Paraseptal Accessory Pathway in Wolff-Parkinson- White-Syndrom: Ablation from the Right,from the Left or within the Coronary Sinus/Middle Cardiac Vein?

Aims: In 1999 the consensus statement living anatomy of the atrioventricular junctions was published. With that new nomenclature the former posteroseptal accessory pathway (APs) are termed paraseptal APs. The aim of this study was to identify ECG features of manifest APs located in this complex paraseptal space.Methods and Results: ECG characteristics of all patients who underwent radiofrequency ablation of an AP during a 3 year period were analyzed. Of the 239 patients with one or more APs, 30 patients had a paraseptal AP with preexcitation. Compared to APs within the coronary sinus (CS) or the middle cardiac vein (MCV) the right sided paraseptal APs significantly more often showed an isoelectric delta wave in lead II and/or a negative delta wave in aVR. The left sided paraseptal APs presented a negative delta wave in II significantly more often compared to the right sided APs.Conclusions: According to the site of radiofrequency ablation, paraseptal APs are classified into 4 subgroups: paraseptal right, paraseptal left, inside the CS or inside the MCV. Subtle differences in preexcitation patterns of the delta wave as well as of the QRS complex exist. However, the definitive localization of APs remains reserved to the periinterventional intracardiac electrogram analysis.     

Characteristics and radiofrequency ablation in posteroseptal and left free-wall subepicardial accessory pathways

Accessory pathways (APs) that can only be ablated from the coronary sinus are likely to be located subepicardially. The electrocardiographic (ECG) and electrophysiological characteristics as well as the immediate radiofrequency ablation success rate and the recurrence rate were compared in 15 patients (11 posteroseptal and 4 left free-wall) with subepicardial APs and in 31 control patients with posteroseptal (15) and left free-wall (16) APs matched with age, sex, and AP location during the same study period in whom APs were successfully ablated from the endocardial approach. Patients with posteroseptal subepicardial APs had a longer tachycardia cycle length (355 +/- 32 vs 286 +/- 49 milliseconds, P < .05), a lower success rate (9 /11 vs 15/15, P = .09), and a higher recurrence rate (3/9 vs 0/15, P < .05) as compared with control patients. A negative delta wave with QS or QR pattern in lead II was present in all 4 patients with a manifest posteroseptal subepicardial AP located in the middle cardiac vein as compared with none of the 5 control patients with posteroseptal APs located in the proximal coronary sinus and 1 of the 9 control patients (P < .01). A positive delta wave in lead I along with an R/S of less than 1 in lead V 1 , and a negative delta wave in lead II, was noted in 1 of the 2 patients with left free-wall subepicardial APs and none of the 7 controls (P = .047). The local activation time is significantly shorter in the 4 patients with left free-wall subepicardial AP than in the 16 control patients (31 +/- 9 vs 89 +/- milliseconds, P = .044). CONCLUSIONS: Some ECG characteristics are suggestive of APs located in the middle cardiac vein and left free-wall subepicardial site, while a longer local activation time is characteristic of left free-wall APs. The success rate is lower and the recurrence rate higher with radiofrequency ablation in patients with subepicardial AP.     

Ablation of posteroseptal and left posterior accessory pathways guided by left atrium-coronary sinus musculature activation sequence

Introduction: While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature.
Methods and Results: Forty patients with posteroseptal or left posterior AP were included. The LA–CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP.
Conclusion: During retrograde AP conduction, the sequence of LA–CS musculature activation—as deduced from analysis of electrograms recorded at the earliest site inside the CS—can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach.     

