent right valve favors blood flow to the left atrium through the patent foramen ovale or through an atrial septal defect deviating the course of the blood away from the right ventricle. This could cause the hypoplasia of the right ventricle. When the valve bulges it obstructs the blood flowing into the right ventricle. The diagnosis of these malformations can be made by echocardiographic, angiocardiographic procedures and nuclear magnetic resonance.     

犬上腔静脉肌袖与右房心肌某些通道亚单位mRNA的表达

目的研究犬上腔静脉肌袖与右房游离壁快速激活延迟整流钾电流(IKr),L型钙电流(ICa-L),短暂外向钾电流(Ito)通道亚单位mRNA表达水平。方法8只健康杂种犬,取上腔静脉肌袖及右房游离壁,采用逆转录聚合酶链反应的方法测定IKrα亚单位ERG、ICa-Lα1亚单位CaV1.2、Itoα亚单位Kv4.3及β亚单位KChIP2mRNA表达水平并进行半定量分析。结果上腔静脉肌袖中ERG表达水平高于右房(P<0.05),而CaV1.2、Kv4.3、KChIP2的mRNA表达均低于右房(P<0.05)。结论上腔静脉肌袖与右房之间存在离子通道基因表达水平的差异。     

不同浓度乙酰甲胆碱介导犬心房颤动的电生理标测和射频消融

目的 研究静滴不同浓度乙酰甲胆碱（Mach）诱发的犬心房颤动（AF）模型,观察电生理标测及不同部位射频消融的结果。方法 实验选用6只犬。于低浓度、中等浓度及高浓度Mach静滴时诱发AF并行电生理标测。低浓度时3只犬先作上腔静脉至下腔静脉的右房后侧壁线性消融,再作右房前侧壁的线性消融。3只犬仅作右房前侧壁的线性消融。中等浓度时作Bachmann’s束（BB）的射频消融。高浓度时选择电生理标测到的规则周期波部位作局部射频消融。结果 低浓度Mach［（1.04±0.37）μg/(kg·min)］介导的AF,右房小梁部心内电图较间隔部及左房相对紊乱且周长较短。对该部位作射频消融可使AF不被诱发,但提高Mach浓度后即不再有效。中等浓度Mach［（2.70±0.49）μg/(kg·min)］介导的AF,左房及间隔部心内电图较小梁部相对紊乱且周长较短。BB消融后5只犬AF终止,4只不再被诱发,但倍增Mach浓度后,该部位的消融亦不再有效。高浓度Mach ［（5.42±0.97）μg/(kg·min)］介导的AF,2例分别于BB左侧及左心耳基底部记录到局部规则周期波,其中1例行局部射频消融后,AF终止,但仍可再诱发。结论 低浓度Mach介导的AF,右房小梁部是其发生的关键部位。中等浓度Mach介导的AF,房间隔或左房是其发生和维持的关键部位。高浓度Mach介导的AF有局灶起源部位。不同浓度Mach介导AF的有效消融区域不同。