Mechanistic Insights into Roof-Dependent Macroreentrant Atrial Flutter with Endocardial Block of the Roof Line:A Case Report

Background:Epicardial roof-dependent atrial tachycardia is rare among macroreentrant tachycardias.The importance of epicardial structure or fiber involving septopulmonary bundle(SPB)has not been realized generally.Case presentation:A 74-year-old woman who underwent catheter ablation of atrial fibrillation previously accepted a second-time radiofrequency ablation due to atrial flutter.The mapping and entrainment results of the tachycardia tended to be an epicardial SPB-dependent macroreentrant atrial tachycardia and it was ablated to sinus rate at the first single targeting site,just located in the breakout site of SPB into the posterior wall(PW)of left atrial(LA).The twice-activation mapping of PW of LA also proved the presence of SPB.No recurrent arrhythmia was seen at follow-up at 3 months.Conclusion:In this case,an uncommon phenomenon was observed post-ablation for persistent atrial fibrillation,where the epicardial muscular structure of the LA-SPB was involved in atypical atrial flutter.This should be considered as a potential factor in such cases.Further similar cases may be required to improve diagnostic accuracy and to formulate effective ablation strategies for this type of tachycardia.

CHANGES OF PLASMA ENDOTHELIN AND ATRIAL NATRIURETIC PEPTIDE DURING THE ONSET AND AFTER TERMINATION OF PAROXYSMAL SUPRAVENTRICULAR TACHYCARDIA

Radioimmunoassays were used to measure the concentration changes of plasma endothelin(ET) and atrial natriuretic peptide(ANP) during the onset and after termination of paroxysmal supraventricular tachycardia(SVT). 30 cases were reviewed and compansons with 42 normal subjects were made. There are very significant differences(P<0.0001) in the concentration changes of both plasma ET and ANP during the onset and 30 minutes after the termination of SVT. During the onset period of SVT. the plasma ET and ANP were markedly elevated and 30 minutes after its termination they were lowered significantly, but their concentrations were still 2-fold higher than ihose of the control group. As the biological effects of ANP and ET are antagonistic to each other. their parallel elevation and lowering of plasma concentrations during and.after the termination of SVT reveal that these 2 hormones parucipate in the pathophysiological process of SVT. This phenomenon is possibly one of the homeostatic regulatory functions in the organism.

Radiofrequency catheter ablation of atrial tachycardias related to myocardial scar or incision

Objectives Intra-atrial re-entrant tachycardias(IARTs)are common late after heart surgery.Conventional mapping and ablation is relatively difficult because of the complicated anatomy and multiple potential re-entry loops.In this study we aimed to evaluate the electrophysiological characteristics and radiofrequency catheter ablation of atrial tachycardia(AT)induced by myocardial scar or incision.Methods In 6 patients(three male and three female,aged 33.3±11.8 years)who had AT related to myocardial scar or incision, electrophysiological study and radiofrequency catheter ablation(RFCA)were performed.Earliest activation combined with entrain- ment mapping was adopted to determine a critical isthmus.Results Re-entry related to the lateral atriotomy scar was inducible in 5 of 6 patients.With entrainment mapping,the PPI(post-pacing interval)-TCL(tachycardia cycle length)difference was＜30 ms when pacing at the inferior margins of the right lateral atriotomy scar.Among them,3 patients had successful linear ablation between scar area to inferior vena cava,and 2 patients between scar area to tricuspid annulus.Re-entry involving an ASD patch was demonstrated in 1 of 6 patients.PPI-TCL differences＜30 ms were observed when entraining tachycardia at sites near the septal patch.But linear ablation failed in terminating AT.There was no complication during procedure.No recurrence of AT related to incision was observed during follow-up except for the failed patient.Conclusion Under conventional electrophysiological mapping,adopting linear ablation from scar area to anatomic barrier,successful ablation can be obtained in patients with IRATs related to myocardial scar or incision.

