Atrial fibrillation(AF) and heart failure(HF) are complex clinical entities that occur concomitantly in a significant population of patients, and their prevalence is rising in epidemic proportions. Traditionally, both...Atrial fibrillation(AF) and heart failure(HF) are complex clinical entities that occur concomitantly in a significant population of patients, and their prevalence is rising in epidemic proportions. Traditionally, both rate and rhythm control strategies have been regarded as equivalent in the management of dysrhythmia in this AF-HF cohort with escalation of treatment largely guided by symptoms. Both disorders are involved in an elaborate pathophysiological interplay with shared cardiovascular risk factors that contribute to the development and sustenance of both AF and HF. Recent studies and continued development of evidence to support catheter ablation for AF has brought into question the traditional belief in equivalence between rate and rhythm control. Indeed, recent trials, in particular the CASTLE-AF(Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation) study, suggest that catheter ablation for AF improves survival and rates of hospitalisation in patients with concomitant HF and AF, threatening a paradigm shift in the management of this patient cohort. The evident mortality benefit from clinical trials suggests that catheter ablation for AF should be considered as a therapeutic intervention in all suitable patients with the AF-HF syndrome as these patients may derive the greatest benefit from restoration of sinus rhythm. Further research is needed to refine the evidence base, especially to determine which subgroup of HF patients benefit most from catheter ablation and what is the optimal timing.展开更多
Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationsh...Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationship of AFL and AF？ Whether there are some differences in clinical course and mechanism between the new onset LAFL and the with a history of AFL remained unclear. The aim of this study was to assess the impacts of circumferential ablation on the occurrence of arrhythmias in follow-up in 2 groups： （1） patients with a history of AFL and AF, and （2） patients with new onset LAFL. Methods Data from 465 patients who had circumferential pulmonary vein ablation （CPVA） or segmental pulmonary vein ablation （SPVA） were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation were included from analysis. Forty-one patients constituted the history of AFL group （group 1, aged 57±13 years, 7 females） and twenty-eight patients constituted the new onset LAFL group （group 2, aged 55±12 years, 6 females）, bipolar recordings were obtained from the tricuspid annulus, coronary sinus, interatrial septum and left atrium. Target sites were identified by early, fragmented or double potentials and by concealed entrainment. Linear lesions were created between target sites and nearby anatomical barriers （1） typical atrial flutter （cycle length, 242± 39 ms）. cavotricuspid isthmus ablation was performed. （2） new onset LAFL （cycle length, 282±153 ms）. 20 episodes of AAFs were documented in 20/28 （71.4%） patients. Target sites were identified around pulmonary veins （n=10）, gap in linear lesion （n=7）, left atrial roof lines （1 case）. For those cases the ablation line between PV and mitral annulus was performed. Patients in Group 2 had larger left atria, incidence of AFL pre-CPVA, and lower ejection fraction. Results There was no significant difference in post-CPVA AF recurrence between Groups 1 and 2, but AFL incidence after CPVA was higher in Group 2 （33% vs 4%, P 〈 0.0001）. Ablation of AFL in group 1 patients resulted in an 88% acute success rate （group2, 86%） and 12% （group2,17%） recurrence over a mean follow-up of 287 ±101 days.Condusions In patients with a history of atrial flutter, post-CPVA AF recurrence is similar to patients with new onset LAFL. However, LAFL is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with LAFL, mitral Isthmus ablation is needed and can be performed effectively. Its eleetrophysiologieal eonse-quenees could be considered analogus to the results achieved by eavotrieuspid isthmus ablation.展开更多
AIM To identify predictors of need for repeat procedures after initial atrial fibrillation(AF) ablation. METHODS We identified a cohort undergoing first time AF ablation at our institution from January 2004 to Februar...AIM To identify predictors of need for repeat procedures after initial atrial fibrillation(AF) ablation. METHODS We identified a cohort undergoing first time AF ablation at our institution from January 2004 to February 2014 who had cardiac magnetic resonance(CMR) imaging performed prior to ablation. Clinical variables and anatomic characteristics(determined from CMR) were assessed as predictors of need for repeat ablation. The decision regarding need for and timing of repeat ablation was at the discretion of the treating physician. RESULTS From a cohort of 331 patients, 142 patients(43%) underwent repeat ablation at a mean of 13.6 ± 18.4 mo afterthe index procedure. Both male gender(81% vs 71%, P = 0.05) and lower ejection fraction(57.4% ± 10.3% vs 59.8% ± 9.4%, P = 0.04) were associated with need for repeat ablation. On pre-ablation CMR, mean pulmonary vein(PV) diameters were significantly larger in all four PVs among patients requiring repeat procedures. In multivariate analysis, increased right superior PV diameter significantly predicted need for repeat ablation(odds ratio 1.08 per millimeter increase in diameter, 95%CI: 1.00-1.16, P = 0.05). There were also trends toward significance for increased left and right inferior PV sizes among those requiring repeat procedures.CONCLUSION Increased PV size predicts the need for repeat AF ablation, with each millimeter increase in PV diameter associated with an approximately 5%-10% increased risk of requiring repeat procedures.展开更多
Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the ...Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the surgery strategy.Methods Mini-maze procedure was defined as follow: Pulmonary vein encircling incision and roof line connecting the two circles lesion,left atrial isthmus lesion,and the right atrial isthmus lesion.There were 517 patients with rheumatic valvular disease and pre-operative atrial fibrillation (AF) undergoing valve surgery plus mini-maze procedure in our hospital in the last 3 years,and 93 patients(18%) had recurrent atrial arrhythmia.Twelve patients(6 males and 6 females,mean age 53.8±7.8 ys) underwent electrophysiological study using 3-D mapping system(10 pts) or conventional mapping method(2 pts).Results The first recurrent time from surgery was 4.4±2.2 months.The mean follow-up time after catheter ablation was(12.0±6.0) months.One patient with sinus bradycardia had recurrent incessant atrial tachycardia (AT),but the AT was terminated by catheter position and never could be induced any more.She underwent a repeat procedure but failed just as the course in the first time, and was treated with DDDR pacemaker plus amiodarone.Six patients had 10 kinds of stable AT,including 5 at right atrial isthmus,2 at roof line,1 related to right atrial incision, 1 at anterior wall of left atrial,and 1 related to left superior pulmonary vene.All the stable AT were eliminated and remained sinus rhythm.Three patients had ATs with variable cycle length and the 3-D mapping suggested macro-reentry AT around mitral annulus.We tried to ablate at routine mitral isthmus and also in coronary sinus,but could not reach bi-directional conduction blocking.The other 2 patients were AF with reconnection at all previous ablation sites.Ablation strategy for AF included lesion at re-conduction sites and complex fractionated atrial electrogram.The patients with AF and mitral isthmus related AT were administrated with DC cardioversion and then took amiodarone.One AT and one AF recurred. Conclusions The recurrent atrial arrhythmia after mini-maze mostly related to reconnection at previous lesion sites and catheter ablation for AT could have a high success rate.It would be very hard to block mitral isthmus after valve replacement,so transmural lesion during surgery procedure is the most important strategy for preventing postoperative atrial arrhythmia.展开更多
Background Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation h...Background Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited.展开更多
Objectives To assessed the feasibility and effectiveness of electrophysiological mapping of pulmonary veins with a circumferential 10 - electrode catheter and radiofrequency catheter ablation therapy for patients with...Objectives To assessed the feasibility and effectiveness of electrophysiological mapping of pulmonary veins with a circumferential 10 - electrode catheter and radiofrequency catheter ablation therapy for patients with paroxysmal atrial fibrillation. Background Standard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. Mapping and ablation pulmonary veins guide with a circular catheter could overcome these limitations. Methods 16 patients [male 11, female 5, mean age (51 ±14. 5) years] with paroxysmal atrial fibrillation refractory to antiarrhythmic drugs were included in this group. A circumferential 10 - electrode catheter was used to pulmonary vein mapping during sinus rhythm or CSd pacing to determine the origin of atrial premature contractions. When the ablative target pulmonary vein was found, the pulmonary vein potentials' distribution and activation were assessment pulmonary veins' ostial ablation was performed at the segments showing earliest activation of pulmonary vein potentials. The end point was designed: 1) elimination of pulmonary vein potential; 2) pulmonary vein potential dissociation from atrial waves; 3) atrial ectopic beats disappear. Results A total of 36 pulmonary veins were ablated, including 16 left superior, 12 right superior, 7 left inferior and 1 right inferior. 1 pulmonary vein in 2 patients was ablated, 2 pulmonary veins in 8 patients were ablated, 3 pulmonary veins were ablated in 5 patients and 4 pulmonary veins were ablated in 1 pa- tient. Procedure duration and fluoroscopy time respectively were 186. 7±63. 8 min and 51. 5±15. 0 min. During the follow-up 1-12 months, 11 patients (68. 7 % ) were free of AF without any antiarrhythmic drugs, 2 of them were reablation, effective in 3/16 (18. 7 % ) and unsuccessful in 2/16 (12. 6 % ) . 2 cases recurred with atrial premature, 1 was treated with amiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with paroxysmal a-trial fibrillation recurred, 3 of them were treated with amiodarone (2 cases) or sotalol (1 case) , one was implantled with DDDR pacemaker (having programmer of anti - atrial fibrillation), one was repeat ablation. PV's diameter in 2 of them reduced more than 50 % , but they were asymptomatic during the follow - up period. 1 case had pneumothorax complication and disappeared after 7 days. Conclusions This study suggests that careful mapping and elimination of these ectopic foci under the guide of circular catheter may have higher success rate and splendid future.展开更多
Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal ...Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal of this study was to examine the underlying mechanism of low success in clinical outcome. MRI images from one patient were used to reconstruct a human atrial anatomical model, and fibrotic tissue was manually added to represent the arrhythmia substrate. AF was induced with standard protocols used in clinical practice. 2C3L and stepwise were then used to test the efficacy of arrhythmia termination in our model. The results showed that re-entries induced in our model could not be terminated by using either 2C3L or the stepwise protocol. Although some of the induced re-entries were terminated, others emerged in new areas. Ablation using only the 2C3L or stepwise method was not sufficient to terminate all re-entries in our model, which may partially explain the poor long-term arrhythmiafree outcomes in clinical practice. Our findings also suggest that computational heart modelling is an important tool to assist in the establishment of optimal ablation strategies.展开更多
Background The success and complication rates of atrial fibrillation （AF） ablation may be related to regional differences in left atrial （LA） wall thickness. The purpose of this study was to investigate the transm...Background The success and complication rates of atrial fibrillation （AF） ablation may be related to regional differences in left atrial （LA） wall thickness. The purpose of this study was to investigate the transmural LA wall thickness in various regions. Methods We measured LA wall thickness in 36 human heart specimens using calipers at three planes including left pulmonary veins （PVs） vestibule plane, right PVs vestibule plane and the middle plane between the two. In each plane, eight points were selected, including superior, middle and inferior levels at anterior and posterior wall, roof and bottom. Results The anterior and posterior wall thickness displayed gradient from superior to inferior level （anterior wall： （2.73＋1.01） mm, （2.08＋0.91） mm and （1.54＋0.69） mm; posterior wall： （1.74＋0.68） mm, （1.48＋0.39） mm and （1.27＋0.42） mm）. At the roof, LA wall thickness was thickest in middle plane （（2.01＋1.02） mm） and was thinnest in left PVs vestibule plane （（1.29＋0.41） mm）. The posterior wall thickness in left PVs vestibule plane was thinner than in the other two planes （P 〈0.05-0.001）, and was thinner in right PVs vestibule plane than in middle plane （P 〈0.01-0.001）. Whereas in anterior wall, the wall thickness in left PVs vestibule plane was thicker than in middle and right PVs vestibule plane. Conclusions Significant variations exist for mean LA wall thickness at different regions which are often targeted during circumferential pulmonary venous ablation （CPVA）. Appreciating these differences may have significant implications in catheter ablation of AF.展开更多
Background Recurrent atrial tachyarrhythmia （ATa） after circumferential pulmonary vein ablation （CPVA） includes atrial tachycardia （AT） and atrial fribrillation （AF）. However, whether there are some difference...Background Recurrent atrial tachyarrhythmia （ATa） after circumferential pulmonary vein ablation （CPVA） includes atrial tachycardia （AT） and atrial fribrillation （AF）. However, whether there are some differences in clinical course and mechanisms between the recurrent AT and the recurrent AF remained unclear. This study was conducted to investigate the incidence, mechanism, clinical course of the recurrent AT and AF in patients under CPVA.Methods One hundred and thirty consecutive patients （M/F = 95/35 ） with highly symptomatic ano multiple antiarrhythmic drugs （AADs） refractory paroxysmal （ n = 91 ） or persistent （ n = 39 ） AF were included. The ablation protocol consisted solely of two continuous circular lesions around the ipsilateral pulmonary veins （PV） guided by CARTO system. The endpoint of CPVA is PV isolation. For patients with recurrent ATa within 2 months after the initial procedure, cardioversion with direct current was attempted if the ATa lasted for more than 24 hours. A repeat ablation procedure was performed only for patients with AADs refractory recurrent ATa and at least followed up for 2 months after the initial procedure.Results Within 2 months after the initial procedure, 52 patients （40. 0% ） had experienced episodes of symptomatic recurrent ATa. Among them, 23 patients （44.2%） with recurred AT alone （AT group ）, 14 patients （26.9%） with recurred AF alone （AF group）, and 15 patients （28.8%） with recurred AT and AF （AT plus AF group）. The delayed cure rate （65.2%） in AT group was significant higher than that in AF group （21.4%, P〈0.05） and AF plus AT group （26.7%, P 〈0.05）. A repeat ablation was performed in 21 patients, including 6 patients with recurrent AT alone, 8 patients with recurrent AF alone, and 7 patients with recurrent AF plus AT. The mean number of PV gaps was 1.2 ± 0. 4 in AT group, which was significantly lower than that in AF group （2.6 ± 0. 7, P 〈 0.05） and AF plus AT group （2.0 ± 0.6, P 〈 0.05）. Delayed cure rate and number of PV gaps between AF group and AF plus AT group were comparable （P 〉 0.05 ）. Conclusions Present study indicates that recurrent AT and AF after CPVA have the different clinical course and different electrophysiological findings during repeat procedure as follows： （1）After CPVA, spontaneous resolution of recurrent ATa was mainly found in patients with recurrent AT alone （about two thirds patients）. （2） The type of recurrent ATa after CPVA is associated with the numberof PV gaps.展开更多
