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 —In patients with paroxysmal atrial fibrillation ( AF ) , catheter ablation maintains sinus rhythm more effectively than antiarrhythmic drugs ( AADs ) , but its effect on symptoms and quality of life ( QOL ) has not been fully characterized . Methods and Results —We evaluated symptoms and QOL in a multicenter , r and omized trial comparing catheter ablation with AADs as second-line treatment for patients with paroxysmal AF . The Short Form (SF)-36 health survey and the AF Symptom Checklist were administered at baseline and 3 , 6 , and 9 months after a blanking or dose-titration period . The primary between-group comparisons were conducted at 3 months because of permitted crossover from AAD to ablation beyond this time . Additional analyses based on subsequent follow-up were performed , including the construction of mixed linear regression models to assess the impact of multiple factors on follow-up QOL scores . At baseline in both the ablation ( n=103 ) and the AAD ( n=56 ) groups , 7 of 8 SF-36 scales were well below population norms , as were the physical ( PCS ) and mental ( MCS ) summary scores . At 3 months , the same 7 SF-36 scales were significantly ( P<0.01 ) higher in the ablation than in the AAD group , as were the PCS ( 52.0±7.8 versus 47.1±10.6 ; P<0.01 ) and MCS ( 52.4±8.1 versus 46.6±9.8 ; P<0.01 ) scores , whereas symptom frequency ( 9.3±9.2 versus 19.0±12.6 ; P<0.001 ) and symptom severity ( 7.7±7.2 versus 16.2±10.0 ; P<0.001 ) were significantly reduced . In multivariable analysis , ablation and recurrent arrhythmias most strongly correlated with QOL changes over time . Conclusions —For second-line therapy of paroxysmal AF , ablation is superior to AAD treatment at improving symptoms and QOL . Clinical Trial Registration —URL : http://www . clinical trials.gov . Unique identifier : NCT00116428 Background In contrast to surveys in cardiologist setting s , presentation and management of  atrial fibrillation ( AF ) in primary care patients is less well studied . Methods and results The prospect i ve ATRIUM ( OutpatientRegistry Upon Morbidity of Atrial Fibrillation ) collected data from patients with AF seen by 730 physicians representing a r and om sample of all primary care physicians in Germany . ATRIUM enrolled 3,667 patients ( mean age , 72 ± 9 years ; 58 % male , mean CHADS2 score 2.2 ± 1.3 ) , 994 ( 27.1 % ) with paroxysmal , 944 ( 25.7 % ) with persistent or long-st and ing persistent and 1,525 ( 41.6 % ) with permanent AF ( no AF type was specified in 204 patients ) . Mean duration since initial diagnosis of AF was 61 ± 66 months ( median 42 , interquartile range 14–88 ) . Reported symptoms included palpitations ( 43 % ) , shortness of breath ( 49 % ) , fatigue ( 49 % ) , dizziness ( 37 % ) and angina ( 20 % ) . Most common concomitant conditions were hypertension ( 84 % ) , heart failure ( 43 % ) , coronary artery disease ( 345 % ) , diabetes ( 35 % ) and chronic kidney disease ( 20 % ) . Prior myocardial infa rct ion was present in 11 % of patients , prior stroke in 10 % and prior transient ischemic attack in 10 % .  Antithrombotic medication was used by 93 % of the patients ( oral anticoagulants , 83 % ) .  Rate control  therapy was reported in 75 % and rhythm control therapy in 33 % , often added to rate control . Drugs for rhythm and rate control included ß-blockers ( 75 % ) , calcium antagonists ( 15 % ) , digitalis ( 29 % ) , sodium channel blockers of type IA ( quinidine , 1.0 % ) or IC ( flecainide or propafenone , 5 % ) , and potassium channel blockers including amiodarone ( 11 % ) . In the year prior to enrollment , 46 % of the patients had been cardioverted ( 23 % by drugs , 22 % electrically ) , catheter ablation had been performed in 5 % , and 10 % received a pacemaker or  defibrillator . A high proportion ( 44 % ) of the patients were hospitalized in the year prior to enrollment . Conclusions Patients with AF managed in primary care often receive guideline -conforming therapy including antithrombotic therapy , rate control and rhythm control ( numbers given above ) . Despite this apparent adherence , almost half of the patients were hospitalized in the year prior to enrollment , suggesting that the therapies applied do not stabilize patients sufficiently to keep them out of hospital 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 BACKGROUND The aim of this prospect i ve study was to evaluate the recurrences of atrial fibrillation ( AF ) and flutter ( AFL ) after circumferential pulmonary vein ablation ( CPVA )  using repetitive long-term Holter recordings , and to evaluate the change in quality of life ( QoL ) , especially in patients with asymptomatic AF recurrences . METHODS A total of 149 patients with AF were followed up with 7-day Holter monitoring at 3 , 6 , and 12 months after CPVA .  