Interatrial right-to-left conduction in patients with paroxysmal atrial fibrillation

Purpose  We wanted to illustrate the right-to-left impulse propagation routes during sinus in patients with paroxysmal atrial fibrillation (PAF), as alterations in conduction patterns have been linked to the pathogenesis of PAF, and as no large patient materials have been published. Methods  Patients underwent 3-D electroanatomical contact mapping prior to catheter ablation. The site of the earliest left atrial (LA) activation was determined. Results  Three different interatrial routes were identified, either as solitary pathways (36/50 patients, 72%) or in their combinations (14/50). Bachmann’s bundle (BB) was involved in the majority of the cases with solitary routes (25/36). More seldom, impulse propagation occurred near the oval fossa (FO) (7/36) or the coronary sinus ostium (4/36). In patients with combined routes, both the BB (10/14) and FO routes (11/14) were included in most cases. Conclusions  In PAF patients, LA can be activated during sinus rhythm through three distinct connections, either encompassing a single route or via any combination of these connections. In one third, the earliest LA activation occurs outside BB. The knowledge of the propagation patterns may give insight into the pathophysiology of PAF and into refining ablation therapy.     

Characterization of paroxysmal and persistent atrial fibrillation in the human left atrium during initiation and sustained episodes

INTRODUCTION: Atrial fibrillation (AF) in the left atrium (LA) is poorly defined in terms of regional differences in the degree of organization, characteristics of paroxysmal and persistent variants, and electrophysiologic events that develop at the onset of episodes. METHODS AND RESULTS: The study population consisted of 21 patients (15 men and 6 women; mean age 58+/-9.4 years) with paroxysmal (10 patients) or persistent (11 patients) AF. Mapping of the LA during sustained episodes and the onset of AF was performed with a 64-electrode basket catheter. At the onset of AF, repetitive beats starting with atrial premature complexes and ending with generation of the earliest fibrillatory activity were defined as intermediary rhythm. Patients with paroxysmal AF had longer AF cycle lengths and more pronounced regional differences than patients with persistent AF. In total, AF cycle lengths in the LA in patients with persistent AF were 20% shorter than in patients with paroxysmal AF. Initiation of AF was preceded by an intermediary rhythm of 5.5+/-2.5 cycles (6.3+/-2.7 cycles in paroxysmal AF vs 4.2+/-1.0 cycles in persistent AF; P = 0.026). At the onset of AF, the earliest generators of fibrillatory activity were located more frequently in the posterior wall of the LA. CONCLUSION: AF in the LA displays substantial regional differences in terms of AF cycle lengths and degree of organization. Patients with persistent AF have shorter cycle lengths and a higher degree of disorganized activity than patients with paroxysmal AF. Intermediary rhythms play an important role in initiation of AF via activation of generator regions in the LA.     

阵发性心房颤动患者心房内阻滞的评价

目的对阵发性心房颤动(房颤)患者心房内阻滞的情况进行评价.方法入选78例阵发性房颤患者和8创无阵发性房颤的射频消融患者,电生理检查时分别放置高位右心房、希氏束、冠状静脉窦电极导管作起搏和标测用,在高位右心房进行S1S2程序刺激,S1刺激固定于500ms,S2从450ms开始,-10ms扫描,记录不同刺激时心房内和心房间传导时间及心房不应期.结果S1刺激时阵发性房颤组和对照组S1-AHB间期分别为(56.7±15.4)ms和(60.8±14.2)ms;S1-ACSd间期在两组分别为(110.2±24.3)ms和(107.5±25.6)ms;差异均无显著性(P＞0.05).S2刺激时,心房内传导时间最长延长1倍以上的患者在两组分别为15/78例和11/80例,心房间传导最长延长1倍以上的患者在两组间分别为13/78例和9/80例,两组间差异无显著性(P＞0.05).心房不应期在两组分别为(218.0±28.2)ms和(216.0±24.7)ms,两者间差异无显著性(P＞0.05).结论多数阵发性房颤患者无明显的心房内阻滞和不应期改变,传导时间延长也并非特异地发生在阵发性房颤组,提示心房内阻滞和不应期缩短在阵发性房颤的发生中的作用尚不明确.     