Objective To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets.Methods Fifteen con...Objective To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets.Methods Fifteen consecutive patients with focal AT were referred for radiofrequency catheter ablation (RFCA). Both unipolar (from the tip electrode of ablating catheter) and bipolar (from the distal pair of electrode of ablating catheter) electrograms were used to identify the ablation targets of focal AT.Results Successful ablation was echieved in 14 patients. Radiofrequency energy was delivered at a total of 27 sites. The bipolar electrograms associated with successful ablation sites showed earlier atrial deflection relative to P wave onset (36 ms±15 ms vs 30 ms±11 ms, P <0.05) than the electrograms associated with failed ablation sites. At the 14 successful ablation sites, the unipolar electrograms displayed a completely negative atrial wave (“QS” morphology ) beginning with intrinsic deflection. However, at the 13 unsuccessful ablation sites,a “rS” morphology of atrial wave was shown on the unipolar electrogram.Conclusion The “QS” morphology of the atrial wave on unipolar electrograms appears to represent a reliable marker for identifying the successful ablation targets of focal AT, with a high sensitivity and specificity .展开更多
Objective To determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block.Methods Since 1996 to 2002, 30 consecutive patients underwent ablation proced...Objective To determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block.Methods Since 1996 to 2002, 30 consecutive patients underwent ablation procedures for isthmus-dependent atrial flutter. There were 23 males and 7 females [ mean age (47. 85 ±9. 35) years]. With the use of fluoroscopic view of anatomy, radiofrequency ablation was performed during coronary sinus pacing at a cycle length of 600 ms.Results Bidirectional block was achieved with ablation in 29 (97%) of 30 patients. The transisthmus intervals before ablation and after complete transisthmus block were (73.82±13. 01 ) ms and (140. 47±20. 48) ms, respectively, in the clockwise direction (P<0. 0001), and (77. 63±8. 36) ms and (138. 17 ±15. 55) ms, respectively, in the counterclockwise direction (P<0. 0001). A period of incomplete isthmus block was observed during 17 (58%) of the 29 ablation procedures. The clockwise transisthmus intervals during incomplete block [(107. 65 ±21. 33) ms] were (45.5 ± 8. 7)% longer than the baseline transisthmus intervals. An increase in the transisthmus interval by ≥50% in both directions after ablation predicted complete bidirectional block with 100.0% sensitivity and 83. 3% specificity. The positive and negative predictive values were 90. 6% and 100.0% , repectively. The diagnostic accuracy of a≥50% prolongation in the transisthmus interval was 83. 3%.Conclusion The analysis of transisthmus interval is a valuable method for determining complete bidirectional isthmus block.展开更多
文摘Atrial fibrillation(AF) and heart failure(HF) are complex clinical entities that occur concomitantly in a significant population of patients, and their prevalence is rising in epidemic proportions. Traditionally, both rate and rhythm control strategies have been regarded as equivalent in the management of dysrhythmia in this AF-HF cohort with escalation of treatment largely guided by symptoms. Both disorders are involved in an elaborate pathophysiological interplay with shared cardiovascular risk factors that contribute to the development and sustenance of both AF and HF. Recent studies and continued development of evidence to support catheter ablation for AF has brought into question the traditional belief in equivalence between rate and rhythm control. Indeed, recent trials, in particular the CASTLE-AF(Catheter Ablation versus Standard Conventional Therapy in Patients with Left Ventricular Dysfunction and Atrial Fibrillation) study, suggest that catheter ablation for AF improves survival and rates of hospitalisation in patients with concomitant HF and AF, threatening a paradigm shift in the management of this patient cohort. The evident mortality benefit from clinical trials suggests that catheter ablation for AF should be considered as a therapeutic intervention in all suitable patients with the AF-HF syndrome as these patients may derive the greatest benefit from restoration of sinus rhythm. Further research is needed to refine the evidence base, especially to determine which subgroup of HF patients benefit most from catheter ablation and what is the optimal timing.