Radiofrequency Catheter Ablation of Posteroseptal Accessory Pathways–Results of a Step-by-Step Ablation Approach

Introduction: Transcatheter radiofrequency ablation of posteroseptal accessory pathways (AP) is challenging. A number of different interventional approaches have been suggested by different groups. The selection of the initial approach is crucial in order to reduce radiation exposure and the number of unsuccessful lesions applied. We present our ablation technique as guided by a simplified electrocardiographic analysis of the delta wave polarity and the electrophysiologic mapping results. Methods and Results: Out of 35 manifest APs encountered in the right (n=17) or the left posteroseptum (n=18) in 35 patients, 34 were successfully ablated. Despite their left sided location, 7 of the 18 left sided APs were ablated after switching from an initial arterial to a venous approach looking for an appropriate target site in the right posteroseptal space or within the coronary sinus network. The other 11 left sided APs were ablated in the mitral ring, on 2 occasions, on their atrial aspect through a retrograde transmitral approach. On the contrary, 16 of the 17 right sided APs were successfully ablated exclusively through a venous approach. Fourteen of these were ablated in the right posteroseptum, in 2 cases, only after reaching their ventricular aspect. Two right sided APs were interrupted in the coronary sinus os and the middle cardiac vein respectively. Conclusion: It appears that even though the electrocardiographic and electrophysiologic location of the AP in the posteroseptal space helps select the appropriate initial approach, it does not always guarantee a successful ablation procedure in the expected site of the corresponding atrioventricular ring. Not uncommonly, it will be necessary to look after intermediate target sites within the coronary sinus to improve the overall ablation success rate.     

"Atypical" posteroseptal accessory pathway in Wolff-Parkinson-White syndrome

The posteroseptal accessory pathway in the Wolff-Parkinson-White syndrome is associated with a delta wave that is negative in the inferior electrocardiographic (ECG) leads and the occurrence of the earliest retrograde atrial activation near the orifice of the coronary sinus during atrioventricular (AV) reentrant tachycardia. Seventy-two patients with a posteroseptal accessory pathway underwent epicardial mapping before operative ablation. The earliest epicardial activation occurred at the posterosuperior process of the left ventricle in all patients. Dissection of the posteroseptal region (right atrial-left ventricular sulcus) resulted in permanent loss of preexcitation in 69 patients and failure to abolish preexcitation permanently in 3. At reoperation in two patients, preexcitation was abolished by discrete cryoablation of the left side of the interatrial septum near the AV node approached through the atrial septum in the normothermic beating heart. At reoperation, one patient had extensive AV node dissection. All patients have had permanent loss of preexcitation. The vast majority of posteroseptal accessory pathways ("typical") are epicardial and ablated by dissection of the posteroseptal region. Rarely, posteroseptal accessory pathways are "atypical" in that they are intraseptally located near the AV node on the left atrial endocardial surface.     

Angiographic patterns of coronary sinus anatomy and its relation to successful ablation sites in accessory pathway patients

BackgroundThe epicardial coronary venous system assumes importance in accessory pathway (AP) ablation especially in case of lengthy or failed attempts of ablation. Epicardial accessory pathways may be related to CS myocardial coat along one of its tributaries or to a CS diverticulum. The purpose of the present study was to use CS angiography to evaluate the relation of different patterns of CS anatomy to successful ablation sites of APs.Methods and resultsThe CS-angiographic features and incidence of structural anomalies were prospectively studied in 56 patients undergoing AP radiofrequency ablation. Retrograde CS angiography was successfully performed in 46/56 pt (82%), (33 males/13 females). The CS angiographic findings of the 46 patients were compared to the AP localization established by electrophysiological mapping and to the successful ablation sites. CS anomalies were identified in 17 (37%) patients and included the following: CS diverticulum (seven patients), funnel shaped ostium (three patients), CS aneurysm (two patients), subthebasian pouch (one patient), sharp angulation (one patient), and bulbous malformation (one patient). CS diverticuli represented (41%) of the encountered CS anomalies. Seventy-one percent of the CS diverticuli were seen in posteroseptal and left posterior locations of APs. Successful ablation site was related to CS-anomalies in seven (15.2%) patients (five patients with CS diverticulum, one patient with CS aneurysm, and one patient with CS angulation). Successful ablation was achieved from within the CS (coronary sinus – accessory pathway) (CS AP) in 10 patients (21.7%) (in relation to CS tributary in six (13%) and in relation to the neck of a CS diverticulum in four patients). CS AP represented 50% of the encountered posteroseptal and left posterior APs.ConclusionCS angiography can guide us in reaching successful ablation sites of AP inside or outside the CS. CS diverticulum is the most common CS anomaly in posteroseptal and left posterior APs.     

