human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background — Data regarding the long-term efficacy of atrial fibrillation ( AF ) ablation are still lacking . Methods and Results —Two hundred four consecutive patients symptomatic for paroxysmal or persistent/permanent AF were r and omly assigned to 2 different ablation schemes : pulmonary vein isolation ( PVI ) and PVI plus left linear lesions ( LL ) . Primary end point was to assess the maintenance of sinus rhythm ( SR ) after procedures 1 and 2 in the absence of antiarrhythmic drugs in a long-term follow-up of at least 3 years . Paroxysmal AF — With a single procedure at 12-month follow-up , 46 % of patients treated with PVI maintained SR , whereas at 3-year follow-up , 29 % were in SR ; using the “ PVI plus LL ” at the 12-month follow-up , 57 % of patients were in SR , whereas at the 3-year follow-up , 53 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 62 % with PVI and 85 % with PVI plus LL . Persistent/Permanent AF — With a single procedure at the 12-month follow-up , 27 % of patients treated with PVI were in SR , whereas at the 3-year follow-up , 19 % maintained SR ; using the PVI plus LL with a single procedure at the 12-month follow-up 45 % of patients were in SR , whereas at the 3-year follow-up , 41 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 39 % with PVI and 75 % with PVI plus LL . Conclusions —A long-term follow-up of AF ablation shows that short-term results can not be considered permanent because AF recurrences are still present after the first year especially in patients who have had “ PVI ” strategy .  PVI isolation plus LL is superior to the PVI strategy in maintaining SR without antiarrhythmic drugs after procedures 1 and 2 both in paroxysmal and persistent AF BACKGROUND Recent data have shown that the septum and anterior left atrial ( LA ) wall may contain " rotor " sites required for AF maintenance . However , whether adding ablation of such sites to st and ard ICE-guided PVAI improves outcome is not well known . OBJECTIVE To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF . METHODS One hundred AF patients ( 60 paroxysmal , 40 persistent/permanent ) undergoing first-time PVAI were enrolled over three months to receive adjuvant anterior LA ablation ( Group I ) . These patients were compared with 100 r and omly selected , matched first-time PVAI controls from the preceding three months who did not receive adjuvant ablation ( Group II ) . All 200 patients underwent ICE-guided PVAI during which all four PV antra and SVC were isolated . In group I , a decapolar lasso catheter was used to map the septum and anterior LA wall during AF ( induced or spontaneous ) for continuous high-frequency , fractionated electrograms ( CFAE ) . Sites where CFAE were identified were ablated until the local EGM was eliminated . A complete anterior line of block was not a requisite endpoint . Patients were followed up for 12 months . Recurrence was assessed post-PVAI by symptoms , clinic visits , and Holter at 3 , 6 , and 12 months . Patients also wore rhythm transmitters for the first 3 months . Recurrence was any AF/AFL > 1 min occurring > 2 months post-PVAI . RESULTS Patients ( age 56 + /- 11 years , 37 % female , EF 53%+/- 11 % ) did not differ in baseline characteristics between group I and II by design . Group I patients had longer procedure time ( 188 + /- 45 min vs 162 + /- 37 min ) and RF duration ( 57 + /- 12 min vs 44 + /- 20 min ) than group II ( P < 0.05 for both ) . Overall recurrence occurred in 15/100 ( 15 % ) in group I and 20/100 ( 20 % ) in group II ( P = 0.054 ) . Success rates did not differ for paroxysmal patients between group I and II ( 87 % vs 85 % , respectively ) . However , for persistent/permanent patients , group I had a higher success rate compared with group II ( 82 % vs 72 % , P = 0.047 ) . CONCLUSIONS Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF AIMS To investigate the effectiveness of additional substrate modification ( SM ) by left atrial ( LA ) linear lesions as compared with pulmonary vein isolation ( PVI ) alone in patients with persistent atrial fibrillation ( AF ) in a prospect i ve r and omized study . Percutaneous PVI has evolved as an accepted treatment for paroxysmal AF but seemed to be less effective in patients with persistent AF . The benefit of PVI alone and additional linear lesions has not been vali date d in a r and omized study so far . METHODS AND RESULTS Sixty-two patients with persistent AF ( median duration 7 , range 1 - 18 months ) were r and omly assigned to either PVI alone ( n = 30 ) or additional SM ( n = 32 ) consisting of a roof line connecting both left superior and right superior PV and LA isthmus ablation between left inferior PV and mitral annulus . Procedures including SM were performed using a three-dimensional mapping system ( EnSite NavX , St Jude Medical , St Paul , MN , USA ) . Anti-arrhythmic drugs were discontinued within 8 weeks after ablation in both groups . Follow-up included daily trans-telephonic ECG transmitted irrespective of the patient 's symptoms . PVI was successful in 98 % of all targeted veins in both groups . Additional SM did not increase fluoroscopy time ( 72.1+/-18.7 vs. 72.9+/-17.3 min , P=0.92 ) because of the use of three-dimensional navigation in the PVI+SM group . AF recurrences within the first 4 weeks following ablation were more common after PVI alone ( 77 % ) than additional SM ( 44 % , P=0.002 ) . After a follow-up time of 487 ( 429 - 570 ) days , only 20 % of patients undergoing st and alone PVI  remained in sinus rhythm when compared with 69 % following PVI combined with SM ( P=0.0001 ) . Two patients assigned to PVI+SM experienced procedure-related complications ( cardiac tamponade and minor stroke ) which resolved without sequelae . CONCLUSION PVI alone is insufficient in the treatment of persistent AF . However , additional left linear lesions increase the success rate significantly . Early AF-relapses are associated with a negative outcome after PVI alone but not following additional SM Background —With electrogram-guided radiofrequency ablation ( RFA ) of long-lasting persistent atrial fibrillation ( AF ) , the best results have been reported when complex fractionated electrograms ( CFAEs ) in both the left ( LA ) and right ( RA ) atria were targeted . However , many studies have reported excellent outcomes from RFA of long-lasting persistent AF with the use of other ablation strategies that were limited to the LA . The incremental value of RFA of RA CFAEs is yet to be defined . Methods and Results —In 85 patients with long-lasting persistent AF ( age=59±10 years ) , RFA was directed at CFAEs in the LA and coronary sinus until AF terminated ( 19 ) or all identified LA CFAEs were eliminated . Sixty-six patients who remained in AF were r and omly assigned to cardioversion and no further RFA ( n=33 ) or to RFA of RA CFAEs ( n=33 ) . RA sites consisted of the crista terminalis ( 69 % ) , septum ( 38 % ) , superior vena cava ( 28 % ) , coronary sinus ostium ( 22 % ) , and the base of the appendage ( 31 % ) . AF terminated in 1 ( 3 % ) of 33 patients during RA RFA . At 17±6 months after a single ablation procedure , 74 % of the patients in whom AF terminated during LA RFA were in sinus rhythm . Rates of freedom from AF were similar in the patients r and omized to no RFA in the RA ( 24 % ) and those r and omized to RFA of RA CFAEs ( 30 % , P=0.8 ) . The ablation procedure was repeated in 26 patients ( 31 % ) for AF ( n=22 ) or atrial flutter ( n=4 ) . At 16±7 months after the final procedure , 89 % of the patients in whom AF terminated during LA RFA were in sinus rhythm . Among the r and omized patients , the proportion of patients who remained in sinus rhythm was similar in patients who did not undergo RFA of RA CFAEs ( 52 % ) and those who did ( 58 % , P=0.6 ) . Conclusion —After RFA of CFAEs in the LA and coronary sinus , ablation of CFAEs in the RA provides little or no increment in efficacy among patients with long-lasting persistent AF Background — Pulmonary vein ( PV ) isolation is a promising new treatment for  atrial fibrillation ( AF ) . We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV . Methods and Results — A total of 110 patients , 67 with paroxysmal AF and 43 with persistent AF , were r and omly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs . The isolation of each individual PV was an electrophysiologically guided , ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter ( group I ) . Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block ( group II ) . In both groups , an irrigated-tip ablation catheter ( 25 to 35 W ) was used to achieve complete isolation . Procedure and ablation times were longer in group II , whereas fluoroscopic time was significantly shorter ( P≤0.001 ) . After a follow-up period of 15±4 months , 27 patients in group I ( 49 % ) and 37 patients in group II ( 67 % ) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure ( P≤0.05 ) . Conclusions — The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation BACKGROUND The role of pulmonary veins ( PV ) isolation in patients with persistent atrial fibrillation ( AF ) is still debated . The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation ( anatomical approach ) . METHODS We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach ( group A , n = 36 , mean age = 60 + /- 8 years , 29 males ) or an integrated approach ( group B , n = 61 , mean age 59 + /- 10 years , 48 males ) . In all patients , radiofrequency ( RF ) ablation was performed by means of a nonfluoroscopic navigation system , in order to anatomically create circumferential lines around the PV . In group B , the persistence of PV potentials was ascertained with a multipolar circular catheter . If PV potentials persisted , RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV . Past a 2-month period of observation , success was defined as absence of any atrial tachyarrhythmia recurrence lasting > 30 seconds . RESULTS Total procedure duration ( 220 + /- 62 minutes vs 140 + /- 43 minutes , P < 0.001 ) , fluoroscopy time ( 35 + /- 15 minutes vs 17 + /- 9 minutes , P < 0.001 ) , and RF delivery time ( 48 + /- 22 minutes vs 27 + /- 9 minutes , P < 0.001 ) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 + /- 9.1 months , 21 patients in group A ( 58 % ) and 34 patients in group B ( 56 % ) were free of atrial tachyarrhythmia recurrence ( P = 0.9 ) . CONCLUSIONS In patients with persistent AF , who underwent an anatomical approach , electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times , without effect on the long-term outcomes BACKGROUND Pulmonary veins ( PVs ) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation ( AF ) . However , additional non-PV triggers , arising from different areas , have been reported as well . One of the most common non-PV sites described is the superior vena cava . AIMS The purpose of the study was to investigate the impact result ing from the systematic isolation of the superior vena cava ( SVCI ) in addition to pulmonary vein antrum isolation ( PVAI ) on the outcome of paroxysmal , persistent , and permanent AF ablation . METHODS 
    Output:
    
agent
Where data were available , the relative benefits seen held true both after a single or multiple procedure(s ) .
For patients with persistent atrial fibrillation , CA achieves significantly greater freedom from recurrent atrial fibrillation compared with medical therapy .
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Background — Data regarding the long-term efficacy of atrial fibrillation ( AF ) ablation are still lacking . Methods and Results —Two hundred four consecutive patients symptomatic for paroxysmal or persistent/permanent AF were r and omly assigned to 2 different ablation schemes : pulmonary vein isolation ( PVI ) and PVI plus left linear lesions ( LL ) . Primary end point was to assess the maintenance of sinus rhythm ( SR ) after procedures 1 and 2 in the absence of antiarrhythmic drugs in a long-term follow-up of at least 3 years . Paroxysmal AF — With a single procedure at 12-month follow-up , 46 % of patients treated with PVI maintained SR , whereas at 3-year follow-up , 29 % were in SR ; using the “ PVI plus LL ” at the 12-month follow-up , 57 % of patients were in SR , whereas at the 3-year follow-up , 53 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 62 % with PVI and 85 % with PVI plus LL . Persistent/Permanent AF — With a single procedure at the 12-month follow-up , 27 % of patients treated with PVI were in SR , whereas at the 3-year follow-up , 19 % maintained SR ; using the PVI plus LL with a single procedure at the 12-month follow-up 45 % of patients were in SR , whereas at the 3-year follow-up , 41 % remained in SR . After a second procedure , the long-term overall success rate without antiarrhythmic drugs was 39 % with PVI and 75 % with PVI plus LL . Conclusions —A long-term follow-up of AF ablation shows that short-term results can not be considered permanent because AF recurrences are still present after the first year especially in patients who have had “ PVI ” strategy .  PVI isolation plus LL is superior to the PVI strategy in maintaining SR without antiarrhythmic drugs after procedures 1 and 2 both in paroxysmal and persistent AF BACKGROUND Recent data have shown that the septum and anterior left atrial ( LA ) wall may contain " rotor " sites required for AF maintenance . However , whether adding ablation of such sites to st and ard ICE-guided PVAI improves outcome is not well known . OBJECTIVE To determine if adjuvant anterior LA ablation during PVAI improves the cure rate of paroxysmal and permanent AF . METHODS One hundred AF patients ( 60 paroxysmal , 40 persistent/permanent ) undergoing first-time PVAI were enrolled over three months to receive adjuvant anterior LA ablation ( Group I ) . These patients were compared with 100 r and omly selected , matched first-time PVAI controls from the preceding three months who did not receive adjuvant ablation ( Group II ) . All 200 patients underwent ICE-guided PVAI during which all four PV antra and SVC were isolated . In group I , a decapolar lasso catheter was used to map the septum and anterior LA wall during AF ( induced or spontaneous ) for continuous