We calculated the burden of AF/AFL defined as the percentage of time in AF/AFL , and patients with documented arrhythmia were divided into isolated symptomatic episodes of arrhythmia , mixed symptomatic/asymptomatic arrhythmia , or isolated asymptomatic arrhythmia . The QoL was analyzed with SF-36 question naires in patients with sinus rhythm after CPVA , and in patients with recurrence of symptomatic and asymptomatic arrhythmia , respectively . RESULTS Asymptomatic arrhythmia was observed in 44 % of the patients with documented arrhythmia at 12 months of follow-up . In patients with persistent AF , 63 % of the documented arrhythmia at 12 months of follow-up was asymptomatic and often persistent . In the subgroup of patients with asymptomatic arrhythmia , the QoL improved significantly in the physical scores , in contrast to patients with symptomatic arrhythmia who had unchanged or worsened QoL scores . CONCLUSIONS Asymptomatic arrhythmia is very common after AF ablation . Our data indicate that these patients improve their physical component of the QoL significantly , which may be considered a palliative success of treatment . We suggest that patients with asymptomatic AF recurrences are carefully evaluated before considering reablation . Repetitive rhythm monitoring after AF ablation is very important considering the postablation management of anticoagulant therapy 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 —The modification of atrial fibrillation cycle length ( AFCL ) during  catheter ablation in humans has not been evaluated . Methods and Results —Seventy patients undergoing ablation of prolonged episodes of AF were r and omized to pulmonary vein ( PV ) isolation or additional ablation of the mitral isthmus .  Mean AFCL was determined at a distance from the ablated area ( coronary sinus ) at the following intervals : before ablation , after 2- and 4-PV isolations , and after linear ablation . Inducibility of sustained AF ( ≥10 minutes ) was determined before and after ablation . Spontaneous sustained AF ( 715±845 minutes ) was present in 30 patients and induced in 26 ( AFCL , 186±19 ms ) . PV isolation terminated AF in 75 % , with the number of PVs requiring isolation before termination increasing with AF duration ( P = 0.018 ) . PV isolation result ed in progressive or abrupt AFCL prolongation to various extents , depending on the PV : to 214±24 ms ( P < 0.0001 ) when AF terminated and to 194±19 ms ( P < 0.002 ) when AF persisted . The increase in AFCL ( 30±17 versus 14±11 ms ; P = 0.005 ) and the decrease in fragmentation ( 30.0±26.8 % to 10.3±14.5 % ; P < 0.0001 ) were significantly greater in patients with AF termination . Linear ablation prolonged AFCL , with a greater prolongation in patients with AF termination ( 44±13 versus 22±23 ms ; P = 0.08 ) . Sustained AF was noninducible in 57 % after PV isolation and in 77 
    Output:
    
agent
There is limited evidence to suggest which ablation method was the best .
There is limited evidence to suggest that CA may be a better treatment option compared to medical therapies in the management of persistent AF .
This review was also unable to recommend the best CA method
***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 —In patients with paroxysmal atrial fibrillation ( AF ) , catheter ablation maintains sinus rhythm more effectively than antiarrhythmic drugs ( AADs ) , but its effect on symptoms and quality of life ( QOL ) has not been fully characterized . Methods and Results —We evaluated symptoms and QOL in a multicenter , r and omized trial comparing catheter ablation with AADs as second-line treatment for patients with paroxysmal AF . The Short Form (SF)-36 health survey and the AF Symptom Checklist were administered at baseline and 3 , 6 , and 9 months after a blanking or dose-titration period . The primary between-group comparisons were conducted at 3 months because of permitted crossover from AAD to ablation beyond this time . Additional analyses based on subsequent follow-up were performed , including the construction of mixed linear regression models to assess the impact of multiple factors on follow-up QOL scores . At baseline in both the ablation ( n=103 ) and the AAD ( n=56 ) groups , 7 of 8 SF-36 scales were well below population norms , as were the physical ( PCS ) and mental ( MCS ) summary scores . At 3 months , the same 7 SF-36 scales were significantly ( P<0.01 ) higher in the ablation than in the AAD group , as were the PCS ( 52.0±7.8 versus 47.1±10.6 ; P<0.01 ) and MCS ( 52.4±8.1 versus 46.6±9.8 ; P<0.01 ) scores , whereas symptom frequency ( 9.3±9.2 versus 19.0±12.6 ; P<0.001 ) and symptom severity ( 7.7±7.2 versus 16.2±10.0 ; P<0.001 ) were significantly reduced . In multivariable analysis , ablation and recurrent arrhythmias most strongly correlated with QOL changes over time . Conclusions —For second-line therapy of paroxysmal AF , ablation is superior to AAD treatment at improving symptoms and QOL . Clinical Trial Registration —URL : http://www . clinical trials.gov . Unique identifier : NCT00116428 Background In contrast to surveys in cardiologist setting s , presentation and management of  atrial fibrillation ( AF ) in primary care patients is less well studied . Methods and results The prospect i ve ATRIUM ( OutpatientRegistry Upon Morbidity of Atrial Fibrillation ) collected data from patients with AF seen by 730 physicians representing a r and om sample of all primary care physicians in Germany . ATRIUM enrolled 3,667 patients ( mean age , 72 ± 9 years ; 58 % male , mean CHADS2 score 2.2 ± 1.3 ) , 994 ( 27.1 % ) with paroxysmal , 944 ( 25.7 % ) with persistent or long-st and ing persistent and 1,525 ( 41.6 % ) with permanent AF ( no AF type was specified in 204 patients ) . Mean duration since initial diagnosis of AF was 61 ± 66 months ( median 42 , interquartile range 14–88 ) . Reported symptoms included palpitations ( 43 % ) , shortness of breath ( 49 % ) , fatigue ( 49 % ) , dizziness ( 37 % ) and angina ( 20 % ) . Most common concomitant conditions were hypertension ( 84 % ) , heart failure ( 43 % ) , coronary artery disease ( 345 % ) , diabetes ( 35 % ) and chronic kidney disease ( 20 % ) . Prior myocardial infa rct ion was present in 11 % of patients , prior stroke in 10 % and prior transient ischemic attack in 10 % .  