A Case Report of Radiofrequency Ablation of Typical Atrial Flutter Combined with Atrial Tachycardia

A 63-year-old female patient with a history of pulmonary heart disease underwent radiofrequency ablation because of a persistent atrial fl utter.Endocardial mapping with the carto3 system confi rmed atrial fl utter counterclockwise reentry around the tricuspid annulus.Routine ablation of the cavo-tricuspid isthmus line to bi-directional block was performed.However,tachycardia with the same cycle length was induced again.After remapping,the tachycardia was confi rmed to be focal atrial tachycardia located in the crista terminalis.After ablation,the tachycardia was terminated and could not be induced again.

Radiofrequency ablation of atrial tachycardia in patients with repaired atrial septal defect

Objective:To evaluate the electrophysiological characteristics and radiofrequency catheter ablation of atrial tachycardia (AT) in patients with repaired atrial septal defects(ASD). Methods: In 76 consecutive patients with AT who underwent the electrophysiological study and radiofrequency catheter ablation (RFCA). 4 patients (one male and three female aged 35. 5±11. 5 years) had AT-related myocardial scar or incision. Earliest activation combined with entrainment mapping was adopted to determine a critical isthmus. Results: Re-entry related to the lateral atriotomy scar was inducible in 3 of 4 patients. With en-trainment mapping, the PPI-TCL difference was <30 ms when pacing at the inferior margins of the right lateral atriotomy scar. Among them, 2 patients had successful linear ablation between scar area to inferior vena cava, and 1 patient between scar areas to tricuspid annulus. Re-entry involving an ASD patch was demonstrated in 1 of 4 patients. PPI-TCL differences <30 ms were found when entraining tachycardia at sites near the septal patch. But linear ablation failed in terminating AT. There was no complication during procedure. No recurrence of incision-related AT was found during follow-up except for the failed patient. Conclusion: Under conventional electrophysiological mapping, adopting linear ablation from scar area to anatomic barrier, successful ablation also can be obtained in patients with IRAT related to myocardial scar or incision.

Lactic Acidosis and Atrial Tachycardia: Unusual Presentations of Disseminated Burkitt-Like Lymphoma

Lactic acidosis is a rare complication of malignancies and is seen more frequently in high grade lymphoma and leukemia. Although, its pathogenesis is not well understood, it remains a surrogate of poor prognosis. Herein, we present a case of Burkitt-like lymphoma presenting with metabolic abnormalities including lactic acidosis and hypoglycemia along with atrial tachycardia. We will discuss the different mechanisms involved in these metabolic disturbances and we will provide insight on novel therapeutic strategies based on our understanding of the underlying pathophysiology.

Electrophysiological characteristics of atrial tachycardia originating from the coronary sinus

A 22-year-old girl was admitted to our cardiology institute with Permanent tachycardia in last 6 years for diagnostic assessment and therapy. Doppler echocardiography show structural of heart is normal, ECG revealed a varied resting rate from 120 to 140 bpm, 1:1 AV ratio and long RP interval. P wave morphology was negative on leads I, II, III, aVF, and V4 to V6, positive on lead V1, and diphasic 1 /2 on lead aVL. Electrophysiology (EP) study was performed, Although the exactly mapping was performed in left inferior pulmonary vein and mitral annulus, however, no target point was found ahead of CS1-2, the tried discharge was invalid. The ablation catheter was entered the coronary sinus to guide electrical isolation, curing the tachycardia. The ECG returned to normal sinus rhythm. Through three years follow up, no AT recurrence.

对心房颤动以外的快速性房性心律失常的认识

过去临床普遍认为,房性早搏(简称房早)、房性心动过速(简称房速)等心房颤动(简称房颤)以外的快速性房性心律失常并无重要临床意义。但近年来,随着检测手段的不断发展,越来越多的临床研究发现,房早、房速等除房颤以外的心房异位活动与脑卒中的风险相关,并可能进一步导致死亡率升高。同时,此类房性心律失常的发生次数与房颤、缺血性脑卒中等不良事件发生率之间存在正相关,其机制可能与亚临床心房心肌病的介导作用有关。对该类心律失常的临床临界值和室上异位活动,目前仍无明确定义。因此,通过动态心电图等手段、遵循规范化流程,对房颤以外的快速性房性心律失常进行规律检测和处理至关重要。本文介绍此类房性心律失常与心源性脑卒中的关系,以及对此类心律失常的检测在心源性脑卒中评估中的作用。

