Tachycardia transition during ablation of persistent atrial fibrillation.

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.

Peri-mitral atrial flutter in patients with atrial fibrillation ablation.

BACKGROUND: Peri-mitral atrial flutter (PMFL) is commonly encountered in patients undergoing atrial fibrillation (AF) ablation. OBJECTIVE: The purpose of this study was to determine the electrophysiologic characteristics, procedural success, and medium-term outcomes in patients with PMFL. METHODS: The study consisted of 50 consecutive patients (45 men and 5 women, age 57 +/- 12 years) with PMFL following or during AF ablation. Of the 50 PMFLs, 24 occurred during AF ablation (16 at index ablation and 8 at repeat procedure for recurrent AF), and 26 developed during follow-up. Ablation of PMFL was performed by creating a linear lesion joining the mitral annulus to the left inferior pulmonary vein. RESULTS: The incidence of PMFL was higher in patients with mitral isthmus (MI) ablation performed during AF ablation, prior to the development of PMFL, than in those in whom MI ablation was not performed (23% vs 8%, P = .04). Following the procedure, PMFL was more frequent in patients with prior MI ablation than in those without (41% vs 15%, P <.01). Seventy percent (35/50) were terminated by ablation with 6.4 +/- 6.9 minutes of radiofrequency application. Among patients in whom PMFL terminated, supplemental ablation was required for bidirectional conduction block in 66% (23/35). MI block was achieved in 92% (46/50) using 13.6 +/- 7.4 minutes of ablation. At mean follow-up of 19 +/- 4 months, 96% of patients were free from PMFL. CONCLUSION: PMFL can be terminated by MI ablation, but the procedure is proarrhythmic. Supplemental ablation is necessary to establish bidirectional block of the line despite termination of PMFL in the majority of patients.

Clinical predictors of termination and clinical outcome of catheter ablation for persistent atrial fibrillation.

OBJECTIVES: This study evaluated the role of pre-procedural clinical variables to predict procedural and clinical outcomes of catheter ablation in patients with long-lasting persistent atrial fibrillation (AF). BACKGROUND: Catheter ablation of persistent AF remains a challenging task. METHODS: Catheter ablation was performed in 90 patients (76 men, age 57 +/- 11 years) with long-lasting persistent AF. The history of AF, echocardiographic parameters, presence of structural heart disease, and surface electrocardiogram (ECG) AF cycle length (CL) were assessed before ablation and analyzed with respect to procedural termination and clinical outcome. Mean follow-up was 28 +/- 4 months. RESULTS: Persistent AF was terminated in 76 of 90 patients (84%) by ablation. The duration of continuous AF was shorter (p < 0.0001), the surface ECG AFCL was longer (p < 0.0001), and the left atrium was smaller (p < 0.01) in patients in whom AF was terminated by catheter ablation. The surface ECG AFCL was the only independent predictor of AF termination (p < 0.01). Maintenance of sinus rhythm was associated with a shorter duration of continuous AF (p < 0.0001), a longer surface ECG AFCL (p < 0.001), and a smaller left atrium (p < 0.05) compared with those with recurrent arrhythmia. In multivariate analysis, the surface ECG AFCL and the AF duration predicted clinical success of persistent AF ablation (p < 0.01 and p < 0.05, respectively). CONCLUSIONS: The surface ECG AFCL is a clinically useful pre-ablation tool for predicting patients in whom sinus rhythm can be restored by catheter ablation. The duration of continuous AF and the surface ECG AFCL are predictive of maintenance of sinus rhythm.

Long-term follow-up of persistent atrial fibrillation ablation using termination as a procedural endpoint.

AIMS: Catheter ablation of long-lasting persistent atrial fibrillation (AF) has been performed with varying results using a combination of different techniques. Whether arrhythmia termination during ablation is associated with an improved clinical outcome is controversial. METHODS AND RESULTS: In this prospective study, 153 consecutive patients (56 +/- 10 years) underwent catheter ablation of persistent AF (25 +/- 33 months) using a stepwise approach with the desired procedural endpoint being AF termination. Repeat ablation was performed for patients with recurrent AF or atrial tachycardia (AT) after a 1 month blanking period. A minimum follow-up of 12 months with repeated Holter monitoring was performed. Atrial fibrillation was terminated in 130 patients (85%). There was a lower incidence of AF in those patients in whom AF was terminated during the index procedure compared with those who had not (5 vs. 39% P < 0.0001, mean follow-up 32 +/- 11 months). Seventy-nine patients underwent repeat procedures: 64/130 in the termination group (6 AF, 58 AT) and 15 in the non-termination group (9 AF, 7 AT). After repeat ablation, sinus rhythm was maintained in 95% in whom AF was terminated compared with 52% in those in whom AF could not be terminated. CONCLUSION: Procedural termination of long-lasting AF by catheter ablation alone is associated with an improved outcome.