Antithrombotic medication was used by 93 % of the patients ( oral anticoagulants , 83 % ) .  Rate control  therapy was reported in 75 % and rhythm control therapy in 33 % , often added to rate control . Drugs for rhythm and rate control included ß-blockers ( 75 % ) , calcium antagonists ( 15 % ) , digitalis ( 29 % ) , sodium channel blockers of type IA ( quinidine , 1.0 % ) or IC ( flecainide or propafenone , 5 % ) , and potassium channel blockers including amiodarone ( 11 % ) . In the year prior to enrollment , 46 % of the patients had been cardioverted ( 23 % by drugs , 22 % electrically ) , catheter ablation had been performed in 5 % , and 10 % received a pacemaker or  defibrillator . A high proportion ( 44 % ) of the patients were hospitalized in the year prior to enrollment . Conclusions Patients with AF managed in primary care often receive guideline -conforming therapy including antithrombotic therapy , rate control and rhythm control ( numbers given above ) . Despite this apparent adherence , almost half of the patients were hospitalized in the year prior to enrollment , suggesting that the therapies applied do not stabilize patients sufficiently to keep them out of hospital 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 BACKGROUND The aim of this prospect i ve study was to evaluate the recurrences of atrial fibrillation ( AF ) and flutter ( AFL ) after circumferential pulmonary vein ablation ( CPVA )  using repetitive long-term Holter recordings , and to evaluate the change in quality of life ( QoL ) , especially in patients with asymptomatic AF recurrences . METHODS A total of 149 patients with AF were followed up with 7-day Holter monitoring at 3 , 6 , and 12 months after CPVA .  We calculated the burden of AF/AFL defined as the percentage of time in AF/AFL , and patients with documented arrhythmia were divided into isolated symptomatic episodes of arrhythmia , mixed symptomatic/asymptomatic arrhythmia , or isolated asymptomatic arrhythmia . The QoL was analyzed with SF-36 question naires in patients with sinus rhythm after CPVA , and in patients with recurrence of symptomatic and asymptomatic arrhythmia , respectively . RESULTS Asymptomatic arrhythmia was observed in 44 % of the patients with documented arrhythmia at 12 months of follow-up . In patients with persistent AF , 63 % of the documented arrhythmia at 12 months of follow-up was asymptomatic and often persistent . In the subgroup of patients with asymptomatic arrhythmia , the QoL improved significantly in the physical scores , in contrast to patients with symptomatic arrhythmia who had unchanged or worsened QoL scores . CONCLUSIONS Asymptomatic arrhythmia is very common after AF ablation . Our data indicate that these patients improve their physical component of the QoL significantly , which may be considered a palliative success of treatment . We suggest that patients with asymptomatic AF recurrences are carefully evaluated before considering reablation . Repetitive rhythm monitoring after AF ablation is very important considering the postablation management of anticoagulant therapy 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 —The modification of atrial fibrillation cycle length ( AFCL ) during  catheter ablation in humans has not been evaluated . Methods and Results —Seventy patients undergoing ablation of prolonged episodes of AF were r and omized to pulmonary vein ( PV ) isolation or additional ablation of the mitral isthmus .  Mean AFCL was determined at a distance from the ablated area ( coronary sinus ) at the following intervals : before ablation , after 2- and 4-PV isolations , and after linear ablation . Inducibility of sustained AF ( ≥10 minutes ) was determined before and after ablation . Spontaneous sustained AF ( 715±845 minutes ) was present in 30 patients and induced in 26 ( AFCL , 186±19 ms ) . PV isolation terminated AF in 75 % , with the number of PVs requiring isolation before termination increasing with AF duration ( P = 0.018 ) . PV isolation result ed in progressive or abrupt AFCL prolongation to various extents , depending on the PV : to 214±24 ms ( P < 0.0001 ) when AF terminated and to 194±19 ms ( P < 0.002 ) when AF persisted . The increase in AFCL ( 30±17 versus 14±11 ms ; P = 0.005 ) and the decrease in fragmentation ( 30.0±26.8 % to 10.3±14.5 % ; P < 0.0001 ) were significantly greater in patients with AF termination . Linear ablation prolonged AFCL , with a greater prolongation in patients with AF termination ( 44±13 versus 22±23 ms ; P = 0.08 ) . Sustained AF was noninducible in 57 % after PV isolation and in 77 
    Output:
    