Radiofrequency catheter ablation of accessory pathways during pre-excited atrial fibrillation: acute success rate and long-term clinical follow-up results as compared to those patients undergoing successful catheter ablation during sinus rhythm

The onset of recurrent or sustained atrial fibrillation (AF) is common during electrophysiological (EP) studies of accessory pathways (AP). We report our experience in patients with Wolff-Parkinson-White (WPW) syndrome in whom AF with rapid antegrade conduction over the AP occurred during an EP study and mapping and ablation were done during sustained AF, as compared to patients ablated during sinus rhythm. The study group consisted of 18 patients (group 1) with WPW syndrome who underwent catheter ablation during pre-excited AF. Two hundred and sixty-three patients, comparable for clinical characteristics, whose manifest APs were ablated under sinus rhythm formed the control group (group 2). Bipolar electrogram criteria recorded from the ablation catheter showing early ventricular activation relative to the delta wave on the surface ECG and AP potentials preceding the onset of ventricular activation were used as targets for ablation. Clinically documented atrial fibrillation was significantly more frequent and antegrade ERP of AP was significantly shorter in group 1 than in group 2 (39% vs 14%, P = 0.014 and 268 ± 37 vs 283 ± 16, P < 0.001, respectively). Procedure-related variables, acute success rates (17/18 [94%] in group 1, 251/263 [95%] in group 2; P > 0.05) and late recurrence rates (0/18 [0%] in group 1 vs 5/263 [2%] in group 2; P > 0.05) during a mean follow-up of 25 ± 9 months (range 8–52 months) did not differ significantly. Our results show that both right- and left-sided accessory pathways can be mapped and ablated safely during pre-excited AF without delay, and that acute success and recurrence rates and long-term follow-up results are similar to those of pathways ablated during sinus rhythm.     

Concordance of distinguishing electrocardiographic features during sinus rhythm with the location of accessory pathways in the Wolff-Parkinson-White syndrome

Knowledge of the location of accessory pathways in patients with Wolff-Parkinson-White (WPW) syndrome is pertinent to patient management. Despite the recognition that features of delta waves present during maximal preexcitation reflect ventricular activation at different sites around the anulus fibrosus, the value of electrocardiographic patterns observed during sinus rhythm, when ventricular preexcitation is often not maximal for identifying accessory pathway locations, has not been determined. In this study, 12-lead electrocardiograms recorded during sinus rhythm from 66 patients with WPW syndrome were analyzed for delta-wave polarity, QRS axis in the frontal plane, the pattern of precordial R-wave transition, and concordance between electrocardiographic patterns and the site of the accessory pathway determined using catheter and intraoperative computer mapping. Electrocardiograms from patients with left lateral sites showed negative delta waves in leads I or aVL, a normal QRS axis and early precordial R-wave transition (20 of 24 patients); left posterior sites manifested negative delta waves in II, III and aVF and a prominent R wave in V1 (14 of 16 patients); posteroseptal sites had negative delta waves in II, III and aVF, a superior QRS axis and an R less than S in V1 (all 16 patients); right free wall locations manifested negative delta waves in aVR, a normal QRS axis, and R-wave transition in V3-V5 (6 of 6 patients); and anterior septal sites had negative delta waves in V1 and V2, a normal QRS axis, and R-wave transition in V3-V5 (4 of 4 patients). Characteristic electrocardiographic patterns were not observed in 5 patients because of insufficient preexcitation. Each had a left lateral or left posterior pathway. Overall, the proposed electrocardiographic criteria derived during sinus rhythm identified correctly the accessory pathway location in 60 of 66 patients (91%). Thus, the electrocardiogram provides the physician with a reliable noninvasive means of regionalizing the location of accessory pathways in patients with WPW syndrome.     