文摘Objectives There are two kind of atrial flutter during circumferential ablation for atrial fibrillation （AF）： new onset left atrial flutter （LAFL）, with a history of atrial flutter （AFL）. What is the relationship of AFL and AF？ Whether there are some differences in clinical course and mechanism between the new onset LAFL and the with a history of AFL remained unclear. The aim of this study was to assess the impacts of circumferential ablation on the occurrence of arrhythmias in follow-up in 2 groups： （1） patients with a history of AFL and AF, and （2） patients with new onset LAFL. Methods Data from 465 patients who had circumferential pulmonary vein ablation （CPVA） or segmental pulmonary vein ablation （SPVA） were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation were included from analysis. Forty-one patients constituted the history of AFL group （group 1, aged 57±13 years, 7 females） and twenty-eight patients constituted the new onset LAFL group （group 2, aged 55±12 years, 6 females）, bipolar recordings were obtained from the tricuspid annulus, coronary sinus, interatrial septum and left atrium. Target sites were identified by early, fragmented or double potentials and by concealed entrainment. Linear lesions were created between target sites and nearby anatomical barriers （1） typical atrial flutter （cycle length, 242± 39 ms）. cavotricuspid isthmus ablation was performed. （2） new onset LAFL （cycle length, 282±153 ms）. 20 episodes of AAFs were documented in 20/28 （71.4%） patients. Target sites were identified around pulmonary veins （n=10）, gap in linear lesion （n=7）, left atrial roof lines （1 case）. For those cases the ablation line between PV and mitral annulus was performed. Patients in Group 2 had larger left atria, incidence of AFL pre-CPVA, and lower ejection fraction. Results There was no significant difference in post-CPVA AF recurrence between Groups 1 and 2, but AFL incidence after CPVA was higher in Group 2 （33% vs 4%, P 〈 0.0001）. Ablation of AFL in group 1 patients resulted in an 88% acute success rate （group2, 86%） and 12% （group2,17%） recurrence over a mean follow-up of 287 ±101 days.Condusions In patients with a history of atrial flutter, post-CPVA AF recurrence is similar to patients with new onset LAFL. However, LAFL is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with LAFL, mitral Isthmus ablation is needed and can be performed effectively. Its eleetrophysiologieal eonse-quenees could be considered analogus to the results achieved by eavotrieuspid isthmus ablation.
文摘AIM To identify predictors of need for repeat procedures after initial atrial fibrillation(AF) ablation. METHODS We identified a cohort undergoing first time AF ablation at our institution from January 2004 to February 2014 who had cardiac magnetic resonance(CMR) imaging performed prior to ablation. Clinical variables and anatomic characteristics(determined from CMR) were assessed as predictors of need for repeat ablation. The decision regarding need for and timing of repeat ablation was at the discretion of the treating physician. RESULTS From a cohort of 331 patients, 142 patients(43%) underwent repeat ablation at a mean of 13.6 ± 18.4 mo afterthe index procedure. Both male gender(81% vs 71%, P = 0.05) and lower ejection fraction(57.4% ± 10.3% vs 59.8% ± 9.4%, P = 0.04) were associated with need for repeat ablation. On pre-ablation CMR, mean pulmonary vein(PV) diameters were significantly larger in all four PVs among patients requiring repeat procedures. In multivariate analysis, increased right superior PV diameter significantly predicted need for repeat ablation(odds ratio 1.08 per millimeter increase in diameter, 95%CI: 1.00-1.16, P = 0.05). There were also trends toward significance for increased left and right inferior PV sizes among those requiring repeat procedures.CONCLUSION Increased PV size predicts the need for repeat AF ablation, with each millimeter increase in PV diameter associated with an approximately 5%-10% increased risk of requiring repeat procedures.