Time course of left atrial mechanical recovery after linear lesions: normal sinus rhythm versus a chronic atrial fibrillation dog model

INTRODUCTION: The extent of left atrial (LA) mechanical function recovery after creation of linear lesions using the loop catheter has not been determined. METHODS AND RESULTS: LA mechanical function was assessed before and after linear lesions using transthoracic two-dimensional and Doppler echocardiography in two groups: (1) normal, which consisted of eight healthy dogs in normal sinus rhythm (NSR); and (2) atrial fibrillation (AF), which consisted of nine dogs in spontaneous AF for 6 months following rapid pacing-induced AF. NSR was restored with linear lesions in all AF dogs. All animals were in NSR 5 months after linear lesions. In the normal dogs, the maximal velocity of the transmitral flow "A" wave was reduced by 42% during the first week postablation and by 24% at 5 months versus preablation. At 5 months, no differences in LA function were noted between the normal and the AF group for all measured Doppler parameters. At 5 months, the LA systolic area in AF dogs was reduced by 40% (preablation 12.9 +/- 2.9 cm2, postablation 7.6 +/- 1.2 cm2; P < 0.01) and in the normal dogs by 21% (preablation 10.0 +/- 0.9 cm2, postablation 7.8 +/- 1.2 cm2; P < 0.02), being the same in both groups within 3 months of recovery. CONCLUSION: The creation of linear lesions with the loop catheter does not result in LA expansion. In normal dogs, LA mechanical activity is reduced for 3 weeks postablation. The time course of LA mechanical function recovery is the same for the AF and the NSR dogs, and it is complete at 3 months postablation. At 5 months, LA systolic function parameters in both groups are reduced by 24% versus the preablation values of the normal dogs. Linear lesions result in a significant reduction in LA size.     

Tachycardia transition during ablation of persistent atrial fibrillation

Tachycardia Transition . Background: The “sequential ablation” strategy for persistent AF is aimed at progressive organization of AF until the rhythm converts to sinus rhythm or atrial tachycardia (AT). During ablation of an AT, apparently seamless transitions from one organized AT to another occur. The purpose of our study was to quantify the occurrence and the mechanism of this transition. Methods and Results: Twenty‐nine of 90 patients undergoing ablation for persistent AF had multiple AT during the procedure and constitute the study group. Thirty‐nine direct transitions from one AT to another during ablation were observed classified in four types: type I (79.4%), i.e., a direct transition of a faster to a slower tachycardia without significant intervening pause; type II (7.69%)—transition after intervening ectopy or longer pause; type III (10.26%)—A slower AT accelerated; type IV (2.56%)—alteration of activation sequence but with no change on CL. Conclusions: Transition to a second AT occurs frequently in the midst of ablation of AT in persistent AF patients. This transition occurs most commonly abruptly within the range of a single cycle length of the original AT. This is best explained by a continuation of AT that was “present” simultaneously with the pretransition tachycardia, being “entrained” (for a reentrant tachycardia) or “overdriven” for an automatic focal tachycardia. The presence of multiple tachycardia mechanisms active simultaneously would be consistent with the eclectic pathophysiology of persistent AF. (J Cardiovasc Electrophysiol, Vol. 22, pp. 506‐512 May 2011)     

心房颤动递进式线性消融后的左心房扑动

目的旨在探讨心房颤动（房颤）递进式线性消融术中出现的房性心律失常的电生理特点及消融的结果。方法对80例房颤消融中出现规律的房性心律失常进行非接触激动顺序标测,判断电生理机制并指导消融。结果共146阵心动过速,4阵为左心房房性心动过速（房速）,周长为（225±49）ms,其余142阵为左心房扑动,左心房激动时间占心动过速周长的100％,周长为（205±37）ms,均与房颤“7”字消融线上的缝隙有关。根据缝隙的位置将心房扑动的折返环分为3类：Ⅰ类（n=68）,缝隙位于左心耳-左上肺静脉间的嵴部,Ⅱ类（n=50）,缝隙位于左心房顶部,Ⅲ类（n=24）,缝隙位于二尖瓣环峡部。其中130阵消融成功,其余16阵因消融反应欠佳后经药物或体外电转复为窦性心律。随访（16．2±6．7）个月,82．5％（66／80）的患者可维持窦性心律。结论房颤递进式线性消融术中出现的房性心律失常多为大折返机制,且与“7”字消融线上的缝隙有关,这些缝隙主要位于左心耳-左上肺静脉间的嵴部。非接触标测技术能快速准确地识别这些缝隙并指导消融。     