Dual independent atrial tachycardias after ablation of chronic atrial fibrillation.

We report the case of a 71-year-old man with two atrial tachycardias evolving simultaneously and independently in two dissociated regions after extensive ablation for chronic atrial fibrillation. One tachycardia was a focal tachycardia originating from the right inferior pulmonary vein and activating the posterior left atrium with a 2:1 conduction block, while the other tachycardia was an atrial flutter circulating around the tricuspid annulus, activating the right atrium and the anterior wall of the left atrium. These two atrial tachycardias were successfully ablated prior to restoration of sinus rhythm.

Cycle length dependent block in the "mitral-pulmonary vein" isthmus.

We report a case of cycle length dependent activation sequence in the coronary sinus catheter during assessment of mitral-pulmonary vein isthmus block. A 61-year-old patient presented with atrial tachycardia following a recent pulmonary vein isolation for paroxysmal atrial fibrillation. A perimitral macroreentrant atrial tachycardia was demonstrated during mapping. The isthmus block observed following initial ablation of the mitral-pulmonary vein appeared to be pacing cycle dependent and to our knowledge has not been previously described.

Focal arrhythmia confined within the coronary sinus and maintaining atrial fibrillation.

INTRODUCTION: The coronary sinus (CS) is a complex structure comprising a mesh of circumferential muscular fibers with oblique connections to both atria. We describe further evidence for the clinical importance of CS arrhythmogenicity in maintaining atrial fibrillation (AF) in humans. METHODS: Since January 2004, following a sequential approach, the CS and the inferior left atrium were ablated in 144 patients with symptomatic drug refractory AF. Patients were included for analysis when this step resulted in the electrical dissociation of the CS from both atria with restoration of sinus rhythm, but with continued arrhythmic activity in the CS. The electrophysiologic mechanism of the confined arrhythmia was considered as focal activity (automaticity or triggered activity) by the presence of electrograms spanning less than 75% of the cycle length in the CS. RESULTS: After restoration of sinus rhythm, four male patients (3% of the patients, three persistent and one permanent AF) were identified in whom arrhythmia continued within the CS. Repetitive activity confined to the disconnected CS was inconsistent in occurrence, as well as in duration (1 sec to 15 min) and cycle length (from 158 to 380 ms). For all four patients, electrogram mapping of the entire CS was compatible with a focal mechanism. In two patients, bursts alternating with slow dissociated activity suggested automaticity. In one patient, local activity consistently coupled to the previous sinus beat favored triggered activity. CONCLUSIONS: This study provides evidence that the CS may be a potential source of focal rapid activity maintaining AF.

Catheter ablation of persistent and permanent atrial fibrillation: Bordeaux experience.

The seminal observation that ectopics from the pulmonary veins may initiate paroxysmal atrial fibrillation (AF) heralded an era of potentially curative catheter ablation therapy for AF. In recent years, catheter ablation has been performed for not only paroxysmal but also persistent and permanent AF. It is anticipated that the number of procedures will continue to increase and the indication for catheter ablation will expand. This article details our experience with catheter ablation therapy for patients with persistent and chronic AF.

Avaliação da qualidade de vida em pacientes com fibrilação atrial submetidos à ablação por cateter / Quality of life in patients with atrial fibrillation subjected to catheter ablation