文摘Background Recurrent atrial arrhythmia is very common in patients after mitral valve surgery plus mini-maze procedure.Investigation about the mechanism for these patients may have important implication to improve the surgery strategy.Methods Mini-maze procedure was defined as follow: Pulmonary vein encircling incision and roof line connecting the two circles lesion,left atrial isthmus lesion,and the right atrial isthmus lesion.There were 517 patients with rheumatic valvular disease and pre-operative atrial fibrillation (AF) undergoing valve surgery plus mini-maze procedure in our hospital in the last 3 years,and 93 patients(18%) had recurrent atrial arrhythmia.Twelve patients(6 males and 6 females,mean age 53.8±7.8 ys) underwent electrophysiological study using 3-D mapping system(10 pts) or conventional mapping method(2 pts).Results The first recurrent time from surgery was 4.4±2.2 months.The mean follow-up time after catheter ablation was(12.0±6.0) months.One patient with sinus bradycardia had recurrent incessant atrial tachycardia (AT),but the AT was terminated by catheter position and never could be induced any more.She underwent a repeat procedure but failed just as the course in the first time, and was treated with DDDR pacemaker plus amiodarone.Six patients had 10 kinds of stable AT,including 5 at right atrial isthmus,2 at roof line,1 related to right atrial incision, 1 at anterior wall of left atrial,and 1 related to left superior pulmonary vene.All the stable AT were eliminated and remained sinus rhythm.Three patients had ATs with variable cycle length and the 3-D mapping suggested macro-reentry AT around mitral annulus.We tried to ablate at routine mitral isthmus and also in coronary sinus,but could not reach bi-directional conduction blocking.The other 2 patients were AF with reconnection at all previous ablation sites.Ablation strategy for AF included lesion at re-conduction sites and complex fractionated atrial electrogram.The patients with AF and mitral isthmus related AT were administrated with DC cardioversion and then took amiodarone.One AT and one AF recurred. Conclusions The recurrent atrial arrhythmia after mini-maze mostly related to reconnection at previous lesion sites and catheter ablation for AT could have a high success rate.It would be very hard to block mitral isthmus after valve replacement,so transmural lesion during surgery procedure is the most important strategy for preventing postoperative atrial arrhythmia.
基金Funded by the National Institutes of Health and the Canadian Institutes of Health ResearchClinical Trials.gov number,NCT00903370
文摘Background Among patients undergoing mitral-valve surgery, 30 to 50% present with atrial fibrillation, which is associated with reduced survival and increased risk of stroke. Surgical ablation of atrial fibrillation has been widely adopted, but evidence regarding its safety and effectiveness is limited.
文摘Objectives To assessed the feasibility and effectiveness of electrophysiological mapping of pulmonary veins with a circumferential 10 - electrode catheter and radiofrequency catheter ablation therapy for patients with paroxysmal atrial fibrillation. Background Standard mapping and ablation of focal sources of atrial fibrillation are associated with very long procedure times and low efficacy. Mapping and ablation pulmonary veins guide with a circular catheter could overcome these limitations. Methods 16 patients [male 11, female 5, mean age (51 ±14. 5) years] with paroxysmal atrial fibrillation refractory to antiarrhythmic drugs were included in this group. A circumferential 10 - electrode catheter was used to pulmonary vein mapping during sinus rhythm or CSd pacing to determine the origin of atrial premature contractions. When the ablative target pulmonary vein was found, the pulmonary vein potentials' distribution and activation were assessment pulmonary veins' ostial ablation was performed at the segments showing earliest activation of pulmonary vein potentials. The end point was designed: 1) elimination of pulmonary vein potential; 2) pulmonary vein potential dissociation from atrial waves; 3) atrial ectopic beats disappear. Results A total of 36 pulmonary veins were ablated, including 16 left superior, 12 right superior, 7 left inferior and 1 right inferior. 1 pulmonary vein in 2 patients was ablated, 2 pulmonary veins in 8 patients were ablated, 3 pulmonary veins were ablated in 5 patients and 4 pulmonary veins were ablated in 1 pa- tient. Procedure duration and fluoroscopy time respectively were 186. 7±63. 8 min and 51. 5±15. 0 min. During the follow-up 1-12 months, 11 patients (68. 7 % ) were free of AF without any antiarrhythmic drugs, 2 of them were reablation, effective in 3/16 (18. 7 % ) and unsuccessful in 2/16 (12. 6 % ) . 2 cases recurred with atrial premature, 1 was treated with amiodarone and the other was repeat electrophysiologi-cal mapping and ablation, 5 cases with paroxysmal a-trial fibrillation recurred, 3 of them were treated with amiodarone (2 cases) or sotalol (1 case) , one was implantled with DDDR pacemaker (having programmer of anti - atrial fibrillation), one was repeat ablation. PV's diameter in 2 of them reduced more than 50 % , but they were asymptomatic during the follow - up period. 1 case had pneumothorax complication and disappeared after 7 days. Conclusions This study suggests that careful mapping and elimination of these ectopic foci under the guide of circular catheter may have higher success rate and splendid future.