high-frequency , fractionated electrograms ( CFAE ) . Sites where CFAE were identified were ablated until the local EGM was eliminated . A complete anterior line of block was not a requisite endpoint . Patients were followed up for 12 months . Recurrence was assessed post-PVAI by symptoms , clinic visits , and Holter at 3 , 6 , and 12 months . Patients also wore rhythm transmitters for the first 3 months . Recurrence was any AF/AFL > 1 min occurring > 2 months post-PVAI . RESULTS Patients ( age 56 + /- 11 years , 37 % female , EF 53%+/- 11 % ) did not differ in baseline characteristics between group I and II by design . Group I patients had longer procedure time ( 188 + /- 45 min vs 162 + /- 37 min ) and RF duration ( 57 + /- 12 min vs 44 + /- 20 min ) than group II ( P < 0.05 for both ) . Overall recurrence occurred in 15/100 ( 15 % ) in group I and 20/100 ( 20 % ) in group II ( P = 0.054 ) . Success rates did not differ for paroxysmal patients between group I and II ( 87 % vs 85 % , respectively ) . However , for persistent/permanent patients , group I had a higher success rate compared with group II ( 82 % vs 72 % , P = 0.047 ) . CONCLUSIONS Adjuvant anterior LA ablation does not appear to impact procedural outcome in patients with paroxysmal AF but may offer benefit to patients with persistent/permanent AF AIMS To investigate the effectiveness of additional substrate modification ( SM ) by left atrial ( LA ) linear lesions as compared with pulmonary vein isolation ( PVI ) alone in patients with persistent atrial fibrillation ( AF ) in a prospect i ve r and omized study . Percutaneous PVI has evolved as an accepted treatment for paroxysmal AF but seemed to be less effective in patients with persistent AF . The benefit of PVI alone and additional linear lesions has not been vali date d in a r and omized study so far . METHODS AND RESULTS Sixty-two patients with persistent AF ( median duration 7 , range 1 - 18 months ) were r and omly assigned to either PVI alone ( n = 30 ) or additional SM ( n = 32 ) consisting of a roof line connecting both left superior and right superior PV and LA isthmus ablation between left inferior PV and mitral annulus . Procedures including SM were performed using a three-dimensional mapping system ( EnSite NavX , St Jude Medical , St Paul , MN , USA ) . Anti-arrhythmic drugs were discontinued within 8 weeks after ablation in both groups . Follow-up included daily trans-telephonic ECG transmitted irrespective of the patient 's symptoms . PVI was successful in 98 % of all targeted veins in both groups . Additional SM did not increase fluoroscopy time ( 72.1+/-18.7 vs. 72.9+/-17.3 min , P=0.92 ) because of the use of three-dimensional navigation in the PVI+SM group . AF recurrences within the first 4 weeks following ablation were more common after PVI alone ( 77 % ) than additional SM ( 44 % , P=0.002 ) . After a follow-up time of 487 ( 429 - 570 ) days , only 20 % of patients undergoing st and alone PVI  remained in sinus rhythm when compared with 69 % following PVI combined with SM ( P=0.0001 ) . Two patients assigned to PVI+SM experienced procedure-related complications ( cardiac tamponade and minor stroke ) which resolved without sequelae . CONCLUSION PVI alone is insufficient in the treatment of persistent AF . However , additional left linear lesions increase the success rate significantly . Early AF-relapses are associated with a negative outcome after PVI alone but not following additional SM Background —With electrogram-guided radiofrequency ablation ( RFA ) of long-lasting persistent atrial fibrillation ( AF ) , the best results have been reported when complex fractionated electrograms ( CFAEs ) in both the left ( LA ) and right ( RA ) atria were targeted . However , many studies have reported excellent outcomes from RFA of long-lasting persistent AF with the use of other ablation strategies that were limited to the LA . The incremental value of RFA of RA CFAEs is yet to be defined . Methods and Results —In 85 patients with long-lasting persistent AF ( age=59±10 years ) , RFA was directed at CFAEs in the LA and coronary sinus until AF terminated ( 19 ) or all identified LA CFAEs were eliminated . Sixty-six patients who remained in AF were r and omly assigned to cardioversion and no further RFA ( n=33 ) or to RFA of RA CFAEs ( n=33 ) . RA sites consisted of the crista terminalis ( 69 % ) , septum ( 38 % ) , superior vena cava ( 28 % ) , coronary sinus ostium ( 22 % ) , and the base of the appendage ( 31 % ) . AF terminated in 1 ( 3 % ) of 33 patients during RA RFA . At 17±6 months after a single ablation procedure , 74 % of the patients in whom AF terminated during LA RFA were in sinus rhythm . Rates of freedom from AF were similar in the patients r and omized to no RFA in