Chi Keong Ching

Ablation for longstanding permanent atrial fibrillation: Results from a randomized study comparing three different strategies

BACKGROUND This prospective multicenter randomized study aimed to compare the efficacy of 3 common ablation methods used for longstanding permanent atrial fibrillation (AF). METHODS A total of 144 patients with longstanding permanent AF (median duration 28 months) were randomly assigned to circumferential pulmonary vein ablation (CPVA, group 1, n = 47), to pulmonary vein antrum isolation (PVAI, group 2, n = 48) or to a hybrid strategy combining ablation of complex fractionated or rapid atrial electrograms (CFAE) in both atria followed by a pulmonary vein antrum isolation (CFAE + PVAI, group 3, n = 49). RESULTS Scarring in the left atrium and structural heart disease/hypertension were present in most patients (65%). After a mean follow-up of 16 months, 11% of patients in group 1, 40% of patients in group 2 and 61% of patients in group 3 were in sinus rhythm after one procedure and with no antiarrhythmic drugs (P < .001). Sinus rhythm maintenance would increase respectively to 28% (group 1), 83% (group 2), and 94% (group 3) after 2 procedures and with antiarrhythmic drugs (AADs, P < .001). The AF terminated during ablation, either by conversion to sinus rhythm or organization into an atrial tachyarrhythmia, in 13% of patients (group 1), 44% (group 2), and 74% (group 3) respectively. CFAE alone, performed as the first step of the ablation in group 3, organized AF in only 1 patient. CONCLUSION In this study, the hybrid AF ablation strategy including antrum isolation and CFAE ablation had the highest likelihood of maintaining sinus rhythm in patients with longstanding permanent AF. Electrical isolation of the PVs, although inadequate if performed alone, is relevant to achieve long-term sinus rhythm maintenance after ablation. Bi-atrial CFAE ablation had a minimal impact on AF termination during ablation.

Atrial Fibrillation Ablation Strategies for Paroxysmal Patients: randomized comparison between different techniques.

Background— Whether different ablation strategies affect paroxysmal atrial fibrillation (AF) long-term freedom from AF/atrial tachyarrhythmia is unclear. We sought to compare the effect of 3 different ablation approaches on the long-term success in patients with paroxysmal AF. Methods and Results— One hundred three consecutive patients with paroxysmal AF scheduled for ablation and presenting in the electrophysiology laboratory in AF were selected for this study. Patients were randomized to pulmonary vein antrum isolation (PVAI; n=35) versus biatrial ablation of the complex fractionated atrial electrograms (CFAEs; n=34) versus PVAI followed by CFAEs (n=34). Patients were given event recorders and followed up at 3, 6, 9, 12, and 15 months postablation. There was no statistical significant difference between the groups in term of sex, age, AF duration, left atrial size, and ejection fraction. At 1 year follow-up, freedom from AF/atrial tachyarrhythmia was documented in 89% of patients in the PVAI group, 91% in the PVAI plus CFAEs group, and 23% in the CFAEs group ( P <0.001) after a single procedure and with antiarrhythmic drugs. Conclusion— No difference in terms of success rate was seen between PVAI alone and PVAI associated with defragmentation. CFAEs ablation alone had the smallest impact on AF recurrences at 1-year follow-up. These results suggest that antral isolation is sufficient to treat most patients with paroxysmal AF. Received March 19, 2008; accepted February 11, 2009. # CLINICAL PERSPECTIVE {#article-title-2}Background—Whether different ablation strategies affect paroxysmal atrial fibrillation (AF) long-term freedom from AF/atrial tachyarrhythmia is unclear. We sought to compare the effect of 3 different ablation approaches on the long-term success in patients with paroxysmal AF. Methods and Results—One hundred three consecutive patients with paroxysmal AF scheduled for ablation and presenting in the electrophysiology laboratory in AF were selected for this study. Patients were randomized to pulmonary vein antrum isolation (PVAI; n=35) versus biatrial ablation of the complex fractionated atrial electrograms (CFAEs; n=34) versus PVAI followed by CFAEs (n=34). Patients were given event recorders and followed up at 3, 6, 9, 12, and 15 months postablation. There was no statistical significant difference between the groups in term of sex, age, AF duration, left atrial size, and ejection fraction. At 1 year follow-up, freedom from AF/atrial tachyarrhythmia was documented in 89% of patients in the PVAI group, 91% in the PVAI plus CFAEs group, and 23% in the CFAEs group (P<0.001) after a single procedure and with antiarrhythmic drugs. Conclusion—No difference in terms of success rate was seen between PVAI alone and PVAI associated with defragmentation. CFAEs ablation alone had the smallest impact on AF recurrences at 1-year follow-up. These results suggest that antral isolation is sufficient to treat most patients with paroxysmal AF.