Objetivo: Determinar a qualidade de vida em 25 pacientes portadores de fibrilação atrial, antes e após aablação por cateter. Métodos: Aplicação de dois questionários, sendo um genérico (SF-36) para avaliar a qualidade de vida relacionada à saúde, compreendendo oito domínios. Ooutro questionário aplicado foi específico: Qualidade de Vida em Fibrilação Atrial (QVFA), compreendendo sete componentes. Os questionários foram aplicados em 25pacientes (20 do sexo masculino) portadores de fibrilação atrial paroxística, indicados para se submeterem à ablação por cateter, no período de julho de 2004 a novembro de2005, e três meses após o procedimento. As variáveis foram comparadas, utilizando-se o teste de Willcoxon. Resultados: Os resultados mostraram uma melhora significativa em cinco domínios do questionário QVFA,com os seguintes escores: palpitação (11,43 e pós 7,18), dispnéia (6,68 e pós 3,08), tontura (5,08 e pós 2,64),medicação (3,88 e pós 2,52) e total do escore (33,02 e pós 19,80). Nos resultados do questionário SF-36, observouse uma melhora significativa no domínio de capacidade funcional (64,06 e pós 77,29). Conclusões: Pacientes com fibrilação atrial obtiveramuma melhora na qualidade de vida relacionada à saúde após ablação por cateter.

Objective: To assess the quality of life in 25 patients with atrial fibrillation after catheter ablation. Methods: Two questionnaires were completed. Onewas the more general Short Form SF-36 Health Survey Questionnaire that assesses the quality of life througheight aspects, scored from 0 to 100, with higher scores reflecting a better quality of life. The other was the morespecific Quality of Life with Atrial Fibrillation (QVFA) questionnaire, with seven subscales. These questionnaireswere competed by 25 patients (twenty of them male) with paroxysmal atrial fibrillation recommended for catheterablation, and then repeated three months after the procedure, between July 2004 and November 2005. Thevariables were compared through the Willcoxon Test. Results: The findings showed significant improvementsfor five aspects covered by the QVFA questionnaire, with the following scores: palpitations (before: 11.43 / after: 7.18); dyspnea (before: 6.68 / after: 3.08); dizziness (before: 5.08 / after: 2.64); medication (before: 3.88 / after:2.52); and the total scores (before: 33.02 / after: 19.80). The findings of the SF-36 questionnaire showed asignificant improvement in their functional capacity (before: 64.06 / after: 77.29). Conclusions: Patients with atrial fibrillation presented abetter quality of life in terms of their health after catheter ablation. The QFVA questionnaire is more sensitive than the more general SF-36 questionnaire, in terms of reflecting differences in the quality of life of patients with atrial fibrillation.

Impact of catheter ablation of the coronary sinus on paroxysmal or persistent atrial fibrillation.

OBJECTIVES: This study evaluated the impact of catheter ablation of the coronary sinus (CS) region during paroxysmal and persistent atrial fibrillation (AF). BACKGROUND: The CS musculature and connections have been implicated in the genesis of atrial arrhythmias. METHODS: Forty-five patients undergoing catheter ablation of AF were studied. The CS was targeted if AF persisted after ablation of pulmonary veins and selected left atrial tissue. CS ablation was commenced endocardially by dragging along the inferior paramitral left atrium. Ablation was continued from within the vessel (epicardial) if CS electrograms had cycle lengths shorter than that of the left atrial appendage. RF energy was limited to 35 W endocardially and 25 W epicardially. The impact of ablation was evaluated on CS electrogram cycle length (CSCL) and activation sequence, atrial fibrillatory cycle length measured in the left atrial appendage (AFCL) and on perpetuation of AF. RESULTS: Endocardial ablation significantly prolonged CSCL by 17 +/- 5 msec and organized the CS activation sequence (from 13% of patients before to 51% after ablation); subsequent epicardial ablation further increased local CSCL by 32 +/- 27 msec (P < 0.001). AFCL prolonged significantly both during endocardial and epicardial ablation (median: 152 to 167 msec P = 0.03) and was associated with AF termination in 16 (35%) patients (46% of paroxysmal and 30% of persistent AF). AFCL prolongation > or =5 msec and/or AF termination was associated with more rapid activity in the CS region originally: P < or = 0.04. CONCLUSION: Catheter ablation targeting both the endocardial and epicardial aspects of the CS region significantly prolongs fibrillatory cycle length and terminates AF persisting after PV isolation in 35% of patients.

Contribution of the electrophysiological and anatomical analysis of the atypical atrioventricular nodal tachycardia circuit.