美托洛尔联合稳心颗粒治疗心房颤动患者导管消融术后房性心动过速的价值

目的 探讨美托洛尔联合稳心颗粒对心房颤动(AF)患者导管消融术后房性心动过速(AT)的治疗价值。方法 选取2018年5月至2022年1月在苏北人民医院心血管内科诊断为AF并成功行导管消融术的患者253例,采用掷币法随机分为稳心颗粒组(56例)、美托洛尔组(79例)、联合组(79例)、对照组(39例)。比较4组患者治疗AT次数、最长AT心搏次数、平均心率及不良反应等情况。结果 对照组术后1年平均心率、AT阵数、AT最长心搏次数及Ⅰ、Ⅱ、Ⅲ类房性过早搏动次数均高于基线,差异有统计学意义(P<0.01)。稳心颗粒组、美托洛尔组、联合组术后1年平均心率、AT阵数、AT最长心搏次数及Ⅰ、Ⅱ、Ⅲ类房性过早搏动次数均低于基线,差异有统计学意义(P<0.01);联合组术后1年平均心率、AT阵数、AT最长心搏次数及Ⅰ、Ⅱ、Ⅲ类房性过早搏动次数均低于稳心颗粒组和美托洛尔组,差异有统计学意义(P<0.05);稳心颗粒组、美托洛尔组、联合组不良反应总发生率比较无显著差异(7.1%vs 13.9%vs 8.9%,P=0.301)。结论 美托洛尔联合稳心颗粒可用于治疗AF患者导管消融术后AT,可有效降低平均心率,减少AT发生次数、房性过早搏动次数、减少AT最长心搏次数,可能减少术后AF复发,安全性较高。

经导管主动脉瓣置换术后房性心动过速射频消融1例

经导管主动脉瓣置换术(TAVR)作为主动脉瓣病变的治疗新选择,显示出广阔的应用前景。但随之而来的是,TAVR术后快速型心律失常问题逐渐凸显,备受医学界关注。当前,药物治疗是处理TAVR相关房性心律失常的主流方法,而导管消融的治疗潜力尚待进一步探索。特别是当心律失常病灶与人工瓣膜紧密相关时,消融术的实际应用效果与安全性还有待验证。近期,同济大学附属东方医院成功为1例具有此类复杂病症的患者实施了射频消融术,初步探索了在人工瓣膜表面实施导管消融术的有效性和安全性。

伊伐布雷定敏感性房性心动过速的研究进展

房性心动过速(房速)是常见的心律失常,部分表现为局灶起源无休止房速,易导致心动过速性心肌病,常规抗心律失常药效果不理想。伊伐布雷定对部分房速敏感,不仅可有效控制心室率,还可促进房速转复及窦性心律的维持,称为伊伐布雷定敏感性房速。心房异位节律点存在类窦房结样组织,以及超极化激活环核苷酸门控阳离子通道介导的I_(f)电流导致自律性增高,是伊伐布雷定敏感性房速的发病机制。现对伊伐布雷定敏感性房速的研究进展做一综述。

Prolonged asystole following adenosine. Was it necessary?

A77-year-old woman presented with interchangeable episodes of both fast and slow heart rate.Past history was notable for paroxysmal atrial fibrillation treated with eliquis and tambocor and atrial septal defect closure 35 years ago.Except for mild tachycardia,vitals and physical examination were unremarkable.The 12-lead electrocardiogram(Figure 1)showed narrow complex tachycardia at 106 beats/min without obvious P-waves.