Atrial fibrillation termination as a procedural endpoint during ablation in long-standing persistent atrial fibrillation

BACKGROUND Ablation of long-standing persistent atrial fibrillation (AF) remains challenging, with a lower success rate than paroxysmal AF. A reliable ablation endpoint has not been demonstrated yet, although AF termination during ablation may be associated with higher long-term maintenance of sinus rhythm (SR). OBJECTIVE The purpose of this study was to determine whether the method of AF termination during ablation predicts mode of recurrence or long-term outcome. METHODS Three hundred six patients with long-standing persistent AF, free of antiarrhythmic drugs (AADs), undergoing a first radiofrequency ablation (pulmonary vein [PV] antrum isolation and complex fractionated atrial electrograms) were prospectively included. Organized atrial tachyarrhythmias (AT) that occurred during AF ablation were targeted. AF termination mode during ablation was studied in relation to other variables (characteristics of arrhythmia recurrence, redo procedures, the use of adenosine/isoproterenol for redo, and comparison of focal versus macroreentrant ATs). Long-term maintenance of SR was assessed during the follow-up. RESULTS During AF ablation, six of 306 patients converted directly to SR, 172 patients organized into AT (with 38 of them converting in SR with further ablation), and 128 did not organize or terminate and were cardioverted. Two hundred eleven of 306 patients (69%) maintained in long-term SR without AADs after a mean follow-up of 25 +/- 6.9 months, with no statistical difference between the various AF termination modes during ablation. Presence or absence of organization during ablation clearly predicted the predominant mode of recurrence, respectively, AT or AF (P = .022). Among the 74 redo ablation patients, 24 patients (32%) had extra PV triggers revealed by adenosine/isoproterenol. Termination of focal ATs was correlated with higher long-term success rate (24/29, 83%) than termination of macroreentrant ATs (20/35, 57%; P = .026). CONCLUSION AF termination during ablation (conversion to AT or SR) could predict the mode of arrhythmia recurrence (AT vs. AF) but did not impact the long-term SR maintenance after one or two procedures. AT termination with further ablation did not correlate with better long-term outcome, except with focal ATs, for which termination seems critical.

Low Incidence of Left Atrial or Left Atrial Appendage Thrombus in Patients with Paroxysmal Atrial Fibrillation and Normal EF Who Present for Pulmonary Vein Antrum Isolation Procedure

Introduction: The incidence of left atrial appendage (LAA) thrombus in patients with paroxysmal atrial fibrillation (PAF) who present for pulmonary vein antrum isolation procedure (PVAI) is unknown.

Esophageal Luminal Temperature Measurement Underestimates Esophageal Tissue Temperature During Radiofrequency Ablation Within the Canine Left Atrium: Comparison Between 8 mm Tip and Open Irrigation Catheters

Introduction: Evaluation of luminal temperature during left atrial ablation is used clinically; however, luminal temperature does not necessarily reflect temperature within the esophageal wall and poses a risk of atrioesophageal fistula. This animal study evaluates luminal esophageal temperature and its relation to the temperature of the external esophageal tissue during left atrial lesions using the 8 mm solid tip and the open irrigated tip catheters (OIC).