Incidence of atrial fibrillation post-cavotricuspid isthmus ablation in patients with typical atrial flutter: left-atrial size as an independent predictor of atrial fibrillation recurrence

Introduction: Atrial fibrillation and atrial flutter often coexist. The long-term occurrence of atrial fibrillation in patients presenting with atrial flutter alone is unknown. We report the long-term follow-up in patients who underwent cavotricuspid isthmus ablation for treatment of lone atrial flutter.
Methods and Results: Between January 1997 and June 2002, 632 patients underwent cavotricuspid isthmus ablation for the treatment of typical atrial flutter at the Cleveland Clinic Foundation. Three hundred sixty-three patients were included in this study and followed for a mean duration of 39 ± 11 months. The mean duration of atrial flutter symptoms was 12 ± 5 months. Mean left-atrial size and left-ventricular ejection fraction were 4.2 ± 0.8 cm and 47 ± 13%, respectively. After a mean follow-up time of 39 ± 11 months, 13% (48 of 363) of the patients remained in sinus rhythm. Five percent (18 of 363) of patients experienced recurrence of atrial flutter only. Sixty-eight percent (246 of 363) experienced the onset of atrial fibrillation and 14% (51 of 363) experienced recurrence of atrial flutter and the new onset of atrial fibrillation. Overall, 82% (297 of 363) of the patients experienced new onset of drug refractory atrial fibrillation. Left-atrial size was a predictor of atrial fibrillation recurrence post-atrial flutter ablation.
Conclusion: At long-term follow-up, approximately 82% of patients post-cavotricuspid isthmus ablation for atrial flutter developed drug refractory atrial fibrillation. This finding suggests that elimination of atrial flutter might delay, but does not prevent, atrial fibrillation. Evidence suggests both arrhythmias may share common triggers and such patients may derive a better long-term benefit from anatomical ablative treatment of atrial fibrillation as well.     

Acute effects of left atrial radiofrequency ablation on atrial fibrillation

INTRODUCTION: Acutely, when left atrial ablation is performed during atrial fibrillation (AF), the AF may persist and require cardioversion, or it may convert to sinus rhythm or to atrial tachycardia/flutter. The prevalence of these acute outcomes has not been described. METHODS AND RESULTS: Left atrial ablation, usually including encirclement of the pulmonary veins, was performed during AF in 144 patients with drug-refractory AF. Conversion to sinus rhythm occurred in 19 patients (13%), to left atrial tachycardia in 6 (4%), and to atrial flutter in 6 (4%). In the 6 patients with a focal atrial tachycardia, the mean cycle length was 294 +/- 45 ms. The tachycardia arose in the left atrial roof in 3 patients, the left atrial appendage in 2, and the anterior left atrium in 1. In 3 of 6 patients, the focal atrial tachycardia originated in an area that displayed a relatively short cycle length during AF. In 6 patients, AF converted to macroreentrant atrial flutter with a mean cycle length of 253 +/- 47 ms, involving the mitral isthmus in 5 patients and the septum in 1 patient. All atrial tachycardias and flutters were successfully ablated with 1 to 15 applications of radiofrequency energy. CONCLUSION: When left atrial ablation is performed during AF, the AF may convert to atrial tachycardia or flutter in approximately 10% of patients. Focal atrial tachycardias that occur during ablation of AF may be attributable to driving mechanisms that persist after AF has been eliminated, whereas atrial flutter results from incomplete ablation lines.     

Electroanatomic remodeling of the left atrium in paroxysmal and persistent atrial fibrillation patients without structural heart disease