后间隔旁道体表心电图及心内电图的特征

总结射频消融成功的后间隔旁道３７例体表及心内电图特征，结果显示：显性后间隔旁道体表心电图Ⅱ、Ⅲ、ａＶＦ导联δ波负向，ＱＲＳ波群在Ｖ２导联呈Ｒ或Ｒｓ形时，若Ｖ１导联为ｒＳＲ或Ｒｓ形诊断为左后间隔旁道，其敏感性７３．３％、特异性９１．７％；Ｖ１导联为ＱＳ形诊断为右后间隔旁道，其敏感性５８．３％、特异性１００％。冠状窦电极为间距１ｃｍ的４极标测电极，近端电极置于窦口。心动过速时，心内电图ΔＶＡＨ－ＣＳ（ＶＡＨ与最短ＶＡｃｓ的差值）≥２５ｍｓ提示左侧，敏感性６２．８％、特异性９３．７％；ΔＶＡｃｓ（冠状窦电极记录的最长与最短ＶＡ的差值）≤１５ｍｓ提示左侧，敏感性８７．５％，特异性９５．４％。此外，左后间隔旁道逆行Ａ波最早出现在冠状窦近端（ＣＳｐ）或冠状窦中端（ＣＳｍ），且冠状窦中端Ａ波（Ａｃｓｍ）均早于希氏束远端（Ｈｉｓｄ）Ａ波（ＡＨｉｓｄ）；右后间隔旁道逆行Ａ波最早出现在Ｈｉｓｄ或ＣＳｐ处，Ａｃｓｍ均晚于ＡＨｉｓｄ。通过体表心电图和心内电图特征，可简便准确地预测间隔旁道的消融靶点。     

Catheter ablation of left posteroseptal accessory pathways and of long RP' tachycardias with a right endocardial approach

Fifty-four patients with a posteroseptal accessory connection and symptomatic tachycardias underwent catheter ablation of the anomalous pathway. Eight had the permanent form of reciprocating tachycardias (long RP' tachycardia) and 46 had a left posteroseptal preexcitation marked by a prominent R wave in lead VI. In 14 of 19 patients, ventriculoatrial conduction time during tachycardia lengthened in conjunction with functional left bundle branch block; this behaviour was significantly different from a series of patients with right posteroseptal preexcitation in which functional left bundle branch block lengthened the ventriculoatrial time in only one of 12 patients. A quadripolar electrode catheter was left within the proximal coronary sinus in order to locate the earliest atrial or ventricular activation site. The appropriate bipole was used as the radiographic and electrophysiological reference of the insertion of the accessory pathway. A catheter was then positioned on the septal side of the right atrium, outside the coronary sinus, so that atrial activity during reciprocating tachycardia and ventricular activity during preexcitation were synchronous with or earlier than that recorded within the proximal coronary sinus. Accessory pathway potential was not recorded in any patient. Early ventricular potential occurring --1.5 +/- 8 ms relative to delta wave onset was present at that site. In 38 patients, including 5 with permanent junctional tachycardia, high current (14 mA) pacing yielded direct ventricular paced QRS complexes (no delay spike-QRS) with a morphology similar to left posteroseptal maximal preexcitation. Slight movements of catheter position yielded significantly different pace-maps. One to eight 160 J cathodal shocks (510 +/- 213 J cumulative per patient) were delivered at this site in 61 sessions. Following fulguration, tachycardia recurred without drugs in only one patient over a follow-up period of 20 +/- 13 months. Asymptomatic intermittent preexcitation recurred in two patients. In all patients with long RP' tachycardia, the ablation procedure was successful without the need for drugs or permanent cardiac pacing. A long-term follow-up electrophysiological study in 18 patients demonstrated that conduction through the anomalous pathway was absent in 16 and deeply altered in the two patients with intermittent preexcitation; no tachycardia was inducible in any patient. In conclusion, catheter ablation of left posteroseptal accessory pathways is a feasible procedure using a right atrial approach outside the coronary sinus. This technique is also effective for the treatment of the permanent form of reciprocating tachycardia.     