基金The work was supported by the CAMS Fund of the Nonprofit Central Research Institutes （No. 2016ZX330015）, National Natural Science Foundation of China （No. 11421202） and the 111 Project （No. B13003）.
文摘Two clinical ablation protocols, 2C3L and stepwise, have been routinely used in our group to treat atrial fibrillation （AF）, but with a less than 60% long-term arrhythmia-free outcome achieved in patients. The goal of this study was to examine the underlying mechanism of low success in clinical outcome. MRI images from one patient were used to reconstruct a human atrial anatomical model, and fibrotic tissue was manually added to represent the arrhythmia substrate. AF was induced with standard protocols used in clinical practice. 2C3L and stepwise were then used to test the efficacy of arrhythmia termination in our model. The results showed that re-entries induced in our model could not be terminated by using either 2C3L or the stepwise protocol. Although some of the induced re-entries were terminated, others emerged in new areas. Ablation using only the 2C3L or stepwise method was not sufficient to terminate all re-entries in our model, which may partially explain the poor long-term arrhythmiafree outcomes in clinical practice. Our findings also suggest that computational heart modelling is an important tool to assist in the establishment of optimal ablation strategies.
基金This work was supported by a grant from the National Natural Science Foundation of China （No. 30871083） and by a grant from the Scientific and Technological Commission of Shanghai （No. 08411960900）.
文摘Background The success and complication rates of atrial fibrillation （AF） ablation may be related to regional differences in left atrial （LA） wall thickness. The purpose of this study was to investigate the transmural LA wall thickness in various regions. Methods We measured LA wall thickness in 36 human heart specimens using calipers at three planes including left pulmonary veins （PVs） vestibule plane, right PVs vestibule plane and the middle plane between the two. In each plane, eight points were selected, including superior, middle and inferior levels at anterior and posterior wall, roof and bottom. Results The anterior and posterior wall thickness displayed gradient from superior to inferior level （anterior wall： （2.73＋1.01） mm, （2.08＋0.91） mm and （1.54＋0.69） mm; posterior wall： （1.74＋0.68） mm, （1.48＋0.39） mm and （1.27＋0.42） mm）. At the roof, LA wall thickness was thickest in middle plane （（2.01＋1.02） mm） and was thinnest in left PVs vestibule plane （（1.29＋0.41） mm）. The posterior wall thickness in left PVs vestibule plane was thinner than in the other two planes （P 〈0.05-0.001）, and was thinner in right PVs vestibule plane than in middle plane （P 〈0.01-0.001）. Whereas in anterior wall, the wall thickness in left PVs vestibule plane was thicker than in middle and right PVs vestibule plane. Conclusions Significant variations exist for mean LA wall thickness at different regions which are often targeted during circumferential pulmonary venous ablation （CPVA）. Appreciating these differences may have significant implications in catheter ablation of AF.