A three-pulmonary vein isolation approach to treat paroxysmal atrial fibrillation

Objective To investigate the safety and efficacy of a 3-pulmonary vein (PV) isolation approach in treating paroxysmal atrial fibrillation (AF). Methods Radiofrequency catheter ablation was used to eliminate PV potential in 11 patterns with frequent paroxysmal AF refractory to anti-arrhythmic agents. During sinus rhythm, PV potential was mapped in the left and right superior PVs and left inferior PV. The procedural success was defined as the elimination of PV potential in the 3 PVs. Restults PV potential was identified and abolished in a total of 24 PVs, mostly in the left and right superior PV. There was no pulmonary stenosis or other complications during or after the procedures. AF recurred in one patient after an average of 12 ± 3 month follow-up. Conclusions PV potemials were present mostly in the left or right superior PV. The 3-PVs isolation approach is safe and effective in preventing drug-resistant paroxysmal AF.

Inadvertent isolation of a focal tachycardia within the superior vena cava

The superior vena cava (SVC) is known to be a potential source of focal atrial tachycardias. Not uncommonly these tachycardias trigger atrial fibrillation or flutter. Focal ablation is safe and effective in eliminating arrhythmogenic foci within the SVC. We present the case of a patient with focal atrial tachycardia arising from the SVC. During presumably focal ablation inadvertent electrical isolation of the SVC from the right atrium was achieved, with restoration of sinus rhythm in the atria and persistence of the tachycardia within the SVC.

Termination of Recurrent Atrial Fibrillation by Superior Vena Cava Isolation: A Case Report

Background:Paroxysmal atrial fibrillation can be triggered by non-pulmonary vein foci,such as the superior vena cava.Here,we report the case of a patient with a 6-year history of paroxysmal atrial fibrillation who received cryoballoon ablation in 2012 but relapsed in 2014.He then received cardiac radiofrequency ablation,which successfully isolated the left pulmonary vein and superior vena cava,but the arrhythmia recently relapsed again.The tachycardia was finally successfully terminated by ablation on the free wall without recurrence during a 2-year following up.Conclusion:Superior vena cava isolation may not require ablation isolation with a full circle way and can be accomplished by ablating several connection points between the superior vena cava and the right atrium.

RADIOFREQUENCY CATHETER ABLATION FOR TREATMENT OF ATRIAL ARRHYTHMIAS

In this paper,electrophysiologic study and RFCA were attempted in 3 patientswho had clinical episodes of atrial arrhythmias with multiple ECG recordings.Diagnoses were automatic atrial tachycardia in one,reentrant atrialtachycardia in one,and typical atrial flutter in one.Site for atrial flutterablation was based on anatomic barriers in the floor of the right atrinm.Forautomatic atrial tachycardia,the site of earliest activation before the pwave was sought and for reentrant atrial tachycardia,our goal was to identifya site of early activation in a zone of slow conduction.At target sites,20 to40w of radiofrequency energy were delivered during tachycardia.Procedureend point was inability to reinduce tachycardia by atrial pacing and infusionof isoproterenol,Acute success was achieved in all of three patients.Fortachycardia involves reentry(reentrant atrial tachycardia and atrial flutter),successful ablation required severing an isthmus of slow conduction.Foratrial flutter,this was between the tricuspid annulus and the coronary sinus osor between the inferior vena cava and the tricuspid annulus.Abla-tioo ofautomatic and reentrant atrial tachycardia and atrial flutter had a highsuccess rate and caused no complications.Repeat procedures may be requiredfor long-term success,especially in patient with atrial flutter.

A case of recurrent PMT caused by poor atrial pacing

Pacemaker mediated tachycardia(PMT)can occur in patients with DDD pacemaker implantation,and PMT in narrow sense is a kind of circular motor tachycardia,which is often caused by ventricular atrial retrograde conduction.This paper reports a case of patients with high atrial pacing value in the early stage of pacemaker implantation,resulting in atrial retrograde conduction and recurrent PMT,Almost non-stop.Although the pacemaker has the PMT automatic termination procedure,PMT is still a short array of repeated attacks due to the presence of poor atrial pacing,resulting in the patients with shortness of breath,lower extremity edema and other heart failure symptoms.Finally,PMT was stopped by prolonging PVARP,and its lower starting frequency was slowed down to 50bpm,and AV interval was kept unchanged for 250ms,so as to reduce the release of atrial pulse and encourage the emergence of self selling down-propagation excitation.The proportion of atrial and ventricular pacing was significantly reduced,which not only saved the electric energy of pacemaker,but also conformed to the physiology.In a narrow sense,pacemaker mediated tachycardia(PMT)is a kind of circular motor tachycardia,which is often caused by reverse ventricular conduction.Repeated attacks for a long time may affect the patient's heart function.Although most modern pacemakers have PMT automatic termination procedures,they are still relatively passive in the presence of some induced factors.Finally,it is necessary to extend PVARP to truly terminate and prevent PM.A case of recurrent PMT due to poor atrial pacing is reported.