A unipolar coronary sinus mapping study of patients with left-sided atrioventricular accessory pathways

So-called unipolar 'PQS pattern' is widely accepted as a hallmark of successful catheter ablation of the left-sided atrioventricular accessory pathway. However, the unipolar nature of the electrogram and the site-dependent appearance of this characteristic pattern are poorly understood. Therefore, unipolar coronary sinus (CS) mapping was performed using a multipolar fine electrode in patients with Wolff-Parkinson-White (WPW) syndrome associated with an antegrade left-sided accessory pathway (case group) and those with a concealed left-sided accessory pathway or atrioventricular nodal reentrant tachycardia (control group) under sinus rhythm and fixed high right atrial, CS ostial, and distal pacing. In both groups, the unipolar CS atrial electrogram showed intrinsic negative deflection (initial positive followed by negative parts) with considerable variation depending on the recording site. This unipolar configuration of the atrial electrogram was not influenced by different activation sequences during pacing at various sites. The case group exhibited a unipolar 'PQS pattern' at successful ablation sites for the left lateral to anterolateral accessory pathway. However, this was not true for the left posteroseptal accessory pathway, possibly because the negative part of the atrial electrogram distorted the 'PQS pattern' as an intervening dip. In conclusion, the site-dependent variations of the unipolar CS atrial electrogram underlie the limited usefulness of the 'PQS pattern' in left posteroseptal accessory pathway localization.     

Electrocardiographic and electrophysiologic characteristics of midseptal accessory pathways

BACKGROUND : The purpose of the present study was to investigate the electrocardiographic and electrophysiologic characteristics of right midseptal (RMS) and left midseptal (LMS) accessory pathways (APs), and to develop a stepwise algorithm to differentiate RMS from LMS APs. METHODS AND RESULTS: From May 1989 to February 2004, 1591 patients with AP-mediated tachyarrhythmia underwent RF catheter ablation in this institution, and 38 (2.4%) patients had MS APs. The delta wave and precordial QRS transition during sinus rhythm, retrograde P wave during orthodromic tachycardia, and electrophysiologic characteristic and catheter ablation in 30 patients with RMS APs and 8 patients with LMS APs were analyzed. There was no significant difference in electrophysiologic characteristics and catheter ablation between RMS and LMS APs. The polarity of retrograde P wave during orthodromic tachycardia also showed no statistical difference between patients with RMS and LMS APs. The delta wave polarity was positive in leads I, aVL, and V3 to V6 in patients with RMS and LMS APs. Patients with LMS APs had a higher incidence of biphasic delta wave in lead V1 than patients with RMS APs (80% vs. 15%, P=0.012). The distributions of precordial QRS transition were different between RMS APs (leads V2; n = 10, V3; n = 7 and V4; n = 3) and LMS APs (leads V1; n = 1 and V2; n = 4) (P = 0.03). The combination of a delta negative wave in lead V1 or precordial QRS transition in lead V3 or V4 had a sensitivity of 90%, specificity of 80%, positive predictive value of 95%, and negative predictive value of 66% in predicting an RMS AP. CONCLUSIONS: Delta wave polarity in lead V1 and precordial QRS transition may differentiate RMS and LMS APs.     