Transiliac ICD implantation: Defibrillation vector flexibility produces consistent success

BACKGROUND The transiliac approach to implantable cardioverter-defibrillator (ICD) implantation is an alternative in patients for whom pectoral placements are contraindicated. The defibrillation vector is altered from the pectoral configuration because of pulse generator placement in one of the upper abdominal quadrants and separate single-coil, active-fixation defibrillation leads positioned in the high right atrium and right ventricular apex. OBJECTIVE The feasibility, safety, and complications of this approach and the results of defibrillation testing (DFT) with this configuration are described. METHODS Twenty-three patients (16 male and 7 female, mean age 65.7 +/- 13.2 years) required transiliac approach to ICD placement. The leads were inserted through the iliac vein immediately superior to the inguinal ligament. When required, a subcutaneous coil was tunneled posterior to the left ventricle from the left axilla. RESULTS The right iliac vein entry was used in 17 patients, with placement of the pulse generator in the left upper quadrant in 16 patients. Atrial and ventricular lead pacing and sensing function were acceptable. Initial defibrillation success with a safety margin of 10 J was achieved in 15 patients. With the placement of an additional subcutaneous coil in the remaining 8 patients, defibrillation success with a safety margin of 10 J was increased to 19 patients, whereas defibrillation success with a safety margin of 5 J was achieved in all patients, although 1 patient required repeat testing 24 hours after implantation. There were no acute complications. Late complications occurred in 3 patients, comprised of atrial lead malfunction, device infection, and right ventricular defibrillation lead fracture. CONCLUSION The iliac vein approach to ICD implantation is a safe and effective alternative technique. Flexibility in lead placement, defibrillation vectors, and careful DFT are required to produce a consistently effective system.

Is there an association between external cardioversions and long-term mortality and morbidity? Insights from the Atrial Fibrillation Follow-up Investigation of Rhythm Management study.

Background— Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. Methods and Results— We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P<0.0001). Conclusions— In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.Background —Cardiac electrical therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardiac defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regards to cardiovascular mortality and morbidity. Methods and Results —We analyzed the data of the 4,060 patients from the AFFIRM trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality and hospitalizations post ECVe were studied. Over an average follow-up of 3.5 years, 660 patients (16.3%) died, 331(8.2%) from cardiovascular causes. A total of 207(5.1%) and 1697(41.8%) patients had low ejection fraction (EF) and non-paroxysmal atrial fibrillation (AF) respectively. 2460 patients received no ECVe; while 1600 experienced ≥1 ECVe. Death occurred in 412(16.7%), 196(16.5%), 39(13.5%), and 13(10.4%) of patients with 0, 1, 2, and ≥3 ECVe respectively. There was no significant association between ECVe and mortality within any of the four subgroups defined by EF and AF type, although myocardial infarction (MI), coronary artery bypass graft (CABG), and digoxin were significantly associated with death (Estimated hazard ratios: 1.65; 1.59 and 1.62 respectively, p<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% vs. 5.8%; Estimated odds ratio: 1.39, p<0.0001). Conclusions —In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, MI, and CABG were significantly associated with mortality.

Is there an Association Between External Cardioversions and Long Term Mortality and Morbidity - Insights from the AFFIRM Study

Background— Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. Methods and Results— We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P<0.0001). Conclusions— In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.Background —Cardiac electrical therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardiac defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regards to cardiovascular mortality and morbidity. Methods and Results —We analyzed the data of the 4,060 patients from the AFFIRM trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality and hospitalizations post ECVe were studied. Over an average follow-up of 3.5 years, 660 patients (16.3%) died, 331(8.2%) from cardiovascular causes. A total of 207(5.1%) and 1697(41.8%) patients had low ejection fraction (EF) and non-paroxysmal atrial fibrillation (AF) respectively. 2460 patients received no ECVe; while 1600 experienced ≥1 ECVe. Death occurred in 412(16.7%), 196(16.5%), 39(13.5%), and 13(10.4%) of patients with 0, 1, 2, and ≥3 ECVe respectively. There was no significant association between ECVe and mortality within any of the four subgroups defined by EF and AF type, although myocardial infarction (MI), coronary artery bypass graft (CABG), and digoxin were significantly associated with death (Estimated hazard ratios: 1.65; 1.59 and 1.62 respectively, p<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% vs. 5.8%; Estimated odds ratio: 1.39, p<0.0001). Conclusions —In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, MI, and CABG were significantly associated with mortality.