Plasma natriuretic peptides during supraventricular tachycardia: A study in patients with atrioventricular nodal reentry tachycardia

Aims: To characterize the plasma levels of the atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in patients with atrioventricular nodal reentry tachycardia (AVNRT), we measured the plasma levels of these peptides before and during tachycardia. Methods: We included 10 consecutive patients scheduled for ablation of typical AVNRT without structural heart disease. Catheters were inserted in the femoral artery, femoral vein, and coronary sinus (CS) prior to the ablation procedure. Blood samples were drawn before and after 3 min of tachycardia to measure plasma levels of ANP and BNP. Right atrial pressure (RAP) was measured at baseline. Results: Of the 10 patients, in three patients it was not possible to induce tachycardia leaving a total of 7 patients available for analysis. Mean age of the seven included patients was 40 ± 12 years (mean ± SD), five were female. ANP levels increased significantly during tachycardia in the artery (p = 0.0009) and vein (p = 0.003), but only borderline in CS (p = 0.09). BNP levels did not change during tachycardia in any location. Conclusion: ANP levels measured in the peripheral circulation increased acutely during tachycardia due to AVNRT. BNP levels did not increase.

导管消融后需永久起搏的阵发性心房颤动合并快慢综合征患者临床特点及相关因素

目的 部分阵发性心房颤动(简称房颤)合并快慢综合征(TBS)患者导管消融(CA)后仍因症状性心动过缓需要植入永久起搏器,探究此部分患者的临床特点及需要起搏的相关因素。方法 2018年1月1日至2021年12月31日在阜外华中心血管病医院有39例阵发性房颤合并TBS患者接受CA后又因症状性心动过缓植入了永久起搏器,收集患者相关资料,分析此类患者临床特点、CA结果、植入起搏器原因及时间特点,并与同期年龄、性别、左房大小相匹配的39例CA后不需永久起搏TBS患者进行对比研究,筛选TBS患者CA后需永久起搏治疗的危险因素。结果 该组需起搏患者年龄(62.79±8.74)岁,男性25例(64.10%),随访(25.54±6.96)个月,单次消融成功25例(64.10%),多次消融成功29例(74.36%)。71.79%患者起搏器植入时间为CA同期住院或空白期内,1 a后植入起搏器仅有3例(7.69%)。11例(28.21%)因器质性窦房结功能障碍(SND)植入起搏器,余均因快速房性心律失常(ATA)事件后窦性停搏植入起搏器。多因素分析发现,最长长间歇长及长间歇发生在非夜间(06:00—24:00)是患者需行永久起搏的独立危险因素(P<0.05)。结论 阵发性房颤合并TBS患者CA成功率高,仍需植入起搏器的患者起搏器植入时间大多为围手术期或CA空白期,1/4的植入原因为器质性SND,最长长间歇长及长间歇发生于非夜间是此类患者的临床特点。

心房纤维化致右房电极植入失败病例1例

1例长期房性心动过速患者射频消融术中出现心脏停搏,并在三维标测系统指导下行右心房基质标测,后行双腔起搏器植入。三维标测系统指导下标测右心房游离壁及前壁发现大片低电压及疤痕区。起搏器植入术中多次调试右心房电极,起搏阈值参数均不理想,右心房电极植入失败。长期房性心动过速可能导致心房电重构、心房纤维化,从而导致右心房电极植入失败。