the RA ( 24 % ) and those r and omized to RFA of RA CFAEs ( 30 % , P=0.8 ) . The ablation procedure was repeated in 26 patients ( 31 % ) for AF ( n=22 ) or atrial flutter ( n=4 ) . At 16±7 months after the final procedure , 89 % of the patients in whom AF terminated during LA RFA were in sinus rhythm . Among the r and omized patients , the proportion of patients who remained in sinus rhythm was similar in patients who did not undergo RFA of RA CFAEs ( 52 % ) and those who did ( 58 % , P=0.6 ) . Conclusion —After RFA of CFAEs in the LA and coronary sinus , ablation of CFAEs in the RA provides little or no increment in efficacy among patients with long-lasting persistent AF Background — Pulmonary vein ( PV ) isolation is a promising new treatment for  atrial fibrillation ( AF ) . We hypothesized that isolation of large areas around both ipsilateral PVs with verification of conduction block is more effective than the isolation of each individual PV . Methods and Results — A total of 110 patients , 67 with paroxysmal AF and 43 with persistent AF , were r and omly assigned to undergo either isolation of each individual PV or isolation of large areas around both ipsilateral PVs . The isolation of each individual PV was an electrophysiologically guided , ostial segmental ablation with a 64-pole basket catheter or a 20-pole circular mapping catheter ( group I ) . Isolation of large areas was performed around the 2 ipsilateral veins with a nonfluoroscopic navigation system and a circular 20-pole mapping catheter for verification of conduction block ( group II ) . In both groups , an irrigated-tip ablation catheter ( 25 to 35 W ) was used to achieve complete isolation . Procedure and ablation times were longer in group II , whereas fluoroscopic time was significantly shorter ( P≤0.001 ) . After a follow-up period of 15±4 months , 27 patients in group I ( 49 % ) and 37 patients in group II ( 67 % ) remained free of symptoms of AF and had no AF or atrial flutter during repetitive Holter monitoring without antiarrhythmic drug treatment after a single procedure ( P≤0.05 ) . Conclusions — The rate of success was significantly higher and fluoroscopy times were significantly lower in the group with large isolation areas around both ipsilateral PVs than in those who underwent individual PV isolation BACKGROUND The role of pulmonary veins ( PV ) isolation in patients with persistent atrial fibrillation ( AF ) is still debated . The aim of this study was to evaluate the adjunctive role of PV isolation in patients with persistent AF who underwent circumferential PV ablation ( anatomical approach ) . METHODS We treated 97 consecutive patients presenting with drug-refractory persistent AF by an anatomical approach ( group A , n = 36 , mean age = 60 + /- 8 years , 29 males ) or an integrated approach ( group B , n = 61 , mean age 59 + /- 10 years , 48 males ) . In all patients , radiofrequency ( RF ) ablation was performed by means of a nonfluoroscopic navigation system , in order to anatomically create circumferential lines around the PV . In group B , the persistence of PV potentials was ascertained with a multipolar circular catheter . If PV potentials persisted , RF energy targeting the electrophysiological breakthroughs was delivered to disconnect the PV . Past a 2-month period of observation , success was defined as absence of any atrial tachyarrhythmia recurrence lasting > 30 seconds . RESULTS Total procedure duration ( 220 + /- 62 minutes vs 140 + /- 43 minutes , P < 0.001 ) , fluoroscopy time ( 35 + /- 15 minutes vs 17 + /- 9 minutes , P < 0.001 ) , and RF delivery time ( 48 + /- 22 minutes vs 27 + /- 9 minutes , P < 0.001 ) were significantly longer in group B than in group A. One cardiac perforation occurred in group A. After 15 + /- 9.1 months , 21 patients in group A ( 58 % ) and 34 patients in group B ( 56 % ) were free of atrial tachyarrhythmia recurrence ( P = 0.9 ) . CONCLUSIONS In patients with persistent AF , who underwent an anatomical approach , electrophysiological confirmation of PV disconnection significantly increased the fluoroscopy and procedural times , without effect on the long-term outcomes BACKGROUND Pulmonary veins ( PVs ) have been shown to represent the most frequent sites of ectopic beats initiating paroxysmal atrial fibrillation ( AF ) . However , additional non-PV triggers , arising from different areas , have been reported as well . One of the most common non-PV sites described is the superior vena cava . AIMS The purpose of the study was to investigate the impact result ing from the systematic isolation of the superior vena cava ( SVCI ) in addition to pulmonary vein antrum isolation ( PVAI ) on the outcome of paroxysmal , persistent , and permanent AF ablation . METHODS 
    Output:
    