Atrial Remodeling in Atrial Fibrillation. Introduction: The nature of the atrial substrate thought to contribute toward maintaining atrial fibrillation (AF) outside the pulmonary veins remains poorly defined. Therefore, our objective was to determine whether patients with paroxysmal and persistent AF have an abnormal electroanatomic substrate within the left atrium (LA). Methods and Results: Thirty‐one patients with AF (17 paroxysmal AF and 14 persistent AF) were compared with 15 age‐matched controls with left‐sided supraventricular tachycardia (SVT). High‐density 3‐dimensional electroanatomic maps were created and the LA was divided into 8 segments for regional analysis. Bipolar voltage, conduction, and effective refractory periods (ERPs) of the posterior LA, left atrial appendage (LAA), and distal coronary sinus (CSd) and percentage complex signals were assessed. In the majority of LA regions, compared with controls, AF patients had: (1) lower mean voltage and a higher percentage low voltage; (2) slower conduction; and (3) more prevalent complex signals. Many of these changes were more marked in the persistent than the paroxysmal AF group. Conclusions: Patients with AF have lower regional voltage, increased proportion of low voltage, slowed conduction, and increased proportion of complex signals compared to controls. Many of these changes are more pronounced in persistent AF patients, suggesting there may be a progressive nature to the changes. Differences occurred in the absence of structural heart disease. These substrate abnormalities provide further insight into the progressive nature of atrial remodeling and the mechanisms involved in maintenance of AF. (J Cardiovasc Electrophysiol, Vol. 23 p. 232‐238, March 2012.)     

Prevention of paroxysmal atrial fibrillation in patients with sinus bradycardia: role of right atrial linear ablation and pacing site

INTRODUCTION: Right atrial linear lesions (RALL), either alone or in combination with antiarrhythmic drug therapy, may modify the substrate for maintenance of atrial fibrillation (AF). The aim of this prospective randomized study was to determine whether RALL provides additional benefit to right atrial appendage pacing (RAAP) and/or interatrial septum pacing (IASP) and drug therapy in patients with symptomatic paroxysmal AF and sinus bradycardia requiring permanent atrial pacing. METHODS AND RESULTS: Sixty-four patients (33 men and 31 women, mean age 73 +/- 10 years) completed the 6-month follow-up. Patients were randomized to either RALL (n = 33) or non-right atrial linear lesions (NRALL), and then to either IASP (n = 32) or RAAP (n = 32). Fifteen RALL patients were paced at the IAS and 18 at the RAA. Seventeen NRALL patients were paced at the IAS and 14 at the RAA. No statistical difference was observed with regard to the mean atrial tachyarrhythmia (AT) burden between NRALL (84 +/- 169 min/day) and RALL patients (202 +/- 219 min/day). Mean AT burden was significantly lower in the IASP group (70 +/- 150 min/day) than in RAAP group (219 +/- 317 min/day; P < 0.016). In the RALL group, the mean AT burden was 99 +/- 180 min/day in the IASP patients and 288 +/- 372 min/day in the RAAP patients (P < 0.046). In the NRALL group, no statistical difference in the mean AT burden was observed between IASP patients (46 +/- 117 min/day) and RAAP patients (130 +/- 211 min/day). CONCLUSION: The results of the present study indicate that RALL did not provide any additional therapeutic benefit to combined antiarrhythmic drug therapy and septal or nonseptal atrial pacing in patients with sinus bradycardia and paroxysmal AF.     

Substrate modification by pulmonary vein isolation and left atrial linear ablation in patients with persistent atrial fibrillation: its impact on complex-fractionated atrial electrograms

PV and Linear Ablation for CFAEs . Introduction: Linear ablations in the left atrium (LA), in addition to pulmonary vein (PV) isolation, have been demonstrated to be an effective ablation strategy in patients with persistent atrial fibrillation (PsAF). This study investigated the impact of LA linear ablation on the complex‐fractionated atrial electrograms (CFAEs) of PsAF patients. Methods and Results: A total of 40 consecutive PsAF patients (age: 54 ± 10 years, 39 males) who underwent catheter ablation were enrolled in this study. Linear ablation of both roofline between the right and left superior PVs and the mitral isthmus line joining from the mitral annulus to the left inferior PV were performed following PV isolation during AF. High‐density automated CFAE mapping was performed using the NAVX, and maps were obtained 3 times during the procedure (prior to ablation, after PV isolation, and after linear ablations) and were compared. PsAF was terminated by ablation in 13 of 40 patients. The mean total LA surface area and baseline CFAEs area were 120.8 ± 23.6 and 88.0 ± 23.5 cm² (74.2%), respectively. After PV isolation and linear ablations in the LA, the area of CFAEs area was reduced to 71.6 ± 22.6 cm² (58.7%) (P < 0.001) and 44.9 ± 23.0 cm² (39.2%) (P < 0.001), respectively. The LA linear ablations resulted in a significant reduction of the CFAEs area percentage in the region remote from ablation sites (from 56.3 ± 20.6 cm² (59.6%) to 40.4 ± 16.5 cm² (42.9%), P < 0.0001). Conclusion: Both PV isolation and LA linear ablations diminished the CFAEs in PsAF patients, suggesting substrate modification by PV and linear ablations. (J Cardiovasc Electrophysiol, Vol. 23, pp. 962‐970, September 2012)     