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     

Variants of Preexcitation—Specialized Atriofascicular Pathways, Nodofascicular Pathways, and Fasciculoventricuiar Pathways:

Variants of Preexcitation. introduction: In the present report, the electrophysiiologic findings in patients with different types of variants of preeexcitwtion, i.e., atriofascicualr, nodofacicular, and fasciculoventricular fibers, and the results of radiofrequency catheter ablation using different target sites are described. Methods and Results: Twelve patients (mean age 36 ± 17 years) with variants of the preexcitation syndromes underwent electrophysiologic study and radiofrequency catheter ablation. The atrial origin of atriofascicular pathways remote from the normal AV node was assessed by application of late atrial extrastimuli that advanced (“reset”) the timing of the next QRS complex without anterograde penetration into the AV node. In patients with atriofacicular pathways, ablation of the accessory pathway or the retrograde fast AV node pathway was attempted. Ablation of the atriofascicular pathways was guided by a stimulus-delta wave interval mapping in the first live patients and by recording of atriofascicular pathway activation potentials in the next five patients. A nodofascicular pathway was suggested if VA dissociation occurred during tachycardia and if atrial extrastimuli failed to reset the tachycardia without anterograde penetration into the AV node. A fasciculoventricular connection was suggested if the proximal insertion of the accessory pathway was found to arise from the His bundle or bundle branches. The PR interval was expected within normal limits during sinus rhythm and the QRS complex to he slightly prolonged with a discrete slurring of the R wave, suggesting a small delta wave. Ten of the 12 patients had evidence for atriofascicular pathways and one patient each for a nodofascicular and fasciculoventricular pathway. In six patients, the atriofascicular pathways were successfully ablated, and in two patients, the retrograde fast AV node pathway. In one patient, a concealed right posteroseptal accessory AV pathway served as the retrograde limb and was successfully ablated. The nodofascicular pathway was shown to he a bystander during AV node reentrant tachycardia. After successful fast AV node pathway ablation resulting in marked PR prolongation, no preexcitation was present during sinus rhythm because of the proximal insertion of the nodofascicular pathway distal to the delay producing parts of the AV node. The proximal insertion of the fasciculoventricular pathway was suggested to arise distal to the AV node at the site of the penetrating AV bundle. The earliest ventricular activation at the His-bundle recording site indicated the ventricular insertion of this accessory connection into the ventricular summit. The fasciculoventricular connection gave rise to a fixed ventricular preexcitation and served as a bystander during orthodromic AV reentrant tachycardia incorporating a left-sided accessory AV pathway.     

经冠状静脉窦标测和消融后间隔心外膜房室旁道

报道心外膜房室旁道的特点和经冠状静脉窦射频消融术的结果。3例后间隔显性房室旁道患者先经心内膜标测和消融,不成功后改由经冠状静脉窦内标测和消融。术中冠状动脉造影,观察冠状静脉窦形态。结果: 2例冠状静脉窦近端有一憩室,并在憩室的颈部消融阻断房室旁道。成功靶点图为标测到振幅较大的旁道电位,其振幅大于A波和V波。结论:经心内膜标测和消融失败的旁道可能是心外膜旁道,行冠状静脉窦内标测与消融可有效阻断旁道,冠状静脉窦憩室与后间隔旁道可能存在着解剖关系。     

aVR导联临床应用的新视点

aVR导联是一个经常被忽略的导联,但是,近几年的研究显示aVR导联在诸多方面都发挥着重要的作用。aVR导联经典的临床应用包括窦性心律的确认、电轴的确定、右位心和左右手反联及心室肥厚的诊断。其临床应用的新发现包括:急性冠脉综合征时,aVR导联ST段抬高提示左主干、左前降支近端或三支病变;在ST段抬高型心肌梗死中aVR导联ST段抬高或下移是住院患者死亡率的独立预测因子,可用于危险分层;分析心律失常时,aVR导联可用于鉴别宽QRS型、窄QRS型心动过速;体表心电图的aVR导联结合V1、V2导联可以估算右房房颤周长,并且aVR导联P波振幅是心脏手术术后房颤发生的强有力的预测因子;Brugada综合征时出现"aVR征"有助于危险分层;右室负荷过重时,aVR导联ST段抬高是急性肺栓塞的死亡预测因子(单变量回归分析)和并发症的预测因子;aVR导联R波延迟是慢性右室压力负荷过重的独立预测因子且多见于肺动脉狭窄患者;特发性肺动脉高压的患者中,aVR导联R波>4mm,结合V1导联R波>6mm、R/SV1>1,R/SV5与R/SV1比值<0.04,Ⅱ导联P波>2.5mm可以诊断右室肥厚;当疑似预激综合征时,利用体表心电图同时出现PR间期≤120ms和PR离散度≥20ms、aVR导联缺少初始正向波(间隔R波)和V1导联水平面QRS移行提前这3步可识别心室预激,且具有较高的特异性和敏感性;连续监测aVR导联R波和R/S比例有助于预测三环类抗抑郁药物中毒时意识的恢复;急性心包炎时,aVR导联ST段压低、PR段抬高形成了急性心包炎的特征性表现,即"关节征",并且可能是急性心包炎最早甚至是唯一的心电图改变,具有早期诊断价值。     