OBJECTIVES: To analyze retrograde conduction during junctional ectopic tachycardia (JET) episodes and investigate the existence of a relationship between the presence of a retrograde block and the risk of atrioventricular block (AVB) development during radiofrequency ablation procedures in patients with nodal atrioventricular tachycardia (NAVT). METHODS: 145 male and female patients aged 16-84 years, with NAVT who had undergone radiofrequency catheter ablation in the posteroseptal region of the right atrium were studied. Evaluation criteria were anatomical location and electrophysiological behavior of retrograde conduction during NAVT, in order to understand the nodal reentrant circuit (classifying the tachycardia as typical or atypical), and monitoring of retrograde conduction during JET episodes for risk-predicting AVB events. RESULTS: Of the 145 patients studied, 132 (91%) met electrophysiological and anatomical criteria of the typical form of NAVT, and 13 (9%) of atypical form. During the ablation, 5.3% with the typical form and 30.8% of the atypical form presented risk events for AVB. After the ablation, complications were a total AVB episode in one patient and a first-degree AVB episode in another in the typical group, and one first-degree AVB in the atypical group. All three episodes were preceded by risk events and resulted in permanent nodal injury. CONCLUSION: Patients with atypical NAVT presented higher percentages of risk events for atrioventricular block than did patients with the typical form (p=0.021).A careful observation of retrograde conduction during JET episodes is vital in order to avoid permanent damage in AV nodal conduction, such as TAVB, after the ablation procedure.

Contribuição da análise eletrofisiológica e anatômica do circuito atípico da taquicardia atrioventricular nodal / Contribution of the electrophysiological and anatomical analysis of the atypical atrioventricular nodal tachycardia circuit

OBJETIVOS: Analisar a condução retrógrada durante os episódios de ritmo juncional ectópico acelerado (JET) e avaliar a existência da relação entre a presença de um bloqueio retrógrado e o risco de desenvolvimento de bloqueio atrioventricular (BAV) durante os procedimentos de ablação por radiofreqüência de pacientes portadores de taquicardia atrioventricular nodal (TAVN). MÉTODOS: Foram 145 pacientes portadores de TAVN, de ambos os sexos, com 16 a 84 anos submetidos à ablação com cateter de radiofreqüência na região póstero-septal do átrio direito. Critérios avaliados: localização anatômica e comportamento eletrofisiológico da condução retrógrada durante TAVN (definindo a taquicardia como típica ou atípica) e monitorização da condução retrógrada durante o JET para eventos de risco para BAV. RESULTADOS: Dos 145 pacientes estudados, 132 (91 por cento) preencheram critérios eletrofisiológicos e anatômicos da forma típica da TAVN e 13 (9 por cento), da atípica. Durante a ablação, 5,3 por cento do grupo das típicas e 30,8 por cento das atípicas apresentaram eventos de risco para BAV. Complicações após ablação foram um episódio de BAV total e outro de BAV de primeiro grau nas típicas e um de BAV de primeiro grau nas atípicas. Os três episódios foram precedidos de eventos de risco que resultaram em uma injúria nodal após procedimento. CONCLUSÃO: Portadores de TAVN atípica apresentaram porcentualmente mais eventos preditores de risco para BAV do que os da típica (p = 0,021), sendo fundamental a observação criteriosa da condução retrógrada durante o JET, afim de se evitar permanente da condução nodal, como o BAVT, após o procedimento ablativo.

OBJECTIVES: To analyze retrograde conduction during junctional ectopic tachycardia (JET) episodes and investigate the existence of a relationship between the presence of a retrograde block and the risk of atrioventricular block (AVB) development during radiofrequency ablation procedures in patients with nodal atrioventricular tachycardia (NAVT). METHODS: 145 male and female patients aged 16-84 years, with NAVT who had undergone radiofrequency catheter ablation in the posteroseptal region of the right atrium were studied. Evaluation criteria were anatomical location and electrophysiological behavior of retrograde conduction during NAVT, in order to understand the nodal reentrant circuit (classifying the tachycardia as typical or atypical), and monitoring of retrograde conduction during JET episodes for risk-predicting AVB events. RESULTS: Of the 145 patients studied, 132 (91 percent) met electrophysiological and anatomical criteria of the typical form of NAVT, and 13 (9 percent) of atypical form. During the ablation, 5.3 percent with the typical form and 30.8 percent of the atypical form presented risk events for AVB. After the ablation, complications were a total AVB episode in one patient and a first-degree AVB episode in another in the typical group, and one first-degree AVB in the atypical group. All three episodes were preceded by risk events and resulted in permanent nodal injury. CONCLUSION: Patients with atypical NAVT presented higher percentages of risk events for atrioventricular block than did patients with the typical form (p=0.021).A careful observation of retrograde conduction during JET episodes is vital in order to avoid permanent damage in AV nodal conduction, such as TAVB, after the ablation procedure.