Is There an Association Between External Cardioversions and Long-Term Mortality and Morbidity?Clinical Perspective: Insights From the Atrial Fibrillation Follow-Up Investigation of Rhythm Management Study

Background— Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. Methods and Results— We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P<0.0001). Conclusions— In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.Background —Cardiac electrical therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardiac defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regards to cardiovascular mortality and morbidity. Methods and Results —We analyzed the data of the 4,060 patients from the AFFIRM trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality and hospitalizations post ECVe were studied. Over an average follow-up of 3.5 years, 660 patients (16.3%) died, 331(8.2%) from cardiovascular causes. A total of 207(5.1%) and 1697(41.8%) patients had low ejection fraction (EF) and non-paroxysmal atrial fibrillation (AF) respectively. 2460 patients received no ECVe; while 1600 experienced ≥1 ECVe. Death occurred in 412(16.7%), 196(16.5%), 39(13.5%), and 13(10.4%) of patients with 0, 1, 2, and ≥3 ECVe respectively. There was no significant association between ECVe and mortality within any of the four subgroups defined by EF and AF type, although myocardial infarction (MI), coronary artery bypass graft (CABG), and digoxin were significantly associated with death (Estimated hazard ratios: 1.65; 1.59 and 1.62 respectively, p<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% vs. 5.8%; Estimated odds ratio: 1.39, p<0.0001). Conclusions —In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, MI, and CABG were significantly associated with mortality.

Is There an Association Between External Cardioversions and Long-Term Mortality and Morbidity?Clinical Perspective

Background— Cardiac electric therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardioverter-defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regard to cardiovascular mortality and morbidity. Methods and Results— We analyzed the data of the 4060 patients from the AFFIRM (Atrial Fibrillation Follow-up Investigation of Rhythm Management) trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality, and hospitalizations after ECVe were studied. Over an average follow-up of 3.5 years, 660 (16.3%) patients died, 331 (8.2%) from cardiovascular causes. A total of 207 (5.1%) and 1697 (41.8%) patients had low ejection fraction and nonparoxysmal atrial fibrillation, respectively; 2460 patients received no ECVe, whereas 1600 experienced ≥1 ECVe. Death occurred in 412 (16.7%), 196 (16.5%), 39 (13.5%), and 13 (10.4%) of patients with 0, 1, 2, and ≥3 ECVe, respectively. There was no significant association between ECVe and mortality within any of the 4 subgroups defined by ejection fraction and atrial fibrillation type, although myocardial infarction, coronary artery bypass graft, and digoxin were significantly associated with death (estimated hazard ratios, 1.65, 1.59, and 1.62, respectively; P<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% versus 5.8%; estimated odds ratio, 1.39; P<0.0001). Conclusions— In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, myocardial infarction, and coronary artery bypass graft were significantly associated with mortality.Background —Cardiac electrical therapies effectively terminate tachyarrhythmias. Recent data suggest a possible increase in long-term mortality associated with implantable cardiac defibrillator shocks. Little is known about the association between external cardioversion episodes (ECVe) and long-term mortality. We sought to assess the safety of repeated ECVe with regards to cardiovascular mortality and morbidity. Methods and Results —We analyzed the data of the 4,060 patients from the AFFIRM trial. In particular, associations of ECVe with all-cause mortality, cardiovascular mortality and hospitalizations post ECVe were studied. Over an average follow-up of 3.5 years, 660 patients (16.3%) died, 331(8.2%) from cardiovascular causes. A total of 207(5.1%) and 1697(41.8%) patients had low ejection fraction (EF) and non-paroxysmal atrial fibrillation (AF) respectively. 2460 patients received no ECVe; while 1600 experienced ≥1 ECVe. Death occurred in 412(16.7%), 196(16.5%), 39(13.5%), and 13(10.4%) of patients with 0, 1, 2, and ≥3 ECVe respectively. There was no significant association between ECVe and mortality within any of the four subgroups defined by EF and AF type, although myocardial infarction (MI), coronary artery bypass graft (CABG), and digoxin were significantly associated with death (Estimated hazard ratios: 1.65; 1.59 and 1.62 respectively, p<0.0001). ECVe were associated with increased cardiac hospitalization reported at the next follow-up visit (39.3% vs. 5.8%; Estimated odds ratio: 1.39, p<0.0001). Conclusions —In the AFFIRM study, there was no significant association between ECVe and long-term mortality, even though ECVe were associated with increased hospitalizations from cardiac causes. Digoxin, MI, and CABG were significantly associated with mortality.