Decremental conduction properties in overt and concealed atrioventricular accessory pathways.

AIM: Most atrioventricular accessory pathways (AV-APs) exhibit Kent bundle physiology characterized by fast and non-decremental conduction properties. In contrast, atriofascicular APs, which are only capable of reaching slow levels of long antegrade decremental conduction, are uncommon. The aim of this study was to describe antegrade and/or retrograde AV-APs with unusual decremental properties. METHODS AND RESULTS: Five patients with unusual decremental AV-APs underwent electrophysiological evaluation and radiofrequency catheter ablation for symptomatic tachycardias. Three were found to have structural heart disease, and three latent decremental AV-APs in the anterograde and/or retrograde direction that could not be demonstrated by routine electrophysiological testing. In Case 1, a right posteroseptal AV-AP with bidirectionally latent decremental conduction was associated with clinical antidromic circus movement tachycardia (CMT) mimicking ventricular tachycardia and orthodromic CMT, the latter inducible only with isoprenaline. In Case 2, incessant orthodromic CMT was due to a latent retrograde left posterolateral AV-AP. In both cases, double atrial responses to a single paced ventricular beat, initiating orthodromic CMT, were observed. In Case 3 with latent preexcitation unmasked by adenosine and atrial pacing, retrograde latent decremental conduction over a right posteroseptal AV-AP could be shown only with isoprenaline. This patient and the remaining two with overt preexcitation demonstrated anterograde decremental AP conduction that was discontinuous over a right posteroseptal AV-AP in Cases 3 and 4 and was continuous over a midseptal AV-AP in Case 5. In the latter case, the site of decremental conduction could be localized at the proximal AP origin. All five AV-APs were successfully ablated at the annulus level. CONCLUSION: AV-APs with unusual decremental properties that are either latent, demonstrable only during CMT or overt, exhibiting functional longitudinal dissociation are described. These APs could be identified and successfully ablated after detailed electrophysiological analysis.     

射频消融位于冠状静脉窦憩室处的后间隔房室旁路

目的报道５例冠状静脉窦憩室处后间隔房室旁路的射频消融结果。方法对５例后间隔显性房室旁路患者进行电生理检查和射频消融术。术后冠状动脉造影,以观察冠状静脉窦形态。结果所有患者的冠状静脉窦近端有一憩室,并在憩室的颈部消融阻断房室旁路。成功靶点图：心室激动较体表心电图Δ波提前（３１±３．７）ｍｓ,其中４例患者伴有旁路电位。结论冠状静脉窦憩室与后间隔旁路存在着解剖关系。术中冠状静脉窦造影检查有助于发现憩室和确定有效的消融部位。     

New algorithm for the localization of accessory atrioventricular connections using a baseline electrocardiogram