Discrimination of left atrial and pulmonary vein potentials in patients with paroxysmal atrial fibrillation

INTRODUCTION: Ablation of muscular fascicles around the ostium of pulmonary veins (PVs) resulting in electrical isolation of the veins may prove to be an effective treatment for atrial fibrillation (AF). Correctly discriminating atrial and PV potentials is necessary to effectively isolate PVs from the left atrium in patients with paroxysmal AF. METHODS AND RESULTS: A training set of 151 electrode recordings obtained from 10 patients with AF was used to develop an algorithm to discriminate atrial and PV potentials. Bipolar electrograms were collected from a multielectrode basket catheter placed sequentially into each PV. Amplitude, slope, and normalized slopes of both bipolar and quadripolar electrograms (difference between adjacent bipoles) were entered into a binary logistic regression model. A receiver operating characteristic curve was used to define a threshold able to effectively discriminate atrial and PV potentials. The normalized slopes of both domains, bipolar and quadripolar, produced a logistic function that discriminated atrial and PV potentials against a threshold (0.38) with 97.8% sensitivity and 94.9% specificity. The algorithm then was evaluated on a test set of 214 electrode recordings from four patients who also had paroxysmal AF. These patient electrograms also were evaluated by two independent electrophysiologists. The algorithm and electrophysiologists matched identification of activation origin in 84% of electrograms. CONCLUSION: Atrial and PV potentials acquired from a multielectrode basket catheter can be discriminated using the normalized slopes of bipolar and quadripolar electrograms. These additional parameters need to be included by physicians determining the preferential ablation site within PVs.     

Electrophysiologic effects of selective right versus left atrial linear lesions in a canine model of chronic atrial fibrillation

INTRODUCTION: Long linear lesions have been shown to eliminate atrial fibrillation in animal models, but little is known about the electrophysiologic response in one atrium to lesions in the contralateral atrium. METHODS AND RESULTS: Twelve dogs with chronic atrial fibrillation were randomized to either right atrial ablation (n = 4), left atrial ablation first (n = 4), or a sham procedure (n = 4). Simultaneous biatrial endocardial mapping was performed before and after three linear lesions were applied at specific points in either atrium, using an expandable ablation catheter. Atrial fibrillation was reinducible after single atrial ablation in each dog and no longer inducible after biatrial ablation in five dogs. At baseline, the mean atrial fibrillation cycle length was longer on the trabeculated (117+/-15 msec) compared with the smooth right (101+/-16 msec) or left atrium (88+/-10 msec; P < 0.01). Single right and left atrial ablation caused a significant cycle length increase in the ablated atrium. Left atrial ablation increased the cycle length on both the trabeculated (121+/-18 msec vs 137+/-11 msec; P < 0.05) and smooth right atrium (108+/-12 msec vs 124+/-9 msec; P < 0.05). Right atrial ablation, however, had no significant effect on left atrial fibrillation cycle length (82+/-8 msec vs 86+/-7 msec). CONCLUSION: Left atrial linear lesions affect right atrial endocardial activation, whereas right atrial lesions do not affect left atrial activation in a canine model of atrial fibrillation. These findings suggest that the left atrium is the driver during chronic atrial fibrillation in this animal model and may explain the limited success of right atrial ablation alone in human atrial fibrillation.     

Predictive value of HMGB1 for atrial fibrillation recurrence after cryoballoon ablation in paroxysmal atrial fibrillation patients