基金This work was funded by grants of China " Tenth Five" ResearchProject ( No.2004BA714B04) and Young Investigator TrainingProgram from Beijing Municipal Science and Technology Commission(No.H013610150113)
文摘Background Recurrent atrial tachyarrhythmia （ATa） after circumferential pulmonary vein ablation （CPVA） includes atrial tachycardia （AT） and atrial fribrillation （AF）. However, whether there are some differences in clinical course and mechanisms between the recurrent AT and the recurrent AF remained unclear. This study was conducted to investigate the incidence, mechanism, clinical course of the recurrent AT and AF in patients under CPVA.Methods One hundred and thirty consecutive patients （M/F = 95/35 ） with highly symptomatic ano multiple antiarrhythmic drugs （AADs） refractory paroxysmal （ n = 91 ） or persistent （ n = 39 ） AF were included. The ablation protocol consisted solely of two continuous circular lesions around the ipsilateral pulmonary veins （PV） guided by CARTO system. The endpoint of CPVA is PV isolation. For patients with recurrent ATa within 2 months after the initial procedure, cardioversion with direct current was attempted if the ATa lasted for more than 24 hours. A repeat ablation procedure was performed only for patients with AADs refractory recurrent ATa and at least followed up for 2 months after the initial procedure.Results Within 2 months after the initial procedure, 52 patients （40. 0% ） had experienced episodes of symptomatic recurrent ATa. Among them, 23 patients （44.2%） with recurred AT alone （AT group ）, 14 patients （26.9%） with recurred AF alone （AF group）, and 15 patients （28.8%） with recurred AT and AF （AT plus AF group）. The delayed cure rate （65.2%） in AT group was significant higher than that in AF group （21.4%, P〈0.05） and AF plus AT group （26.7%, P 〈0.05）. A repeat ablation was performed in 21 patients, including 6 patients with recurrent AT alone, 8 patients with recurrent AF alone, and 7 patients with recurrent AF plus AT. The mean number of PV gaps was 1.2 ± 0. 4 in AT group, which was significantly lower than that in AF group （2.6 ± 0. 7, P 〈 0.05） and AF plus AT group （2.0 ± 0.6, P 〈 0.05）. Delayed cure rate and number of PV gaps between AF group and AF plus AT group were comparable （P 〉 0.05 ）. Conclusions Present study indicates that recurrent AT and AF after CPVA have the different clinical course and different electrophysiological findings during repeat procedure as follows： （1）After CPVA, spontaneous resolution of recurrent ATa was mainly found in patients with recurrent AT alone （about two thirds patients）. （2） The type of recurrent ATa after CPVA is associated with the numberof PV gaps.
文摘Objective To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets.Methods Fifteen consecutive patients with focal AT were referred for radiofrequency catheter ablation (RFCA). Both unipolar (from the tip electrode of ablating catheter) and bipolar (from the distal pair of electrode of ablating catheter) electrograms were used to identify the ablation targets of focal AT.Results Successful ablation was echieved in 14 patients. Radiofrequency energy was delivered at a total of 27 sites. The bipolar electrograms associated with successful ablation sites showed earlier atrial deflection relative to P wave onset (36 ms±15 ms vs 30 ms±11 ms, P <0.05) than the electrograms associated with failed ablation sites. At the 14 successful ablation sites, the unipolar electrograms displayed a completely negative atrial wave (“QS” morphology ) beginning with intrinsic deflection. However, at the 13 unsuccessful ablation sites,a “rS” morphology of atrial wave was shown on the unipolar electrogram.Conclusion The “QS” morphology of the atrial wave on unipolar electrograms appears to represent a reliable marker for identifying the successful ablation targets of focal AT, with a high sensitivity and specificity .
文摘Objective To determine whether the extent of prolongation of the transisthmus interval after ablation predicts complete bidirectional block.Methods Since 1996 to 2002, 30 consecutive patients underwent ablation procedures for isthmus-dependent atrial flutter. There were 23 males and 7 females [ mean age (47. 85 ±9. 35) years]. With the use of fluoroscopic view of anatomy, radiofrequency ablation was performed during coronary sinus pacing at a cycle length of 600 ms.Results Bidirectional block was achieved with ablation in 29 (97%) of 30 patients. The transisthmus intervals before ablation and after complete transisthmus block were (73.82±13. 01 ) ms and (140. 47±20. 48) ms, respectively, in the clockwise direction (P<0. 0001), and (77. 63±8. 36) ms and (138. 17 ±15. 55) ms, respectively, in the counterclockwise direction (P<0. 0001). A period of incomplete isthmus block was observed during 17 (58%) of the 29 ablation procedures. The clockwise transisthmus intervals during incomplete block [(107. 65 ±21. 33) ms] were (45.5 ± 8. 7)% longer than the baseline transisthmus intervals. An increase in the transisthmus interval by ≥50% in both directions after ablation predicted complete bidirectional block with 100.0% sensitivity and 83. 3% specificity. The positive and negative predictive values were 90. 6% and 100.0% , repectively. The diagnostic accuracy of a≥50% prolongation in the transisthmus interval was 83. 3%.Conclusion The analysis of transisthmus interval is a valuable method for determining complete bidirectional isthmus block.