Objectives. In this study, we propose a new algorithm for accessory atrioventricalar pathway localization using a 12-lead electrocardiogram (ECG).Background. Radiofrequency catheter ablation produces a very discrete lesion, and ECG localization based en surgical dissection is obsolete.Methods. Stepwise discrimination analysis was used to assess the relation of 18 pro-excited ECG (QRS duration >100 ms) variables to the site of successful ablation in 93 patients. The most discriminating variables were combined to form rules for each location. The ECGs were retested by these rules to determine predictive accuracy.Results. If the precordlal QRS transition was at or before lead V₁, the pathway had been ablated on the left side. If it was after lead V₂, the pathway had been ablated on the right side. If the QRS transition was between leads V₁and V₂or at lead V₂, then if the R wave amplitude in lead I was greater the S wave by ≥1.0 mV, it was right-sided; otherwise, It was left-sided (p < 0.0001, sensitivity 100%, specificity 97%). Right-sided pathways. If the QRS transition was between leads V₂and V₃, the pathway was right septal; if after lead V₄, it was right lateral. If it was between leads V₃and V₄, then if the delta wave amplitude in lead II was ≥1.0 mV, it was right septal; otherwise, it was right lateral (p < 0.0001, sensitivity 97% specificity 95%). In right lateral locations, if the delta wave frontal axis was ≥0 °, or if it was <0 ° but the R wave amplitude in lead III was ≥0 mV, it was anterolateral; otherwise, it was pesterolateral (p < 0.0001, sensitivity 100%, specificity 87.3%). Anteroseptal pathways had two or more positive delta waves in leads II, III and aVF (p < 0.0001, sensitivity 100%, specificity 100%). Postereseptal pathways (two or more negative inferior lead delta waves) were less well discriminated from right midseptal pathways (inferior wave sum ≤1≥−1) (p < 0.0001, sensitivity 76.5%, specificity 71%).Leftsided pathway. Two or more positive delta waves in the inferior leads or the presence of an S wave amplitude in lead aVL greater than the R wave, or both, discriminated left anterolateral pathways from posterior pathways (p < 0.001, sensitivity and specificity 100%). If the R wave in lead I was greater than the S wave by ≥0.8 mV, and the sum of inferior delta wave polarities was negative, the location was posteroseptal; otherwise, It was posterolateral (p < 0.05, sensitivity 71.4%, specificity 100%).Conclusions. Using the algorithm derived, a right-sided accessory pathway can be reliably distinguished from one that is left-sided, right free wall from right septal, right anterolateral from posterolateral and anteroseptal from other right septal pathways. Left anterolateral pathways can be distinguished from left posterior pathways and left posterolateral pathways from left posteroseptal pathways.     

Effect of Left Atrial-Coronary Sinus Musculature Connections on the Coronary Sinus Activation Pattern via Retrograde Conduction in Patients with WPW Syndrome

BACKGROUND: Double potential (DP) activation patterns observed in coronary sinus (CS) electrograms recorded during left lateral atrial pacing, were explained by an initial low-frequency left atrial (LA) activation potential and secondary high-frequency CS musculature activation potential in canine hearts. Moreover, the connections between the LA and CS musculature vary greatly in size and location in the human heart. The purpose of this study was to investigate the relationship between the CS activation pattern during retrograde conduction via an accessory pathway (AP) and the location of left-sided APs. METHODS AND RESULTS: Fifty-one patients (31 males, mean age 48.6 years) who underwent radiofrequency catheter ablation of left-sided APs were divided into two groups according to the successful ablation site. The CS electrograms during retrograde AP conduction were classified into 3 types; single, fractionated, and DP activation patterns. A DP pattern was identified in 10 of 12 patients (83.3%) with posteroseptal to posterolateral APs, and in particular, 9 had a divergent sequence. Twenty-six of 39 patients (66.7%) with lateral to anterolateral APs, demonstrated a single pattern. The number of radiofrequency applications was significantly higher in patients with a DP pattern than in those with a single pattern (3.4 +/- 3.3 vs. 7.8 +/- 6.8, p < 0.01). CONCLUSION: Misleading information obtained when mapping for optimal ablation sites might result from DP patterns with a divergent sequence produced by discrete muscular connections between the LA and CS musculature. Ablation around left posterior APs may require meticulous observation of the CS activation patterns.