BackgroundCryoballoon ablation (CBA) is recommended for patients with symptomatic drug refractory paroxysmal atrial fibrillation (pAF). However, substantial atrial fibrillation (AF) recurrence is common during follow‐up. Searching for a potential biomarker representing both myocardial injury and inflammation to identify patients at high risk of AF recurrence after CBA is very meaningful for postoperative management of AF patients.HypothesisTo evaluate the clinical efficacy of high‐mobility group box 1 (HMGB1) protein released from the left atrium to predict AF recurrence in pAF patients after CBA at 1‐year follow‐up.MethodsWe included 72 pAF patients who underwent CBA. To determine the expression levels of HMGB1, left atrial blood samples were collected from the patients before CBA and after the procedure through the transseptal sheath. Patients were followed up for AF recurrence for 1 year.ResultsA total of 19 patients of the 72 experienced AF recurrence. The level of postoperative HMGB1 (HMGB1post) was higher in the AF recurrence group than in the AF non recurrence group (p = .03). However, no differences were noted in the levels of other biomarkers such as preoperative high‐sensitivity C‐reactive protein (hs‐CRP), postoperativehs‐CRP, and preoperative HMGB1 between the two groups. Multiple logistic regression analysis revealed that a higher level of serum HMGB1post was associated with AF recurrence (odds ratio: 5.29 [1.17–23.92], p = .04). Receiver operating characteristic analysis revealed that HMGB1post had a moderate predictive power for AF recurrence (area under the curve: 0.68; sensitivity: 72%; and specificity: 68%). The 1‐year AF‐free survival was significantly lower in patients with a high HMGB1post level than in those with a low HMGB1post level (hazard ratio: 3.81 [1.49–9.75], p = .005).ConclusionIn pAF patients who under went CBA, the level of HMGB1 after CBA was associated with AF recurrence and demonstrated a moderate predictive power. Thus, we offer a potential biomarker to identify pAF patients at high risk of AF recurrence.     

持续性房颤患者左房球形指数与左房自发显影的相关性

目的 探讨持续性房颤患者发生左房自发显影的临床特征,分析其与反映左房球形化的左房球形指数之间的相关性。方法 回顾性分析首都医科大学附属北京同仁医院2021年8月至2022年12月收治的96例非瓣膜性持续性房颤患者的临床资料。根据经食道心脏超声有无左房自发显影表现,将患者分为左房自发显影组(54例)及对照组(42例)。对2组患者合并症、实验室检查结果、心脏超声参数及左房球形指数进行比较。采用SPSS 22.0统计软件进行数据分析。根据数据类型,分别采用t检验、Mann-Whitney U检验或χ²检验进行组间比较。应用Pearson相关分析左房球形指数与合并症及心脏超声参数的相关性。采用logistic回归分析左房自发显影的危险因素。结果 左房自发显影组患者女性患者比例、CHA2DS2-VASc评分、D-二聚体水平、氨基末端B型钠尿肽前体(NT-proBNP)水平、左房前后径与横径、左房球形指数均高于对照组,差异有统计学意义(P<0.05)。左房球形指数与体质量指数(BMI)、心力衰竭、左室舒张末内径(r=0.236,0.272,0.212;P<0.05...     

左心耳电隔离在持续性心房颤动治疗中的研究进展

肺静脉隔离是心房颤动(房颤)导管消融的基石,对于阵发性房颤有良好效果,但在持续性房颤中的效果则不尽人意.肺静脉隔离以外的辅助消融策略有助于提高持续性房颤的手术成功率.左心耳不仅是心腔内血栓的常见起源,还是导致快速性房性心律失常发生或维持的因素,因而左心耳电隔离成为持续性房颤辅助消融策略之一,研究表明其可能有助于提高持续...     

立体心电图分析阵发性房颤患者心房的电生理特性

目的应用立体心电图(three-dimensional electrocardiogram,3D-ECG)分析阵发性房颤患者心房传导时间、心房除极角度和振幅的变化。方法入选在住院的阵发性房颤患者13例,对照组患者15例。分别应用立体心电图仪记录窦律下的立体心电图,分析后比较两组患者心房传导时间,P波除极振幅及角度。同时记录患者入院时超声心动图中左心房内径数值进行比较。结果两组患者比较左心房内径无显著差异。阵发性房颤组与对照组心房传导时间分别为123.75±11.67msvs.111.39±13.52ms,两组比较有显著性差异(p<0.05)。而在心房除极角度、振幅上,两组无显著差异。与对照组比较,阵发性房颤组患者P环初始部的运行方向与泪点疏密程度无明显变化,但在P环中间至终末部分,P环运行方向及泪点疏密出现明显变化,并且可看到明显的曲折、弯曲。但在除极末20ms的振幅,房颤患者较对照组明显降低(0.05±0.013mvvs.0.036±0.014mv,p<0.05),除极末30ms、40ms处两组振幅无显著差异。结论阵发性房颤患者可以出现心房传导时间延长、心房除极末振幅的改变和立体三维P环运行方向及泪点疏密程...